Building a Gr4 replica

Fitting the fender. Fender has to come on and off many, many times to make sure everything aligns.

The upper line of the fender is adjusted after the decklid.

...

Lower rear

For the first time in a very long time, the chassis is actually looking like a pantera

While you are doing that kind of metal work, here are some changes I found worth while.

1. Move the license plate frame up so the license plate fits:

http://www.rc-tech.net/pantera1/lp/lp.htm





2. I altered the decklid latch to use a standard latch found in every automotive hot rod vendor. With a regular pin there is no side to side movement of the deck lid:

http://www.rc-tech.net/pantera...latch/deck_latch.htm

3. I also welded over the rear button and actuated it with a bearclaw latch:



Put a cover over it to clean it up. It has since been painted:

Comp, I really like the mods you did to your car. Very inspiring.

However, for this car I'm trying to get as close as possible to the specs of the factory Gr4 cars, which means only certain chassis mods can be incorporated.

I haven't posted on this thread for a while. That does however not mean that Work has stopped. I'll post the details later but here's the status of today.

The chassis is all together, everything aligned and set correctly. Almost all welds finished. Spend a lot of time hammer-fitting the fenders around the doors so they match the door skin as perfect as possible.

Next I'll pull the door skins from the doorframes and start work on fitting the aluminum door skins.

.....

As always Push.... lookin good. Glad to see one of us is still making progress.

Thanks Rob.

We need to see some progress-pics from over there in Michigan soon !!

What a great thread! Thanks for all the detailed photos and info! Your work shows a fine eye for detail and great craftsmanship! Again Thanks for sharing with us that wish we had your talent! It definitely is inspiring.

OK, in the absence of progress on the chassis, I'll try and keep this thread alive with Pictures of a few parts I've aquired. Actually I got most of the leftovers from the Danish Team Witch Craft that developed and ran two panteras in the European GTC series from 2004 to 2008.

There's a lot of race stuff, including brakes, radiators, lightweight windshield, lots of ZF parts and special fibers parts.

Here are the brake calipers. They wen't through a lot of trouble (and Money) to get the permission from AP to reproduce a few sets of these AP Lockheed 8-piston Armadilo Calipers. They were homologated for the Pantera in '75 and are thus legal for use in FIA Historic competition. They are massive and according to the Team they gave them quite an advantage over the competition on brakes.

They also designed their own radiator. This is a very tight fit in the chassis, actually I'll have to remove the headlight-bucket crossbar, to be able mount the radiator. The advantage is a much increased crosssection of the radiator core compared to fx the common Fluidyne. It's about 4 inches wider and 1-2 higher

I also had the tires mounted on the Wheels, so now I'm ready to cut the fenders for the Gr4 flares.

Those wheels and brakes are awesome....

Especially those wheels....

Rocky

Hey Man! I love those brake calipers. Got any more?

quote:

Got any more?

Yes, I think so. But, be prepared to write a SERIOUS check !!

Chances are big Doug only wants more pictures of those calipers...

quote:

Originally posted by Kid:
Chances are big Doug only wants more pictures of those calipers...

Well as I said, I'm looking for something that does that job but fits the stock Campi wheels.

It is very difficult to beat the cost of the Wilwood's and there is an advantage to them in that you should be able to get parts for them for a bit longer.

I could use Kid's method of removing the excess metal that says Wilwood with a flat file then everyone would wonder.

Remember, I'm not bound by the "class rules" for vintage racing that you guys have there.

Those rules make it quite a bit more expensive to field a car when many of the original limited production parts of the time like the aluminum brake calipers need to be "reproduced".

Actually the Volvo R60 series brake calipers look like they are a good shot at adapting.

They're like Bud Light. "Taste good, less filling".

You can have his brakes, I'll "borrow" the wheels Too bad I'll need to cut the car though....

Maybe I should wait to see what kind of engine goes in, and steal - uh...borrow - that instead :-)

quote:

Originally posted by Push1267:
They are massive and according to the Team they gave them quite an advantage over the competition on brakes.

I believe that. The surface area of the brake pads is almost double that of the stock pads.

I was quoted $1900 for a front pair of the 18-4 aluminum "Girling" calipers but I doubt that they would fit the stock 8"x15" Campis.

