Now the only problem is to exchange the tires until you get the right ones.
Now the only problem is to exchange the tires until you get the right ones.
To all the Pantera wheel offset experts:
As I posted previously, my old 15" Gotti wheels have finally given up the ghost, so I'm researching new replacements.
My question is about front wheel offsets.
I like the way my old wheels, with their 225/50-15 tires, fit in the front wheel wells. And they've never rubbed in all the years I've had them on the car.
I measured my current 15x8" fronts wheels, and they have a 4.5" backspacing, which calculates to a 0 offset.
All of the 17" and 18" front wheel offsets that I have seen (for the same 8" widths) vary from 12mm (5.0" backspacing) to as much as 22mm (5.375" backspacing).
Why do the new wheels need so much more positive offset (added back spacing) compared to my old wheels? I know my old tires are short at only 24", but the 17-18" replacements are only 0.5" to 1.0" taller. And if I stick to 225/235 replacements, they are at most only 0.5" wider.
Slightly Confused
Craig
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To a lesser degree, the same goes when fitting giant rear tires. Best to leave extra clearance in excess of what George mentioned, or do all your handling & appearance updates before buying those max-size wheels & tires. Trading wheels & tires or flaring a fender for enough tire clearance on a 'finished' Pantera WILL be expensive!
I'm reminded of the owner that had his Pantera extensively pro-redone at enormous cost, bought big tires & wheels, drove the finished machine for a month and found that it's stock brakes were no longer adequate and 'looked funny' with the huge wheels & tires. But oversized brakes would not fit the wheel sizes he'd bought! He nearly gave his almost-new aftermarket wheels & tires away, and took a bath on prices for even larger ones when upgrading the brakes. Redesigning a car is a many-aspects thing....
Sorry for the delayed response - I have been off the grid at the Teton Science School outside of Jackson Hole, Wyoming with my son's class as a chaperone.
As per your question, both the front and rear tires on my new wheels are slightly tucked in from the outermost fender lip area (visually about the same amount on front and rear).
I did this on purpose because I like that look more than the tire and wheel being exactly even with the fender lip (just my preference).
Just as Bosswrench mentioned, my car was not exactly even on the front end. The front passenger hub sits slightly farther out towards the fender compared to the driver's side hub. It is not noticeable visually but I figured it out when I started measuring for the new wheels.
Let me know if I can be of any further assistance.
Devin
quote:
Originally posted by CraigCline:
... Why do the new wheels need so much more positive offset (added back spacing) compared to my old wheels ...
Good question Craig. As a generalization most aftermarket Pantera wheels are built with too much front offset and too little rear offset. The front wheels are 8 to 9 inches wide and have 22mm to 25mm offset. A 245mm tire rubs the inner wheel house, and looks excessively recessed. By contrast the rear tires are generally offset to be flush with the fender edge; in fact the 335/35R17 tires stick-out from the fender by 5mm! Then the level ride of the chassis is upset because the rear tires are generally much smaller than OEM, so the rear end must be jacked-up or the front end lowered. You end up with a front tire that fills the fender arch as intended, but a rear tire that has a big gap between it and the fender arch. So the appearance of the tires is imbalanced front to rear in two ways, the amount they are recessed by offset, and by the gap between the tires and the fender arches. On top of that, the front tires are not centered within the fender arches, they are shoved forward. Correcting these things has been a crusade of mine.
Yes small diameter tires and the vehicle's ride height both impact tire clearance. I recommend 6mm offset for 225mm front tires, and 16mm offset for 245mm front tires.
I have a wheel width and offset guide I'll attach below.
quote:
Originally posted by Garvino:
... Let me know if I can be of any further assistance ...
Devin thanks again. You've been a great help. Very cool that you are helping the school with the kids.
I agree with you regarding the appearance of a "small" amount of tire recess. Emphasis on the word small (20mm?). Its also a very practical choice. I'm also excited that you were seeking the same recess front and rear, something I've been harping about for a long time. Finally I'm happy to see somebody "buck" the trend and use something less that 22mm to 25mm front offset.
#6018 has been my guinea pig, and it seems there is some variation between our Panteras. The 325mm rear tires previously installed on 6018, mounted on wheels with 12mm offset, were flush with the top of the fender lip, not recessed. I wonder if that might be due to the tires themselves, as I used Michelins PS2's, and they were very wide. Whatever the explanation, it is a lesson for everyone to keep in mind.
