Looking for springs

himself · 11-03-2009, 05:47 PM

I am running stock springs (which I think are 228#/543#) and want to experiment with some stiffer ones. I currently run R6s, so I don't think extremely stiff ones are going to work - maybe 600#/1000# at most for my test.

If anyone has some stiffer springs lying around I can buy/test, please PM me.

Thanks!

-td

Pete · 11-03-2009, 05:52 PM

I've been looking into this too and from what I've been told, a 100 to 200 # spread between the front and rear is desireable.

LVDell · 11-03-2009, 05:58 PM

On the "softer" side I would suggest a 550/700 option or if you are set on 600 up front run an 800 in the rear. On the stiffer side I would suggest a 900/1100 option. NO WAY would I run a 400# split.

himself · 11-03-2009, 07:12 PM

Quote:

Originally Posted by LVDell

On the "softer" side I would suggest a 550/700 option or if you are set on 600 up front run an 800 in the rear. On the stiffer side I would suggest a 900/1100 option. NO WAY would I run a 400# split.

I didn't mean to imply that I want to run 600/1000, rather that those would be the maximums I think my tires could support. I'm good with anything available to try: 600/800, 800/1000, 550/750, whatever

Also, why wouldn't a 400# spread be workable? The factory split is over 300# already.

-td

LVDell · 11-03-2009, 07:17 PM

A couple things. First, the 300# split isn't really a 300# split and you are looking at linear and progressive springs. Second, the 400 split would run the front really soft and the rear really stiff. Can you saw lots of oversteer?

As far as you spring choice it should be dictated by roughly three things (obviously more than this but these are the obvious). (1) driving style; (2)current dampers; (3)tire choice (remember, tires have their own spring rate).

What dampers are you running?

Pete · 11-03-2009, 07:41 PM

IIRC, the front stock springs are progressive. In addition to what Dell said, if there is a large spread in spring rates front to rear your more prone to a lot of nose dive under heavy braking.

LVDell · 11-03-2009, 07:45 PM

Pete, other way around.....the fronts are linear and the rears are progressive.

NJ-GT · 11-03-2009, 09:10 PM

600/800 for R6 and street use, not too soft, not too hard either.

I ran 750/1000 and felt too stiff for street use. I also ran 450/650, very nice for street, autoX and worked well on tracks.

Get the shocks revalved for the new springs, otherwise you're just running a stiffer car that won't work better, because you won't have enough bump/rebound control for such higher spring rates.

AudiOn19s · 11-03-2009, 11:06 PM

Quote:

Originally Posted by NJ-GT

Get the shocks revalved for the new springs, otherwise you're just running a stiffer car that won't work better, because you won't have enough bump/rebound control for such higher spring rates.

+1. If your attempting to re-spring the stock dampers you can't go more than about 10% up or down without a revalve otherwise the shock won't be able to control the spring

the spring rate question in general is a good one though. 600/800 is what Moton suggests and seems to be what most run however some very quick cars on here were running different rates than that. 171mph had 600/900, rad had 750/1000, I think I even remember one setup with more front spring than rear. Lots of variables in there though. The advertised rates on my 996 were 450/900 but I always doubted thouse were truely accurate. It was neutral but didn't try to spin out as the rates would make you think

IPguy · 11-04-2009, 02:24 AM

Does anyone have the wheel rates or motion ratios for the front and rear on the GT3? This would add some more tech to the discussion.
Mike

Chuck Price · 11-04-2009, 09:38 AM

NJ-GT,

I'm not sure what you mean. Are you saying that for street use, or for track use with R6s, you recommend 600/800? When you ran 750/1000, were you using R6s also? Which felt better to you, if that were the case?

LVDell · 11-04-2009, 10:18 AM

Depends on what your use of the car is going to be. Street more? Track more? 50/50? etc?

As another data point I have run several different spring combos on mine and the latest setup was 900/1100 and while it wasn't unbearable on the street is was definitely not comfortable any time I hit road that was imperfect.

I would run something like 550/700 or 600/800 if the car will get a descent amount of street time. As Rad said (which is why I asked what dampers you were running) you need to make sure and revalve yours if they are still stock.

Pete · 11-04-2009, 11:21 AM

From what I understand, you also have to insert a tender spring and some kind of hat or top perch?

NJ-GT · 11-04-2009, 11:35 AM

Quote:

Originally Posted by Pete

From what I understand, you also have to insert a tender spring and some kind of hat or top perch?

Optional, but really recommended to avoid noises and more important to avoid coil binding and possible strut rod damage when an unloaded wheel suddenly get loaded (transitions) and the spring hooks the bottom of the upper hat.

Reuse your stock hats, use gemini isolators (very nice stuff) and zero rate tenders (ultra thin and decently long). 60mm I.D.

va122 · 11-04-2009, 12:57 PM

remember to use the correct spring lengths. I run 6" in the rear and 4" in the front but I have custom built Motons and I'm super low. Lex at Moton recommends 6"in, he built mine personally.

run 600/800 BTW for Hooters, you can go 800/1000 but I wouldn't stand it on the street. Personal preference on the split. Lex says he likes a 300 split so people don't get in trouble...