The Aluminum Cobra/GT40/Mangusta calipers are available too but I don't see the point of spending that much money for single piston calipers.

Wilwood Ultralites are looking pretty good. 1/2 the price and fit the wheels. Like I said, "taste great, less filling".

These Allied's are sure pretty though. Too bad the brake dust is just going to eat them up alive?

Yes, I agree these calipers are primary for historic racing where you have to comply with regulations.

You can have several sets of Wilwoods for the price of one set of these Lockheeds !!

Below is another piece they developed - airintakes for the rear Windows. They bought the commen "ear-intakes" from the UIS vendors, and after deaming them "useless", they developed their own. They have two outlets, one for a closed airbox for the Webers, and the other for cooling of the fuel-tanks, one each side. I have the moulds for both intakes and airbox.

Here as they sit on the car - still need some trimming.

quote:

Maybe I should wait to see what kind of engine goes in, and steal - uh...borrow - that instead :-)

Well, I haven't gotten very far with the engine. Only thing I know for sure is that it has to be an iron head 351 C - and it will be dry sumped. FIA won't allow me to use alloy heads and block.

Just started looking into the placement of the motor - how far can I move it forward and how much can I lower it.

Too bad for me, good for you

Won't be the engine I will steal, as I have my mind set of a an alloy block and heads :-)

Need to rob a bank first though...lol Might need a fast car for that - can I borrow yours when it is finished? ;-)

Hey Push... those ducts are some cool pieces.
Would it also be feasible then to use one of the duct tubes to run to the rear brakes..?? Do both sides have the dual tubes?

Rob, both scoops have two ducts. I suppose one of the ducts could be used for cooling of the brakes, but I'm not sure airflow is effective enough along the sidescoops.
I do have seperate scoops they designed that sits underneath the car and direct air to the rear brakes. Same principle as the original Gr4 cars, but different design.

I've started on my aluminum doorskin project - just like the Gr4 cars had. Started on the driver side door by pulling the steel doorskin of a perfectly fine and rustfree door !! :-).

Here's the door without the skin (great Picture, right?). Note the side protection bar.

Here's the door after removal og the side bars and some hitten lightening of the door frame where possible.

The door skin need to be shaped to fit the doorframe, so don't attempt to mount these skins without access to a crimp/streatcher Tool. I did quite a bit of Work on the skin to make sure it would fit in the door opening and follow the contours of the fenders.

Here crimping the rear face of the skin.

More "persuasion"

Door ready for the skin!!

Jep - it fits!!

Then, slowly bending the edges with a hammer.

Rear seam in progress

Bottom part

Top of door need to be pulled into place. Top seem is joined with rivets that are slightly countersunk

Finished. Total weightsaving in metal alone on one door (including some drilling of the hinges) is 5 kg (11 lbs)

Some minor finishing to fit the car. Pretty happy with the result

Gaps align nicely.

Tomorrow moving on to the other side !!

Did you clear coat the door to prevent/inhibit rust?

The door appears to be stainless steel!...Mark

MAn, that is impressive!. You motivate me to want to tackle that!

Super work.

I usually don't want to comment on a thread if I can't add value, but your work really looks first class.

I love to see the craftsmanship in metal that we (often) see on this board.

Rocky

Push...as per usual....all I can say is "nicely done"!

Finally got the other door finished

With the skin on

Closing the marker light openings

Now that both doors fit, I could finish welding the outer B-post skins

Also closed the recessed openings for the front bumpers. The gr4 cars had this mod performed and the bumpers replaced with front position lights from a Lancia Fulvia.

The NOS front fender I put on the car was the early type with the narrow bucket opening. So had to widen it to make the wider, late model bucket fit

A 10 mm wider and 10 mm longer opening is required

Front fenders are done

Things are a little slow on the forum, so here are a few progress pictures of my gr4 project.

I decided to add a upper rigidity-bar and hope that it will comply with FIA rules. I've already added some smaller stiffening plates in the rear part of the chassis (see earlier in the thread), but this bar, in my view, is the most important bolt-on addition you can add to the chassis, basically preventing the shock towers from flexing under load and hard braking. In combination with the roll cage this should stiffen the rear up considerebly.

