Stupid idea of the day.

[jtb]

OK, I was looking at the track and wheelbase of an Opel GT and Porsche 944 or 924, and with steinmetz flares on a GT adding 3" per side, the dimensions are remarkably similar.
So here's the stupid idea - grafting a GT body over a Porsche 924/944 suspension and possibly drivetrain. I know the porsche uses macpherson struts on the front, and that the transaxle is in the rear, so this would not be an 'easy' task. That said, I am a sucker for punishment, and am not afraid to hack away at cars. So... bring on the comments!

Thanks,

jtb

[BQS4]

Originally Posted by jtb OK, I was looking at the track and wheelbase of an Opel GT and Porsche 944 or 924, and with steinmetz flares on a GT adding 3" per side, the dimensions are remarkably similar. So here's the stupid idea - grafting a GT body over a Porsche 924/944 suspension and possibly drivetrain. I know the porsche uses macpherson struts on the front, and that the transaxle is in the rear, so this would not be an 'easy' task. That said, I am a sucker for punishment, and am not afraid to hack away at cars. So... bring on the comments! Thanks, jtb

Can't be any wierder than popping a GT body on a Willys frame to make it a 4X4, go for it.....

[charlie1966]

I can't offer any advice but I would like to see lots of build pictures.................pleeeeaaasssee!
Best of luck if you go ahead.

[timemachine]

Originally Posted by BQS4 Can't be any wierder than popping a GT body on a Willys frame to make it a 4X4, go for it.....

Or a CJ5...

http://www.opelgt.com/forums/general...side-show.html

Jim

[blancojp]

Originally Posted by jtb OK, I was looking at the track and wheelbase of an Opel GT and Porsche 944 or 924, and with steinmetz flares on a GT adding 3" per side, the dimensions are remarkably similar. So here's the stupid idea - grafting a GT body over a Porsche 924/944 suspension and possibly drivetrain. I know the porsche uses macpherson struts on the front, and that the transaxle is in the rear, so this would not be an 'easy' task. That said, I am a sucker for punishment, and am not afraid to hack away at cars. So... bring on the comments! Thanks, jtb

You could build another Batmobile!!

[oppositelock]

I work on Porsche 944 race cars every day. Front suspension uses VW Rabbit lower control arms. It would be interesting to see if the struts would fit under the Opel Gt fenders. The hood on the GT is much narrower than the 944 hood. The strut tops would probably end up coming up through the fenders. The 944 engine is a big bore 2.5 liter and is fairly long for a 4 cylinder. (One of my crazy projects I want to do is build a 944 rally car with an Audi 20v 5 cylinder turbo engine. I've done some measuring and the Audi 5 cylinder is actually about 2 inches shorter than the 944 engine.) The 944 engine is also slanted over to the passenger side to allow for a lower hoodline. 944 engines are also expensive to rebuild. A typical race prep rebuild for a 944 Cup car (stock rebuild, stock pistons, rods, etc.) runs around $5000. And for that you get about 150hp. Clutch and flywheel on the engine with torque tube running back to an Audi 5 speed transmission in the back. The short rear overhang on the GT might allow the tail of the Audi transmission to stick out the back a bit. You'd have to take some measurements. Rear suspension uses a torsion bar and semi-trailing arms. The way the shifter is mounted on the torque tube it wouldn't be too difficult to relocate it if necessary to come out in the right location. The good news is it isn't very difficult to find a semi decent 944 for $500-$1000. Seems like it would be a pretty big project to pull off, though.

[baz]

this is what i was going to do to mine with a jaguar xjs floor complete with V12 engine
wheel base was very close and track was about 3 or 4 " so flares would have covered

its more important to work out difference in floor between rockers as tis effects the ability to sit in the car after the change , the gt is narrow to start with and if you lose too much room to the centre you may not get seats in , i think the proker should be ok but with other doners it may be a concern

[jtb]

Hi,

Thanks for all the responses. I think it would be weirder than putting a GT (or other) body on a Jeep frame, because the porsche is a unibody.

As for the height of the struts, that is definitely one of the first measurements to figure out. I'm not adverse to building a tube frame of some description in the front. I think I have seen pictures of this done to a GT.

Right now this is just an idea floating around in my head, I don't have a 944 (although I have seen them cheap on craigslist) or a spare GT at the moment. It would be interesting to use the porsche engine, but it wouldn't bother me to use a different powerplant.

