Upgrading brakes

Pantera Performance center sales Wilwood. The hats are alum and they will move the rear wheels out 1/4". The fronts still stay inboard mount.
Precision proformance sales a brake set up that uses corvette brakes. The rear are outboard mount, I am not sure of the wheel additional off set. I think it is about 1/4".

The wilwoods can be either the stock thickness or 1 1/4" thick rotors. You will need to buy a new part brake with the thicker.
Precision are not as thick as the thicker wilwood and come with park brake.

Kevin

Pantera Performance also sells a slick Wilwood conversion that keeps the back rotors and replaces the front rotors. The best part is they fit inside the stock wheels and keeps the stock wheel position! 1/4" offset can be a killer on wheel and fender clearance.

Here’s a link showing us installing a set http://www.panteraplace.com/page78.htm .

Mike

Boyd,

Sent you this via the e-mail list, but I'll post here for everyone's benefit.

I have moved front and rear rotors outboard on my '74. On the rear I used Sierra hats & Wilwood rotors, up front was Wilwood hats and Coleman rotors. Calipers are all from Sierra.

The particular rotor isn't as important as the caliper mounting brackets depending on what style/width rotors you want. At the rear I went for vented 1.25" rotors in 12.19" dia. 8x7.62" bolt pattern (Wilwood part #'s 160-2900 & 2901). You can get the same rotor in 0.81" thickness (part #'s 160-8474 & 8475) if that suits your current calipers better, but you'll still be making mounting brackets to move the calipers out as that is still a larger dia. rotor than stock.

The Sierra hats are a Larry Stock exclusive as he purchases blanks and drills them for the 4.5 x 5 bolt pattern. For the fronts I used an off the shelf Wilwood hat part # 170-0635 to move the rotors outboard.

Sierra will refer you to Larry if you enquire about their hats/calipers for a Pantera, but I found his prices not too overinflated to Sierra's direct pricing. You will likely need to change your wheel studs for ones with a slightly shorter shoulder length in the process (or chamfer the back of your wheel mounting holes) as the hats are thinner than the oem rotors.

Here's Sierra's website http://sierraracing.com/

It will push your wheels further out by the thickness of the hat, which is about 0.3".

Julian

Thanks for your reply. I am going with Brembo calipers that are from a porsche 996T ( a 911 Turbo) The calipers arearound 13.1" ( I don't have the exact #'s yet. This is a conversion put together by ken Green and includes mounting brackets custom made to the calipers and rotors he has selected. The rotors and hats are colemen. I don't have the model #'s or dimensions yet. I am supposed to be getting them this week. I will look into the info you gave me. I really appreciate it.
Thanks.

Boyd

Ken has been working on that kit for some time, so I'm sure he has done a lot of due diligence and it will fit well.

Good luck,
Julian

Boyd, I mounted my brake rotors outboard of the stub axle by using Coleman billet hats. I did this conversion (with Porsche 993 Turbo brake calipers) nearly ten years ago but I'll see if I can find the specs I used. Previously, I had been using Wilwood hats, mounted in the stock location. All I did was increase the offset of the hat by the thickness of the hub and made sure the I.D. of the hat was sufficient to go over it (the hub). While I was at it, I replaced my stock wheel studs with 1/2"-20 items. Before you attempt this conversion, be aware that some Pantera stub axles have a slight taper to the wheel register that protrudes from the stub axle's hub, so if you put a 1/4" thick brake hat on the outside of the stub axle, your wheels will no longer be hubcentric. This can be dealt with in a number of ways but keeping your wheels hubcentric is very important.

Ron, please explain your comment:

quote:

I dont agree with the ease of changing a rotor and mounting on the front of the axle or splindle ... this means the wheel when bolted on determines how true the rotor will pass thru the caplier ...no good.

I don't see what the wheel has to do with the trueness of the rotor. If the face of the axle is true and the rotor is true (and hubcentric), then the wheel has nothing to do with how the rotor passes through the caliper.

quote:

I put this package together and came up with the following...

Did you change your master cylinder to match the big brakes? How's your pedal effort with the new brakes compared to the stock brakes?

Thanks!
Garth

Ron,
I wonder how many Pantera owners don’t use a torque wrench to tighten their lug nuts! But seriously, I have measured the run-out of my rotors with only two lug nuts holding them on (tightened by hand), and it measured ZERO. Once again, if the rotor (incl. hat) is true and the face of the stub axle is true, there’s no issue with mounting the rotors on the outside of the hub. That’s how Porsche, BMW, Mercedes, etc. mount their rotors. In fact, I believe De Tomaso mounted them like that on the ‘90’s Si models (with Brembo brakes).
Your comment “and if this was meant to be why didnt it come from the factory this way ?” surprises me considering the major changes you’re making to your braking system.
On the subject of brake hats, be aware that the Wilwood hats, that most Pantera owners use, are notoriously “un-true” when new. Every one of them should be checked for run-out prior to installation. Marino Perna (Pantera East) told me that he checks every single one he sells, before it goes out the door. He went on to say that a startling percentage of them are “out” by some degree, and need to be re-machined in order to make them perfectly true.

Ron,
First of all, I do believe most Pantera owners use a torque wrench to tighten their lug nuts. No, that doesn't mean that I think they carry one around in their trunks.

There is no technical advantage to mounting brake rotors on the inboard side of the hub. I'm not sure what De Tomaso was thinking in 1970 when they were designing the Pantera but I do know what they (and Brembo) were thinking when they designed the brakes for the 1990's version of the Pantera (the Si); with outboard mounted rotors. I guess Porsche, BMW, Mercedes, Ferrari, etc. are all thinking the same thing, or perhaps Brembo is doing their thinking for them!

Outboard mounted rotors don't move your tires closer to the fender if you purchase wheels with an appropriate offset, that takes into account the added thickness of the hat. Bearing loads are not increased for the same reason. If you don't believe me, ask Dennis Quella.

My original set of Wilwood hats were all un-true but that was about 15 years ago, so maybe they've cleaned-up their act. Furthermore, I'm not blaming Wilwood for anything. My hats were "off" so I trued them up in a metal lathe. End of story. I only mentioned this because Marino Perna told me (also 15 years ago) that he had found the same problem. The bottom line is: any brake hats should be checked for run-out BEFORE bolting rotors onto them, not just Wilwood hats.

I checked the run-out of my rotors with a dial indicator. I don't know of any other way to do it. I suppose you assumed I had the wheel mounted at the same time !!! Nope, just two lug nuts to snug the rotor to the hub.

I personaly had not given it much thought but after reading your post and thinking about it you have a valid point. Leverage is one of the miggest force muitipliers. So it makes sense that any extension of the wheel mass would be something you would want to avoid. By extending the hat to the outside you are increasing the leverage the entire wheel mass exerts on the axle and the bearings. Even at the small numbers
we are talking about (in regard to increased length of the out side mounted Hat) With the common increase in wheel diameter , weight,and tire width the amount of mass and stress on the components is already increased substantailly beyond the original design values.Increasing this mass, then increasing the leverage by extending the hat length and using aluminum instead of steel sounds like a recipe for trouble. This is all hypothetical but to me it makes sense. When you consider the ramifications of a failure ( possible loss of a wheel, damage to the other compnents including possible body damage and the risk of death if you lost a wheel at a critical moment) all seem like good reasons to make every effort to REDUCE the forces exerted on this area not increase them.
Just my opinion (all based on hypothesis )"your results and opinion my differ"

Boyd

Ron, your claim that moving your hats to an outboard position does not alter there position (ie closer to the fender) assumes that besides changing your hat you are also ordering new wheels at the same time. In my case I had already ordered and paid for my wheels. At $3500.00 I wasn't going to order new wheels to compensate in the .3" change in offset. I would agree that if you were buying new wheel , new brakes and totally reworking youur rear suspension you may be able to simply alter your offset to compensate for the difference in positin for the wheel caused by the extension of the outboard hat. There is another issue they may effect your ability to pick up the extra .3" normally gained by mounting an out board hat, and that is caliper size. While I was exploring reworking my rear suspension the whole process was actually initiated by my desire to install new brakes to go with my new wheels. While creating my brake template for the wheel manufacturer I realized that the caliper rotor assemblies over all diameter was not the only size increase I had to worry about. I had not even occured to me that that the brembo mono bloc calipers where thicker and
they would have prevented me from changing my offset to move the wheel in the additional .3"
needed to compensate for the change in the wheel position caused by the outboard hats.
So there are apparently no absolute truths in either position. You may be able to compensate for the increase in out board wheel position caused by using the outboard hats ( and have no change in the position or forces) But that can be a very big if ( like having to buy new wheels and revise your brake choice) and on the same token changing to outboard rotors may in fact change the wheels position to one closer to the outside fender and subsequently increase the forces exerted on the suspension components.
So in a perfect world where you totaly revise several major components of your rear wheel/ suspension assembly you may not generate any additional forces, but in the real world where modifications are made when some other incident effects your decision to make a modification Like repair a worn rear rotor and once they realize what a pain in the butt it is to change the rotors and someone tells them they can simplify the process in the future by installing out board hats the the facts are that there will be an increase in the forces exerted which is a contradiction of your statement that there will be no increase in the forces exerted.

Boyd

I think you guys are arguing semantics here, 0.3" is nothing on a car where tolerances are generally measured in weeks . Most play is usually in the axles themselves and did you all add new a-arms with heim joints not rubber or poly bushings etc. Don't most have aluminum wheels to go with those Al hats, but wheels don't suffer heat expansion?