This is a piece from Hall.

The inner wheel housings actually have a curvature, which means a little reworking of the attachments plates are required before welding

Also added a few reinforcement plates to the rear mounts

At the front end of the chassis, I added these stiffening plates to the inside of the subframe.

Here are all fours cormers shown

quote:

Originally posted by Push1267:
Also added a few reinforcement plates to the rear mounts

Assembling my suspension parts again, I found out many of the mounts had different widths. Even worse, there was quite a variation in width of the new bushings I bought....duh. Had to have the grinder running overtime The day I start working on my chassis in a way like you are currently doing, I'll take the time to get these things sorted out properly - read, the non-Italian way

as always Push.... lookin great!

quote:

as always Push.... lookin great!

Thanks for the heads up. Things are going very slow at the moment.

I did the flare mock-up some time ago. Here are the fitting of the rear flares with the suspension and wheels on.

There's beén some discussion over the quality of the fiber (and steel) flares. These are from Byars, and are very nice. They fit right on with almost no modification.

After studying old Pictures of factory group 4 cars, and drilling the correct numbers of holes for rivits - next is the scary part that hurts deep down!!!!

This is the mark-up for cutting of the fenders - keep that grinder steady!!!

After cutting !! There's no going back now.

High there, dont know if this is relevent, but on my car , a Gt 5 clone there are I think double the amount of holes, greets

Urbain

Urbain. I know that different amount of rivits are used on different cars.

I'm simply adhering to what the factory did on the Gr4 cars, which was 15 rivits in the rear and 13 in the front (i.e.; above the line on the side of the car) with a spacing of 92 mm.

Congratulations! There are a number of flared-fender clones running around the world in which the original fenders are still inside, making the whole flare system of dubious worth. FWIW, I had the same awful feeling when I cut our '72's front trunk for a dropped battery....

Are you going to roll the cut edge to form a bit of a lip to stiffen things up?

Larry, that was my plan to begin with, but after cutting of the lips the fender hasn't lost much stiffness.

With the flares in place with the Clecos only, the fender is still stiffer than it was before cutting (the fiber flare are very stiff in it self), so I think I'll leave it alone.

I looked at the factory cars, and they were the same - no rolling of the edges.

The flares was fitted with the Wheels on to make sure the Wheel was centered in the lip.

For some reason, the rear wheels are centered a Little towards ¨the rear from the factory. To correct this the Gr4 flare was squized i little and moved rearward (about an inch) where it meets the rocker panel.

Where the flare joins the lower rear panel, I kept it flush with the panel edge

Here's what the spacing looks like on the drivers side

At this point without adjustable a-arms and spacers, the 14" wheels stays juuuust inside the flare.

Pretty bad-ass I think. Tires are 14.0/27.0-15

In the same manner I took a big chunk out of the front fenders - here it was a brand new (NOS) fender!! Yeeearhh. I'm crying

I little trimming is needed but otherwice the flares are done.

Also made progress on the Cage. Almost fully installed. It's from Sassa in Italy and fully FIA certified. It fits right in, but requires fabrication of attachment plates (such that it can be bolted in) and cutting and welding of the rear bars and the side bars.

Here it is installed.

Rear part of cage

Inside

In typical fasion I tried getting as close to what the factory did to the original Gr4 cars - including how they did the attachment plates on the inner rockers. These are copies of the plates found in Les Grays factory Gr4 (thanks Ed Mendez for posting pictures of Les' car on facebook)

Sorry for the lousy quality - will take a better Picture NeXT time I'm in the workshop

Those flares seem to fit extremely well. Where did they come from?

Your work looks amazing!! Really appreciate you keeping us up to date on your work. What a great journey.
A funny story about the fender flares on group4 cars. My red car was a Hall Super Pantera with all steel flares. I had wanted one of the big air dams for the front, so ordered one from Bob Byars. When it came in Les Gray and I were looking at it and there was no way it would fit my car or flares. We put it up to his car and the same thing. We then took one of his front air dam from his group4 race car and Put it up to my car and it fit perfectly. We were wondering what was going on. So we looked at a couple of other Panteras that had put on the group4 flares and it fit their car great. We couldn't figure out what the difference was. Then at a car show right after that we had about 3 or 4 group4 cars there and Les looks over at my car and then theirs and realizes that they had their flares on backwards. Next time you are at an event with a lot of group4 panteras take a look.

