What size rear springs for an LS1?, worried that the 100 lb-ers may be too soft. Options

[dadaDaveed]

For brakes, I'm using PMB restored M calipers and a new 19mm MC on vented rotors front and back. I may go bigger ultimately, but I think I should try these first to see how well they perform.

For stiffening, I have the GT kit and the Engman long kit installed. No plans for anything else yet.


With 914 A-arms the smallest option I've come across is 21mm. So from what I'm hearing, maybe 21 front and 200 rear would be a good combo to start with. And then upgrade to an adjustable front sway bar up front. Sound like a reasonable plan?


@pdlightning: I was planning to use the Renegade setup, which moves the trans back some, I think. I'm using 944 CV's and a rebuilt 901 box with a flipped H.

[Andyrew]

Yes that sounds like a good combo, but from your first post it sounded like you were going to keep everything else stock... Which is why I suggested 140's....

However I would still say stick with stock A arms and just have the upgraded sway bar up front...

[andys]

These characteristics were not the problem of the suspension I used but because the engine gave a higher center of gravity that the stock -4 or -6 engines.

IMO, this is where the fundamental handling issue lies. The high rear CG plays havoc with weight transfer when trying to get the chassis to handle on the track. Rear spring rates need to be pretty high, and a rear sway (given you have LSD) will help settle down the rear. This of course is only part of what's necessary for the track.

The OP is building a street car, so ride comfort would be the preferred goal (if it were me), along with decent stability and balance. His proposed starting point seems reasonable (in post #21). If there's a trait he doesn't like, he can make subsequent changes.

Andys

[dadaDaveed]

Initially, I was hoping to keep the stock front to save some $$. But, it sounds like I need to go more aggressive.

Considering the significant added horsepower, weight, and the higher CG, I'm leaning towards the heavier 21/ 200 combo and adjustable sway. I want the ride to be firm and sporty but reasonably comfortable. Of course, comfort is a relative term. For perspective... I'm 33, lean and fairly fit. And let's face it... this car is all about going fast... so if the ride is firm (but not harsh) I'll be very happy.

Thanks for the input guys! (IMG:style_emoticons/default/beerchug.gif)

[jimkelly]

renegade no longer sells heavy duty springs.

they offer something like this now.

http://www.ground-control-store.com/produc...ption.php/II=76

jim

[andys]

Dave,

If you wish to keep expenses down and use the stock front (with 911 brakes/5 lug/sway), I don't see much issue with this. Now perhaps some may disagree, but the stock torsion bars should be adequate for the street (and give you a better ride)........there's that comfort thing again, but I am twice your age so it figures.

Andys

[jmmotorsports]

When I first built my car with the SBC I ran 21 mm torsion bars. 22 mm sway bar and 200 lb springs. When I put the LS1 in,I changed the rear to 180,front back to stock torsion bars. Still have the 22 mm sway in front with a stock bar in back.
This setup works for me for street and the 2 or 3 autox I do a year.

Jerry