the stubborn quest to autocross an nsx, on the national stage

[W]

I wish you all the best of luck in your quest.

You certainly have quite the uphill battle as any course that you can outperform the S2000's (which will be rare) you will be under-tired in the front and under-torqued compared to the C4 Corvettes.

Have you considered preparing the car for other classes, such as SSM?

Please keep us informed.

 

[shrddr]

Have you considered preparing the car for other classes, such as SSM?

i may choose to go down that route in the future. but for now... i want to give the stock class my best shot

 

[W]

I've run the 17" 245 V710's on the front of my car on 672lb front springs with the stock front bar near stock ride height and it rubs a little at the top of the fender under extreme compression. The 17" 245 I run is the square shouldered version of the V710 so it has a narrower section width than the 16" A6. I'm wondering how the A6 will fit with oem wheels since they have a much more fender friendly offset. FWIW, a 275 17" front won't work as the car will literally sit on the tires but it does look pretty cool. The second bottleneck after tire width is the inability to dial in any front camber and I'm wondering how the A6's will wear.

 

[shrddr]

I've run the 17" 245 V710's on the front of my car on 672lb front springs with the stock front bar near stock ride height and it rubs a little at the top of the fender under extreme compression. The 17" 245 I run is the square shouldered version of the V710 so it has a narrower section width than the 16" A6. I'm wondering how the A6 will fit with oem wheels since they have a much more fender friendly offset. FWIW, a 275 17" front won't work as the car will literally sit on the tires but it does look pretty cool. The second bottleneck after tire width is the inability to dial in any front camber and I'm wondering how the A6's will wear.

i got -1.5 degrees of static camber, which i think is fine considering the car has over 9 degrees of caster. that makes for some serious camber gain when turning the wheel. of course... only time will tell... but i am more concerned with monitoring wear on the outside edge of the rear tires.

 

[W]

i got -1.5 degrees of static camber, which i think is fine considering the car has over 9 degrees of caster. that makes for some serious camber gain when turning the wheel. of course... only time will tell... but i am more concerned with monitoring wear on the outside edge of the rear tires.

Although our setups are different, I'll just throw in what I've experienced. I also run around -1.5 up front and find it's not enough. You know how those Hoosiers love camber even more than the Kumhos. My style of driving is to steer with the rear of the car so I don't take as much advantage of caster. When I ran 225/275 lowered with more front camber, the fronts were wearing significantly faster than the rears and I had too much understeer. Now with a 245/275 setup, the wear and balance of the car seems good. I run stock front bar and no rear bar. I'll eventually run a bigger front bar with oem rear bar as the car is kinda sloppy and takes those precious extra moments to transfer weight/react. I'll probably then run a 245/295 setup.

 

[shrddr]

Although our setups are different, I'll just throw in what I've experienced. I also run around -1.5 up front and find it's not enough. You know how those Hoosiers love camber even more than the Kumhos. My style of driving is to steer with the rear of the car so I don't take as much advantage of caster. When I ran 225/275 lowered with more front camber, the fronts were wearing significantly faster than the rears and I had too much understeer. Now with a 245/275 setup, the wear and balance of the car seems good. I run stock front bar and no rear bar. I'll eventually run a bigger front bar with oem rear bar as the car is kinda sloppy and takes those precious extra moments to transfer weight/react. I'll probably then run a 245/295 setup.

i completely agree. -1.5 is not "enough" but it is workable. and more importantly... it is all i can get in the stock class so i just have to work with it. i appreciate the help! more data points are good

 

[R13]

i completely agree. -1.5 is not "enough" but it is workable. and more importantly... it is all i can get in the stock class so i just have to work with it. i appreciate the help! more data points are good

I haven't looked for the NSX, but the MR2 was easy because Toyota actually sells a set of smaller crash bolts specifically for fixing alignment issues. Since they're "Factory" they are stock legal and can give you actually more camber than tire clearance will allow.

I know the NSX uses a completely different system for camber adjustment, but it might be worth a quick look in the parts book. (just a shot in the dark here, I have done literally no research on this yet).

 

[shrddr]

episode #2 is now posted!
http://nsxftw.blogspot.com/

highlights: 295s (hoosiers) on the rear hit against the spring perch of the bilstein shocks when on the lowered perch. so i had to run the event on my street tires. and despite that, i kept pace with some very well driven s2000's on race tires! i will be raising the car back up to stock height (as required in the stock class anyway) and then hopefully the 295s fit. otherwise, i will need to use narrower rear tires.

more details in the blog post.

 

[R13]

Im gonna go out on a limb and guess that was a fairly open course then? Nice job on the raw times at any rate.

I thought the NSX & S2K were both in what will become B-Stock this year with SCCA (or were you running a modified class due to the ride height)? Alternately, I see this may be a differen sanctioning body...so none of that may make any sense .

Congrats either way on a promising outing.

 

[shrddr]

Im gonna go out on a limb and guess that was a fairly open course then? Nice job on the raw times at any rate.

I thought the NSX & S2K were both in what will become B-Stock this year with SCCA (or were you running a modified class due to the ride height)? Alternately, I see this may be a differen sanctioning body...so none of that may make any sense .

Congrats either way on a promising outing.

actually no, that was the surprising part! the course had few hard accelerating zones, exacerbated further by the lack of grip (cold day). it was a series of sweepers and 2 sets of slaloms. i thought the s2000's with their transitional abilities, and higher ultimate grip (lighter weight on similar size tires) would be hard to catch on this course... but turns out the NSX can put up a pretty darn good fight

yes, both of them are in B-stock this year. technically i was not legal for the class in this event since the car is a bit lowered, but they let me run in it anyway since i was on street tires (local events tend to be a bit lenient).

