Jims79

After going through all the threads on suspension I decided on 460lb front coils, bilstien shocks and a 330 mono spring in the rear. Then I read that members had trouble w/the TRW spring making the car sit to high and to lower it they used 10" bolts which came to close to the side wall on wider tires???? Also the heat of the exhaust pipes w/the wide TRW spring is a concern.

Should I send the TRW spring back and get one from VBP? I like the look of the narrow VBP spring & from what I read the car sits at the correct height level w/the VBP Mono. But I also read that their spring is not as good as others and it comes w/a five yr warrenty and others are life time.

What do you guys think.

vettfixr

I installed a 340 lb. TRW spring years ago when my steel spring decided to break while negotiating a dip in the road. Luckily I was going slow so no further damage occurred. My car sits fine with the mono spring but as I said I bought mine years ago. The only complaint I have with this spring is that it has a bouncy feel to it. Not harsh or soft, just bouncy. Since that time VB&P has marketed specific shocks to compensate for this. I believe they are the KYB GR2 shocks specifically valved for fiberglass rear springs. I haven't tried them so I can't comment on their effectiveness. I have the standard KYB shocks on mine and as I said the rear feels bouncy especially on expansion joints in the road. If I were to do it again I might go with a heavier spring (360 lb.) only because the lack of friction in the fiberglass spring vs. steel leaf spring makes it feel lighter than it actually is. All in all I'm pretty happy with it and I can set it low enough to drag the pipes over dips in the road. Hope this helps.

danthony

I have the TRW and have no problems with it. I had the bouncing issue with the KYB's as well. I recently installed some Koni's and it's worlds better. The car is so much easier to control at high speeds.

One thing to keep in mind is that the fiber springs (no matter who's it is) do not have friction like the steel springs so they will oscillate alot more.

MYBAD79

My '79 was at 29" (between floor and fender) with the 460lbs springs.... the 550lbs springs are not uncomfortable and I recommend these instead of the 460s...

1979 with 460s front and 6"bolts (rear):


.

same car about 18 months later with 550s front and 8" bolts (rear):


.

I'd buy all the suspension stuff from VBP, they have a very good reputation

Kid Vette

Just depends if this stance looks good to you or not.

shafrs3

I've got the 340lbs spring with the specially valved KYB's. I do have longer spring bolts because the front coils lower the front end about an inch. It's been a great spring, only weighs 8lbs as apposed to 40lbs for the steel spring. No bounce with the KYB GR2 shocks.

MN-Brent

green_79

I have rebuilt the rear suspension of my 79. I am using a TRW mono spring. The rear end was at 29.5"(ground to fender well) ride height. I changed out the 8" bolts for 10" bolts. I lowered the ride height to 27.5" to conform to the factory specs. In doing so, I have a problem with the clearance between the tip of the TRW spring and the tire wall. It only had 1/8" clearance. I raised it up to 28.25" and the clearance opened up to 1/2". Of course I now have the 10" bolts hanging down below the end of the rim almost down to the street.
I was concerned about the angle that the struts and the half shafts should be. With the 29.5" ride height, I was worried about the angle being too great, thereby prematurely wearing out the U-Joints. The factory manual states that the struts should angled downwards from the rear end to the trailing arms by 2.21".
This is a bad balancing act. my question is, how can I correct this issue? Do the half shafts have a specified angles that they need to hang at? What are the rear ride height tolerances that this vehicle can tolerate before I damage something by being too high or too low? I would like the rear end to ride even, instead of being jacked up in the rear like some high school kids car.

Kid Vette

The problem is with the TRW spring manufactured by Muskegon Brake. They are notorious for jacking up the rear end because the spring has too much arch. Remove the TRW spring and install a VBP and your problems will be over.

By the way, you want your halfshafts parallel to the ground or slightly (no more than 1/2") higher in the middle than at the wheels. Anymore than that will cause premature u-joint wear.