Building a Gr4 replica

How much weight do you think the "lightening holes" save?

A while back I talked to Jerry ap PIM. The area you put lightening holes in the chassis below the door is an area he routinely adds a plate od steel to. A friend of his was killed in a crash and he said the lower panel there was the failure point.

Can you provide a photo of the failure point?

quote:

The area you put lightening holes in the chassis below the door

Yes, I would like to see the failure point as well.

The holes are actually NOT for lightening (although that is a nice sideeffect) - once the holes have been flared/swaged they stiffen the plate up considerable, that was the reason the factory did it, and the reason I did it too (and for looks ofcourse).

The weak point of the chassis is the lower B-post area. I would assume this would be the area Jerry is referring too. This area is often (almost always) rusty on Panteras that has seen real world driving and rust in this area will weaken the chassis considerable.

I reinforced this area (if you go waaaay back in this thread you can see how) AND the roll cage will support this part of the chassis somewhat more. In addition I seamwelded the seams between the inner and center rocker a long the entire length.

BUT, by no Means a pantera is a safe car :-(.

quote:

How much weight do you think the "lightening holes" save?

Less than a kilo (!!!!) but, as mentioned, the holes primary function is not lightening.

quote:

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

Thanks Ron. I could say the same of your Work. The scoop ducts (there are two in each side) fit right around the rear tower bar. I did weld in the bar such that it would just clear both ducts.

I have some friends that help out in high school robotics clubs that compete regionally and nationally. The have weight limits. They learned quickly you just can't drill enough holes to substantially reduce weight. Looks cool though. ;-)

quote:

Originally posted by Push1267:

quote:

The area you put lightening holes in the chassis below the door

Yes, I would like to see the failure point as well.

The holes are actually NOT for lightening (although that is a nice sideeffect) - once the holes have been flared/swaged they stiffen the plate up considerable, that was the reason the factory did it, and the reason I did it too (and for looks ofcourse).

The weak point of the chassis is the lower B-post area. I would assume this would be the area Jerry is referring too. This area is often (almost always) rusty on Panteras that has seen real world driving and rust in this area will weaken the chassis considerable.

I my car I reinforced this area (if you go waaaay back in this thread you can see how) AND the roll cage will support this part of the chassis somewhat more. In addition I seamwelded the seams between the inner and center rocker a long the entire length.

BUT, by no Means a pantera is a safe car :-(.

When Hall was building the "T-top" car and trying to stiffen the chassis enough to make the roof panels not squeak, he inserted at first a roll cage tube, then a lightened extrusion through the rocker panels on each side.

They bolted to the inner fender wells and the bottom of the roll bar.

Working on the last details before the chassis is send out for paint.

Here's an example of how one project creates another one.

I got two of these specially build race radiators, designed specifically for the Pantera by Aquila Racecars. They have a much larger radiator crosssection than other radiators available on the market. Therefore is's a very tight fit.

This tight!

This create two issues

1) If I wan't to keep the headlight buckets, I will have to make the headlight bucket raising bar removable as the radiator won't go in-and-out of the chassis with the bar in place.
and

2) I can't use the electrical raising mechanism (which I didn't intend to in the first place)


The easy solution would be to junk the entire bucket raising mechanism and replace it with fixed headlights under a plexiglass cover. However, the factory cars retained the buckets, Thus in keeping with the relica/tribute theme of the build, I have to take a direction where I keep the buckets.

One solution is to make a bar that can be separated in the middle with the bucket brackets bolted to the bar in the housing opening. This way the bar can be removed and the radiator installed/removed.

I made the bar in aluminum, saving a couple of pounds too

Here it is finished. Still need to figure out how to raise the buckets!!

Maybe rise the lamps whit a BMW 8 series or Pontiac Fiero system

The 69-70-71 Opel GT had a cable operated manual system.

There's a GT5 in Norway that uses the Miata 2-motor system (similar to a 914 Porsche), and a recent one in the POCA magazine that uses a street-rod linear actuator. This setup raises both lights simultaneously using a bar & lever.