 

[W]

episode #2 is now posted!
http://nsxftw.blogspot.com/

highlights: 295s (hoosiers) on the rear hit against the spring perch of the bilstein shocks when on the lowered perch. so i had to run the event on my street tires. and despite that, i kept pace with some very well driven s2000's on race tires! i will be raising the car back up to stock height (as required in the stock class anyway) and then hopefully the 295s fit. otherwise, i will need to use narrower rear tires.

more details in the blog post.

I'm sure you already know this but you can run a 1/4" spacer (6.35mm) on stock offset wheels to help clear the spring perch.

 

[shrddr]

I'm sure you already know this but you can run a 1/4" spacer (6.35mm) on stock offset wheels to help clear the spring perch.

that isn't enough. i am optimistic about the tire fitting once i set the bilsteins to stock height though.

 

[Patdeisa]

Good luck!

2010 will be my first full season with the NSX. I'm not going all out to the limits of stock class, but I will be upgrading my tires to Kumho Ecsta XS, which the locals say is a great drive to and race tire. I race with the local MB club, as I get more seat time (6-8 runs/day). If I start getting competitive against the 3 S2000s that run with the club (two BSP, one BS), I'll try my hand at a few SCCA events.

The local events are small courses- I've only gotten out of 1st twice. I don't have much advice yet, as I'm still learning the ropes with the NSX (I have a bit of experience with the RSX-S, though).

 

[ANYTIME]

no. i cannot mix and match parts from different model years. i could only use the zanardi springs if i had a 99 coupe, and performed an ENTIRE conversion to use every single part that is on a zanardi... including all the cosmetic bits too (badges, seat material, etc). too much work for not enough gain

How does anyone know which shocks you are using? Or any other model part that is not unique to your year car? Confused

 

[shrddr]

How does anyone know which shocks you are using? Or any other model part that is not unique to your year car? Confused

all cars are open to being visually inspected by competitors. at the national level, people do v ery thorough research on all the cars that are entering and they know what to look for.

besides the risk of getting caught, i want to compete (and win!) with a clear conscience. would some zanardi parts work better? sure they would. but at the price of knowing i broke the rules? no thanks

 

[R13]

all cars are open to being visually inspected by competitors. at the national level, people do v ery thorough research on all the cars that are entering and they know what to look for.

besides the risk of getting caught, i want to compete (and win!) with a clear conscience. would some zanardi parts work better? sure they would. but at the price of knowing i broke the rules? no thanks

Yup, stuff gets real at Nationals. I know of several occasions where owners of winning/very high placing cars were asked to remove valve covers (to look at valve springs/retainers/etc), submit to compression tests, boost pressure tests, and so on.

 

[shrddr]

episode #3 posted.
http://nsxftw.blogspot.com/

highlights: the car is raised to stock height, realigned (-1.1 in the front was the max i could get, -2.0 in the rear), using 1/4 inch wheel spacers in the rear... i finally got the 295s to fit the rear with only 8mm of clearance between the tire and spring perch on the left side, and 5mm of clearance on the right side. i am currently about 2 seconds off the pace where i need to be. most of that is because i did not drive very well at the autocross this weekend, the rest of it will come as i learn to set up the car right.

full details in the blog post

 

[djb_rh]

5mm of clearance? That's infinite! My old CS Toyota Spyder had less than a credit card on the front struts and 225 A6's.

Good luck. I'm rooting for you.


--Donnie

 

[shrddr]

5mm of clearance? That's infinite! My old CS Toyota Spyder had less than a credit card on the front struts and 225 A6's.

Good luck. I'm rooting for you.


--Donnie

i thought it was enough too... but it wasn't. as detailed in the blog post... tire flex from cornering load and bumps combined with the camber gain under compression resulted in some rubbing between the tire and spring perch. i am going to need to shave that perch a little narrower, and back out the rear camber a bit to get a couple more mm of space

 

[djb_rh]

i thought it was enough too... but it wasn't. as detailed in the blog post... tire flex from cornering load and bumps combined with the camber gain under compression resulted in some rubbing between the tire and spring perch. i am going to need to shave that perch a little narrower, and back out the rear camber a bit to get a couple more mm of space

Yeah, the Spyder was strut based, so as long as you weren't touching you didn't have to worry about it doing it at some other location. It can't (at least not with that particular geometry). I forgot you've got that nice thing called camber gain.


--Donnie

 

[shrddr]

part #4 posted
http://nsxftw.blogspot.com/

highlights...
1. changes to the car: backed caster down from -9.0 to -7.2 which resulted in front camber increase from -1.1 to -1.4, reduced rear camber from -2.0 to -1.6 and shaved 2mm off from the rear spring perches to gain some clearance between the tire and perch to prevent rubbing, added daliracing 1" front sway bar (AWESOME!!)
2. had a very experienced autocrosser (and damn knowledgeable setup expert) co-drive with me at the last event. we finished 1st and 2nd in class with me ahead by 0.469 seconds. it helped a lot to get his feedback on the car setup.
3. i will be replacing the bilstein shocks with konis (adjustable!). and coming up at the end of the month is the SCCA TX national tour so the car will gets its first taste of national competition!

 

[R13]

the car will gets its first taste of national competition!

Good luck, I'll be curious to see how you do.

 

[shrddr]

a few pictures from the event :biggrin: