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Last test-fit of the rear ones - so far still good to go Smiler





If spotted by one - these are modified aftermarket shafts - modified because way too heavy... Had the solid shafts drilled, but not all the way through like the original ones, and with less a big hole, and drilled holes in the flanges. Last, I had the shafts themselves grinded down, as I found out they were too oversized for the dimension of the bearings - except for that, both shafts had a different diameter too... Roll Eyes Seen their cost, the grinding I as a customer should not be supposed to do. And to be honest, not a lot of parts I bought stayed unmodified because of a bad fit Roll Eyes Good thing so much parts are still made and available, but the quality should improve!
quote:
Originally posted by Anders Hellberg:
Kid

It looks very nice! Smiler

Is it stock wheel nut thread? I'm looking for open wheel nuts, which fits with my Gr3 brakes so I don't have same length on the wheel studs.
which height is your open wheel nuts?


These are the original US style "Trans-Am" wheel nuts. The were made by American Racing Wheels in the late '60s and '70s.

They are about 2-1/2" long. They use a flat washer against the wheel and the outside of them are open so you can see the tip of the wheel stud.

They are 1/2"-20 NF threads.

I think this is what you are looking for?



I believe that they really are an American thing rather than a European racing item?

I have never seen them on European racing cars UNLESS they are here in the US?


I do know that Curt Voght at Cobra Automotive has them listed as available. He makes his own.

I do not know if he will make them for the metric thread OR with a tapered seat for use without the flat washer BUT since he will custom make parts like this for customers I would tell you to ask him about them for your application.

http://www.cobraautomotive.com/

You need to tell him specifically how you want them made. Just don't say for a Pantera.

He is most familiar with Mustangs, Shelby Mustangs, Cobras and GT40's.

He IS THE GUY TO ASK and your best bet that you won't get killed in the car because the part broke at 220 mph.

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Here they are in his catalog with tapered seats so you need to ask him if he has them in a metric thread?

http://store.cobraautomotive.c...t-lug-nut-set-of-20/

Of course you could also go another route and just change out the metric studs for the US SAE versions? That might be more difficult to do? You would have to find the stud with the hub that fits your flanges?

That probably would be in Dorman for regular production cars? I don't know where you would get Grade 8 studs for racing in those or if they even exist? Can't help you there.

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Small detail.

Had to make shims for the rear calipers.
Nothing extraordinary as all four of the original calipers were mounted with shims (2mm on all four corners).

As I did not want the shims to be visible to avoid a "after-market" look, I made them follow the lines of both calipers and hubs.

Something little that consumed quite some time, but I like to get things right Smiler



Where is the shim... Razzer
The rear ones installed. Needs some minor mods here and there. Need to make the shim a mm thicker too. Still need to work out a solution for the hand-brake cable too... I hope the last "issue" I need to sort out. Caliper just barely fits - hand-brake cable adjustment will be critical will the pad arms not touch the inner side of the wheels!



As for the front wheels - have to make 1mm spacers to get the needed clearance with the calipers. A weekend full of files ahead again Big Grin
@ Kid.

A while ago I asked if there were "racing" front spindles for the Gp4 cars. Your bent spindle is an example why.

So far, the answer is no, and the probability is that there never were?

The thought I had was that when "Ford racers", whether or not it was Shelby Racing, Hollman Moody, and any of the racers that went racing with the Mustang in the Trans Am series, the weakness of the original spindle under severe conditions became apparent.

Very simply, Ford itself, redesigned the spindle enlarging the diameter of the spindle only at the vertical intersection. The outer end of the spindle remained the same. The outer wheel bearing remained the same.

It really came about, not from racing but to handle the 60 series tires on the 1970 model Mustang, not the race car. Simply put, the racers took this improved street car part and substituted it for the original smaller spindle size part and basically it solved the problem.

The original spindle couldn't handle going from something like a 6.95-14 to a D60-15. That is the same size as the Pantera which at most could handle the C60 Arriva. Are you SURE you want to race on that?

People who are familiar with both the Mustang and the Pantera see the similarities between the two cars. In effect, the Pantera is a metric version of the Mustang front suspension dimensionally.

Now considering that the Gp4 cars can fit huge front racing tires, the loading on that spindle is tremendously increased.

I suppose that the simple fix then was just to replace a bent "stock" spindle with another new stock part?

This to me, just seems to be a difference in perspective between how the Europeans and the Americans go about racing? I'm not the one to criticize but thinking about that picture of the pile of bent Gp4 cars behind the Detomaso factory, I can't help but wonder how many of those wound up there because of a failed front spindle?

Apparently they weren't even worth fixing? Just take another car out of production and build another Gr4? Same weak parts. Same results in the end?

All things considered, if I was racing, my worry wouldn't be if it would fail, just when and where on the track. My experiences would say, probably at the worst possible time, in the worst possible place. Just my observation.


I do see that you realized that in order to use a spacer safely they need to be hub-centric. Anything else on this car is suicidal but not everyone is going to take that route unfortunately and not everyone is going to put longer studs in the car.

Unless you have actually experienced it (I have) you won't believe how easy those studs blow off. Kinda' like explosive bolts on the canopy of a fighter jet in an emergency bail out situation, just without the noise?



@ Goodroc.

Using stainless for any fastener "sounds" like a great idea. The problem is that stainless threaded fasteners "chafe" much to easily, cross thread and jamb.

It is so typical that when you disassemble them, pieces of the threads come with it.

I don't know if it is any kind of a great idea to use stainless lug nuts on a car under severe conditions?

Also, lug nuts for "severe duty" use, like racing, should be hardened. Although technically anyone with a Smithy 3 in 1 in the garage could make lug nuts out of hex stock, it really isn't just that simple to cut the stock down, drill them and thread them. Big Grin
Last edited by panteradoug
Peter,

Fronts are 7,48kg/set, rears 6,84kg/set, all without pads.

Discs are front 290x28, rear 290x12,7mm.
Initially I had the fronts made 304mm, but machined them down again to 290. After all, it is easier to macine down, than to add material...lol. As for Gr3... Dunno, as I do not know in what way the Gr3 front is different. Discs are nothing special (any brake specialist can deliver any kind of disc), but the alloy hats are custom made as per my own calculations and requirements.

Doug - except for the 1mm shim/spacer for the front wheels to get the needed wheel/caliper "clearance", no wheel spacers, and stock lenght of studs ;-)
quote:
Originally posted by Kid:


Doug - except for the 1mm shim/spacer for the front wheels to get the needed wheel/caliper "clearance", no wheel spacers, and stock lenght of studs ;-)


With what wheels?

On a race car often the studs are extended for safety.

Mine are 2-1/2" long ARP studs and long lug nuts. I feel safer that way.

I think the lugs are 2" long but I'd have to go check that.
quote:

On a race car often the studs are extended for safety.

Mine are 2-1/2" long ARP studs and long lug nuts. I feel safer that way.

I think the lugs are 2" long but I'd have to go check that.


Fits your ARP studs on a Pantera without rebuilding the original Pantera parts?

How do I know if I have the standard Pantera studs or longer GR4/GT5 studs?
Hello, these are the group 4 brakes with the 8 pot Girling. Those calipers were used on some F1 cars in the '70s and really unavailable. Now I'm reproducing those. Although in the stage of design but allmost ready for small quantity production. As I need them myself for my fia group 4 car next year. The calipers are equipped with 4 pads.
Is there a part number for the rotors?

What was the original installation of the rotor? Is it behind the Pantera hub or does the "hat" sit over the outside of the hub?

Ohhh...almost forgot, everyone has been searching for information of the studs for the lug nuts.

I do not know if they were just stock studs or if there were longer ones made for racing? Did you find any information on that?

Thank you for any information that you have to share.

I am looking forward to the offering of the calipers and the components of that system. Smiler
quote:
Originally posted by Push1267:
The 8-piston calipers used by Detomaso on the Pantera were AP Lockheed Armadillo Calipers. Part no. 507.33.047/048

They use 4 brake pads and They have been reproduced in the past.

Here's a Picture of the set I have for my Gr4.


Will these fit the car with the stock production Campagnolo wheels?

Is this the front caliper?
The cost of the Girling's is already known. The cost of the Lockhead's is not.

I suspect that the cost is going to be similar.


In looking at these brakes we are looking really at how the Pantera was raced in Europe at the time.
Girling brakes are on virtually every car made.

In the US, Panteras that were being raced were all privateers.

Here racers would take what was available to them and adapt them.


In the case of the Trans Am Mustangs, Kar Kraft was the development source of race parts.

What they did initially was source greater capacity brake systems that already existed that were available.

The '67 Thuderbird/big Ford system was a natural.

It gave each caliper 4 BIG pistons and the largest surface area pad available off of the shelf and gave bigger brake torque because of the 12" diameter rotors, greater cooling down rates because of the 1.25" vented iron rotors.

It was designed to stop a 6,500 pound car from 120 mph. Put it on a 3,000 pound car, IT HAS TO BE EFFECTIVE.

ALL off the shelf items and not priced like custom made parts like the Euro cars had. The way race cars go through brakes, this is a big help.


I saw a "vintage Trans Am Mustang" go through FOUR sets of rotors IN PRACTICE. What's your plan on your race Pantera? Find a Sugar Daddy"?


The reason I say all of this is simple, if I was racing a Pantera here then, I'd need all the financial breaks I could get.

I would go with a version of this Thunderbird brake system on the front, take the front Pantera stock calipers and put them in the back of the car.

To add interest to this thought, there is a "classic brake" company here in the US that is making new castings of these brake calipers.

ABOUT four years ago they were offering the calipers in ALUMINUM. In questioning them about the aluminum, they said that they had porosity problems with the castings and stopped selling them.

If you can connect the dots I've laid out here, you can see that to me it makes more sense to use the T-bird calipers, rotors and pads.

I need to make adapters for any of these calipers anyway and I'm not going to charge myself $1500 to make the adapter plates?

An ALUMINUM caliper instead of iron would just make me have an unlimited amount of unprovoked orgasms!


I have already seen pictures of three US Panteras that were heavily raced here in the US and all three had this "Trans Am" brake system on the front and the stock front Pantera calipers on the rear.

Oooops! Sorry. Just another unprovoked orgasm. I've got to get over that. Wifey is getting very jealous. Big Grin
About the pad dimensions, there is no great difference between the 3 pot Girling and the standard Pantera except in the rear.
Group 4 cars were homologated :
3 pot Girling
4 pot Girling like BIG
8 pot Lockheed
All should fit within the 15 inch rim if you have the group 4 wheels.
I will go for my project with the 8 pot which I'm trying to reproduce. My target is to make 20 of them. A lot of work is already put in , even material stress simulation with different types of T6 aluminium.
Does somebody know if the 8 pot calipers are available and would be the price before I have to reproduce myself ?
The 8-piston calipers was reproduced back in 2002 by the Danish Team Witch Craft. That was done with permission from AP using the original drawings. They were allowed to make 10 sets.

If you are to reproduce them, maybe you should ask AP if they are OK with that?

If you PM me I may be able to provide more info about availability and Price.
This is what the T-bird caliper pistons look like.

They are 1-15/16", 1.9375", 49.125mm. There are 4 of them per caliper.

The clamping pressure in many cases is better than expensive race brakes that are available.

These are not much heavier then the stock Girlings are. Certainly lighter than the Group 3 iron Girlings.

Why does anyone WANT to pay $2,000, per caliper? Beats me. Smiler

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Those T-bird calipers may not fit all Pantera wheels. Specifically, that raised ridge at the outside bottom holds the connecting passageway for fluid flow between caliper halves so it cannot be ground away, and it hits passenger car Campagnolo wheels unless a spacer is used. They work OK on some aftermarket wheels without spacers. And the one time I tried turning down the OD of a brake rotor to fit, I wound up using carbide lathe bits and slow speed- those suckers are TOUGH and the cuts are interrupted so your carbide tool chips!
This is a common mod on a 65-70 Mustang. In order to fit them, you machine off that outer "vein". You also may need to take something off the curve on the caliper as well.



Yes, the fit is VERY CLOSE and still requires a 1/8" spacer. Longer competition length studs are a very good idea as well.

I have them on my 68 Shelby. The vein is machined off. (80% +/-, like picture) It is NOT a fluid vein. I have to presume IF it was intended for fluid, it was never used.

I have done two sets of these and neither set had fluid passages in that part of the casting.

I always presumed that it is there as a casting reinforcement?



A simple 18 grit disc in a grinder cuts it right off. It is not high nodular iron. It's soft like GM blocks are. Not like Ford nodular iron is.

ANY way you look at it, it is still cheaper than $2000 a caliper.



The Tbird caliper weight is 6 pounds. I don't have a rotor here to weigh for you but as I recall, the difference between the .830" stock rotor and the 1.25" rotor was much more significant then the calipers? You are doubling the mass of the rotor. That you cannot avoid.

You can't run aluminum rotors, just iron rotors with aluminum hats. That really isn't going to save you much. Maybe a pound total?

SOME of those aftermarket aluminum hats have a very bad reputation for exploding under racing conditions. I'll take my chances with the heavier iron one piece rotors.

How much does that Group 3 Girling set up weigh?



This is still a better deal. Parts are still available for this set up.

I can't post a picture of the Shelby with these on right now. I don't know where that folder is at the moment.

Maybe later this week if someone needs to see that?

Just trying to help here. Very few perfect solutions are available.



If you want a direct bolt on (which for $10,000, those aluminum set ups still need modifications) then you are going to pay someone for that.

Like the commercial says, "pay me now or pay me later" I suppose? Big Grin

Here is a Tbird caliper with most of that vein cut off. Takes about 5 minutes to do. I have seen them with it completely removed.

It does not seem to cause any kind of issue.

This one is about 80% removed.


With a 225/50-15 tire, on an 8" DT rim, you have quite a bit of room to use spacers before you have fender interference. Sitting on pavement, I can put my hand between the tire and the fender lip.

A 245? Well that's a completely different story right Jack? That's the proverbial 10 pounds of mud in a 5 pound sugar sack? But there always is that 5 pound lumping hammer in the tool box. Big Grin

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Last edited by panteradoug
I am working on this now. I can't answer that precisely yet.
The Tbird caliper actually measures EXACTLY the same to the center of the caliper as the stock Girling unit does.
It is a LONGER caliper then the Pantera unit. That enables it to use a larger brake pad.
That and the four MUCH LARGER pistons give it much better clamping force.

Just as I write this now, I found the bolts that I need. They are not local. I need to order them and I will have them in a few days.

I PROBABLY will be able to answer your question early next week?

I think that the Tbird caliper will clear the inside of the 8" DT wheel. I don't think it will fit on the 7" wheel.

Those 7" I don't have anymore. Those I sold. I am using the 8x15 and 10x15 DT wheels.



It is also possibile that IF the caliper does hit the wheel, that one can use a two piece rotor.

The hat could be deeper which would push the rotor further inboard. The caliper can be spaced inboard by shimming.



I am using a 3/8" thick adapter (9.525mm) for the caliper.
So far it has the caliper centered on the rotor.

I won't know precisely until every thing is trial fit.

I have done this before on my Shelby and the fitting can be so tight that even 1/16" can be life or death on whether or not everything will fit.



I actually LIKE doing things like this. For one thing they are not supposed to be possible to do. I like defying the "experts".

They are like Donald Trump and will never admit that they are wrong even when you just proved them wrong, not by just a little bit but by as we say, "a country mile".

When I get this mounted up I'll take some pictures and post them.



The pads that are needed for this setup are the Porterfield R4S. That is a street pad but it is a just a little hard for the street and you need to get them warmed up, unlike the standard pad which is good even when cold.

The difference would be the high temperature limit is higher with the Porterfield. Much higher with the race compound but you will get killed on the street with that one.

When they are cold, it feels like you have no brakes at all?
Last edited by panteradoug

I'm glad that it worked out for you. It was an inexpensive change originally.

Original calipers are harder to find but reproductuons are available as are rotors.

The spacer/adapter is pretty simple and straight forward.

I don't know if the set up will fit with 7 or 8 inch wheels though but I think it should with a 8 inch Campi.

The inside diameter of all the Campi wheels is the same.



I've seen this ised on three US races Panteras. I doubt the Euro guys would run anything but Girlings.

A few notes that I forgot on previous posts. First, the pure-racing GR-4 & GT-4 cars used 1.25" thick one-piece rotors with aluminum  4-piston Girlings, and the racing rear calipers did not use e-brakes so bosses were not included on those caliper castings. There was no e-brake mount in the cabin, either and in fact the whole body was full of preformed sheet steel parts modified from stock stampings with large perforations added. They were done before the car was welded together- to make an accurate repo', you'd have to disassemble the car.