Thanks for all the suggestions. However, as this car is going to see use mostly as a racecar I think I'll look for a more simple solution - and light weight. After all, it's very rare that the headlights are used.

Probably, I'll just remove the electric motor and keep the bracket with the gear such that I can raise the buckets manually. I'll need to trim the bracket to clear the radiator, but the gear should be possible to retain. I have a couple of complete spare gear/motor assemplies that I can play with.

Single-headlight Mangustas used a lever on the floor with (I think) a bowden cable system.

Hi Kristian, I have used these ones with success on various projects. Beauty is they are light, strong and has internal electrical limit Switches at both fully extended and retracted. So that it can be operated with a standard reversing 2 position toggle Switch.

http://www.ebay.de/itm/Linear-...t0l93SGClVhHQX0Zd4Xg
They come with various length and power and would be suitable to fit below one of the Buckets for a totally concealed installation.

best
Jan

That should Work. Thanks for the tip, Jan. Looks very easy to adapt and the lightest version is only 700 grams - great.

See you soon

I see that they are "Rated to IP64, suitable for washing and most outdoor use" so that's good. Seems like at least one adjustable limit switch would be needed as adjusting both the down and up positions with mechanical geometry might be quite difficult.

Hi Richard, not at all. When Kristian design/construct the Geometry of the Linkage he just needs to make the moving Arm the exact lenght that matches: fully retracted=Doors closed and fully extended=Doors open or visa versa. Of course it requires a bit of measuring and perhaps trial/error. But definately possible without trouble and then you avoid the hassle of external Switches. I looked at the wiring diagram briefly and should be possible to use the OE Light Switch and no modification to the Harness apart from shorting the set of wires on both OE limit Switches. But that has to be verified.

I’m amazed at the quality of your work.
And there’s so much to be learned from your build as to the intricate structure of the Pantera chassis.
Well done.
Regards,
Tony.

Goodroc wrote,
"Geometry of the Linkage he just needs to make the moving Arm the exact lenght that matches: fully retracted=Doors closed and fully extended=Doors open or visa versa."

Yes, that's true but as I see the problem there are two variables: the length of the "arm" that is attached to the headlight bar and the mounting point/geometry of the linear motor with respect to that arm. Changing either of them can effect either or both of the up and down position. The exact up position end point is not too critical, you just adjust the headlight alignment accordingly. But, if the down position is wrong, i.e. the bucket is closed all of the way before the limit switch is tripped the motor could burn out. Of course the stock system has this problem too but the limit switch stops make it easy to adjust. So, either a geometric solution using fixed limit switches or adding an external limit switch(s) would work. I'm just wondering which would be easier for a given situation.

Actually, I'm surprised that Gary "comp2" has not commented as he was working on this problem in 2009 but never posted his results.
http://pantera.infopop.cc/eve/...77274/m/93610454/p/1
He posted some interesting links. With the right kind of linear actuator (with a Potentiometer) and a "Linear actuator controller" the actuator can be commanded to go to programmed positions:
http://www.slickcar.com/info_linear_actuator.asp
http://www.slickcar.com/detail...ved-door-handles.asp
some more info on the controller:
http://www.speedwaymotors.com/...t-Actuator,7477.html

I've not looked into making any of this work with the stock headlight circuitry and switch. My guess is that using external limit switches would be necessary.

If you don't care about that and are OK with putting in a separate switch to raise and lower the lights then a power window switch approach would work just fine: just hold the switch on until you get to the position you want (i.e. things stop moving when they hit a mechanical stop) and let go. Just make sure your actuator isn't strong enough to bend things!

Kristian is a very smart guy and he will be able to figure out the geometry very quickly. If someone can tell me how many Degrees of rotation the Headlight Bar is doing from closed to open I will happily provide an exact Drawing. There are several options for stroke length and that affects the length of the Arm and the time it takes for the Doors to open/close. If a 50mm stroke is used it is twice as fast to open/close as if a 100mm stroke is used. Two things are important 1) It works best if the Arm and the Actuator form an angle of 90° when the doors are half way open/closed. 2) You must construct it so that there is a possibility to adjust the position of the Actuator a few millimeters up and down in the fully closed position to compensate for wear and tear over time.