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Finally I'd like to comment about the Pantera's front caster. If you take a look at any Pantera in which Ford reduced caster to about 3 degrees, you'll notice immediately that the front tires are not centered in the fender opening, they are pushed forward. This resulted when Ford moved the upper front ball joints forward about 1/2 inch in order to cut caster in half.
If an owner moves the upper front ball joints rearward 1/2 inch in order to increase caster, restoring it in the range of 5 to 6 degrees, it centers the tires in the fender openings AND looks much better. There shall be no increases in rubbing in as much as the tires are positioned (centered) in the wheel wells as they had been originally intended. If there's any tire rubbing it will be on the inner wheel house, and only with the widest 245mm tires, because the vendors insist upon 22mm to 25mm offset. And even then its only during full lock parking lot maneuvers, nothing dramatic.
Besides appearance the increase in caster improves forward stability, and what is less understood is that cornering "bite" improves as well, because the front tires "lean" into corners more. Ford reduced caster to reduce "bite" and increase understeer. Ford "dumbed down" the Pantera chassis in this way because they believed their customers could not cope with the full capabilities of the chassis (i.e. the immediate response to driver input).
In terms of chassis response to driver input I personally want more! That's why I am a sports car enthusiast. Therefore from my perspective Ford's decision made no sense at all back then ... nor to this day. I don't want to revise the Pantera chassis to make it something better than it was intended to be, but whatever capabilities it was intended to have, I want them all ... undiluted by corporate Ford's committee made decisions.
Craig here's the wheel width and offset guide.
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My car has stock looking 2 slot wheels with 225/50/ZR16 tires on the front and 315/35/ZR17 on the rear. The existing tires are BFG G-Force TA KD.
I haven't been able to find anywhere to get the same type/brand tires for front and rear. Anyone know what options I have. What I am running fit and clear fine.
Thanks
Norm
If you NEVER drive your Pantera in the rain, you can get 225/45-16 or 245/45-16, paired with a 315/35-17, in a Toyo Proxes R888R. It's an autocross tire so it won't last very long but you'll have fun in the meantime. I hesitate to even mention a competition tire for the street but some people seem to be OK with it.
Norm
The wheels you have are obviously not OEM. I suspect they are Pantera East or perhaps Wilkinson wheels. If a tire set is not available via Tire Rack or On-Line Tires then stack your 16 inch and 17 inch wheels in the garage and opt for a more modern tire set in sizes that will be available for a while.
We can't help with a wide range of custom sizes, but as a club we do our best to guide owners towards modern sizes that will best replace the OEM tires. Maybe this little chart we've put together will help … maybe not. But we exist to help you one way or the other. Debbie and I guarantee nobody has put more effort into this subject than we have.
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Thanks
Norm
Thanks
Norm
Thanks
Norm
quote:
I can get Michelin Pilot Sport A/S 3+ in 225/50ZR16 and Pilot Sport PS2 in 335/35ZR17. Would this mix of tire types work OK?
What about Michelin Pilot Super Sports they have a tread pattern quite similar to the PS2's. I have used them in a 17 inch size but not sure if they come in 16's.
Personally, I think smaller OD front wheels look better on most Panteras, but that's just me. I can lock max-width (with unflared fenders) 245-50 x15" front tires with "small" brakes, so the extra money for big brakes went somewhere else (and with a Pantera, there's ALWAYS 'somewhere else'!)
I have installed the new tires (actually bought thru my local Tire Factory store). They are fine. The rears, although narrower tread width, look great, maybe better.
Hope this update for these sizes helps someone.
Thanks for all your help with info.
Norm
Jimmy,
Is the wheel in the pics a 17" or an 18"?
If I recall, you have 17" on the front and 18" on the rear. Does American Republic use the same center on 17" and 18" but with a larger step in the rim for the 18" or do they use a larger center for the 18"?
Hi David, the wheels in the pictures are both sizes. You are correct that the fronts are 17’s and the backs are 18’s.
Another member wanted some info so I thought I would post some close up shots of the wheels.
I believe that the centers are different sizes but am not totally sure. I can’t check right now as the car had a few minor issues so it is at my friends shop.
I also want to say many thanks for the help in answering some of my questions along the way. It was greatly appreciated. Thanks again David.
I can't believe I read this entire thread. My eyes are hammered. Now I have to think about a lot of stuff.
If you figure out a source for a nice looking set of FR500 style (or anything else) that fit a narrowbody car, looks cool, that you can get modern, performance tires for, and doesn't cost over 6-7K for the set, please post up the vendor, wheel specs, and estimated price!
I'm sure a lot of people would appreciate it!
Thanks!
Rocky
Hi
I now beleive the 285/50R15 P7 has actually been produced. I also beleive they are currently in a lorry on their way to Longstone Tyres! which is great news.
They will be on here soon https://www.longstonetyres.co....aso/pantera.html?p=2
Of course i will post on here again when they get here. How exciting, but blimey iot has taken some time, but the Pandemic has cost us an extra 2 years, and i do have other projects in with Pirelli that have just been put on the back burner so it will be great to get these.
i am relatively confident i will be able to keep the price sensible.
It would be great if people could post pictures of their cars fitting these new tyres that they are happy with us using in our advertising or on our web site. (we will fudge out your registration plate to make it a bit annonymous)
Going to run 335/35/17 MICHELIN - possibly on a 13.0 or 13.5 rear and 255/40/17 MICHELIN - possibly on a 10.0 or 10.5 on a factory GT5 with all the GT5 plastic removed and rivet on GT4 flares. Not sure what rims yet - - but looking to possibly use centre lock BBS. Rear tyres took some finding - fronts are a 2 -3 month wait.
According to the literature I found 13 inches would be the widest recommended rim, very common width for the 335 is an 11 inch width.
Larry
You need a 13.0 - 14.0 inch wide rim to fill original fiberglass GP IV flares depending on the backspacing you select. The 335 17 is narrow in width compared to the 345/35/15 I run. Measure multiple times and cut once to get the right look. I have seen 335 tires on too narrow a rim with literally no back space attempting to fill the flare. Remember the factory GP IV cars use a 14” rim.
@lf-tp2511 posted:According to the literature I found 13 inches would be the widest recommended rim, very common width for the 335 is an 11 inch width.
Larry
Larry, an 11" rim isn't ideal for a 335 width tire; however, it is acceptable. Increasing the width of a 2 piece wheel to 11.5", 12" or wider costs considerably more than an 11" wide wheel. That's because the company that supplies rims to Wilkinson, Coddington, American Republic, etc., make an 11" rim but nothing wider. If you want a wider rim, it involves cutting 2 rims in half and welding them back together, to give the width and offset you want.
Thanks all for the suggestions. 11.0" is way too narrow for my purpose, pulls the sidewalls in too much and seems to be often used as a sort of a 'cheat' (for want of a better term) on a narrow bodied car (on my narrow GTS - I am sticking with 15" - PIRELLI CINTURATO) - this is not a narrow body, currently a factory GT5 - going to GT4. Yes - the car currently has 345/35/15 as per factory GT5 (I wish someone made a 345 in suitable 17"), but I want to get away from the 15.0". I have seen a 335/35/17 on a 14.0" - but in my opinion, too much of the rim was hanging outside the sidewall. When I physically have the 335/35/17 in my hands (after the holiday break) - I will be experimenting, and expect at 'worst' - the rim will need to be 13.0" - at 'best' - I am expecting 13.5" - yes slightly narrower than what I 'dream' of - as being able to run a 14.0" - but the 14.0" seems just a tad too wide for the 335 carcass. HA - by "...measure multiple times..." - I assume you mean -'measure ONE THOUSAND TIMES BEFORE CUTTING' - HA - for whatever cutting is required - I will be measuring multiple multiple times - leaving it - coming back the next day - measuring multiple multiple times again - and then doing what is required. My biggest 'headache' - is figuring out a safe way to remove the factory bonded GT5 flares without causing any damage - they are genuine factory plastic parts and I prefer no remove them undamaged. I also intend to run the car as low as I can - that may also cause me a few headaches - and is one reason that I may go from a 255/40/17 on the front to a 245/40/17 - but only time will tell. HA - I have seen a 335 on 15.0" rim - but way too much stretch and only suitable for fad type events. The BBS rims will be multiple piece, and hence I can juggle the width of the hoops to create either the 13.0" or 13.5" (HA - and dream of a 14.0") - HA - following the old saying - "it is only money".
Firstly, why oh why convert a 9000 series GT5 to a Group 4! The factory GT5 is a rare car, likely as few made as GT5-S!
I run aftermarket 17" rims on my factory GT5, apart from the diameter they follow the specs of the GT5/5S 10 spoke Campi's for width and backspacing with 13" rears and 10" up front. Tires are Michelin Pilot Sports 335/35 rear and 275/40 up front. IMO they work great, fill the flares as they should. They are higher profile than OEM tires, so cause the car to sit higher, I have the suspension set as low as I can go and as a result have some cracking on the front flares from tire rub.
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"Firstly, why oh why convert a 9000 series GT5 to a Group 4! The factory GT5 is a rare car, likely as few made as GT5-S!" -- Firstly - I do not care what you think of what I do my my cars - HA - my car - my money - my choice. I am also getting rid of the hideous Italian lounge chairs - AKA - the bucket seats - pulling the factory 351 and installing an all aluminium 434 CLEVELAND (when the DAMN block becomes available) with 8-stack EFI and HALTECH engine management - and I could not care if it was the most rare PANTERA on earth, I do not 'collect' cars for investment - I 'collect' and build to want I want - not to satisfy some 'collector//investor' mindset. I have never liked the GT5 all that much from all angles - hence back to GT4 - which in my opinion is a more clean wide look. And understand re the 275 being a bit too tall on the front - hopefully either the 255/40/17 or 245/40/17 solves my problem.
I totally understand, each to his own, your money your choice how you spend it. Where are you located? I would take those hideous lounge chairs off your hands!
Pirelli make a 245, 255, and 335 in the 17" P Zero. They also make a 335 in the 18". Consider overall tire height as well in your calculations.
Yes – advice re tyre height is well accepted – unfortunately – if one decides to play around with larger diameter rims – DAMN tyre sizing can then quickly ‘ruin your day’ - HA. I hope to end up with the sizes listed for the MICHELIN 335/35/17 @ 26.0” rear overall height – and MICHELIN 255/40/17 @ 25.0” front overall height (not sure if I can get a matching 245/40/17 – otherwise I would test fit a set of those to the front) and I will be running 4.62 gears.
Re anyone modifying their car – I often cringe at the wheels and spoilers and other ‘bling’ that many people install on their car – but – it is their car, they can cover it in pink shag pile carpet for all I care – HA. And I believe we are members of the ‘PANTERA CLUB’ (for want of a better term) where we do not have a ‘spasm’ like the FERRARI club seems to have if a line up of absolutely identical red cars has a different valve cap – HA. PANTERA like LAMBORGHINI (HA – yes – I modified that a well) are what I call exotic hotrods and you do what you want – it is your car and you can do what you want without other people having a ‘spasm’ over changes.
HA – I missed out on an F40 some years ago – and yes – I was going to modify that too – HA – no doubt I would not be typing this now as some lunatic from the FERRARI club would have had me shot – HA.
The GTS of one of my sons, it looks dead stock outside with CINTURATO 225/50/15 and 285/50/15 and mostly stock interior – the only major changes are the mechanical specifications – engine mainly. HA – one change I do to all our vehicles – pull the stupid radio//tape//CD players out. The exhaust is the ONLY music required in these cars for me – HA.
Rethe horrible Italian lounge chairs (AKA – the bucket seats) and all the other parts I will be removing from my cars – all factory parts will be carefully wrapped and stored for the day I die and then my boys can either decide to drive my cars as I left them, or they can return to factory specifications. Same as the matching engines, the factory engines will all be properly put into long term storage, and one day if they decide 750.0 hp is too much, they can always install the somewhat slower factory engines – HA.
Whether someone decides to turn their L into a GT5 clone, or turn a GT5 into an L clone – that is their choice. Such is life.
Re my GT5 to GT4 – I see my biggest headache (other than making sure I do not damage the factory parts when removing them) – is making sure that the GT4 flares are an accurate fit (as one can get) and modern quality construction. Everyone says “my flares are perfect’ – but that is often with a hand over one eye and the other eye closed – HA.
