Just another spring rate thread.

[Bmwdayz]

When i called GC to ask them what they recommended for my car they said they had no idea and wouldn't be able to help me haha. Then I hear about all these recommendations they give people and wonder what kind of day the guy was having. :(

[djjerme]

SE30 can't use smaller springs, so they're stuck with whatever they can get by other methods,
and while they're pretty creative, -2 would be optimistic there, I fear.

You'd be surprise what a lot of them are doing to get up to 3 degree of camber. Any time you try to define a box, you know some one is going to find a way to make that box a little larger..

[sgtskid]

I installed the GC coil over kit yesterday. It started to poor down the rain about the time I finished so I didn't get to take a whole bunch of measurements.

I cut off my front spring perches right at the weld and welded on the new perches using the old weld as a stop. The front adjusters are all the way down and the rear adjusters are up 1/4"

By looks the car is sitting about a 1/2" to 3/4" higher. I also no longer scrape going over my driveway which is a good thing.

I haven't had the chance to really play with them yet but highway driving feels great. Huge difference in stiffness but ride quality still feels good (to me anyway). I am still running the 21mm front sway bar and have the rear bar set at full stiff.

One question, how hard is the front dampening adjuster supposed to be to turn? I can't get the little knob to turn for the life of me! The rear shocks have three clicks of adjustment and I set them in the middle.

I plan on getting new tires and then playing with the car a little more. I'll update once I get a few more miles on it.


Ten miles after install

[TobyB]

Everyone has a slightly different style

Agreed- and #50 or even #100 here or there on springs makes sense. Especially as
some of us use heavy bars, and others use little, blah- de- blah.

But since this is the track section, what tends to make an E30 corner fastest
is when the front and the rear let loose at roughly the same time in steady- state
higher- speed corners. As in, both outside tires are carrying their share of the cornering loads.
The rears probably need a little reserve grip to allow forward traction, but the M20
is no torque monster, and the vector math gives you a LOT of forward bite at the cost
of little side loss, so probably not much is needed.

What makes the most sense to me is that GC is NOT accounting for added front camber.
The stock E30 is very front- grip limited due to inadequate front camber. The rears are
cambered quite well, especially when you factor in an inch or so of lowering. So they
keep the fronts soft since the front tires roll over early, and let the rears take a larger part of
the cornering load, since their geometry can handle it.
This also might go a long ways towards explaining the big difference between SE30 and PRO3 setups. PRO3 can use front camber
plates and small springs, so most of those cars have a minimum of -3.5 degrees front-
and a lot of us can get over -4.
SE30 can't use smaller springs, so they're stuck with whatever they can get by other methods,
and while they're pretty creative, -2 would be optimistic there, I fear.

I dunno. But I do know that camber on radials is stupidly critical for lateral grip,
and variances in THAT could easily explain quite a few things....

t

[Reub_e30]

..and not to forget that shocks/springs are just PART of the suspension. You still have sway bar sizing, stiffness, weight balance, tire size and pressure, brake bias..etc. setting up a competitive track car is more than just slapping a specific set of springs and coilovers on a car and going "ballz out!"

Sent from my 710C using Tapatalk

Yes that to and even the bushings being used will make a difference

[djjerme]

..and not to forget that shocks/springs are just PART of the suspension. You still have sway bar sizing, stiffness, weight balance, tire size and pressure, brake bias..etc. setting up a competitive track car is more than just slapping a specific set of springs and coilovers on a car and going "ballz out!"

Sent from my 710C using Tapatalk

[Reub_e30]

The thing is your driving style. Everyone has a slightly different style and when the suspension isn't setup for the way you drive it will fight against you the whole time. There is no correct setup because everyone drives differently. U St requires some trial and error to get the best setup. Just get some GC Coilovers and buy a few different spring rates, then stick with the ones u like the best.

[sgtskid]

Looky what came today! :devil:

[JRKOUPE]

buy my V plates brand new..never used...

btw..GC has many many folks that love them.....they've done right by me...but still so many no likey

[BlackbirdM3]

I drove a friends M3 with the Ground Control setup and the thing was nervous and twitchy. Even though at the time my car was WAY undersprung, it had way more grip and poise. I'm not sure what springs he had, but the car did not feel settled at all.

I have to admit, I'm not impressed by GCs parts. I have "race" camber plates and not only are they too short, but the contact the tops of the spring hats, and one of the mounting studs pulled through (I have since replaced all the studs and welded them more securely.) I think in the not so distant future I'm going to pick a set of the Vorshlag plates up that are the correct stack height.

Will

[TobyB]

I am puzzled, too-
Bob Mearns' car, which I pretty much copied as a starting point,
has had 600f/700r springs since HE bought it back in 2005ish.
I've driven it half a dozen times, in sprints and enduros. Portland
and Seattle. It's a well- balanced car- if anything it tends towards understeer when
overdriven.

And yet, when I went to 600/700 on mine, I couldn't keep the arse behind me at Portland. At all. 650/700 was a band- aid. I've tried different bars, no bars, fern bars,
and while things do change as you'd expect, I keep coming back to about a #100 split
front/rear.

I expect others do run stiffer rears (800+) but also pretty stiff fronts.
Then again, I'm usually towards the back of the pack, so I never get
much of a chance to look...

t

[JRKOUPE]

this has puzzled me:

Gc has been selling the 350/500 450/600 , 500/700 etc etc faw ever.....yet Toby , who I trust feels its way too biased toward oversteer...

yet again the J stock has big rear ward bias, always has...and folks love it...always have.

I bought, and am currently selling ( never instlld it) 525/700 gc set up.....

I have a friend w/ lotsa track time that runs TCK 600/600 and he looooves it......

so..Im puzzled

and a lot of pro 3 runs huge rear springs, no?..like 800?

[matthugie]

My experience is rather similar to Will's. I tried a few different setups but the Turner J-stock setup I had on my e30 was also by far my favorite. I was running with a 21mm front sway bar and the rear unhooked, and according to my TraqMate was pulling a peak lateral force almost 1.5g on 235 width NT01's.

[BlackbirdM3]

I installed a set of Turner J Stock springs on my M3 late last year. I figured it was going to be way too stiff. I was wrong. They are perfect. 640/1080 springs. The car came with (I think) Koni sport springs with Bilstein front struts and Koni rear shocks. It was too soft, and the damping rates didn't work well together. Went to TC- Klein revalved Koni Sports front and rear, the suspension was WAY too soft and too low. Replaced those springs with what (by the part number on them) I thought were H&R race springs with the TCK Konis, also way too soft, bottomed over everything. Went to Bilstein Sports thinking the Spec E30 setup should be very good. Still way too soft bottomed over everything as well. Installed the Turners and life was good. Currently running the J stock springs with the TC Klein Konis and the car is amazing. Running a UUC 25mm front sway bar with the stock rear. The car is very neutral, very planted and predictable. Turn in is crisp and precise. No more bottoming out pulling into the garage at 2 mph. There is very little body roll as well. Ride quality wise, its firm but not harsh. (The H&R race springs were harsh, and the sport springs before those were even worse as they would blow through the travel and bottom out hard.)

Will

[sgtskid]

The anticipation is brutal. Like the jeopardy theme song on continuous loop. ......