Anybody tried 450#F/600#R springs for track

[JBasham]

I see many people trying 400/500 or 450/550.

Ideally I would go much higher for track, but my struts are the Koni adjustable units TC Kline sells, and I don't think they're up to damping real track spring rates.

450/600 is more of a spread than I see folks doing. But I will be running the Bimmerworld Ground Control front stabilizer bar, and a BMW 18mm bar on the rear.

If I strike out here, I'll try the suspension forum.


Thanks

[Crustashio]

Lots of people do a 150# or 200# split, I don't see an issue. This year I switched to 500F/650R and no rear bar to try a new autocross setup. Running the TCK SAs.

If you have the TCK SA coilovers they should be good for up to 700 in the rear.

[ScotcH]

Should be a good setup, if a little soft. Worst case, if it's really tail happy, you can disconnect the rear bar, though that might make it roll too much

[guymandude]

I have TCK 500/700 as an autocross setup. I like it over the 600 rear I had last year. Not as loose as I was expecting.

You could always, try the setup and if you don't like how it feels, disconnect the rear bar and order lighter springs.

[eye145]

I ran 400/500 and 550/650 on my tckline da's. No issues and managed to set a few track records.

[jonb94118]

I see many people trying 400/500 or 450/550.

Ideally I would go much higher for track, but my struts are the Koni adjustable units TC Kline sells, and I don't think they're up to damping real track spring rates.

450/600 is more of a spread than I see folks doing. But I will be running the Bimmerworld Ground Control front stabilizer bar, and a BMW 18mm bar on the rear.

If I strike out here, I'll try the suspension forum.


Thanks

Keep in mind that the motion ratio on the rear of an e36 about halves the spring rate as compared to the front. 600 spring is about 300 wheel rate. I run 600 front with 900 rear and a rear bar currently on a racecar with revalved Koni doubles. 100-150 spread is the typical 'safe' setup front to rear.

[aeronaut]

Do you have the SA's or DA's? TCK will tell you the rear SA's are at their limit at around 600 (even though their web site says 750 I think). That said, I'm running 550/650 with their SA's, and damping is ok. I'm still have a touch of understeer in mid-corner, but have some front roll bar settings to play with. FYI, mine is E36.

[JBasham]

WOW, thanks everybody, this is great info. I really appreciate it.

I can't believe I forgot to say it's an e36.

Yes, I have the Konis from TC Kline, 8241-1200 Sport. It's top-adjustable, rebound only. This is the rear shock I believe they push to folks buying their single-adjustable front coilovers?

I was under the impression that 600# was about as much spring as I should put on that damper and expect it to survive longer term.

I figured I'll try this and if it's just too soft, I will hit the Koni mobile service center for a revalve.

[cretinx]

Telling us your vehicle's model and weight would be helpful.

Keep in mind, the motion ratio between the Front and the Rear can be wacky on some BMWs.