I hope to find a red Si to purchase – and I intend to change the factory 17.0” rims out to 18.0” rims on that. My ‘theory’ at this stage - is to have the factory Si rims copied in 18.0” – exact same offset – same color finish. The rather low-performance 302 cu in will be replaced with a 427 cu in.
Hi all. New to the Pantera world. Looking to have custom wheels made for my 74 that has gts style fairings on it. I’ve read all 4 pages of info and feel dumber than when I started! Lol. The wheels would be 18x8 and 18x12. I need help with backspacing. Want the deep recessed look in the rear.
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Mike,
I'd only be guessing, because you have GTS fender flares and I'm really only familiar with the dimensions that work on a stock bodied Pantera. Dennis Quella told me, with aftermarket GTS flares, you can add about 1-3/8" to the outer dimension. Another vendor with GTS flare expertise is Ron McCall. I have photos (below) of a GTS bodied Pantera he built and the dish on the rear wheels was HUGE! I'd send him a PM. Looks like you have the same wheels. Perhaps yours could be "re-rimmed". Also, why only 8" and 12" wide? You could go an inch wider, front and back, without difficulty. What tire sizes will you be using?
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Davidnunn
thank you for reaching out to them.
Just doing online searches brought me to those width wheels. Even though it’s flaired, there is a pretty big return lip on both front and rear. My thoughts on tire size are 245/35-18 and 335/30-18.
Thanks again
You must have OEM style GTS flares. Are they fiberglass? The tire sizes you mentioned are perfect but I'd suggest 8-1/2" or 9" front and 12" or 12-1/2" rear. 13" works too but stretches the tire out a bit.
They are fiberglass, molded in, not exterior fastened.
Mike,
If the photos are your black car measuring the existing wheels would be a great start, then you can measure where you want the new wheels to sit in the flare and it should come down to some simple math.
Hello everyone. I am sure that I am not the only one that goes through 'wheel and tyre dimension anxiety' each time they are putting a new project together, but in an effort to hopefully ease my 'wheel and tyre dimension anxiety' a bit (HA - hopefully), I am ordering a tool that I have found online that can be used to calculate offset and also check tyre clearance. I have no personal experience with using such a tool, but as soon as I figure out how to use it (HA - my 'weakness' is never reading instructions properly), I will post my experience with it. There are multiple manufacturers of such devices, but until I receive mine and gain some experience with it, I prefer not mention the brand I am going to use. I do not expect any 'surprises' with it as all the different brands seem to do the same thing, and all seem to do it successfully. CHEERS from AUSTRALIA.
@MikeSchill posted:
Your car has a great stance and those wheels are really nice. What size are they?
tajon.
Thanks. The current wheels are 17x8 and 17x11. I’ll be putting them up for sale once I figure out the new set.
If you like the centers of your current wheels, as they are 3 piece you could simply get new outer hoops to widen and bring them out further.
These are made by SIMMONS in AUSTRALIA (simmonswheels.com.au) - this is a 17" version. They make them in a range of diameter, width and colors. SIMMONS has been around for many decades and make quality products. I purchased my first set of SIMMONS near on 35-years ago, and they are still going strong on the car I sold. They also have other designs.
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So I finally had time to pull the wheels and do some measurements. Current setup is 17x9 with 6” backspace (+1” offset)
17x11 with 6” backspace (-1/2” offset). I’m thinking of upping the to 18x9 and keeping same dimensions due to the 245/35-18 being a little wider tire. The existing setup is pretty close to full turn fender rub about 1/2” The rears 18x12 with 6” backspace would push the tire closer to flush of fender lip. Can’t really go wider or pull wheel in more because it’s already close to exhaust pipe and 335/30-18 should work. The car has adjustable coil overs on all corners and wilwood disk brake conversion all around.
Do my calculations look correct?
To be clear with builder 62 mm bore and 5x4.50 bolt pattern?
Thanks
Did you guys know Pirelli have made this tyre again?
https://www.longstonetyres.co....li-cinturato-p7.html
Making the 15" wheels a viable option again.
Yes, and Lucas Classic Tires out of California have them in stock.
HA - I wish PIRELLI made a 345/35/17.