As we all know coilovers from JDM land have the higher spring rates up front. I know a lot of people on this forum disagree with the higher spring rates up front and run higher rates in the rear for better rotation on the track. currently i am running zeal B2's 12k/8k. is it okay to switch the springs around? is the valving the same in the front and rear shocks? Has anyone switched spring rates around already and what did you think vs. the original way?

 

IM Todd00. He played around with Zeal B6's a lot and can tell you.

 

I'll just reply instead

The B2's might be near the limits at 12kg/mm in the rear, but they should be ok. B6's will handle it with no problem. AJ-Racing might know more about the limits of the B2's though, but the piston diameter on the shocks is smaller on the B2s than it is on the B6s.

And on the Zeals, you'll be fine swapping spring rates around as long as you don't do something wild like 24kg/mm unless you are using the Super Function.

Feeling is just like it is with swapping around rates on a set of GC's with Konis. It is also pretty easy to do with the Zeals.

So you would have 448/652 with the 8/12 combo. You might be better off getting a set of 10kg for the front so you would have 560/652. 448/652 = 32% difference. The popular setup, 600/800 is only a 25% difference from front to rear, and that makes plenty of rotation. Heck, my 560/560 setup made a ton of rotation on my B6s when I would crank the rears to full stiff.

Also, is this a street car? I wouldn't feel safe having such an offset on a car that I drive daily. I once had an old lady hit her brakes in the middle of a cloverleaf and it about spun me out on my 560/560 setup because I had to let off and tromp my brakes. Very scarry.

 

Thanks for the info Todd00. my ITR is not my daily driver, i drive it on the weekend some, but mostly use it for autocross and track events. so you are running 10k/10k and feel there is plenty of rotation with the rear shocks set full stiff, what do you have the front shocks set to? I got to try out my B2's on the track for the first time at VIR last weekend and the 12k/8k setup felt pretty safe(the car didn't oversteer at all) with the shocks set at 4. I was considering swithching the springs around to get it to oversteer some, but don't want too much rotation. maybe i will just try turning up the rears more next time.

 

I would usually do something like 3/6 or 3/5 depending upon the course, how my car was behaving, etc. I would hardly ever run my front over 4 though, and my rears were always around 5-6.

 

Instead of switching around the springs, have you thought of any other options to get your desired oversteer? To me, your 12K front seems like a good rate at minimizing brake dive. Changing it to 8K might not be enough for your almost track-only car (depends on your preference).

How about raise the rear ride height by 1/2"? Thicker rear sway bar? Set the rear dampers stiffer? Rear toe out? Less rear camber?