J STOCK springs are BACK!!!!!!!!!

[JCGus]

Would value any feedback on the ride height - do we think the front is too high? It is lower than the rear by about 1/1.5cm measured from the sills

[mwagner10702]

Good looking car. Ride height looks fine (to me) based on the angle the picture was taken at. I probably would not want to go any lower in the front so as to avoid scraping your oil pan. Because the front wheel arch is higher than the rear wheel arch you are always going to have the illusion that the front is higher than the rear. Measuring from the underside jack points would help you determine overall front to back rake. Keep in mind your numbers may be different than other owner's numbers based on tire diameters, spring pad thicknesses used, etc.

[JCGus]

Thanks!

The front is around 1-1.5cm lower than the rear (measured from the sill but uneven ground measurement) so I'm probably going to be happy running the same height to protect the pan...am running the rear 9mm lower pad and only option upper pad, on the front I am running 2x 9mm upper pads, so it could go down another 6mm if I use the standard lower pad at 3mm.

Will see how long the CV19 lockdown runs on and how much of a loose end I get to...

[JCGus]

After getting these on the road - they aren't actually too bad. They are obviously pretty stiff but not unbearable, even on UK roads. The fronts feel perfectly damped and the rears do feel a little stiff but OK.

It's nice being a bit stiffer as it hasn't bottomed out once (exhaust) which gives me confidence.

I am debating if I try H&R Race as that seems the 2nd stiffest E30 spring available without going coilover - does anyone have any idea if they would work better with the TMS J Stock Bilstein front/Bilstein Motorsport rear shocks? Or would I be better off with the Bilstein B8?

I am probably just being fussy at this point...

[mwagner10702]

Did you get the rear dampers revalved? The Bilstein Motorsport dampers are valved at 200/200 where as the original spec TMS J-Stock dampers were valved at 200/125. Rebound is the same but the compression was higher on the Bilstein Motorsport units. If your rear feels a little stiff it could be you are feeling the effects of the higher compression rate.

Here are the spring rates (F/R) for the J-Stock and H&R Race springs

H&R Race -------------------------315------------------------ 570
TMS J-Stock -------------------680--------------------------1026

At half the spring rate of the J-Stocks the H&R Race springs with the J-Stock dampers would probably result in a worse ride than what you currently have.

There are a number of threads on here that talk about the combination of H&R Race springs with the B8 Performance Plus dampers. Most who run them like them, although I doubt they would have the J-Stock setup to compare to. A couple of owners have complained that the race springs resulted in too low a ride height, but from an overall ride quality perspective they liked the combination.

I am sure someone who actually knows what they are talking about will chime in and set both of us straight.

[JCGus]

I did not - they won't do it in the UK, so figured I would give it a go without. TBH it's not as stiff as I was worried it would be, but I need a few more real world miles to nail down an opinion. I am not a damper expert by any means - but the rear MS dampers feel fine on compression...it's the rebound that seems faster. I am probably not describing it well.

I have the B8s so it wouldn't be too tough to compare if I got my hands on a set...just a bit of a faff.

Tough to find info on the internet from people who have compared the two in reality.

[redneckvtek]

Bump to an old thread but I think this is still relevant.

The J-Stock front shocks are good and gone these days.
The B8's sold now don't appear to be rebuildable to have the bump stop and valving modified due to the "crimped" design instead of a circlip closure.

Does anyone have suggestions or thoughts on a solution for front shocks?


The rear shock solutions posted in this thread are still relevant and available in 2023.

[mwagner10702]

Bump to an old thread but I think this is still relevant.

The J-Stock front shocks are good and gone these days.
The B8's sold now don't appear to be rebuildable to have the bump stop and valving modified due to the "crimped" design instead of a circlip closure.

Does anyone have suggestions or thoughts on a solution for front shocks?


The rear shock solutions posted in this thread are still relevant and available in 2023.

You want to use the Bilstein Motorsport dampers.

Front = 34-046296 (valved 300/300)
Rear = 26-000642 (valved 200/200)

These are one of the damper specifications BMW ran on their Group N cars.

BTW - you have it backwards. The front damper can still be modified, it is the rear damper that has the crimp and cannot be re-valved.

TC Kline could probably re-valve a set of Koni dampers to handle the J-Stock spring rates. If you consider this route I'd recommend the TC Kline-specific DA rears. I know people have bad-mouthed Koni dampers saying they don't last and higher rate springs will blow them out. I believe this is due to using mis-matched spring and damper rates. Properly configured they should be fine.