Benefits:

- Increased fluid capacity
- Lower fluid temperature
- Reduces cavitation
- Longer travel
- More consistent damping and longer damper life
- Tuner friendly (add spring rate on the fly)

Maintaining lower fluid temperature has a lot to do with it.

Dave

 

What data acq was that data from? We were pulling 1.4g lateral at HPT. I've seen data from other STU cars that show 1.15g.

 

Peak maybe, but there's not way an Evo was doing 1.4G steady state at HPT.

The particular data I have was from a maxqdata system, but I've instrumented mine with a variety of systems from a $500 GPS unit up to a $15k, 500hz Competition Data one.


d

EDIT: this is my point by the way. The difference in transient Gs is larger than the difference in steady state lateral acceleration.

 

Makes sense that increase fluid capacity will lead to lower temps due to increased mass and thus reduce cavitation, which in turn leads to longer damper life. I guess you could also think of the external reservoir as an effective heatsink. ... While the difference in temps with external reservoirs may be greater with ones from a higher end product eg: Motons (due to size of the reservoir and the length of the tube between the shock and the reservoir) the ones attached to the KW V3 are tiny and pretty much attached the shock body ... I guess I was primarily thinking of those while I typed up my reply.

Don't know about the tuner friendly point .... aren't all well designed coilovers supposed to be "tuner friendly" ...

 

Doh, I missed the 'steady state' in your post. Even so on a 100' skid pad on our home lot (which registers lower peak accel then HPT, usually 1.33-1.35) we average 1.28-ish.

I guess all i'm saying is the difference seems to be larger between BSP and STU then you mentioned, admittadly not by much. I think our conclusions are about the same. 8k front springs are too soft for any FSB that i know of. 12k front sounds good to me.

 

I do have to admit the best part of the ZZYZX EM package is they come with Steve's knowledge, expertise and support. Steve's an all round great guy and extremely friendly. I have the utmost respect for him and what he does for the SOLO community. There are times I wished I had that kind of support.

Silencer: You running the EVO X this year? Just wondering since your sig lists STU

 

See? We're in agreement.

cheers,

d

 

Well 8k/10k for my setup shouldnt be low. I would run STU with 245 RE01R's so I most likely dont have enough tire (nor enough seat time) to warrant anything over 10k...not saying it wouldn't benefit me though. As far as STU I will have to take stuff off my car anyways to be legal in SCCA. Locally in BSCC I run prepared sedan which is kind of between STU and BSP. If Steves setup becomes more available I may go for it. But I live in the Seattle area and see some bad weather, so that makes me think I will probably go for the Ohlins unless Steves EM's become more available.

One thing I am pondering is though is with 8kf and 10kr springrates would my swaybar be necessary or cause more harm then good. I could always stick it on softest like DaWorst reccomended. So anybody have experience with similiar spring rates and having the RSB?

 

You should keep your RSB. There are several of us with much higher rates and we still use RSB's.

 

Well I dont think I could find much more of a strait forward answer from somebody experienced. Thank you Dave

 

Ahh, understand.

The "tuner friendly" part was based on adding Nitrogen to the reservoirs ultimately increasing spring rate. Far more easier than changing springs during test sessions. At least up to 150 lbs of it (don't recall the conversion at the moment).

Dave

 

I had plans to build one for STU and even reserved the first one at my local dealer. I decided that the weight would be too much of an issue to overcome and that the limited aftermarket support in the first year would result in custom one-off's similar to my VIII in it's first year of production. Even with the AYC offsetting some of it's disadvantages, the X IMO, is not a contender. I'm really looking for an RS or a lighter version of the X. I'm also entertaining the idea of purchasing an IX SE for next year. But then again the BMW 135i looks interesting too.

This year will be on a limited schedule and co-driving a newer ESP Camaro Z28 entry at a couple tours and possibly Nationals. I am signed up for the DC Pro in STU though.

Dave

 

I believe it is about 4-6lbs/in spring rate for every 10 psi of nitrogen charge.

 

Is changing the wastegate duty cycle in the ECU allow in STU?

 

No. The only things that you can legally change via the ecu is the air/fuel ratio and the timing. You really don't need to muck with anything else, the cars are plenty powerful. I believe at some point more power can hurt you on street tires.