65 GTO LS1 QA1 spring suggestion

[crustysack]

I drove my 65 GTO for the 1st time on monday and the front is way to stiff. I have installed 2" drop spindles and QA1 coil overs.(Global West control arms)If I dial up the springs so the front tires do not rub I have about 2" of shock thread exposed on the bottom of the shock, and the ride is very harsh.The shocks are set to the softest setting(single adjustable) Does it make sense to get a longer spring with a lower rate?? and can anyone who has done a similar conversion(on any a-body) tell me what they are running and how their ride is. This car is going to be a daily driver and not taken to the track.Thanks

[bret]

I happen to be driving this car for the last week or so http://www.ridetech.com/garage/1966-chevelle/

I have LOTS of seat time in this car...nearly all of it with ShockWaves. We recently fitted our new coilovers on this car. I have to admit...it rides at well as it did with the Shockwaves. Even I am impressed!

Here is a link to the tech end of things:
http://www.ridetech.com/store/suspension-systems/?subcats=Y&features_hash=V253.V40

Our control arms have a dropped lower mount that allows us to use a bit longer shock offering more wheel travel. The monotube design does an extemely nice job of controlling the car...better than nanything we have used yet.

You will not be disappointed.

[crustysack]

I'm sure your products are nice, but if you read the thread I'm looking for a spring replacement, not to drop $3500 on a whole new front suspension. If as president of Ride Tech you would like to sponsor me and donate a complete suspension package I would be more than happy to try your line of products, even slap a sticker on my car. If you could re -read the thread and answer any of the questions I posted with pertinent information I would appreciate that. As president it would seem you may have some knowledge about suspensions that you could enlighten me with instead of just directing me to a web page to buy new stuff. No where in any of that does it state what spring length and rate you are using. Looking forward to a reply with some information

[dhutton]

Crusty, there is a pdf from Chris Alston here that tells you how to calculate the required spring rate to allow proper shock height:

https://www.pro-touring.com/showthread.php?69444-Broken-Varishock/page2&highlight=

I think shocks may have more to do with ride quality than spring rate. But for a starting value I run 550 lb springs on my AME subframe with an LS1. I also used the pdf above to arrive at a spring rate for my G-Bar that gives the correct shock height.

For what it is worth I think running with a lot of preload on a coilover spring can lead to poor ride quality but I have no analysis to back that up, it is just my observation.

If you read the entire thread that I posted you will find out what happened when I ran a longer spring with a lower rate...

[Chad-1stGen]

If I dial up the springs so the front tires do not rub I have about 2" of shock thread exposed on the bottom of the shock, and the ride is very harsh.The shocks are set to the softest setting(single adjustable)

Crusty, When you say you dialed up the springs to prevent the front tires from rubbing, is that to prevent rubbing when the suspension is compressing over bumps or to keep the tires from rubbing at ride height? It sounds like you have possibly preloaded the spring an excessive amount to prevent rubbing when the suspension compresses. Doing such a thing while leaving your adjustable shocks at the softest setting is contradictory. Assuming your spring rate isn't totally out of whack, the shock is going to do more to prevent the suspension from excessively compressing and causing tire rub than the springs. Try increasing the rate of the shock.

[bret]

I'm sure your products are nice, but if you read the thread I'm looking for a spring replacement, not to drop $3500 on a whole new front suspension. If as president of Ride Tech you would like to sponsor me and donate a complete suspension package I would be more than happy to try your line of products, even slap a sticker on my car. If you could re -read the thread and answer any of the questions I posted with pertinent information I would appreciate that. As president it would seem you may have some knowledge about suspensions that you could enlighten me with instead of just directing me to a web page to buy new stuff. No where in any of that does it state what spring length and rate you are using. Looking forward to a reply with some information

If you scroll down that page a bit you will find a coilover package starting at $550/pair instead of the $3100 full car package. We use a 4.1" stroke shock with a 550 lb spring for that chassis with an LS engine

While our springs are likely compatible with your current shocks, I won't pretend that will fix your problem... It might just uncover more problems. If you use a control arm/coilover/spindle package that is designed to work together, I KNOW I can fix your ride quality problem.

With one caveat...do not set your ride height just to keep the fender off the tires. The suspension/coilover/spindle package has an intended ride height, within a window of around 1/2" in either direction. The farther you deviate from that intended ride height the more the performance is compromised. [perfromance defined as ride quality and/or cornering ability]. Set the appropriate ride height of the car then make sure your wheels and tires fit.

Don't automatically dismiss the information you see on our website. It was developed through years of experience with both components that worked and ones that didn't. I think the main point is to attempt to solve the problem, not just treat the symptom[s]. Lots of things affect ride quality. Some are easy to fix...some are expensive.

[crustysack]

Crusty, When you say you dialed up the springs to prevent the front tires from rubbing, is that to prevent rubbing when the suspension is compressing over bumps or to keep the tires from rubbing at ride height? It sounds like you have possibly preloaded the spring an excessive amount to prevent rubbing when the suspension compresses. Doing such a thing while leaving your adjustable shocks at the softest setting is contradictory. Assuming your spring rate isn't totally out of whack, the shock is going to do more to prevent the suspension from excessively compressing and causing tire rub than the springs. Try increasing the rate of the shock.

I have dialed up the shock to avoid rubbing at ride height-looking last night the exposed amount of lower shock is 8 shock threads( about 1 1/2")I will adjust the shock. That makes sense that the shock is to soft and no dampening is taking place just riding on the spring.
Don, thank you for the pdf chart that is the kind of information I am looking for.
Bret, thanks for the spring rate and shock stroke. I will try and tweak my system to get a comfortable ride since I believe the package I got IS suppose to work together.
I will do some experimentation this weekend and get back to you.
Being a beginner at this I appreciate all the information. As with a lot of things on this build its just getting the right info from more experienced people than myself. :cheers:
Scott

[crustysack]

Well my new rear springs came in, installed those. Dialed the shock springs up 2 more threads and set the shock adjuster to the middle (+5 clicks) and she rides great. firm but not harsh at all. the shock seems to be doing its job fine and the spring rate seems perfect now. thanks for the helpful tips