steering and suspension Spring Rate Poll

[Mr Sizzle]

what would you suggest tim?

300 front 350 rear?

[FB73tii]

Interesting that most here use stiffer rear springs than front. When I first set up my car I followed Jeff Ireland's suggestions and it has worked for me:

2002 Racing Suspension
http://www.bmw2002faq.com/articles.html/_/technical-articles/racing-and-safety/2002-racing-suspension-r13

 

I now have 7" 425lb front and 8" 350lb rear. Found best deal on SSS 5" springs at pitstopusa. Sway bars are 22mm hollow front and 22 solid rear, adjustable camber front and rear, of course.

 

Fred '69 & '74tii

[M3M3]

as you know, the actual spring rate seen by the wheels is different than the rate of the spring.  springs are mounted inboard in the rear, so to have the same effective rate front and rear, the rear must be higher rated springs..

 

but, so many other factors are in play with sway bars, tire type, car weight, track, etc that no one spring rate combo will be perfect for everything.

 

while i was using 400 rears, i just jacked it back up to 450.  why?  car was "falling over" in the rear due to the lower effective spring rate.  when one end is lower, it will compress more causing  the inside diagonal wheel to go airborne.  in my case the inside front wheel was seriously airborn in turns.  adding rear sway did not get it under control, now trying more spring.

 

and this issue did not show itself on toyo r888's.  only appeared when i dialed up the tire a lot with hankook 214's.  more grip, more load transfer, more need for different suspension setup.....everything is a variable, that is what makes suspension tuning fun, and the ability to dial in a car so critical to going fast.

[2590402]

To bring back an older thread, i have been looking at getting new springs. I Know SSS makes standard 5" spring in any rate, but has anybody looked in to the swift spring? Im going to go with 450 in/lb for the rear. In the front I'm going to be running 8" 400 in/lb springs. I have Korman sway bars, the front is a fixed 22mm and the rear is 19mm adjustable. Im going to set that on the softest setting. Just my 2 cents.

Andrew

 

Edit: The car is going to be a street/track, mostly DE days etc. 

Edited August 6, 2013 by 2590402

[M3M3]

race springs are a commodity.  if the free length, diameter and rate are the same, does not matter who makes them.

 

the difference lies in the accuracy of the spring rate specified and how close to the same a pair are.

[2590402]

Thats not really true....

 

http://www.northamericanmotoring.com/forums/suspension/157535-swift-springs-dynoed.html

 

This is one of many threads out there comparing "Race" Springs with Swifts, and they all seem to have the same type of report. The Swifts seem to be much more linear, with each inch of compression the rate remains within a couple %. Its kind of a long read but worth it. These seem to be the best out there right now (lighter, more stroke, more consistent compression).  I will report  my experiences. 

Edited August 7, 2013 by 2590402

[Honolulu]

An acquaintance who has raced at a high level had a math wiz do a vibration analysis for a 2002 setup while preparing for the Nelson Ledges 24hour race. He wouldn't say exactly what the conclusions were, other than to comment that stock was surprisingly close.

I realize this doesn't contribute a data point, and one mans ceiling is another mans floor, but it could be something to consider. I also don't know what his shock Dino was saying.

[2590402]

I'm really interested, I'm just trying to figure out what you mean by stock was very close. Maybe some context would be helpful...

[M3M3]

Thats not really true....

 

http://www.northamericanmotoring.com/forums/suspension/157535-swift-springs-dynoed.html

 

This is one of many threads out there comparing "Race" Springs with Swifts, and they all seem to have the same type of report. The Swifts seem to be much more linear, with each inch of compression the rate remains within a couple %. Its kind of a long read but worth it. These seem to be the best out there right now (lighter, more stroke, more consistent compression).  I will report  my experiences. 

 

please reread my post......second sentence....

race springs are a commodity.  if the free length, diameter and rate are the same, does not matter who makes them.

 

the difference lies in the accuracy of the spring rate specified and how close to the same a pair are.

[2590402]

If the condition you placed was accuracy, and all springs are the same, but swifts are more accurate by a large amount, are all springs equal?

[tjones02]

Woof! Like a barking dog, this is going nowhere.

[2590402]

I agree. I was simply pointing out that there are options that may gain a more consistent setup.

Edited August 7, 2013 by 2590402

[jrkoupe]

this is going to be a harsh daily/weekend warrior, so im thinking a 300F 350R,(im not too worried about the ride, i had a e30 with a 1,000lb rear, daily)

1000 on a daily?..

 

I have an e30 set up for track days w/ HR race sprgs.....about 550 rear........I cannot fathom driving to the Glen (( I drive to events) w/ a rear rate about double my current rate....yeooow.....

[ClarenceTE72]

Thats not really true....

 

http://www.northamericanmotoring.com/forums/suspension/157535-swift-springs-dynoed.html

 

This is one of many threads out there comparing "Race" Springs with Swifts, and they all seem to have the same type of report. The Swifts seem to be much more linear, with each inch of compression the rate remains within a couple %. Its kind of a long read but worth it. These seem to be the best out there right now (lighter, more stroke, more consistent compression).  I will report  my experiences. 

 Hello,

 

To bring back this old thread.

 

I'm currently planning on doing a coil over setup with swift springs. I wanted to ask what was your experience with the 2002 and what spring rates are you running>? Is your car a race car or street car? I come from a japanese car background so I'm new to suspension setup on an 02. Though tuning is specific to driver, I'd like to get an idea of what I'm getting myself into to decrease the trial and error process.

 

I also wanted to ask if anyone was running helper springs in their coil over setup also as I'm planning to add them.

 

Thanks!

Edited January 14, 2015 by ClarenceTE72

[danco_]

 Hello,

 

To bring back this old thread.

 

I'm currently planning on doing a coil over setup with swift springs. I wanted to ask what was your experience with the 2002 and what spring rates are you running>? Is your car a race car or street car? I come from a japanese car background so I'm new to suspension setup on an 02. Though tuning is specific to driver, I'd like to get an idea of what I'm getting myself into to decrease the trial and error process.

 

I also wanted to ask if anyone was running helper springs in their coil over setup also as I'm planning to add them.

 

Thanks!

 

What shocks and strut inserts do you plan on pairing with the springs? Do you intend on lowering the car past the point of proper damping of the bmw 2002-specific Bilstein offerings?

 

And what is your overall goal for the car?

 

What swaybars do you have, and what size/make/model tire do you plan on running with this setup?

 

 

 

Like Marshall mentioned above, too many variables in play to give you one difinitive answer. 

 

Logic would dictate that you want a stiffer spring in the rear, but that is subjective to the other variables I ask about above. 

I'd much rather control oversteer than understeer. 

Edited January 14, 2015 by danco_