Ground Control (Group Purchace List) Very close!

[DILLIGAF]

Randy has to wait a day for coupon offer to start.

[calicadi]

Originally Posted by wildwhl

Close-up pics of the magic spacers please

WW

Here ya go. About 1" OD, 5/8" ID, and 1/2" height.

Oh and Post Script on missing parts. Got a phone call from Stan and the confirm from UPS. Missing items on the way. Should arrive tomorrow. Many apologies from GC staff. No big deal to me. Can't install 'till next weekend anyway. So as Shakespere says... all's well that ends well. Next stops; Chevy dealer for Z06 endlinks, then installer.

[wildwhl]

Thanks CC!

WW

[Venomous-V]

Are we still in agreement on the 500/550 for daily drivers with fe4 and fe2?

[StealthV]

The four spring choices are -

1. Street Performance
2. Hot Rod Caddy (+10%)
3. Track Day/AutoX (+25%)
4. Call...

What do the four choices mean in lbs/in?

1. 400/400 stock?
2. 450/500?
3. 500/550?
4. custom

When I was professionally building cars and racing, our chassis setup baseline was to use the lightest spring rate we could to the point of preventing the chassis from bottoming out on the particular track. Let the shocks with proper comp/rebound and sway bars do their thing to maintain the tire contact patch. Fine tune the balance with a little wedge or lead weight positioning.

The higher +50 lb/in rear rate I can see to free up the balance but stepping up 100 lb/in across the board from there I need help with to make the spring choice. Since making sparks with the frame rails hasn't been a problem on the V, what is the advantage for a V going to the higher spring rates beside making the chassis more susceptible to surface imperfections? Seems like going with a light(er) combo of springs (400/450 or 350/400), FG2 shocks (revalve?) and custom (or adjustable/interchangeable) sway bars would be a better ulitmate path to get that last 10% of suspension performance over factory?

If the higher +100 (500/550) package is for roll control, wouldn't it be better to focus on the shocks and bars for that and use a lighter spring package to better maintain ride quality and putting the power to the ground with 450+ hp at the rear wheels? To come up with the 500/550 were the suspension/FG2 shocks dyno tested or is it an experienced ballpark with one customer, Wildwhl, w/ a Maggie and wider than stock rear wheels/tires saying "...handling...quite well."?

Springs are cost effective, maybe I'll just order a bunch of differet rates.

[jm3]

Here is some info, just to make it more complicated:

The springs for "street performance" and "hot_rod" were not priority selected for handling specifically. It is very easy to make the Caddy handle great, but not ride good. Very very easy in fact. So, within the big window of springs that make the CTS-V handle better, we gravitated toward the pairs that gave the best ride by keeping pitch to the absolute minimum.

This is the "ride frequency" that you read about. So... you type that phrase into google, and see a bunch of "should be x.x Hz" and "optimal". Well guess what? All that crap goes out the wiindow when you actually drive instead of fiddling with your laptop.

That is the reason for our changing springs so many times on Zeemers car, and ending up completely different from where we anticipated. The inner ear is mightier than the silicon chip!

Not the first time that has happened, and certainly won't be the last.

The Track day /Auto-x kit is prioritized for handling over ride incidentally.

disclaimer: intentional spelling misatakes are to avoid embedded links.

[StealthV]

You sold me - Dreamin and GC know more about making a V handle better than I do.

One big dog kit ordered.

[stkshkr]

Would there be any benefit for drag racing with this kit? i.e. weight transfer from front to rear? If so what spring rate.
OK guys...I know....try the curves yada yada but I really would like some hep with the launch

[99m3]

My car has the stock shocks but CCW, 9.5 inch wheels, would ths have any impact on the kit I order?

[wildwhl]

Originally Posted by StealthV

The four spring choices are -

1. Street Performance
2. Hot Rod Caddy (+10%)
3. Track Day/AutoX (+25%)
4. Call...

What do the four choices mean in lbs/in?

1. 400/400 stock?
2. 450/500?
3. 500/550?
4. custom

When I was professionally building cars and racing, our chassis setup baseline was to use the lightest spring rate we could to the point of preventing the chassis from bottoming out on the particular track. Let the shocks with proper comp/rebound and sway bars do their thing to maintain the tire contact patch. Fine tune the balance with a little wedge or lead weight positioning.

The higher +50 lb/in rear rate I can see to free up the balance but stepping up 100 lb/in across the board from there I need help with to make the spring choice. Since making sparks with the frame rails hasn't been a problem on the V, what is the advantage for a V going to the higher spring rates beside making the chassis more susceptible to surface imperfections? Seems like going with a light(er) combo of springs (400/450 or 350/400), FG2 shocks (revalve?) and custom (or adjustable/interchangeable) sway bars would be a better ulitmate path to get that last 10% of suspension performance over factory?

If the higher +100 (500/550) package is for roll control, wouldn't it be better to focus on the shocks and bars for that and use a lighter spring package to better maintain ride quality and putting the power to the ground with 450+ hp at the rear wheels? To come up with the 500/550 were the suspension/FG2 shocks dyno tested or is it an experienced ballpark with one customer, Wildwhl, w/ a Maggie and wider than stock rear wheels/tires saying "...handling...quite well."?

Springs are cost effective, maybe I'll just order a bunch of differet rates.

While I can't answer all your questions, I do want to point out that:

I tried the 500/550 rates with both FG2 and FE4 shocks, with both stock width tires and widened rears (GSD3's) as well as winter runflats. The 500/550 were much, much better with the FG2's than the stock springs, however, with the FE4's (or the supposed FE4's that are still in question) the match wasn't nearly as good.

I suspect slightly lighter rates or heavier rates could be more optimum for certain situations, but I'll rely on the experts and the rest of this forum to figure that out. I've had the suspension out of my car somewhere in the neighborhood of 50 times now, without a lift, or airtools (usually). I'm leaving it alone

Just my .02

WW

[Venomous-V]

so just when i thought i was gonna die if this kit never came out, I find myself more confused about what spring setup to go with and cant order! I thought everyone was set on the 500/550 and now there seems to be lots of questions and everybody who was interested before is all hush hush now. whats the deal? I'm counting on the experts and testers for some real life answers here. I have fe4's and i dont want to sacrifice handling most importantly. Second i dont want to sacrifice ride quality much. HELP!

It's a hard driven daily driver with twisties and straights.

[wildwhl]

Dreamin can answer the FE4 question with certainty.

WW

[calicadi]

Originally Posted by Venomous-V

so just when i thought i was gonna die if this kit never came out, I find myself more confused about what spring setup to go with and cant order! I thought everyone was set on the 500/550 and now there seems to be lots of questions and everybody who was interested before is all hush hush now. whats the deal? I'm counting on the experts and testers for some real life answers here. I have fe4's and i dont want to sacrifice handling most importantly. Second i dont want to sacrifice ride quality much. HELP!

It's a hard driven daily driver with twisties and straights.

Of course mine is not installed yet but here's my rational on rate choice and thoughts for your decision. The +100 makes sense to me in order to optimize AutoX and Track Day action. I sacrificed some ride smoothness to go with the FG2s and am willing to sacrifice slightly more to gain superior stability in high performance situations. Being able to lower the car for a lower center of gravity is also a big reason I'm picking up the kit, regardless the spring rate.

If you enjoy the ride quality of the FE4s and are looking primarily to lower the stance and slightly tighten the feel, I'd buy the kit and go with the 400/450 rate. Drive it for a year to understand the difference in handling through all four seasons. After that, if you think you could tolerate more stiffness (go ahead Florian, I gave you another great straight line!) buy the 500/550 set. The springs themselves are relatively inexpensive (see Stealth V comment above). And you could probably sell the 400/450 set here on the forum if you decide the stiffer set suits you best.

[Florian]

Originally Posted by calicadi

if you think you could tolerate more stiffness (go ahead Florian, I gave you another great straight line!)

Too easy....but thanks for the softball! BTW, Ill be ordering up next week.....

ALL GOOD!


F

[99m3]

I just talked to Stan and I'm ordering my springs today, Stan was a lot of help and I can't wait to get my kit. I'm going with the 500/550 or street performance.