11-03-2009, 05:47 PM	#1
himself Addict Rennlist Member Join Date: Apr 2006 Posts: 1,678	Looking for springs I am running stock springs (which I think are 228#/543#) and want to experiment with some stiffer ones. I currently run R6s, so I don't think extremely stiff ones are going to work - maybe 600#/1000# at most for my test. If anyone has some stiffer springs lying around I can buy/test, please PM me. Thanks! -td __________________ 6GT3 335i E350 --------------- 00 996

11-03-2009, 09:10 PM	#8
NJ-GT Addict Rennlist Member Join Date: Jan 2003 Location: Los Angeles Posts: 3,464	600/800 for R6 and street use, not too soft, not too hard either. I ran 750/1000 and felt too stiff for street use. I also ran 450/650, very nice for street, autoX and worked well on tracks. Get the shocks revalved for the new springs, otherwise you're just running a stiffer car that won't work better, because you won't have enough bump/rebound control for such higher spring rates. __________________ Rennlist Member #: 040525-3732 Autocross and Track Videos

11-04-2009, 09:38 AM	#11
Chuck Price Addict Rennlist Member Join Date: Jan 2002 Location: Ann Arbor, Michigan Posts: 880	NJ-GT, I'm not sure what you mean. Are you saying that for street use, or for track use with R6s, you recommend 600/800? When you ran 750/1000, were you using R6s also? Which felt better to you, if that were the case? __________________ Chuck Price 2004 GT3 White '96 Polar Silver 993 '87 911 Red

11-04-2009, 12:57 PM	#15
va122 Addict Rennlist Member Join Date: Jul 2006 Location: On Rennlist avoiding work Posts: 1,784	remember to use the correct spring lengths. I run 6" in the rear and 4" in the front but I have custom built Motons and I'm super low. Lex at Moton recommends 6"in, he built mine personally. run 600/800 BTW for Hooters, you can go 800/1000 but I wouldn't stand it on the street. Personal preference on the split. Lex says he likes a 300 split so people don't get in trouble... __________________ Victor Nationally certified PCA instructor.

11-03-2009, 05:52 PM	#2
Pete Rennlist F1 Professor Emeritus PhD, No BS Rennlist Member Join Date: Jul 2006 Posts: 3,609	I've been looking into this too and from what I've been told, a 100 to 200 # spread between the front and rear is desireable.

11-03-2009, 05:58 PM	#3
LVDell Addict Rennlist Member Join Date: Oct 2003 Location: Wake Zone Coffee House in Apex, NC Posts: 17,443	On the "softer" side I would suggest a 550/700 option or if you are set on 600 up front run an 800 in the rear. On the stiffer side I would suggest a 900/1100 option. NO WAY would I run a 400# split.

11-03-2009, 07:17 PM	#5
LVDell Addict Rennlist Member Join Date: Oct 2003 Location: Wake Zone Coffee House in Apex, NC Posts: 17,443	A couple things. First, the 300# split isn't really a 300# split and you are looking at linear and progressive springs. Second, the 400 split would run the front really soft and the rear really stiff. Can you saw lots of oversteer? As far as you spring choice it should be dictated by roughly three things (obviously more than this but these are the obvious). (1) driving style; (2)current dampers; (3)tire choice (remember, tires have their own spring rate). What dampers are you running?

11-03-2009, 07:41 PM	#6
Pete Rennlist F1 Professor Emeritus PhD, No BS Rennlist Member Join Date: Jul 2006 Posts: 3,609	IIRC, the front stock springs are progressive. In addition to what Dell said, if there is a large spread in spring rates front to rear your more prone to a lot of nose dive under heavy braking.

11-03-2009, 07:45 PM	#7
LVDell Addict Rennlist Member Join Date: Oct 2003 Location: Wake Zone Coffee House in Apex, NC Posts: 17,443	Pete, other way around.....the fronts are linear and the rears are progressive.

11-04-2009, 02:24 AM	#10
IPguy Addict Rennlist Member Join Date: Feb 2004 Posts: 158	Does anyone have the wheel rates or motion ratios for the front and rear on the GT3? This would add some more tech to the discussion. Mike

11-04-2009, 10:18 AM	#12
LVDell Addict Rennlist Member Join Date: Oct 2003 Location: Wake Zone Coffee House in Apex, NC Posts: 17,443	Depends on what your use of the car is going to be. Street more? Track more? 50/50? etc? As another data point I have run several different spring combos on mine and the latest setup was 900/1100 and while it wasn't unbearable on the street is was definitely not comfortable any time I hit road that was imperfect. I would run something like 550/700 or 600/800 if the car will get a descent amount of street time. As Rad said (which is why I asked what dampers you were running) you need to make sure and revalve yours if they are still stock.

11-04-2009, 11:21 AM	#13
Pete Rennlist F1 Professor Emeritus PhD, No BS Rennlist Member Join Date: Jul 2006 Posts: 3,609	From what I understand, you also have to insert a tender spring and some kind of hat or top perch?