You guys been sleeping? I used to make kits. I don't have time to mess with it any more. I sent my stuff to Scott so he could duplicate it. Might ask if he had time to mess with it:

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

Here are some adjustable brackets so you can see how to make them:



These are brackets to fit the bearing in the headlight bucket bracket which also strengthens it:









Here is a pannel for the short lift headlight "frog eyes"



Here is a video:

http://www.rc-tech.net/cars2/p.../hlight/MVI_0260.MOV

Headlights work great! I like the big headlamps too

Funny seeing them move not 100% in sync.

quote:

Originally posted by Push1267:
... car is going to see use mostly as a racecar I think I'll look for a more simple solution - and light weight. After all, it's very rare that the headlights are used....

wild thought...how about a gas spring that would open the headlights and a latch on the gear to hold them closed when pushed closed by hand. use an open limit switch to prevent the lights from burning when not open

(addition)
to operate the latch, I was thinking a door lock solenoid with a headlight close permissive limit switch that would be off the headlight on power

Nice solution Gary. As always, brilliant enginering and workmanship.

1 actuator operating the aluminum bar seems like the simple and light weight solution I'm looking for. I ordered one of the actuators Jan recommended, and will experiment with linkage when it gets here.

quote:

Originally posted by JFB #05177:

quote:

Originally posted by Push1267:
... car is going to see use mostly as a racecar I think I'll look for a more simple solution - and light weight. After all, it's very rare that the headlights are used....

wild thought...how about a gas spring that would open the headlights and a latch on the gear to hold them closed when pushed closed by hand. use an open limit switch to prevent the lights from burning when not open

Incredible idea Joe!
You could easily have a pull cable to release the catch and then simply push the doors down by hand to latch them back. It would be very light and simple to implement.

Ron

I'm with Ron... Great idea Joe!

I agree. That would be very simple and lightweight.

A concern is what happens when the damper is released. Unless the damper has very low pressure, the buckets will snap open very violently.

I Wonder if there are short, slow releasing, low pressure dampers available from somewhere?

Hi Push,
I don't think you would be able to go to the local auto parts store for this application, due to the very points you mentioned. I would take a look at McMaster Carr. They have a large variety of lift struts with as low as 5 lbs force. I think so long as you match the strength to the need, this could be a sexy solution. An added thought.... to ensure stable function, w/o the doors bouncing, you may want to consider multiple low force struts. Just a thought...

Check out some of the options I found here..
McMaster Strut Link

I thought gas struts alos used hydrualic damping to control the opening rate

If worried that gas spring would not hold positively open, a latch at open could be added. but now it is begining to get complicated

Kristian, this is where I bought my Gas Struts for the rear Deck Lid. You can ask them for any combination of power, Stroke and Speed. They also have them in special light weight types. And they are located right here in DK.



Their Catalogue:
http://www.sindby.dk/fileadmin...85-2-k201309-web.pdf

Ok, the waiting has started. The body is ready for paint, but the paint shop is not. There's been a lot of small additions between the last post and this one, but this is what the body looks like waiting for transport.

I've decided to have the car painted with the steel deck and front Hood, I may have to use them at certain events. The fiberglass deck and aluminum Hood need some finishing before they are ready.

rear

I did add a few fix points for the Cage to tie it better into the chassis. Here's one of them at the firewall

I also enlarged the opening in the deck to make room for webers. The deck came of a car that was used for racing so it had allready been modified. So decided to modify the deck to replice that the factory did to the gr4 cars when they introduced webers.

Here the deck before cutting with mark-up

After. I'll do the same to the fiber deck

I also filled in the openings for the seatbelt retracters to stiffen the inner rockers a little

Finished

Very nice!!!!


