[tscdennab]

Hi,

I have in plan to replace my M-Sport suspension with an adjustable suspension. Does anyone think that a good set of adjustable dampers (eg. Ohlins Road & Track which I can get for a reasonable price, or Bilstein PSS10 or even KW V3) can help with eliminating wheel hop and increasing traction off the line ?

I was thinking at the following settings:

- front - set the rebound rate as soft as possible
- rear -set the rebound rate as hard as possible

But if the rebound rate is soft in the rear, doesn't this promote wheel hop ?

If the suspension has adjustable compression (like KW V3) this could also play a role, but I am not sure if this matters given the springs which control compression ?

Also, what springs would be better for drag racing ? Softer or stiffer springs ?

[BoostAddict]

Generally, the idea is to have a higher spring rate up front, and a lower in the rear. This allows weight transfer to the rear of the car allowing the to "squat" and go reducing wheel spin. I'm not a pro with rebound settings, so I can't help you there.

[zeenon53]

The more you car squats in between shifts the slower you are going to be. You want the rear to be stiff, that's why some guys will use spring blocks, this way the rear squats as little as possible.

[BoostAddict]

A stiff rear is just going to cause wheel spin. I've been through it with my 350Z, I couldn't make the car hook up at all with 295/40/18 semi slicks on the rear.

[BEAR-AvHistory]

A long time ago when I was racing a strip only car I was using 90/10 front & 50/50 rear to allow for good weight transfer but still control wheel hop.

BTW 90/10 are a bad plan for a street car.

[Turkeybaster115]

For best launch at the dragstrip, with no will hop, won't an LSD solve the problem?

[SeanS54]

I had a 2005 E46 M3 with Bilstein PSS9's and no matter how I adjusted it, I still had some wheel hop... it's the curse of the independent rear suspension...

I would suggest having more weight in the rear (half tank of gas, leave seats in) and get some good tires with fat sidewalls, ie 17's

[subieworx]

You want softer rear springs. Stiffer front springs won't matter too much. To go with the softer rear springs you want a damper that has very little compression and a shit load of rebound. The low compression damping will allow the rear to compress easily, but the high rebound will keep the springs from extending keeping the rear squatted and load transferred to the rear. You will also want very little camber in the rear as the more it squats the more negative camber is gained.

[bigdaddyaaron]

bump for more answers and experiences

[bigdnno98]

Tires and pressure are also a cause of wheel hop. Shiv had a set of $4500 coilovers on that car with lightweight Kosei K1s and Hoosier bias plies. All recipes for good traction without wheel hop

[theweebabySeamus]

Deflection and play within a suspension can be a big part of wheel hop. Hence why a lot of BMWs have issues with wheel hop, soft suspension bushings used to dampen NVH.

[jjbmuu]

Whatever suspension mods you may end up doing make sure you lock the diff down with some sort of brace. Even if I went polly bushings and an lsd I'd still do it because any little bit that diff moves when loaded will transfer power to the passenger rear wheel unevenly assuming you are going forward not backwards lol.

On a side note being stock suspension just springs and shocks all of my wheel spin and hop is basically gone after installing the diff brace. Hooks solid with proper tires and I'm very satisfied. Running fbo plus meth and with a little e85 my car is making around 500hp and 550tq at the crank mustang dyno proven after taking drivetrain loss into consideration (about 15% according to the operator) which overall makes me happy. Just a very bumpy ride...

[bigdaddyaaron]

Originally Posted by J.J4ck0wsk1

Whatever suspension mods you may end up doing make sure you lock the diff down with some sort of brace. Even if I went polly bushings and an lsd I'd still do it because any little bit that diff moves when loaded will transfer power to the passenger rear wheel unevenly assuming you are going forward not backwards lol.

On a side note being stock suspension just springs and shocks all of my wheel spin and hop is basically gone after installing the diff brace. Hooks solid with proper tires and I'm very satisfied. Running fbo plus meth and with a little e85 my car is making around 500hp and 550tq at the crank mustang dyno proven after taking drivetrain loss into consideration (about 15% according to the operator) which overall makes me happy. Just a very bumpy ride...

Yeah I've got rear subframe inserts and a lockdown. What other non strut/shock/tire mods can help with traction for the 60ft?

[bigdaddyaaron]

Originally Posted by theweebabySeamus

Deflection and play within a suspension can be a big part of wheel hop. Hence why a lot of BMWs have issues with wheel hop, soft suspension bushings used to dampen NVH.

Any idea on what bushings are affecting a launch? I know the rear subframe is; which I've addressed with inserts. Not too familiar with how suspension geometry works :/

[theweebabySeamus]

Originally Posted by bigdaddyaaron

Any idea on what bushings are affecting a launch? I know the rear subframe is; which I've addressed with inserts. Not too familiar with how suspension geometry works :/

Most of my experience with this is regarding F-bodies and their garbage stock suspension components. Our hard parts are much better, sure, but it being a luxury car they still run pretty soft suspension bushings.

I'd look towards any bushings that are part of the wheel to chassis connection, like suspension arm bushings.

[dlbrooks18]

Originally Posted by J.J4ck0wsk1

Whatever suspension mods you may end up doing make sure you lock the diff down with some sort of brace. Even if I went polly bushings and an lsd I'd still do it because any little bit that diff moves when loaded will transfer power to the passenger rear wheel unevenly assuming you are going forward not backwards lol.

On a side note being stock suspension just springs and shocks all of my wheel spin and hop is basically gone after installing the diff brace. Hooks solid with proper tires and I'm very satisfied. Running fbo plus meth and with a little e85 my car is making around 500hp and 550tq at the crank mustang dyno proven after taking drivetrain loss into consideration (about 15% according to the operator) which overall makes me happy. Just a very bumpy ride...

Good thread here, .. where did you get your diff brace? Thanks.

[bigdaddyaaron]

Originally Posted by dlbrooks18

Good thread here, .. where did you get your diff brace? Thanks.

There's a guy on n54 tech that makes them for around 120 i believe. That's where i got mine.

[J. Dub]

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