Hi everybody, I'm an Italian owner of corvette, trans-am ( 1971 HO) and harley davidson.

I sold a 1979 L82, and now I'm restoring a 1975 L48. I made a frame off with a friend of mine, and the new engine will be a 383 stroker with alu heads performer rpm, intake manifold performer rpm, demon carburator, and other gooooooood things .
I had a problem becouse I'll use this car for drag racing here in Italy, and I wanna use all the horsepower I have.
To do this I'm looking for rear&front end suspension.
For the front end I'd like to put the QA1 coil-over code GMP44.
The rear end is the probem..... I've seen Guldstrand rear suspension with parallel upper and lower links, and I'd like to know from you if anyone has utilized this (G02-300) or there's something like that for sale complete with coil-over.

Thanks
Andrea

 

Well, nobody has knowledge about this thing ?

I don't believe so........

 

add to your title because i know people here will know something.

 

Sounds good.
Coil overs are not needed for the front- that's an easy way to add coils.
I like the parallel upper and lower links rears, however haven't done it nor have I seen anyone on the forum w/ it.

 

Sounds good.
Coil overs are not needed for the front- that's an easy way to add coils.
I like the parallel upper and lower links rears, however haven't done it nor have I seen anyone on the forum w/ it.

 

if its going to be a drag only car, forget all that garbage and tub the car with a solid axle.

 

Hello,

I sure hate to sound rude but a 1975 L48 is hardly the best base for a race car.

Anyway, regarding your suspension questions - I am a big fan of Vette Brakes & Products: www.vbandp.com

I am sure they will be able to offer you good advice, although I would suggest phoning them rather than email.

 

Somebody on this board had a Gulstrand 5 link rear suspension for sale for $1600.
Bee Jay

 

Ouch... Does any vette deserve that fate


Remember
"Dont crush them restore them"

 

I agree with you, but he's right about if its only going to be a drag car, a straight axle is best, but i applaud his efforts in trying to keep a vette a vette.

 

Hi Andrea, sounds like a fun project. Will the car be set up just for drag racing or will it occasional race car but mostly a street car? Your engine sounds like a nice street motor, you don't have to be worried about your stock IRS with that.

As for the front you have been eyeing for the QA1's, right? The GMP44 is for big block cars, with the small block topped with aluminum heads that might not be the best solution. You might want to consider the GMP43 which is designed to be used with small block. Those are both semi coil overs, would you consider going for full coil over set up with tubular a-arms? Here's my front suspension:



As for the rear I'm currently installing Guldstrands 5 link set up. It requires a lot modification to the frame to make it right. The Biggest problem is the upper strut rods, which do hit the frame where it makes that bend just above the trailing arm pocket. I did cut the whole section out and build it much stronger while I was at it. Dick says he can do it in few hours with the body of, I'm sure he can, but IMO if you want it to be as strong or stronger than the stock frame is you'll have to modify it more.

Here's how it looked before the "surgery" the upper struts are hitting the frame.


Here you can see how much I removed off the frame.


Here you can see how much the frame needs to be widened.


I have now finished the widening bit on both sides, next I'll have to start working on the bit where the control arm bracket mounts to.

 

Heidt's Hot Rod Shop (heidts.com) sells an independent suspension built around a Ford 9" centersection using 1350 u-joints. As you probably know the Ford 9" is one of the favorites for drag racing .... lots of companies make upgrades to the centersection (aluminum housings, bigger bearings, aluminum yokes, spools, stronger gears, ..... the list goes on and on and on). It mounts to a custom crossmember that would have to be welded into your frame, but next to a solid axle its probably the strongest way to go (even if it is a little expensive ~$4k).

 

thanks everybody for the answer

@ groovyjay, you're right, I'll use the vette ALSO for drag race( for fun of course), but mostly like a street car. For this reason the engine is 383... IMHO is the best configuration for drag and steet car.
I like your front end, you made it or is a kit ? For the coil-over, the gmp44 is for SB ( pag 52 QA1 catalogue).

I've a lot to study about this things, so thanks again for your support !

Andrea

 

The QA1 catalog shows it wrong, friend of mine ordered those for his BB 77 and he got a call from QA1 telling him that they had listed the product numbers wrong way around and the GMP44 is indeed for BB and GMP43 is for SB. I got the front suspension from JMRP.

 

Wow Jay, that's some serious cutting required for a kit that bolts in w/ "minimal welding'. How long are those trailing rods that the kit uses? I thought they were 20" I've seen some installs of the kit and have never seen anyone having to cut out the frame like that to clear the upper trailing rod. Only have seen where they removed the underside of the frame to stretch the pocket on the upper side.

My arms are shorter (if I remember correctly they're 16" rods) but it sure bolts in easy without any major modifications (have to plate over the little notch that is cut into the side, it's for access to the bolt and will be plated over w/ a section that has an access hole in it)

 

geeeeeeeeezzzzzzzzz when you guys do suspension upgrades you go all out.

 

I have said it before but I say it again, I really like you set up better over the guldstrand set up. I have all the measurements in the shop, will go there again tomorrow will check them then.

This pic illustrates how much cutting is needed to get enough clearance for the upper control arm:



Reason I took "a little" more off the frame was that I wanted to make it stronger than stock and somehow keep it look "stock". If I were to cover up that small cut seen in the pic above I would have needed to make bulge type of piece to cover it. I chose to cut out more and start shaping the whole thing so that doesn't have that bend anymore. Like so:

 

Great Looking job so far !

Are you going to use the QA1s with the stock A-Arms ?

 

You're right. A 2006 Z06 is the best base for a race car.

Sorry, I had to.

 

If you are refering to me, I'm using the JMRP A-arms with the QA1's.

Here's couple of shots how the frame looks now:









I still need to tidy things up here and there before the frame is ready for paint, but I'm getting there!