Baz, is a proker a porsche? I think I follow what you are saying.

cheers,

jtb

[baz]

yep its the nickname we use for porsche's here



as for the struts they can be from another car if they mate up to the hubs so hight can be worked round or shorter ones made for lowering a car can be used to reduce hight

[jtb]

Originally Posted by baz as for the struts they can be from another car if they mate up to the hubs so hight can be worked round or shorter ones made for lowering a car can be used to reduce hight

From another porsche or another make of car? The whole unit with the coil, I would guess? Have to keep the spring rates similar?

I did a little more research, found that the 87-88 924S has all the 944 goodies (suspension, brakes, engine) in the narrower 924 body.

Thanks,

jtb

[RallyBob]

I took some Porsche 924S front struts and modified them to fit another car, since they use the screw-in top on the strut housing to hold the strut inserts in place. I simply removed the strut insert, cut the housing tubing to length, made some flanges to mount the strut to the new car's upright, and then got another strut insert from Bilstein in the proper body length and stroke. Some cars have really short struts (1st gen Toyota MR2 comes to mind for example), so you just need to find something with the proper insert length and OD. I went with a coil-over setup so I deleted the stock spring perches altogether.

If you shorten the overall suspension travel compared to stock, you'd need to stiffen the spring to reduce the chances of the suspension bottoming out. I'm not sure about the 944, but the 924S has very soft front spring rates.

[heimue]

Originally Posted by RallyBob I took some Porsche 924S front struts and modified them to fit another car, since they use the screw-in top on the strut housing to hold the strut inserts in place. I simply removed the strut insert, cut the housing tubing to length, made some flanges to mount the strut to the new car's upright, and then got another strut insert from Bilstein in the proper body length and stroke. Some cars have really short struts (1st gen Toyota MR2 comes to mind for example), so you just need to find something with the proper insert length and OD. I went with a coil-over setup so I deleted the stock spring perches altogether. If you shorten the overall suspension travel compared to stock, you'd need to stiffen the spring to reduce the chances of the suspension bottoming out. I'm not sure about the 944, but the 924S has very soft front spring rates.

So Bob, you are saying it is really THAT easy...???

Dieter

[RallyBob]

Originally Posted by heimue So Bob, you are saying it is really THAT easy...??? Dieter

It is if you stay in a Holiday Inn Express the night before.....

[baz]

Originally Posted by jtb From another porsche or another make of car? The whole unit with the coil, I would guess? Have to keep the spring rates similar? I did a little more research, found that the 87-88 924S has all the 944 goodies (suspension, brakes, engine) in the narrower 924 body. Thanks, jtb

struts can be mixed from other uses its the rate that you need to know not the end user's name


the 924 uses an audi van engine btw and is not that light an engine at that

[RallyBob]

Originally Posted by baz struts can be mixed from other uses its the rate that you need to know not the end user's name the 924 uses an audi van engine btw and is not that light an engine at that

Baz, I don't know if you guys got it over there, but the US-spec 924S had the complete 944 driveline (2.5 litre Porsche engine included). As mentioned it was a two-year run only. It was quite different mechanically from the earlier 2.0 litre Audi-engined 924.

Something about the narrower, more aerodynamic (and cheaper) 924S being able to outrun the 944 made them cancel it!

[RallyBob]

I found a site that lists the front spring rates as follows:

Early type 924, 140 lbs

'82-'84 944, 160 lbs

'87-'89 944 and 924S, 2946 N
(M030 optional) 3050 N

Not sure of the actual nomenclature or conversion for that!

[jtb]

Wow! Thanks for the replies!

I expected people to say things like "what would you want to do that for?" or "that's way too much work, it's not practical".

As I mentioned, it's mostly the suspension and brakes from the porsche I'm interested in, although the rear transaxle is a nice idea for weight distribution. I could be convinced to use a different engine...

jtb

[oppositelock]

Originally Posted by jtb Wow! Thanks for the replies! I expected people to say things like "what would you want to do that for?" or "that's way too much work, it's not practical". jtb

Well, I tend to agree with both of those statements, but don't let that stop you! I've been known to partake in some crazy projects myself...

Some more measurements from the 944 that may be helpful:

-Centerline of front strut top mounts, distance apart: 37 inches.

-Rear torsion bar housing mounts are about 53 inches apart (width). This is just forward of the rear wheelwells.

-Transaxle case extends about 20-21 inches behind rear axle centerline. Check that rear overhang.

If it's the brakes you want then you are going to want the Turbo brakes. They are the ones with the nice 4 pot calipers. The normally aspirated 944's use a boring single piston sliding caliper, though they work well for what they are.