Ron

As always Push.... as always... all I can say is "nice work" man. I love your attention to detail and workmanship.
I'm jealous about the deck lid having already been modified.. in a sick way.. :-) I was dreaming last week about putting webers on 6001 but just couldn't get myself to cut a good deck lid. I like the way you did it. Almost can't tell. Never seen it done that way. Very cool.

She's going to be a sweet ride. Keep the posts coming. They keep me fired up

all the work is pure art!

the opening of the deck lid over the engine area looks like that should have been done origianlly to the car. can't wait to see the painted, then final results.

I bet that deck lid would look great with a modified mesh cover over stock air cleaner

Great idea on the decklid. I really like it. Will you modify the screen cover and make it a bit longer or are you just not going to use it? I guess it would have to be modified anyway to fit the webers.

Amazing craftsmanship! The filled-in retractor areas and modified hood look as if the factory did it! Nice work, enjoy the pictures & posts. Thank you.

Yes Rob, I probably wouldn't cut the decklid if it was uncut to begin with. I have the original uncut deck for the car in storage.

This decklid is a spare I bought that came of a race car (#1508). It actually was first used for Bonneville speed records, so it has had a cover of sorts mounted for aero reasons. There were lots of holes to fill. then it was briefly used for Gr4 racing in europe on one of the Danish Team witch Craft gr4 cars. Since it was more or less ruined, I may have gone a little overboard with the hole punching !!!

The idea of enlarging the entire opening is not mine - as mentioned, the Detomaso factory did this to the factory Gr4 cars, when they switched from running Holleys to Webers.

This car will be mostly for racing (I intend to do some historic racing under FIA rules), so there will be no engine cover

I first saw that decklid modification in Las Vegas about 10 years ago on another Weber equipped car. When I first viewed it I wondered how they had managed to avoid cutting the decklid like everyone else did. Only after comparing it to an adjacent car with a stock decklid did I realize what they had done. To make the alteration more invisible the owner had finished the opening with edging trim the same as a stock car.

I have always felt it was the most pleasing decklid modification to accommodate the Webbers. Congratulations on discovering it and putting it into play on your car.

I did not know that it had ever been done as a factory modification.

Larry

I kept my original decklid and put a fiberglass on mine. I cut the same opening, glued some hard plastic tubing, filled the radius with some fiberglass filler and smoothed it out. The rib really helped clean it up:

Very nice Work as always, Gary.

Here's a Picture of #2860, the Dubois car. The Changed opening is obvious, they probably installed a different deck skin.

Wow, just learned something here. Another secret of the Gp4 cars revealed.

It does look good without the notch though?

Great picture.

Very nice work Kristian ;-) How did it work out with your Headlight project? We might plan to come to the Devils Island on the 6th if the hangover is not too bad after christmas Lunch with Friends on the 5th.............

Small update. Car has been sitting waiting for a while now. The paint shop is pretty busy with winter fender-benders, so I'll have to wait a little more.
Decided to do some of the paint preb myself, so armed with lots of materials from the paintshop I spend quite some time getting the finish to my liking.
The car was basically straight to begin with so it just needed a thin coat of primer and filler. 2-3 rounds of filler and bloksanding and it's ready for the final Work at the paintshop.
One of the paint supplyers came up with some paint samples based on the original 71/72 paint codes for the red, but I wasn't sure if they are right (seemed too dark), so he's right now analyzing some remains of the original 71 red on an old headlight bucket I had lying around. It's kind of orange-red with a brownish tone.

Wasn't happy with the alignment of one of the flares so had to move it a Little - drilling new holes and welding the old ones shut

Deck still need some work

...

Lookin good Push. Was wondering when I'd see some updates...

That rear view is sick..! Holy crap, can't wait to see it with the rubber in the wells.

quote:

That rear view is sick..! Holy crap, can't wait to see it with the rubber in the wells.

Funny that you should mention that - I had that same urge some time ago

awesome...
Ok, so not to get too demanding...but how about both tires on for that full rear shot like the above pic. Pleeeeeeze...

quote:

Originally posted by Push1267:

quote:

That rear view is sick..! Holy crap, can't wait to see it with the rubber in the wells.

