Sticky #8: Size options when upgrading tires and/or wheels

This is my first post here as I just aquired my father's 1972 Pre-L (#2725) after his death. Now on to my question.

I've basically given up on 15" tires and have decided to move on to Campi Clones as the car has maintained it's "stock" appearance and I would like to continue that look. Question:

Which tire-wheel combo will keep that 4" clearance that I love so much?

I read this article over at pantera international on wheels, tires, and stance, but could find no solid conclusions.
http://www.panteracars.com/Goranwheels1.pdf
Original Post
Clockwork,

Welcome to the forum and to Pantera ownership. Sorry to hear about your father.

Could you please clarify or post a picture of what you mean by 4" clearance? After reading the PDF article I am guessing you are talking about ride height of the car.

Devin

P.S. Where are you located in Wyoming?
Clockwork, I'm sure others will disagree with me but I always thought the look of 225/50-15 and 285/50-15 P7's on 8" & 10" Campy's was perfect for a stock bodied Pantera and the "stance" with that combo was great. As a 225/50-15 is only 23.85" tall, finding a 17" tire with a similar diameter is pretty tough, keeping in mind that you need to find a rear tire that matches.

Most owners wind up going taller on the front and shorter on the back, than the late OEM P7's. A 235/40-17 is about 24.4" tall and a 245/40-17 is about 24.7" tall. Some Vendors recommend a 225/45-17 on the front but since it's even taller than a 235/40 or 245/40, I can't imagine why. A 335/35-17 is about 26" tall and a 315/35-17 a bit shorter. My recommendation would be a 235/40-17 up front and a 335/35-17 (or 335/30-18) in the rear. You could go to a 335/30-19 (Nitto NT05 - 26.89" diameter - great dry tire) at the rear but you run the risk of not being able to buy new tires at some point in the future, because it's an unusual size.

If you want to go bigger, like 18" front and 20" rear, that's fine but be careful going too tall on the front. A 235/35-18 is 24.5" tall and a 245/35-18 is 24.8" tall. If you went with one of those sizes up front, you'd likely pair it with a 325/25-20 at the rear. Keep in mind, with a good spring/shock package, the "stance" of the car no longer depends upon tire diameters.
Clockwork,

I have the stock rims and a set of 17” HRE rims for my 74 Pantera. I liked the ride height of my car with the stock rims on it, but I always thought it could have sat a little lower.

When my 17” rims arrived I threw them on the car and was really disappointed at how the car looked. The rear of the car sat way too high, however, the front was fine. I pondered pulling the spacers out of my stock shocks but eventually came to the conclusion that I wanted the ability to adjust the ride height of my car to my specific liking. I ended up buying a new set of Koni’s with Hyperco springs and am glad that I did.

I can’t remember what my front 17" tire size on the car is – and it is down at my shop, but the rears are 315/35/17.

Devin
David,
Thank you for your imput. I too believe that since the Pantera was designed around the 225/50-15 and 285/50-15 tires and the 8" and 10" Campy wheels that the look and stance was just right for the car.

I do like your suggestoin for the 17" rims w/235/40-17s and 335/35-17s and it seems that several vendors offer this combo. It's too bad that 15" tires are so difficult to find in the sizes that we need. Thanks again!

Garvino-I was afraid that the 17s would push the rear upwards as you suggested. My car has had the spacers knocked out of the stock shocks long ago and I really like the handling and stance w/them gone. I guess unless I want to scour the earth and spend ungodly amounts of money to purchase some 15" tires again, I'll have to make due with what's available to us! BTW where in Wyoming are you from? I'm up in Cody.
Clockwork,

That would be great. If I get all my little projects finished up on my car this winter I may drive it to Powell for one of my trips.

Either way it would be cool to swing in and see yours. I have another buddy in Casper that has a yellow Pantera. I guess there is also one located in Jackson. Besides that they seem to be a little rare in our state.

Devin
D-

Welcome aboard. Sympathy for the loss of your father.



Ride Height
quote:
Originally posted by Clockwork:

Which tire-wheel combo will keep that 4" clearance (ride height) that I love so much?

Using tires on the small end of acceptable diameters (24" front, 26" rear) will only lower the car 1/2 inch compared to tires that are on the large end of acceptable diameters (25" front and 27" rear). I'll explain what I mean by "acceptable diameter" further below, but for now the point I'd like to make is that small diameter tires don't lower the car tremendously, the low ride height you're seeking is more a function of chassis set-up.

Ride height involves two aspects, the overall height of the car and the relation between front height and rear height. The overall way in which a car sits on the ground is referred to as "stance" these days. As is very common, the Pantera was designed for a level chassis. Some guys like to give it a "slight" nose down stance for looks.
quote:


Originally posted by Clockwork:

... My car has had the spacers knocked out of the stock shocks long ago and I really like the handling and stance w/them gone ...


North American Panteras were equipped with spacers between the springs and shocks to raise their ride height about 1", these are the spacers referred to by the OP. The spacers were omitted from the European models. In other words, the European "standard body" Panteras sit 1" lower to the ground than their North American cousins. If a reader's US Pantera still has those spacers installed, then the first step towards achieving a lower "stance" is to remove the spacers.

However, rather than rely on the ride height built into the factory shocks and springs, ride height and stance can be "dialed-in" much better utilizing modern gas shocks that feature the ability to adjust spring pre-load. David and Devin both hinted at this:
quote:
Originally posted by David_Nunn:

... with a good spring/shock package, the "stance" of the car no longer depends upon tire diameters.

quote:
Originally posted by Garvino:

... came to the conclusion that I wanted the ability to adjust the ride height of my car to my specific liking. I ended up buying a new set of Koni’s with Hyperco springs and am glad that I did.

Shocks with adjustable spring pre-load make it possible to fine tune the front and rear ride height individually. Frankly, everyone should consider it a pre-requisite to install modern gas shocks when they install modern low-profile tires. The modern gas shocks perform better than the OEM shocks with the shorter/stiffer sidewalls of modern tires.



Setting-Up a Pantera Chassis

Whereas many automobiles are “lowered” by their owners to improve handling, the Pantera was originally designed to be about as “low as you can go” right off the showroom floor (before Ford raised the Pantera's ride height by 1 inch). If you set-up your Pantera to ride as it was originally intended by its famous designer (Gian Paolo Dallara), I don't think you'll be disappointed.

In preparation the fuel tank should be half full with fuel, the driver & passenger should be sitting in the seats, and the tires should be filled to the appropriate air pressure.

If the shocks have pre-load adjustment (its optional with the steel body Koni shocks) the chassis needs to be leveled; i.e. the frame rails that run below the doors should be equal distant to the ground front to back, and side to side. The minimum ride height sets the rear lower control arms level with the ground. To achieve that ride height adjust the rear springs first, then level the chassis by adjusting the front springs.

At this point the car is about as low as its going to get. My Pantera is set-up this way, and a racing style floor jack barely fits under the jacking points. The car bottoms out on large high speed bumps and dips, and the middle of the car scrapes certain driveways and speed bumps. I personally wouldn't want the ride height of my Pantera to be any lower than this.

That ride height is too low for some folks. If you want to set the ride a little higher than that, that's OK too, after all Ford did it. But don't go too high. May I suggest setting the front springs first to give the front tire even spacing between it and the fender opening all around the circumference. Afterwards level the chassis by adjusting the rear springs.

Some people like their Pantera to have a "nose down" stance. But raising the rear of the Pantera in relation to the front decreases positive front caster which there is already too little of, so this is discouraged.

If your Pantera is equipped with a front/rear tire combination in which the rear tires are about 2 inches greater in diameter than the front tires, then after adjusting the front and rear ride height in this manner the tires should be centered in the fender openings, and the gaps between the tires and fender openings should be fairly equal front to rear.





Upgrading to Modern Wheels and Tires

My understanding regarding the topic of tires and wheels has evolved over the last 10 years. I updated this post in February 2017 to present the information in a more logical format, and to make changes in the information based upon what I've learned. Thanks to all those who have provided feedback and helped this old dog learn a few new tricks.

Here's my disclaimer ...

It is not my intention to tell people what they "want" to hear, but what they "need" to hear in order to make informed decisions. But in doing so, it is not my intention to criticize another person's preference in wheels and tires, nor to convince them to make the same decisions I would make. I do not know what is right for you, but provided with the right information it is my hope you can figure that out for yourself.

quote:


Originally posted by Clockwork:

... I've basically given up on 15" tires and have decided to move on to Campi Clones ...


De Tomaso owners considering the purchase of aftermarket wheels in the year 2012 are doing so for one to three reasons:

• Because they are frustrated with the availability of 15", 16", or 17" tires. They need wheels designed for tire sets in sizes that are available from several tire manufacturers now and shall continue to be available into the future.
• Because they want to modernize the appearance of their Pantera.
• Because they want to improve the performance of their Pantera, which includes equipping it with modern tires.

All 3 needs are addressed by the same solution, installation of wheels in diameters designed for modern tires. The auto industry is currently installing 19" and 20" wheels on current high performance production automobiles. Aspect ratios are 35, 30 and even as low as 25. A 4 inch sidewall is a tall one in today's world; in some cases sidewall height has dropped a bit below 3 inches.

Unfortunately many owners are resistant to wheels in those diameters and the short sidewalls of the tires they are designed for. Their acceptance of the looks of such low profile tires has not evolved at the same rate as tire technology.



Safety and Transportation Authority Approval

If registration of your car involves critical inspection and approval from a government transportation authority (department or ministry of transportation) they may not accept replacement tires and wheels at all. If they do, here is a list of things they "MAY" check for; the items on this list are also worth the consideration of any safety minded owner:

• The tire set should use the same make and model tire front and rear.
• The tire set should be designed for passenger cars, not light trucks.
• The tire set should be designed for highway use, not DOT approved racing tires.
• The tire set should be of equal or better quality than the OEM tires (V speed rating).
• The aspect ratio of the front tires should be the same as the aspect ratio of the rear tires; or the front tire/rear tire aspect ratios should be at least within 5% of each other.
• The rear tire diameter should be sized appropriately in terms of speedometer/odometer accuracy.
• The replacement tires should be equal in diameter and/or load rating to the tires which were original equipment. Tires of equal width and diameter usually have the same load rating regardless of the wheel's diameter.
• The difference between front tire and rear tire diameters should not upset the chassis stance. This is one reason why the difference between the diameter of the front tires and the diameter of the rear tires should be within the range of 1.65 inch and 2.35 inch.



Tire Diameter
quote:

Originally posted by Clockwork:

David, Thank you for your input. I too believe that since the Pantera was designed around the 225/50-15 and 285/50-15 tires and the 8" and 10" Campy wheels that the look and stance was just right for the car ...


The Pantera was designed around 185/70R15 and 215/70R15 tires. Tires that are 25.19" diameter in the front, and 26.85" diameter in the rear. Tjaarda designed the wheel well radius to be filled by tires of that diameter. Tom Tjaarda's original intention was for the tires to fill the wheel wells. The Pirelli P7 tires came along about 8 years later ... Tjaarda was gone by then. The P7 tires are about 1" smaller in diameter both front and rear. They change the look of the car in so far as how the tires fill the wheel wells. If a person prefers this later look over the original look, it is neither good nor bad, its a matter of personal preference. I never mean to criticize another person's taste. Please don't take my comments in that way, because they are not meant that way.

Like any car the Pantera's front and rear wheel wells will only look “GOOD” with front and rear tires that are within a small range of diameters. One unusual aspect of the Pantera is that the front fender openings were deigned for tires approximately 2 inches smaller in diameter than the Pantera's rear tires.

A front tire 25 inches in diameter fills the front fender opening quite fully, whereas a front tire smaller than 24 inches in diameter begins to look proportionally too small for the fender opening. Therefore front tire diameter should remain within the range of 24” to 25”.

A rear tire 27 inches in diameter fills the rear fender opening quite fully, whereas a rear tire smaller than 26 inches in diameter begins to look proportionally too small for the rear fender opening. Therefore rear tire diameter should remain within the range of 26” to 27”. These ranges are what I was describing as "acceptable diameters" in the first paragraph.

In terms of appearance the tire set should use front and rear tires with diameters that fill the front and rear fender openings the same amount. This is another reason why the difference between the diameter of the front tires and the diameter of the rear tires should be within the range of 1.65 inch and 2.35 inch.



Tire Width

245mm is the widest front tire that can be installed without rubbing issues. A tire in that width is therefore capable of offering the best performance in terms of response to driver input, cornering grip, and braking. The only drawback I am aware of in comparison to a narrower tire shall be increased steering effort during parking maneuvers.

335mm is usually acknowledged as the widest rear tire that can be installed without rubbing issues. Some claim a 345mm wide rear tire will fit, but I've never seen the details of such an installation presented (rubbing, offset, ride height, etc.). It is not my intention to be argumentative or misleading, but 335mm seems to be a safe (if conservative) recommendation.

Campy clone wheels or aftermarket wheels (such as Kinesis) designed for ultra-wide rear tires are a common choice with many Pantera owners. It appeals to the folks who want to personalize or customize their cars. Ultra-wide rear tires add super car "presence" to a Pantera. The use of ultra-wide rear tires is entrenched and accepted within the Pantera hobby. If this is your choice and your dream it is certainly a valid one.

However, ultra-wide rear tires are not for everybody. Proponents of the ultra-wide tires do not realize that those with more conservative tastes are not supported at all by the Pantera vendors when it comes to wheels. I have 3 hopes for the community of Pantera owners:

• I hope we are all open minded enough to accept opinions differing from our own
• I hope we are all secure enough to accept cultivation of another equally valid option without being insulted
• I hope we are all thoughtful enough to want the dreams and needs of each owner to be met, whether or not we agree with them

Panteras equipped with Pirelli P7 tires had OEM rear tires which were 285mm wide. A 285mm wide rear tire is "conservative" only in comparison to an ultra-wide super car tire, it is actually a very wide looking tire offering plenty of traction. Rear tires having widths in the range of 275mm to 295mm offer several practical advantages in comparison to ultra-wide rear tires. Those advantages include lighter weight, faster acceleration, improved suspension compliance, improved fuel economy, lower price, a higher number of available tires sets, and fewer obsolescence and availability issues.

Tires of approximately 245mm width in the front and 285mm width in the rear have been a very common tire complement amongst modern sports cars for more than a decade, excepting the very expensive "super cars" which normally have wider (and more expensive) rear tires.

(Note) As manufacturers have upgraded their wheels and tires to 19" and 20" diameter the width of the rear tires have grown in 10mm increments to 295mm and in some cases 305mm. This was not due to the need for more grip than what had been provided by the 285mm tire, it was a necessity in order to keep the rear tire's outer diameter equivalent to the diameter of the previous tire. This is common when upgrading tires wider than 255mm.

As an example, the German engineered 2017 Audi R8 is propelled by a naturally aspirated 5.2 liter V10 engine rated at 540 BHP and 398 ft./lbs. torque. Its curb weight is 3649 pounds; that weight is distributed 42% on the front tires and 58% on the rear tires. It accelerates from a standstill to 60 MPH in 3.5 seconds. It circles the skid pad at 1.00 G; and it stops from 70 MPH in 153 feet. It is equipped with 245/35R19 front tires and 295/35R19 rear tires as standard equipment. I am confident that a tire complement similar to this is well suited for most Panteras.





Future Tire Availability:
quote:

Originally posted by Clockwork:

... I guess unless I want to scour the earth and spend ungodly amounts of money to purchase some 15" tires again, I'll have to make due with what's available to us ...


If an owner is interested in purchasing a new wheel and tire set in order to make tire availability better than what it is for 15" wheels, a 17" wheel and tire set shall no longer accomplish this. Tires for 17" wheels just aren't being supported these days any better than tires for 15" or 16" wheels, especially in the wider "rear tire" sizes. This is why we do not advocate selecting 17" wheel sets. Debbie and I understand that some folks don't like the looks of modern "short sidewall" tires, but that is beside the point. The point is, in spite of everyone's opinion the tire industry continues to evolve. We have no control of this, it is the reality of the tire market and we have no choice other than to cope with it.

Automotive tires have evolved in steps throughout my life ... and most likely yours too. Tires are in a period of evolution at this moment, sidewalls are becoming shorter and wheels are becoming larger in diameter ... again! Time has taught us that older tires (designed for smaller diameter wheels) are not adequately supported by the tire industry unless they are tires in high demand, i.e. OEM tires for mass produced cars that are still on the road. Unfortunately for us, sports cars are never mass produced!

Appearance is always high on everyone's criteria when it comes to upgrading tires and/or wheels. But another possible criteria for selecting tires or wheels is the availability of front/rear tire sets. Acquiring tires in sizes which aren't supported by the tire industry can be frustrating and expensive. Life is frustrating enough without spending a lot of money on a wheel set which adds to life's frustration. Spending a sizeable amount of money on something that adds to life's frustration is tantamount to shooting yourself in the foot!

If you're going to spend a substantial amount of money on a new set of wheels, it makes sense to purchase the wheels for a tire set that shall be available for the next 15 to 20 years, and for which more than one make and model of tire is available. At this time a new set of wheels should incorporate 18" or 19" front tires and 19" or 20" rear tires. Wheels for 18" rear tires are already a bad investment. I've noticed a trend in the last year, Pantera tire sets with 18" front tires are going down in number, while Pantera tire sets with 19" front tires are increasing in number. I foresee 18" front tires dropping off the list at some point in the future too.

These two internet sites help in judging the availability of tires, they both allow you to perform a search based on tire size. One very beneficial feature offered by both web sites, they allow you to search by size for "sets" of tires wherein the front tires and rear tires are a different size.

Tire Rack.com/

On Line Tires.com/

The web site linked below lists the OEM applications of the various tire sizes, and the years. Obviously more applications, and/or more recent usage will indicate good prospects for future availability.

Size My Tires



Tire Specs

There are not one, but two possible groupings of tires to choose from. This concept of two tire groupings will come as a surprise or "eye opener" to many owners. It is based upon the understanding that the Panteras manufactured from 1971 to 1978 were equipped with either 70 series radial tires or 60 series Goodyear Arrivas, all having approximately 25" diameter front tires and 27" diameter rear tires. Tires of those diameters constitute the first grouping.

Beginning about 1979, in an unusual move, De Tomaso began equipping narrow body Panteras with 50 series Pirelli P7s having approximately 24" diameter front tires and 26" diameter rear tires. This was an unusual move because auto manufacturers don't normally change the diameters of a cars tires this drastically without an accompanying change in the size of the fender openings. These smaller diameter tires constitute the second grouping.



As you study the charts below you shall see that the aspect ratios of each tire grouping are different for any given wheel diameter, and each has its own logical and mathematical progression in "plus 1, plus 2, plus 3 and plus 4" tire sizes. Choose tires from one chart below or the other. Do not mix front tires from one chart with rear tires from the other. And keep in mind that the difference between the diameter of the front tires and the diameter of the rear tires should be within the range of 1.65 inch and 2.35 inch.

I'd like to point-out one thing, the list of smaller P7 substitute tires offers very few choices in front tires. This is because the availability of modern tires diminishes for tire diameters below 25".







Wheel Width

Unlike the average car in which all 4 tires are the same size, and all 4 wheels are identical (same width and offset) the Pantera uses front and rear tires differing in width and diameter by a significant amount, and requires wheels of different widths and offsets for front and rear.

In the past, when tire sidewalls were "taller", the width of sports car wheels was usually 50% of the tire’s rim width range, or at least as wide as the tire's tread. If a wheel with that width was not available, a wider wheel would be chosen. This helped stiffen the sidewall for better handling. However, with modern "performance" tires having such "short" sidewall height, the "need" to do this is a moot point ... the sidewalls are plenty stiff already.

• With the "short" sidewalls of modern tires wheel width should be a bit narrower than tread-width. This squares-up the sidewall which protects the wheel from damage in pot-holes and also helps in protecting the wheels from curb rash. So the wheel widths should be narrower than what we would have chosen in the past.

• Tires with short sidewalls do not look good if the wheel is even just a bit wider than the tread, because the inwardly angled appearance of the sidewall is amplified by the sidewall’s short height. So the wheel widths should "square-up" the tire sidewalls for best appearance too. Since wheel width affects the tires appearance, the front/rear wheel widths should "square-up" the sidewalls of the front/rear tires a similar amount for balanced front/rear appearance in this regard.

Wheel width is one aspect in which some of the people in the wheel and tire industry have not grasped the needs of modern short sidewall tires. Wheels are being sold every day that are too wide for the tires they are paired with. I've noticed some very expensive high-end cars with OEM tires mounted on OEM wheels that are too wide. There are a lot of old dogs still thinking the way we did back in the 1980s and 1990s. Until recently I was one of them. Everyone shall eventually be on the same page, but it will take some time.

• Rear wheels that are 15", 16", or 17" diameter are limited to 6-1/2" "calculated" back-space (or an actually measured back-space of 6-1/4"). A wheel in those diameters shall rub the lower rear control arms at 6-3/8" actual back-space. This normally limits rear wheels in those diameters to 11" width and 12mm offset. This impacts wheels designed for 335/35R17 tires.

• Wheels larger than 17" diameter have enough clearance to avoid rubbing the lower rear control arms; the limitation mentioned above doesn't apply to them.



Wheel Offset

The trend in aftermarket wheels for the Pantera has been to set the front tires too far inwardly (excess offset) and the rear tires too far outwardly (insufficient offset). The result is an imbalance in the appearance of the car. Front and rear offset should set the edges of the tires' outer sidewalls inwardly from the front and rear fender edges an equal amount for balanced front/rear appearance.

The wheel offsets should position the tires and wheels in relation to the fender edges, wheelhouses, chassis structure and suspension control arms to avoid rubbing issues. The occurrence of rubbing is impacted by ride height, tire diameter, tire width, camber settings, front caster, spring rates, anti-sway bar thickness, and whether or not the fender edges have been "rolled".

The front offset is the most difficult to determine because the front tires must be prevented from rubbing the fender edges when the front wheels are turned in either direction at the same time the suspension compresses, such as turning into a steep driveway or when the body "rolls" during high speed cornering. This makes front tire clearance (the amount it is recessed) the limiting factor. Once the front offset needed for front tire clearance is determined it is rather easy to set the rear offset to recess the rear tires within the rear fender openings an amount that is visually equal to the amount the front tires are recessed within the front fender openings.





Pantera Tire Rubbing Issues

• 245mm cross-section front tires and 335mm cross-section rear tires are the limits in tire width in terms of avoiding rubbing issues in a narrow body Pantera.

• Offset at the front or rear making the outer sidewall of the tires flush with the fenders’ edges MAY result in rubbing at the fender opening flanges, and MAY make it necessary to “roll” them. Rubbing is also impacted by tire diameter, ride height, and camber settings ... tires larger in diameter are more likely to rub than tires smaller in diameter.

• Front tires with 245mm cross-section mounted on wheels with 22mm offset MAY rub the wiper motor’s protective housing in the right wheel house at full lock, and MAY rub the inner wheel house at full-lock as well; in general 22mm front wheel offset has worked well in avoiding any rubbing issues. If rubbing occurs it shall be minor and only occur in low speed parking maneuvers; it shall not be a significant problem.

• On rare occasions front tires greater than 25.0 inches diameter have rubbed the lower front corner of the fender openings, this is because the front tires are not centered within the fender openings, they are positioned forward of center. This situation is the result of Ford’s decision in 1971 to reduce caster in order to promote “understeer”. This can be reversed by moving the upper ball joints 1/2 inch (13mm) rearward via modification of the upper front control arms. This revision centers the front tires within the fender openings thus improving appearance and eliminating rubbing in the lower front corners of the fender openings (if rubbing is a problem). It also restores the Pantera’s originally intended 6° of caster which improves directional stability and reduces understeer.

• Rear tires greater than 26.5 inches diameter and wider than 285mm MAY rub the OEM Ansa mufflers, and MAY require modification of the mufflers to create clearance.

• New shock absorbers have more travel built into them than the OEM shocks. Rear tires often rub the upper portion of the wheel houses over large bumps due to the additional travel built into the new shocks. This rubbing is resolved as it was with the OEM shocks, by limiting shock travel ... not by altering offset. Shock travel is easily limited via installation of a second set of "stop rubbers" on the shock absorber shafts.



Wheel Specs

The information below is our current best recommendation regarding the subject of Pantera wheels (as of February 2017). Both the wheel width and offset are very specific for one tire width, they are not useful for someone seeking a specification for one-size wheel that fits several size tires. This is the way it is with these modern short sidewall tires.

I have not had the opportunity to experiment with front wheel offset enough to have the same confidence in the front offset recommendations as I do in the rear offset recommendations . The front offset recommended in the chart below are "safe" settings, they work for many chassis set-ups, but they may be more than necessary, or recess the front tires more than described.





Modern Replacement Tire and Wheel Sets

The chart below details the "modern" replacements we advocate. The engineering and design goals I've discussed, plus future availability, have all been taken into consideration in our recommendations. We've done the engineering for you.





Where To Acquire Pantera Wheels In Diameters Appropriate For Modern Tires
quote:

Originally posted by Clockwork:

... I'll have to make due with what's available to us ...


We wish we could simply write and announce the Pantera vendors had the wheels you need for modern tires, but we can't. The vendors selling Campy Clone wheels have not kept-up with modern tire sizes. They are selling expensive wheel sets for tires that in some cases aren't available in matching sets, that have only one choice in make and model, or that have "off and on" availability issues. In other words, the availability of tires for the current 17" Campy clone wheels is just as slim as the availability of tires for 15" wheels.

Note to Vendors: Please inform us if you update your wheel offerings.

Here's some wheel choices which are available to you ...

• Custom manufactured Campy clone wheels, which can be ordered in larger diameters, are available from American Republic Wheels (Boyd Coddington USA web address). The "Campi" wheels are among their "Elite Series" of wheels. The centers of these wheels have 3 dimensional "depth" like the OEM Campy wheels, more so than other Campy clone wheels. For instance the frames around the "windows" tilt outwards at an angle whereas other Campy clones are flat as a pancake. To machine the wheel at multi-angles like that requires more time on the CNC machine, and makes the wheel more expensive. These wheels are gorgeous, and a good option for Pantera owners.

Boyd Coddington once manufactured the wheels for Pantera East, the Pantera East wheels had several features which made them closer in appearance and function to the OEM Campy wheels than other Campy clones on the market.

  • 62mm hub bore diameter
  • wheel center designed for the OEM logo disc held-in by a circlip, instead of a "pop-in" cap
  • reproduction of the intermediate "step" built into the original wheel
  • old-style (traditional) wheel "lip" design

Boyd Coddington is under new ownership, it has been owned by American Republic Wheels since 2010. Please be forewarned their standard "Campi wheel" spec is a rather generic style wheel spec. It lacks the features listed above that were found in the wheels formerly produced for Pantera East. It is not marketed as a "Pantera wheel", it is intended for owners of classic American hot rods and muscle cars who like the Campi look. If you want a wheel that is more Pantera-specific or similar to the Pantera East wheel, be sure to start the exchange by explaining the wheels are for a Pantera AND you want wheels machined and assembled to the former Pantera East specification, except in terms of diameter, width, and offset. Be specific with what you're looking for. They have a CNC program for the Pantera East wheel, owners have been able to have wheels produced to that spec.

Please be forewarned doing business with American Republic Wheels has been an exercise in frustration and disappointment for some folks. If you do business with them, please share with us your experiences.

• If you're thinking about a high-end set of two-piece or three-piece wheels, Evod Industries of Escondido California should be high on your list of businesses to consider making those wheels for you. Evod is owned by Shaun Dove, a fellow Pantera owner and a Pantera International member. He shares our passion.

• MHT Wheels has a Pantera wheel (#F219) amongst the wheels they manufacture under the "Foose" name. This was the wheel designed by Chip Foose for his first Pantera project.

• Another option is the F14 wheel sold by Forgestar.

• Other options are the T1000 and SP540 wheels sold by CCW (a division of Weld Wheels).

• A wheel solution Debbie and I promote is to:
  • Purchase and install longer wheel studs (available from Pantera vendors)
  • Purchase "off-the-shelf" one piece cast wheels from Enkei or TSW. These wheels are high quality, manufactured in either Japan (Enkei) or Europe (TSW); they are also lightweight, and strong. They are available on eBay and Amazon.
  • Adjust the offset using hub and wheel-centric spacers. Custom billet aluminum spacers up to 30mm thick are available from several companies, including Motorsport Tech.

Even factoring-in the price of studs and spacers (about $800 USD) the overall price of a wheel package such as this is still substantially below other options.





The 2017 Ford GT in the picture below has tires of the same width and aspect ratio as the tires in set number 6 (20" wheel diameters however). I know a lot of you have not "warmed-up" to the appearance of modern "short sidewall" tires. So keep in mind even though the tire sidewalls of set number 6 are the same height as those of the Ford GT tires, they shall appear proportionally taller on 18" and 19" wheels. The wheels of the Ford GT are also 8.5" wide up front, and 11.5" wide in the rear, same as the specification we recommend.

Our goal is for your Pantera's tire and wheel set to look as well designed and to fit into your Pantera's fender openings as well as those of the 2017 Ford GT.

