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06 MX5 solo nationals STR setup

Posted: Sat Sep 27, 2014 3:50 pm
by elloco54
I plan to make a run at the solo nationals in STR next year. My current setup has done very well at local and a divisional solo. But I know there is more in the car. What I have now is motoeast intake & tune,complete max power exhaust,IL motor mounts and the M3 sport roll bar. On the suspension side it's H&R springs, Bilstein sport shocks, Hotchkis sways and FCM bump stops. Right now I'm running 17x8 wheels and 225/45-17 RS3's. My planned upgrades are 17x9 with 255/40, the GW chassis braces and powerflex bushings. Here is where I'm undecided, swap the bilsteins for koni's or bite the bullet for the Ohlins coilovers. I know there are alot of advantages with coilovers and from my research the Ohlins seem to be the only real choice in coilovers,but is there enough of an advantage over my current setup with the addition of adjustable Koni's to warrant the extra expense.

Re: 06 MX5 solo nationals STR setup

Posted: Sat Sep 27, 2014 9:52 pm
by Brian
YES...you need coilovers. Not competitive in STR with national level drivers without good coilovers that include the ability to precisely control height and corner balance the car with your weight in the car, etc.

Skip the braces and use those funds toward the coilovers. The braces make the car feel solid and new...and though feedback to the driver is improved, and NVH is reduced, with the possible exception of the toe links the braces don't make the car faster (any improvement in speed marginal compared with the benefit of the coilovers).

Yes, 17x9 Enkei RP-F1 with 255/40/17

Re: 06 MX5 solo nationals STR setup

Posted: Sun Sep 28, 2014 4:55 pm
by BrianC3343
elloco54,

I would also suggest that you do a thorough reading of the rules. In particular rules regarding what bracing can be added or deleted and roll over protection. I am not sure exactly which roll bar you have, but it may not meet the rules for SCCA solo racing for fore and aft bracing.

Also Brian is spot on about his comment about coilovers. For a nationally competitive car a good set of coilovers is next on the list after wheels and tires.

Brian Clemons
Portland, Oregon

Re: 06 MX5 solo nationals STR setup

Posted: Mon Sep 29, 2014 12:38 pm
by Viggen
Would the off the shelf standard Ohlins work for him or would he need to consider a setup with different spring rates and valving?

Re: 06 MX5 solo nationals STR setup

Posted: Mon Sep 29, 2014 1:03 pm
by Brian
Ryan Otis drove to 6th overall at 2012 Nationals... and set top STR time on the West course... on the off-the-shelf Ohlins.

Re: 06 MX5 solo nationals STR setup

Posted: Mon Sep 29, 2014 2:16 pm
by BrianC3343
The valving was off the shelf on Morris's car, but the spring rates were changed. Morris would have to verify, but I am almost certain springs are 9kg front, 7 kg rear.

Brian C.

Re: 06 MX5 solo nationals STR setup

Posted: Mon Sep 29, 2014 2:22 pm
by Brian
BrianC3343 wrote:The valving was off the shelf on Morris's car, but the spring rates were changed. Morris would have to verify, but I am almost certain springs are 9kg front, 7 kg rear.

Brian C.
Good point, that is my recollection too.

Re: 06 MX5 solo nationals STR setup

Posted: Mon Sep 29, 2014 7:20 pm
by elloco54
Roll bar is not required for STR but mine is legal for track days with a the petty bar installed. So Brian can you go 9kg/7kg without a revalve.

Re: 06 MX5 solo nationals STR setup

Posted: Tue Sep 30, 2014 5:42 am
by Brian
You can do those rates without a revalve, most coilvers can handle a push of 2kg in rates, but the revalve will give you better control over those rates.

Re: 06 MX5 solo nationals STR setup

Posted: Thu Oct 02, 2014 9:50 pm
by morrisg
Yes, factory Ohlins valving with 9kg front Swifts and 7kg tapered Tein rear springs on the car. And Ryan coned away his fastest West course time which would have placed him 4th overall.

Morris