Funny that you should mention that - I had that same urge some time ago

I like it. The flares fit nicely. What color are you going to use?

As mentioned in the post, we are working on analyzing the original factory red - so it's going red/Black.

Surpricingly, one of the paint companies we talked to had the formulas for the original 1972 red (there are two different codes) - but the one they test sprayed did not match the remnants of the factory red I had all that well, I thought, - so they're back to work on one of the other codes.

There are two reds. Mine is Pantera Red #2. By deduction, there must be a #1 but more likely just called Pantera red.
Red and black are the factory race colors.
Interesting because they are the German national colors as well.

Rob - just for you. You're right - it looks kinda sick!!

Even sicker!!

Nice!

Very nice!!

Thanks man... you brought a smile to my face after a long hard day

Looks absolutely great Kristian, I am sure it will be a real Beast when its finished.

quote:

posted January 26, 2016 11:55
There are two reds. Mine is Pantera Red #2. By deduction, there must be a #1 but more likely just called Pantera red.
Red and black are the factory race colors.
Interesting because they are the German national colors as well.

I am sure Kristian knows Black and Red is factory race colors and that is probably exactly why he choose that combination But Panteradoug I am not sure about the relation to the German national colors you are making ??????? If you are relating to their Flag it is black/red/yellow!

If we all had stupid amounts of money it'd be interesting to put a bunch of matt clear coats over the paint as it is and "rat rod" it for a bit....

Awesome! Get her on the road as is.

OK, as mentioned, we found the original 1971 V108 red on a spare headlight bucket we had lying around. The color is from a very early car chassis #1395. It's very orange-red-like and looks pretty similar to what I have seen in pictures on original Gr4 cars and also early 1971-72 production cars. So, that's the color we were aiming for.

We stripped the top layers off the bucket and polished through to the original red color underneath.

A paint scan came up with a near perfect match from a .... Renault (!!!). I can't distinguish the test spray from the original color so this will be a go :-).

Bravo Kristian!

It's actually a very nice color. It really glows in the sun like it's radioactive.

I think if you look at a color wheel it is right on the line between orange and red. Just a little step towards red?

Ford had a color like it too from the 64-1/2 Mustangs. At one time they called it Coral but mostly is just referred to by it's paint number.

http://thecoralsnake.com/

Great colour! Reminds me a lot of the "tangerine" Holden used on their Torana's here in AU back in the 70's.

A tangerine LJ XU-1 Torana would be a nice addition to the garage.

damn Push, good find. I can't tell the difference...

Waiting ........

quote:

Originally posted by Push1267:
OK, as mentioned, we found the original 1971 V108 red on a spare headlight bucket we had lying around. The color is from a very early car chassis #1395. It's very orange-red-like and looks pretty similar to what I have seen in pictures on original Gr4 cars and also early 1971-72 production cars. So, that's the color we were aiming for.



We stripped the top layers off the bucket and polished through to the original red color underneath.

A paint scan came up with a near perfect match from a .... Renault (!!!). I can't distinguish the test spray from the original color so this will be a go :-).

Its hard to see on my 2 pics but my painter used a Ford red from the early 70's to paint my engine bay and the bonnet and boot lid after I stripped the engine out to tidy it up. It is a little orange which initially I didn't care for, but now I really like it and it brightens up the car, whereas some dark reds can be dull. None of the paint has yet been polished.

Peter -

That looks great!


Rocky

quote:

Originally posted by Rocky:
Peter -

That looks great!


Rocky

You have no idea how nice it is to have a kind remark.

It makes it all worthwhile for an amateur.

Cheers Rocky.

ps am tidying up the front area where its been jacked up and split open over the last many many years, but my skills with the welder Wouldn't cut the mustard as much as this truly interesting refit which has bought me much more knowledge of the Pantera that I didn't know.

Peter, that's a great color. Enginebay looks great too. Is that color similar to the original?

I think that is the Ford "Poppy Red"? It looks really nice.

The Detomaso Pantera Red is somewhat orangey also.

It really jumps at you in the bright daylight and I like it a lot more than the Ferrari red.

Looks great. Nice job.

My car is 2003 Lamborghini red . If the sun hit it just right it can look orange too.

I guess it's time for an update on the progress on my gr4 car which, well, is close to none. The car still sits in the paintshop and not much has happened. Hopefully things will get going this month - atleast that's what he has promised.

Meanwhile a few parts have turned up. It took AP RACING 6 month to finish the rear calipers for the car. Again, these have to be homologated for them to be used in historic events here in europe.

I had the choice between the Girling 16/4s made by Bg Development and the AP Lockheeds of AP RACING historic range. I went with the APs (remember, I have AP 8-piston calipers for the fronts), as they are lighter than the Girlings and have a greater brake pad area. They are availible with different piston sizes, including the 41.3 mm homologated for the Gr4 Pantera. Also, a feature I liked was that they have blank lug mounts, meaning I can drill them to match the bolt pattern on the rear uprights and thus avoid using adapters.

Here's a Picture:

Another

The rotors are 304x28 mm, also from AP, Again size is dictated by what is allowed by the FIA

Another neat piece is this dual master pedal assemply kit that Scott (SACC restorations) put together for me. Pretty much his standard set-up, but with Girling masters instead of the Wilwoods. The kit includes a proportioning valve and a remote adjustable balance bar.

Very nice components. I just reviewed your entire build post. Terrific work all the way through!

Allthough progress is INCREDIBLE slow, there IS Progress at the paintshop. They finished prepping the body, and expect to start painting the car Next week!!

I'm pretty obsessed with getting the red color for this car right, i.e., getting it as close to the original red as possible.

So i did one further check of the color we came up with. The red was mixed from a scan from the original red on an early '71 headlight bucket BUT, is the early '71 red, the same as the red used on the later '72 euro GTS and Gr4??

So I send the paintsample to Chris Beck in Switzerland to compare it to his original GTS red.

I think it's pretty convincing, they compare really well. Good thing is, that the color is a modern paint from a Renault that can be mixed at any time.

Seems to me that the colour matches perfect

quote:

Originally posted by Push1267:
The rotors are 304x28 mm, also from AP, Again size is dictated by what is allowed by the FIA

Hello Kristian
Did you build some hats for those rotors ?
I've got the same for my gr4 project, still not have the hats ...
Thanks
Philippe

Philippe,


I do have some set of hats, but I'm not sure they will be right. I'll be experimenting with rotor offset when I get the car back.

The hats for the AP rotors will likely need to be custom made. AP doesn't offer universal hats.

Wilwood offers a few hats with the AP 12X7 rotor circle and ford 5X4.5 bolt circle that may work.

Hello Push,

on your original post a long time ago now you mentioned the history of your car, sold by Claud etc etc.

I also own a 72 Euro GTS number 3840 and am interested in where you found out about the history of your car.
Santiago Detomaso I cannot contact for some reason

regards Peter

quote:

Originally posted by Push1267:
Philippe,


I do have some set of hats, but I'm not sure they will be right. I'll be experimenting with rotor offset when I get the car back.

The hats for the AP rotors will likely need to be custom made. AP doesn't offer universal hats.

Wilwood offers a few hats with the AP 12X7 rotor circle and ford 5X4.5 bolt circle that may work.

Thanks Kristian
that was my idea

I always loved the rear view of a wide body car

Here's a $100 project for those wanting to shed some weight of their Pantera.

Building an aluminum skinned front lid.

This is of course for my Gr4 build, but it would be pretty cool on a street Pantera too.

I had an old accident bend front lid lying around that I wanted to experiment with. So I separated the outer skin from the inner structure.

While I had the inner structure media blasted I started working on the outer skin. Bought a 1 mm aluminum sheet. Using an intact lid as a template I cut the sheet into shape

Then, again using the intact lid as a form, I carefully bend the sheet around the lid and slowly shaped the edges with a hammer, while keeping track of measurements.

A couple of hours and the skin was almost finshed