Whatever your goals are in terms of your Pantera's stance and appearance as impacted by the wheels and tires, we sincerely hope everyone's input shall help you get started, happy shopping!

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George, I must disagree with a couple of items mentioned in your most recent posting, with regard to tire sizes.

Re: 245 width tires on the front. Very few Pantera owners would ever benefit from the extra traction gained by going to a 245 over a 235. The improved appearance of the shorter tire, combined with reduced rubbing and reduced unsprung weight, make it the better choice. 235/40-17 is an OEM size so tires will always be available. Furthermore, many modern high performance sports cars use this width of tire up front (Porsche 997, Ferrari, Lamborghini, McLaren F1, etc.). Of course, when moving up to 18", you have less selection of 235/35-18's than 245's but they are readily available.

Re: 275 or 285 width tires on the rear. Back when we were all running 15" wheels, these were fine and a 285 width P7 was a much better tire than a 295 or 305 width BFG Radial T/A (or other similar domestic tire); however, now that we're all switching to 17", 18", 19" or even 20" rear wheels, there's no reason to use anything less than a 305 width tire. Even most '05-'12 Porsche 997's come with 305/30-19's (on 19" x 11" wheels) on the rear and that car certainly doesn't have to deal with the kind of torque that a Pantera puts to its rear wheels.

There's also the safety factor to consider. It's simple physics, with mid-engined cars, the heavy end always wants to lead. Manufacturers put wider tires out back to compensate for the greater weight and load on the rear tires but there's another reason as well. If you are in a cornering situation where the rear of the car steps out, for whatever reason, a wider tire will scrub off speed more quickly than a narrower tire, allowing quicker recovery from the spin or slide. Wider rear tires simply make the "tail heavy" Pantera more forgiving and give the driver a larger margin of error. Considering the power we all put to our rear wheels and the clearance available in our rear wheel wells, it makes sense to use a 305, 315, 325 or 335 width tire at the rear. Looks cool too! OK; I admit it: that's the best reason of all!

Re: all-season radials on a Pantera. You're kidding, right? I understand some people who are still running 15" wheels are forced to do this because they have no choice but how many Pantera owners would sacrifice dry road traction, or even wet road traction, so they can drive in mud and snow? Also, if you have to buy all-season tires because you can't afford Z-Rated summer tires, you're driving the wrong car. Personally, I park my Pantera when it's snowing and I try not to take it off road :-)

Here's another little known fact about tires: in general, a tire with a taller sidewall has a more gradual break-away than a tire with a shorter sidewall. That's the reason Gordon Murray specified a 28" tall rear tire (315/45-17) for the McLaren F1. A tall tire will squeal loudly as it approaches its limit of adhesion and will loose grip gradually, as opposed to a super low profile tire that tends to give no warning then break away suddenly.

George, I don't enjoy voicing an opinion contrary to yours on this, or any other topic and I'm not trying to imply that your opinion isn't valid, but I felt it was necessary to show another side to this subject.

As they say: "IMO"!
Thank you guys again for your iput-it really helps me alot! I've been out of the pantera game for quite some time and your opionions help me greatly!

Mikael those 17"s look really nice-our cars look almost identical except for your blacked-out door levers, the wheels, and your paint job. My 72's was painted poorly by the previous owner, in a Porsche red similar to the color of yours. ATM my '72 has a 20' paint job! Hopefully in the next couple of years I can get it painted.
quote:
Originally posted by No Quarter:

Hell, I like Panteras!



Smiler right on!

quote:
Originally posted by Clockwork:

... Mikael those 17"s look really nice ...



Agreed!

quote:
Originally posted by David_Nunn:

.... George, I don't enjoy voicing an opinion contrary to yours ...



David, you are more than welcome to disagree with me. The respect you expressed is appreciated. But don't apologize for having a differing opinion. I appreciate and value your opinions, experience and the knowledge you've gained along the path of De Tomaso ownership. I learn from you.

The wheel & tire combinations I've listed embraces a wide spectrum of tastes. I realize my recommmendations for narrower rear tires, or lower profile tires, will not please everyone. None of us can please everyone. There are only a few owners who drive their cars year 'round, in all sorts of cold, wet, nasty weather. I'm proud to say I'm one of them. When I'm driving my Pantera in heavy rain, or on icy cold asphalt, I want to know I have tires designed for the task. Its nuts like us who appreciate the cold weather tire compounds. I do miss the ultimate grip when I'm negotiating a mountain road on a warm day, but that's a compromise I'm willing to make.

-G
quote:
Mikael those 17"s look really nice-our cars look almost identical except for your blacked-out door levers, the wheels, and your paint job. My 72's was painted poorly by the previous owner, in a Porsche red similar to the color of yours. ATM my '72 has a 20' paint job! Hopefully in the next couple of years I can get it painted.


Clockwork, our cars are more alike than you think. My paintwork is what we Europeans arrogantly call a US paintwork (it's a California car): Straight and shiny. But open the door and you see brushmarks, door handles and side markers were masked not removed, cracks in many places. At a distance or at speed it's great...

Funny you mention the door levers, I've been looking for reasonably priced shiny replacements since I got the car, they would go better with the shiny trim.
George, I should mention that before I grew-up and got a real career, I spent a few years of my life in the "high end" wheel and tire business, so I consider my opinion to be an educated and experienced one. Accordingly, the biggest mistake most people make is going too big. I'm not referring specifically to Pantera owners but car owners in general.

One point you made is extremely important when selecting tires and it applies to every make and size. That is, tire width specifications should be taken with a grain of salt. One manufacturer's 335 width tire could be +/- an inch different in width when comparing it to another manufacturer's 335. Sidewall design and stiffness, combined with differences in tread width, all contribute to these differences which the specifications don't necessarily reveal. I have Hoosier Autocross tires on my Pantera and they're so wide I can't imagine how Hoosier had the nerve to publish such inaccurate specs for these tires.

As far as the all-season radial matter is concerned, it's still my opinion they are totally unsuitable for use on a Pantera. They simply do nothing well, except be quiet and last forever. There are some summer tires that work quite well in the cold, such as the outstanding Michelin Pilot Sport PS2. I know this from personal experience as I live in the Pacific Northwest and have a set on my daily driver. As long as it's not snowing, they work great, even in sub-zero temperatures.

In 2009, Edmonds and the Tire Rack got together and ran a test with summer tires, all-season radials and snow tires. They tested all three types of tires in the dry, in the wet and in the snow. Here are a couple of their conclusions:

------------------------------

" no single tire type excels on all surfaces, and the differences between each are sometimes striking. These differences are so massive, in fact, that we feel that certain generalizations can be extrapolated from our small trio of carefully selected test tires.

To the surprise of exactly no one, our winter tires dominate in snow and the summer tires dominate in the dry. The eye-opener here relates to wet performance, where a well-developed summer tire embarrasses an all-season tire made for the same car by the same folks. Anyone who never sees or visits snow would be very well served by summer tires for year-round use". They went on to say "in delivering this capability (part-time snow tire), all-season tires sacrifice a noticeable bit of dry and wet performance. Meanwhile, snow and summer tires provide clear benefits to those who can use them. In this particular test, at least, all-season tires live up to the old figure of speech our old dad used to trot out on occasion: "jack of all trades, master of none".

-------------------------------

By the way, I've driven my Pantera in the snow (long story) and can attest to the fact it's not a good idea :-(
Interesting posts guys. Finding it very informative. However if I can ask without stirring a hornets nest Smiler; What tire size/type recomendations do you make for the wider bodied GT5S?

I'm needing new rubber soon, and possibly new wheels. Would appreciate your advice. Currently I have 335/r1740 and 245/40r17. The 245's seem a bit narrow up front (sit well in from the wheel guard - 1.75")and was thinking of going wider.
Lui, without changing wheels, I think your only option would be to use a 255/40-17 in the front. You can go wider, but they get too tall, IMO. I'm not aware of anything that's available in a 35 series, until you get up to 295/35-17, which would require at least a 10" wide rim. If it's mainly appearance you're concerned with, and you don't want to buy new wheels, the only option I can think of is using spacers. It's not an ideal solution but it can work safely if done properly. Before people get upset with this suggestion, keep in mind the factory fitted spacers on GT5's and Porsche has been doing it since the '70's. The correct way to do it is to make sure the spacer is tightly hubcentric and also make sure you're using the strongest wheel studs possible, with adequate length. This likely means having custom spacers made and be as conservative as possible in deciding on a thickness.

Mistersolo, yes, if your brake rotors are mounted on the outside of the hubs, you need to add the thickness of the rotor hat to your backspacing or offset calculations. Also, the Pantera's wheel registers (hubs) are slightly tapered, so if you mount your rotors on the outside of the hubs, the diameter of the wheel's center bore must be slightly smaller, in order to maintain proper hubcentricity.
Here's my two cents: Go with the narrower tire combination. I think it's been said here before that a tire on the rear that's too wide can throw the balance of the car off and cause significant detrement to handling. So, I think there's two paths you can choose for a stock narrow-bodied car:

1. Wide rear tires (the 325's or 335's) and standard 225, 235, or even 245 front tires. The combination seems to be well liked and is offered by many of the vendors. However, it probably doesn't "balance" the narrow-bodied, mostly stock-suspensioned car for the track and is really meant for the street. If you had a wider front tire with a wide-body or flared car, then that's different. If you have significant modifications to the suspension to bring it into modern theory and design, then that's different as well.

2. Reasonably wide rear tires with the standard 225, 235, or 245 front tires. We're talking the size George mentioned, and maybe up to 305 tires. Jack (Bosswrench) and others will probably agree that this combination seems to be the better choice for the track for the Pantera. However, street use will be great and the car was never meant to be a drag racer in my opinion. You can't compare a 40-year-old car to newer car technology, so saying that a certain modern supercar uses a certain combination, well, fine, but that might not be relevant to the Pantera with a stock narrow body and mostly stock suspension.

Seems to be kind of a paradox- if you want better track performance in a stock narrow-bodied car, don't put the widest things you can find on the rear and throw the balance off. If you want to impress and don't mind the reduction in handling, then go with the wider rear tires. I agree with the wisdom to find a popular tire size since it's less likely to be removed from production. I think the choice in rim size is important, too. Too much of a good thing can be bad. I also agree/think for the Pantera that won't be driven much in the rain or snow, the summer tires are probably the wise choice.
quote:
Originally posted by Lui:

What tire size/type recomendations do you make for the wider bodied GT5S?



Lui we can't make a tire recommendation without knowing the width of the wheels. The width of your Pantera's wheels is going to limit the tire sizes that can be mounted on them.

In regards to modern low profile tires, a tire should be mounted on a wheel that's a bit narrower than the tread. This squares up the sidewalls.

The OEM tires of a narrow body Pantera have 1-3/4" different diameters front to back, this is reflected in the radius of the wheel wells, and this is why staggering the wheel diameters compliments the appearance of narrow body cars. The OEM tires of a GT4, GT5 or GT5-S were about 24" OD in the front, 24.5" OD in the rear. There is very little stagger in diameter, and this is also reflected in the radius of the wheel wells. Staggering wheel diameter doesn't make sense with the wide body Panteras.

The problem with the wide bodies is finding modern low profile tires that are approximately the oem cross section (285 front, 345 rear) but only 24" to 24.5" in diameter. Most guys usually settle for using a larger diameter tire.

-G
quote:
Originally posted by Lui:
What tire size/type recomendations do you make for the wider bodied GT5S?

Lui,

If your 17" wheels are true wide body replacements they should be 13" wide rear and 10" wide front. The 335/35-17 tire is good for the rear and typically on the front guys are using a 275/40-17. The challenge can be in finding the same tread pattern for both in a single manufacturer. Here in the US Michelin Pilot Sport PS2 and Kumho Ecsta XS are both available for front & rear and equally priced. The rear Michelin's have come way down in price, they used to be over $400 ea now selling for $226 at Tirerack.
This is why I come to this site for information: reasonable, intelligent, informed, insightful and respectful dialogs on topics I'm interested in learning about. No flaming, no grandstanding, just good conversation and ideas. Thanks guys!
Merging threads

quote:
Originally posted by Vicramos:
Someone along the lines changed the stock campys to Enkies (look very close to centerline rims). The Enkies are 14" front and 15" rears running 205 60 front and 275 50 rears. They are long past their retirement..... So I am thinking of getting new rims and tires for my 74L narrow body (#6347). Stock shocks, exhaust and no rolled front quarters.

I searched the forum and found a wide variety of rim, tire and backspace
measurements. Am very confused........

Looking at the TSW Valencia or Carthage wheel with a Ford Mustang 5x114 bolt pattern. 17 x 8 in the front and 18 x 9.5 in the rear. Both have a 20mm offset which equates to a backspace of 5.25" in the front and 6.0" in the rears. Tires would be 245 45 17 fronts and 285 35 (or 40) 18 rears.

Will this fit?? Should I go 35 or 40 height in the rears???

Thanks for any advice.

Victor
I think you need to re-visit your wheel and tire choices. The front wheel you're looking at will work fine but a little bit more offset would be better (22mm is perfect). On the rear, 20mm is too much offset. For a 9.5" wheel, I think you need about zero offset, for it to look right. It's very important that the wheels are hub-centric too. They need to have a 62mm center bore. As far as your tire choice is concerned, a 245/45-17 is too tall up front. Consider a 235/40-17 or 245/40-17. At the rear, a 285/35-18 or a 285/40-18 will work. Keep in mind, there's enough room for a 335 width tire at the rear on a stock bodied Pantera.
Yes, lower offset will bring the wheel further out and higher offset will push the wheel further in. A 9.5" wide wheel with zero offset has a 5.25" backspacing.

As a point of reference, the Campi clones that many Pantera owners now use, are typically 17x8 with 22mm offset (5.375" B.S.) and 17x11 with 12mm offset (6.5" B.S.).
Select tires for the front of your narrow body Pantera which are 24" to 25" OD, 225 to 245 cross-section.

It is a common mistake to try and set the front tires too far outward, closer to the fender lip. What happens is you'll end up with a tire that rubs the fender lip in high speed corners.

225mm front tire: 6mm offset - 7.5 inch wheel
235mm front tire: 11mm offset - 8 inch wheel
245mm front tire: 16mm offset - 8.5 inch wheel

8" wide Campy clone wheels (Pantera East) are designed with 23mm offset, 9" wide Kinesis wheels are designed with 25mm offset.
________________________________________________________________

Select tires for the rear of your narrow body Pantera which are 26" to 27" OD. My preference is tire with 275mm to 285mm cross-section. Others prefer 325mm to 335mm cross-section.

My reason for suggesting a cross-section that is narrower than the typical 325/335 cross-section is to provide you with more choices, less cost and less chance of obsolescence. There are those who will cast stones at me for daring to write such blasphemy. But there are "performance" advantages to the narrower tires too (acceleration, fuel economy, handling).

275mm rear tire: 8mm offset - 9.5 inch wheel
285mm rear tire: 13mm offset - 10 inch wheel
315/35R17 rear tire: 12mm offset - 11 inch wheel
335/35R17 rear tire: 12mm offset - 11 inch wheel
335/30R18 rear tire: 38mm offset - 12 inch wheel
335/35R18 rear tire: 38mm offset - 12 inch wheel
325/30R19 rear tire: 33mm offset - 11.5 inch wheel
335/25R20 rear tire: 38mm offset - 12 inch wheel

-G
Spacers are OK if done properly. That means they must be hub-centric and the wheel studs should be upgraded to 1/2"-20 or 14mm. You won't find the appropriate spacers in anyone's inventory so they would need to be custom made.

My advice is to simply buy wheels in the correct sizes, with the correct offsets.
Merging threads

quote:
Originally posted by ttam23:
I am planing on buying 235/45/17 fronts and 285/40/17 rear to go on 8" and 11" rims. I know a lots of pantera owners like the 335/35/17 on the rear , but i don't see the point I only have stock engine so it not like i have to transfer 600hp to the road . any thoughts thanks
Isn't 11" too wide for a 285? Check the manufacturers chart.

It is going to tell you the minimum and maximum recommended wheel width, then will tell you the "design" width for that tire.

It is the design width that you want to match.

The size of the tire on those wheels is not out there because of the power that needs to get to the ground.

It is for the look of the tire and what the owner thinks fills the wheel well "correctly".

All those "turbo look" Porsches don't need the tire for power.

Personally I think the car handles better with the 285 than the 335.

What happens is that you really are getting inadequate loading on the bigger tire and all you do really is just spin them.

The car is going to be similar to using racing tires on the street and that simply means the tires are constantly slipping in order to gain more traction, if that makes sense.

On the race track you practice with your set up but on the street if you drive it hard then your tires are slipping as if they are on wet pavement and is that really what you want to do?

Lots to consider with going to those wheels. It only seems simple.
There was a post by George Pence back in January, 2012 (for which I made a hard copy, but cannot readily find at the moment)which stated the original Pantera diameter was about 25" front and 26.8 rear and went on to suggest 245/40/17 front and 285/40/17 rear.
I have been looking in www.tirerack.com to look for matching tread patterns, wheel width specs, overall diameter (for speedometer consideration)and sidewall profiles.
so are the 235/45ZR17 ( 25.28 in )too tall for the front, will i have rubbing issues with the stock suspension. what if i take out the spring spacers? i would go with 235/40zr17 but i am finding it hard to find a matching set with a 285/40/17. I could buy 225/45/17 (25 in) that's the size recommended buy PI Motorsports, Inc. but is hard for me to believe that .28 " could make a difference

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