Coilover preload for the track

AndyW · 08-20-2019, 02:33 PM

So I have a new to me set of KW Clubsports(thx berns ). No helper springs. Swift linear springs. I have zero experience with coilovers so trying to learn.

With zero preload the ride height is still a bit more than I want in the front. Is it ok to have some negative preload as long as the spring lines up on the perches when I lower the car back down? I realize this does reduce bump travel for the shock. I read on a Miata forum that for racing, it is fine if the spring is loose when unloaded as the sway bar prevents the spring from becoming unseated when cornering, even if fully unloaded but I am not sure if that is correct. Request advice from the collective wisdom here...

fe1rx · 08-20-2019, 03:05 PM

If the spring can't miss the perch when you lower the car, then you are definitely ok (which is probably about -10 mm "preload"). More than that, you may still be ok, for the reason you state. If you need to go lower than that, I would proceed cautiously with lowering, and if you don't hear any nasty noises in transitions, carry on.

I also suggest confirming how much suspension travel you have from static to the bump stop contacting. Obviously if you lower too much you will be riding on your bump stops statically. If you have at least 15 mm static clearance to your bump stops, you are probably ok.

AndyW · 08-20-2019, 08:36 PM

Quote:

Originally Posted by fe1rx

If the spring can't miss the perch when you lower the car, then you are definitely ok (which is probably about -10 mm "preload"). More than that, you may still be ok, for the reason you state. If you need to go lower than that, I would proceed cautiously with lowering, and if you don't hear any nasty noises in transitions, carry on.

I also suggest confirming how much suspension travel you have from static to the bump stop contacting. Obviously if you lower too much you will be riding on your bump stops statically. If you have at least 15 mm static clearance to your bump stops, you are probably ok.

Thx! This was helpful. I adjusted to where the spring just can't "escape" when the car is on the lift - probably about 10mm. I definitely have more than 15mm to the bump stops.

08-20-2019, 02:33 PM	#1
AndyW Supreme Galactic Commander (one galaxy over...) 666 Rep 1,777 Posts Drives: '08 E93, '12 E82, '13 E93 M3 Join Date: Feb 2012 Location: Washington, USA iTrader: (5)	Coilover preload for the track So I have a new to me set of KW Clubsports(thx berns ). No helper springs. Swift linear springs. I have zero experience with coilovers so trying to learn. With zero preload the ride height is still a bit more than I want in the front. Is it ok to have some negative preload as long as the spring lines up on the perches when I lower the car back down? I realize this does reduce bump travel for the shock. I read on a Miata forum that for racing, it is fine if the spring is loose when unloaded as the sway bar prevents the spring from becoming unseated when cornering, even if fully unloaded but I am not sure if that is correct. Request advice from the collective wisdom here... __________________ Best, Andy '12 E82-PS2,Stoptechs,Clubsports+M3 bits,Accusump,Wagner DP+EVO III FMIC,ERCP,BMS Intake,Mason Strut Bar,Wedge Tune
	Appreciate 1 berns1560.00 Tweet Quote

08-20-2019, 03:05 PM	#2
fe1rx Captain 1395 Rep 777 Posts Drives: 135i, 328i, Cayman S Join Date: Jan 2008 Location: Canada iTrader: (3)	If the spring can't miss the perch when you lower the car, then you are definitely ok (which is probably about -10 mm "preload"). More than that, you may still be ok, for the reason you state. If you need to go lower than that, I would proceed cautiously with lowering, and if you don't hear any nasty noises in transitions, carry on. I also suggest confirming how much suspension travel you have from static to the bump stop contacting. Obviously if you lower too much you will be riding on your bump stops statically. If you have at least 15 mm static clearance to your bump stops, you are probably ok.
	Appreciate 1 AndyW665.50 Quote