I built an air dam out of aluminum to fit. It was not as hard as I expected it to be.


http://www.rc-tech.net/pantera1/airdam/ad.htm

You presume that everyone is sane, would go to a Pantera vendor or at least copy a Pantera flare.

There are a number of Pantera owners I have come across that do not qualify on not even one of those accounts?

I've heard of using VW flares on these things.

Do not tell these people they are cutting their nose off to spite their face. They will go out and do it just because they can.

Comp2, great build on that aluminum air dam. I do not have half the talent.

Push1267, the air dam was from Bob Byars and I delivered it back to him personally along with my car because Don and Bob were putting new seats in my car and a few other things, but the fiberglass air dam was inches away from connecting to my flares and they saw it. And another interesting fact, Les gray, Bob Byars, and Don Byars all worked at Hall Pantera and helped build my car. Back then it was being built for Oliver Ring who is LLoyds partner in the ZF business and makes most of the gears and parts that LLoyd sells.

I think you are right, if some one bought the fiberglass group4 kit I do not think they could get the flares on the backwards. What I think happened was that when they made the mold they made them backwards. On the factory group4 the flares are wider in the front and narrower behind the wheel. But when you look at the car it is narrower in front and gets wider in back. So at some point someone thought the flares should go that way. By the way this was 8 years ago and may have been fixed back then. I really do not know.
BTW I love all the metal work you have done. The cars is amazing.

On the front flares wouldn't that simply mean that the left side is on the right and right on the left?

Yes for the most part

quote:

Originally posted by Rapid:
Comp2, great build on that aluminum air dam. I do not have half the talent.

I didn't think I did either.

quote:

I didn't think I did either.

You guys kill me - in a good way.

All these threads are an inspiration to Pantera owners everywhere. You guys are showing us the "state of the art", the "art of the possible".

It's great to see the good work that is showcased here. All these threads encourage people like me to stretch a little bit, and see what WE can do.

Keep up the great work, and keep posting pictures. That's what this site is all about.

Rocky -

Here's a Picture of the Gt4 that travelled the world in '72 with a good view of the Gt4 flares. That was of course before they added the huge air-dam for the '73 season.

That is a really a great look. But so far yours is a killer - especially with those fantastic wheels! Excellent work. Can't wait to see more pics.

Yup, those are installed correctly.

Just a small update on the Progress on the Gr4 car. Dragged the body outside the other day to mediablast the chassis seams in preparation for seam welding.

Then spend a few nights seam welding the most stressed areas of the chassis - maybe 50-60 % of the seams all together

To replicate the original Gr4 cars I also decided to fit a flat decklid instead of the original ridged lid.

IMO the flat deck also gives the car a cleaner look.

Actually had to fit 2 decks, one in steel and one in fiberglass such that I 'll have the option to use the lighter fiber deck when the rules permits.

Here's a shot of the steel deck

hey Push,
Haven't checked in for a while... Just went through 4 pages of your progress... Fantastic. Cutting the fenders had to be torture! Measure 21 times, move them a mm, measure another 12 times...stare at it for 20 minutes. Cut it in 3.5 minutes. Go vomit. Anyway..it looks Those steam rollers out back look awesome.

Keep up the great work man. Really fantastic.

Yes, these things take time (atleast for me). It may have taken weeks from when I first decided to cut the fenders until I actually did the cutting. Thinking, measuring, thinking .....

Meanwhile, I'm slowly continuing my efforts to replicate as many of the factory Gr4 mods.

Here I started doing the panel strengthening of the inner rockers by flaring holes. Studied a lot of Pictures of original Gr4 cars, and interestingly, the holes placement and size seem to vary a little from car to car. Apparently this was done by hand at the factory - I ended up somewhere in between.

Here's the center console with holes. I'm using a cup drill and a simple swage Tool to finish the holes.

The rear panel also got the treatment

Amazing attention to detail! Thanks for posting the incredible pictures! How do your window scoops/air ducts fit with the roll cage rear bars?


Ron