Hey, you can always go the Corvette style route with inboard brakes on the transaxle side and remove the unsprung weight altogether, Ted Mitchell sells a system.

Yes it's imprtant to make sure any new brake system is compatible with the wheels you are using and caliper to wheel clearance can easily be overlooked.

Agreed that the vendors Al caliper brackets are one up from useless.

Julian

Inboard brakes are not widely used because if you break any part of a half-shaft, you have no braking ability on that corner of the car. Otherwise, the advantage in the reduction of unsprung weight would override any maintenence issues.

I had my brake adapters machined from steel; however, and in the defence of our Vendors, I don't believe there's ever been a case of an aluminum caliper adapter breaking.

I'd also argue that Coleman's brake hats, which are machined from forged billets of 7075 aluminum, are significantly stronger than Wilwood's generic, non-forged hats, albeit four times the price. They can make them for conventional mounting but because they're thicker, no shims are required between the base of the wheel studs and the hats. That being said, the Wilwood hats are certainly adequate. I just got carried away . . . again !

TO AC Cobra,
I did not mis quote you, in fact I was defending your position. It Was the other guy who said (and this is not an exact quote) installing out board hats does not chnge the position of the wheel (if you compensate for the change in position by altering the wheels offset)
I said most people were noy going to buy another set of new wheels, I just spent $3500 and I wasn't going to do it again to make up for the .3" I would gain in length if I went with out board hats. ( that was defending your position that the out board hats move the wheels closer to the fender) I also said that adding legth to the wheel mass (and doing it with aluminum instead of steel) was a double whammy because more length = more leverage =more stress. So next time try to realize who is basicaly agreeing with your position and don't assume they are quoting you.You are so wound up in defending your position you don't realize when someone is agreeing with you.
Boyd

Just for kicks and to satisfy my curiosity I asked the Wilwood Tech guys what their thoughts were on rotor mounting. They said they have no experince of mounting hats behind the axle flange and would always recommend the hat on the outside so the wheel tightens against the hat.

Julian

quote:

They said they have no experience

So who are we to follow??

Some telephone tech guy who probably has never even ridden in a mid-engined car with exotic pedigree, or our illustrious benefactor, the late great Alejandro and his skilled team of designers, engineers and craftsmen?

Let's ask Tom about this in Monterey. THAT should be good for some friendly banter.



Larry

Talk about not getting personal! What is your malfunction. I defended your position . I agreed that using outboard hats would alter the position of the wheel by brining it closer to the outside (the fender) I also agreed that using aluminum for a part that was going to be subjected to more stress and using a weaker material for the part was a bad idea. I also pointed out that the oyher posters stattement that the use of outboard hats would not alter the position of the wheels was not really accurate because most people wouldn't be willing to order new wheels with altered offsets which would be neccesary to make his statement ( about the wheel position not changing untrue). Sure he could get the wheels and dimensions to wind up just about anywhere he wanted to if he is willing to spend a ridiculous amount of money. Before I would spend another $ to make new wheels with adjusted offsets to compensate fot the repositionng of the wheels furthur out and closer to the fenders I would spend the money on CV joints and custom rear suspension that would improve the accesability of the rear rotors and improve the transfer of power to the rear wheels, and improve on the antiquated ball bearings. You still didn't pick up on the fact that I was supporting your basic position that any convinience you might pick up using aluminum hats to install outboard hats was out weighed by the additional problems that such a modification might cause. Aparently you don't like people agreeing with you anymoore then you like people disagreeing with you. Why do you bother gettinng involved in a diaoluge. Just send your self an e-mail and then you probably won't get into a disagreement. But if this last exchange is any example you will probably still argue even though you are the only one participating. You have no idea how I use my car, how it is equipped and how I drive it. So before you tell me to just paint my calipers take a look in the mirror. I'm not convinced you even know what that guy is doing with his car let alone what I am doing with mine. I have had several sports cars over the years that ranged from stock to race equipped and not street legal. I have also had an offshore race boat, a worked 750CC Kawasaki race jet ski and a variety of motorcycles. I crashed my NSX at over 150MPH. So don't assume to tell me what to do with My Pantera. I don't talk about my other go fast stuff because this is a pantera forum. What happened ? Did they throw you off the Cobra forum or did you stop participating because you already knew everything?
Boyd

quote:

antiquated ball bearings

If they are old, they are antique. But if it is just the design that is old, they are time tested. Ball bearings are used in current top-of-the-sport racing. They are far from inherently bad or inferior to tapered bearings

quote:

I crashed my NSX at over 150MPH

I crashed my Pantera at about 65MPH. Driver error. I could easily crash an NSX at 150MPH using the same technique.

I don't think you gave yourself any credence with THAT admission.

Larry