I think the DeTomaso Race Shop used seam-welding in many areas rather than production spot-welding, for more chassis stiffness. There was also no heater box/AC and the welded heater/AC mount brackets under the dash were never done on racers. The tabs for the lower front a-arm mounts were lowered by about 0.300" from factory and the entire racer used NO rubber in the suspension at all. There were many, many little tweeks on the GR-4s that were not found on Gr-3 or other production based Panteras. I once wrote an illustrated article for POCA based on Guy Trigaux and Les Gray's real GR-4s, that showed how one could tell a real Gr-4 from a clone, or as they now say- a 'tribute' car.   

The Gr-3 production racers used iron 3-piston Girling calipers front and rear, with stock pair-of-pliers e-brakes. The uprights used very wide straight roller bearings at the inboard position.  DeTomaso used to sell a complete kit of Gr-3 brakes and that's what I installed on one owner's car in the early '90s. When I say 'complete' I mean it: Everything including the front & rear uprights, bearings & spindles were included. Even dash-3 Aeroquip brake hoses and brake pads were in the kit!  Everything cleared 8" & 10" Campagnolo wheels. Everything fit so it took me all day to mount & bleed the kit and rough-align the wheels. The next day he drove to an alignment shop. That car still exists in N CA- the owner is a POCA member.

The street based GT5/GT5-s brakes in the mid '80s were essentially the same as the early '70s Gr-3 brakes: all-iron 3-piston calipers and 1.25" wide 1-piece rotors. GT5 rears were from a Rolls-Royce, and the Rolls e-brake calipers were modified to clear slightly larger OD rear rotors used on DeTomasos (maybe front rotors? Dunno.) There's a long cross-bolt that passes very close to the rear of the GT-5 rotor. DeTomaso cold-bent a curve into that bolt for clearance. And being a hardened bolt, a number of them cracked in service. This modified bolt was frequently replaced on street GT-5/5s cars. I think someone began making an annealed version of the metric bolt that didn't crack.

As far as I know from the FIA Homologation papers, ONLY Girling calipers (aluminum or iron depending on class) were legal for International racing classes through the '70s. Later, after Panteras were obsolete, the door for brakes and other stuff was thrown wide open. The '91 ADA Pantera run at the last LeMans used a Hewland transaxle from one of Gurney's IMSA racers, and a Porsche suspension! If you're really serious about vintage-racing a modified Pantera and winning, check the current rules for the group you'll be dealing with. It likely will not look much like a classic Pantera! Not going that far, contact Anders Hellburg in Sweden on his Pantera Gr-3 website <www.scuderiadetomaso.se> He is still active (note time zone). I got an e-mail from Anders only a few days ago.

There is a "classic brake shop" in LA that had the calipers cast up in aluminum.

I didn't get there fast enough to get a set. Apparently they only tried an initial set of 50 or so and had problems with the foundry casts as porous?

I am also told that Ford did cast some up as SK parts and tested them by passing them out to racers for free to try. That is or was how Ford Engineering worked then. For whatever reason the part was not approved to go further into production.



I can tell you that side by side the 4 piston Ford caliper is VERY similar to the Gurling in many respects but Ford eventually abandoned the design in favor of one large piston that went into production in the '68 model year.

The T-bird 4 piston calipers had the tendency of freezing up one or more of the pistons in daily useage. So the design was probaly one of those 51% problem, 49% no problem parts that looked for a better, and cheaper design for production cars.



It can be pointed out that an aluminum caliper saves unsprung weight but there is little you can do to reduce the added mass of a 12 inch by 1.25" rotor.



In my own useage of both the 67 t-bird calipeer, the 68 Mustang caliper and the Pantera Girling caliper, the Girlings freeze up more then the others do.

The T-bird brakes are a very good solution to more braking in the front with minimal switch over issues.  The "issues" being fairly simple to fix even for the do-it-yourself doer. Although not everyone has a mill in the basement to carve out such beautiful adapters like those Dudejack? Very nice.

Last edited by panteradoug

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