'79 Rear Spring

[Bob_K]

I called VBP today to decide on my new suspension setup. We decided that I either need the Grand Touring Plus package, Poly Front End Rebuild Kit, and Rear Poly Bushing Kit or the Performance Plus system. I really like the features of the Perf Plus package and even talked my wife into allowing me to consider it. As part of my decision I crawled under the car to look at the condition of my A-Arms hoping to find out that they needed replacement anyways so the decision would be made for me. As I was looking, I noticed that my exhaust pipes run within about 1" (maybe 2") from the rear spring. The salesman today said there should be 3" clearance to keep from damaging the spring. The car has an aftermarket exhaust from a previous owner so I looked in my Haynes manual to see the stock configuration. The only picture that I saw showed a similar arrangement. Are the pipes supposed to be that close? Would I be able to use a heat shielding wrap in that area to protect the spring? This is very discouraging since both of the packages I like use a composite spring that will get damaged by excessive heat. Also, any input on the GT Plus and Performance Plus packages is welcomed.

 

[Bob_K]

Sorry, I started looking at the GT plus. The VBP guy told me I'd be better off with the Street & Slalom. Doesn't surprise me, I want to feel the road more, otherwise I'd drive a Caddy. My other choice is still the Performance Plus.

 

[Fishman]

My 78 has a new metal spring (my mechanic recommended against the composites, but do as you please) and brand-new suspension. I just rolled under the car and measured about 1" on both sides. I did not notice any marks on the pipes or heat scars on the spring. I don't know how your going to get 3"... or how that will make the car look different from behind. So, good luck on the heat shield idea.

 

[Bob_K]

The more I look the more I think I may be headed towards that same steel spring. That would mean I'd save $500-$1000 on my suspension system, since it doesn't make sense to me to go all out with a steel spring. I'll still go all poly bushings and front end rebuild kit, but my main suspension pkg would have to be the grand touring then. I'm not sure if I like that idea but I don't see amny options (other than side pipes, which I couldn't get away with...stupid emissions). On the brighter side it would help pay for the AFR heads that I'm trying to justify to my wallet. I guess it will probably depend on what other ideas people can come up with. As for heat shielding, I found an adhesive backed blanket rated for temperatures up to 2000 F in Jegs that isn't too expensive. If I wrap multiple layers it may provide enough protection. It says it reflects 90% of radiant heat. I would think that would be enough.

 

[Fishman]

The more I look the more I think I may be headed towards that same steel spring.

great, then you won't need

2000 F in Jegs

... whatever that means. :Silly

 

[Bob_K]

The insulation is rates to 2000 degrees, so it shouldn't catch on fire. I was thinking if I put one layer on the exhaust and one layer on the spring I should be OK. That way even if one gets damages my spring should still be protected. I'll probably end up calling the VBP guys today to see what they think.

 

[intex99]

I was thinking of the composite spring myself and have been wondering about the heat shield problem as well.I would think the manufacturers would have done something to fix a heat problem if they are building them for Corvettes with exhaust that close to them.
Has anyone figured out a way to solve the heat problem yet??
I have also seen on these posts that alot of guys are using KYB shocks!Which would be better the regular KYB or the KYB G2's??
Should the front be changed at the same time as the back or wouldn't that matter??

 

[groovyjay]

Hi Bob, when I did my first suspension rebuild on my 79 I went with the GT kit from VB&P. I must say it made a big difference over the worn out, over 15 years old, stock suspension. I went with poly bushings and big sway bars. I know that many old vette owners are keen to have lot of tirewall since it looks stock and all that, but when you do a suspension upgrade that last thing that will ruin the whole purpose of good suspenion are the tires. No matter how firm and tight your suspesion might be if you have tall tire wall you'll loost the cornering feel with the bad tires and the new suspension won't do you much good. Maybe I little sidetracked here, but it's something you might want to think about when you are shopping for new suspension, do you want it to ride and corner well or do you want it to ride like it did when it first rolled out the factory?

Any back to the topic, I was pretty pleased with the GT package overall, I did run 3" undercar exhaust and they were approx. 2" away from the composite spring, I never had any problems with it. I have seen people using ThermoTec to isolate the heat with good results. The composite leaf also saves you a lot of weight, which is a good thing in my book.

Now I have the VB&P Performance Plus kit in the same car, and I just love it to bits. It was easy to install, it's lighter than stock on both ends and the adjustability is there. I mean I can change the spring damping rate or the ride height in minutes. I know not all of us are into road racing etc, but it gives you a choice to try out different set ups on the track. And in the every day driving you can choose different set up so it won't be too solid.

IMO if you are after a good -stock like- daily driver, go with the GT kit, but if you really want to improve the suspension go with the Performance +. Also take in consideration the tire thing I mentioned, it doesn't have to be huge wheels, it can be 16" with less tire wall and hig performance tires.

FYI I think TRW makes composite springs with heat shields already inplace, so that's something you might want to look at before placing your order.

Sorry for the novel

 

[Bob_K]

I decided to get the performance plus system. I already have the rear suspension out, just working on removing the differential to get it rebuilt as long as I've got the car apart. Once I'm done with the rear then it's on to the front suspension, tranny, engine, and A/C. All I need now is for santa to drop off a few thousand dollars and I'll be set.

 

[Hib Halverson]

I've been running VB&P rear spring (either the 360 lbs/in or the 330 lbs/in) for nearly 20 years. While the company recommends a 3-in. separation, in practice, unless the rear part of your exhaust radiates a tremendous amount of heat, the distance doesn't need to be that much.

If you're worried, though, just wrap the pipes aft of the engine with Thermo Tec exhaust wrap. That will significantly decrease heat radiated from the exhaust.