First Autocross Event in the NSX

[THonda]

Just as brackground info, I have beening autocrossing for about 4 years now including a miata/boxster s/e46 M3 and now the NSX.... although I am totally not competitive (i.e. I suck) I do enjoy doing it and knowing how my car handles.

My nsx is a 2000, w/ Tein RA suspension setting 8 all around, running 215/35 18 and 275/35 18 Kumho MXs Tire Pressure F 35 R 40

First time out, i couldn't believe how easily my rear would come out, it was a very smooth transition, so much so that I was actually able to drift the car through a sweeper...very cool looking i am sure, but not the fastest way around the course.

The second & third run, trying to adjust my driving style, the rear would still come out very very easily, it was almost like driving on ice but w/ more ability to control it of course. I actually even spun out once...

To make a long story short, by end of the day, I have adjust the suspension to front 6 (1-16 levels 1 being the most stiff) and the rear to 12, didn't change the tire pressure and I was able to keep the car in line... I did not mess w/ the tire pressure as I did not want to add too many variable figuring out what a adjustment would change.

My best time was a 38.4xx, the FTD was 36.5xx but that 2 seconds is an eternity as you fellow autocrossers would know

So - Here are some questions:

-Anything obvious I am doing wrong?

-An MR2 driver told me that for a mid engine car, in order to gain more traction I would need to stiffen the rear shocks instead of soften it? True or False?

-If you are running the Tein RA suspension what Adjustment are you using on the track?

-What tire pressure are you running

-Last but not least, what competition tires are avilable for the NSX out there on the OEM 16/17 Rims, what sizes is the "standard"

Thank you very much for your assistance!

 

[NetViper]

I don't have any advice, but I am hopefully doing my first autocross event this weekend. I am wondering if my car (which is 99% stock) will have the same issues.

 

[John McCain Racing]

So - Here are some questions:

-Anything obvious I am doing wrong?

-An MR2 driver told me that for a mid engine car, in order to gain more traction I would need to stiffen the rear shocks instead of soften it? True or False?

-If you are running the Tein RA suspension what Adjustment are you using on the track?

-What tire pressure are you running

I was acutally wondering the same thing! I did my first autocross yesterday and have lots of changes to make I think. I had my Tein's set on 14 front and 16 rear...really soft and my tires at 38 and 40. I had one of the best spin outs yesterday for sure! The back was just way to easy to bring around. I had an instructor ride with me my second run who previously owned a NSX and he commented on the same thing. He thought most of it was due to more power, but I think I can still do lots of tweaking. I tried runs with and without the Traction Control on and I got my best run with it on. I was a bit farther behind the FTD, he ran a 69.30 and my best was a 76.80, my worst was a 90 second run! It sure was fun though Anyone have thoughts on some changes I can make?

Thanks in Advance...

 

[Forums Nazi]

what competition tires are avilable for the NSX out there on the OEM 16/17 Rims, what sizes is the "standard"

http://www.nsxprime.com/forums/showthread.php?t=34184
http://www.nsxprime.com/forums/showthread.php?t=29747
http://www.nsxprime.com/forums/showthread.php?t=24629

 

[THonda]

I don't have any advice, but I am hopefully doing my first autocross event this weekend. I am wondering if my car (which is 99% stock) will have the same issues.

I don't think it is really an "issue".... It acutally comes out very smoothly, and I am pretty sure it will bring a grin to your face It is not a violent snap around, but then again I am only going about 30-40 mph Good luck and hope you have lots of FUN!

 

[John McCain Racing]

I don't have any advice, but I am hopefully doing my first autocross event this weekend. I am wondering if my car (which is 99% stock) will have the same issues.

I will agree that it's not an "issue" but more just learning your car and improving your driving skills. I think the best part of the day was riding the edge and yes we had a few spins. I think that is part of the learning, plus it was a blast!

 

[Ponyboy]

So - Here are some questions:

-Anything obvious I am doing wrong?

Take some vid. There may be technique issues. You should be in 2nd gear the whole time, well most of the time. Shifting takes too much time and the NSX has a very wide powerband.

-An MR2 driver told me that for a mid engine car, in order to gain more traction I would need to stiffen the rear shocks instead of soften it? True or False?

Ummm, don't know about that one. In general, softening up the suspension is going to give you more traction. Try adjusting the shock compression and maybe the air pressures and see for yourself. Of course, there's a balance b/t understeer and oversteer that you want, especially on a cone packing course. I'd be more tempted to have more oversteer to get the car to rotate.

Just my .02. Good luck!

 

[Tank]

J

-Anything obvious I am doing wrong?

-

Nothing obvious. I spent almost 2 years getting my 94 sorted out. The one thing you didn't talk about was alignment settings. That can make a big difference. So can spring rates. Once I went to 3 degrees of toe-in in the rear, my spinning stopped. And my tire wear shot through the roof. So I got a fully adjustable suspension. I finally dialed that in after lessening the toe in the rear. I got it to dead neutral then loosened up the rear end just a bit to get rotation.

Unfortunately you have to pick a starting point. I would work with the shocks first. It sounds to me that you are too stiff all around to start with (a blind guess). Soften the fronts a bit and soften the rears by a lot. This trial and error will take several events unless you can get to a skid pad. But each item in the suspension is tied to all the others so it can take a while. My alignment setting wouldn't work with your car unless everything else was totally the same between them. You really do have to sort this out by yourself.

As for tires on OEM rims, there are really only 2 worth your time: Kumho V700 Ecstas (very sticky and fairly costly) and Falken Azenis (pretty sticky and cheap)

And as a final word, I would tap into your local autox'ers for advice. This sport isn't quite like tracking and the opinions of die hard autox drivers come from a deep well of experience.

Have fun

t

 

[JPS Europa]

I have never autocrossed my NSX, but have run some of my other cars including a purpose built car.
Just some comments.
You want some oversteer with a Mid-engine rig...not too much though. Helps you around the tight corners.
If the car is flat and one end is hooking up and the other is not, try reducing tire pressures in the end that hooks up or increasinging them in the loose end. This is suitable for tuning once you are already at the course when tools and alignment equipment are at a premium. Sometimes you have to make a pretty big change! First time out in the Europa, I had awful understeer (this is in a car which felt good on the street). I dropped the rear tire pressure by 8 PSI and knocked more than 2 seconds off my time.
More rear toe will definitely make for more understeer...to a point...then it just wears out tires.
A car which is perfectly set up for autocross is a handfull for anything else.

 

[docjohn]

What spring rates do you have on the tien?I have heard that the 10/10 and to a lesser degree the 12/10 kg/mm setups will over-steer as you stated you were doing-loose iow.You did the correct thing to stiffen the front shocks and soften the rears but you need to be more deliberate and experiment with settings.Make a log book and go to a secluded parking lot and try to get a sense of it all before the local authorities tell you to stop disturbing the peace,in the big empty lot!Ask me how I know.

 

[apapada]

I don't have any advice, but I am hopefully doing my first autocross event this weekend. I am wondering if my car (which is 99% stock) will have the same issues.

it should. Lowering the rear tire pressure helps make the oversteering a bit more controllable and less "snappy". Depending on the course, you'll either love autoXing the NSX or hate it. I personnally turn using the throttle and correct with the steering wheel. Lot's of fun when done right, lot's of cones when not

 

[Bobby_Generic]

. Once I went to 3 degrees of toe-in in the rear, my spinning stopped. And my tire wear shot through the roof.

Are you sure you are not talking about .3 degrees of toe-in? As you go though the initial runs you may want to release air pressure especially in the back with your oversteer cause tires get really hot after a run. If i were you I would mess with camber and set toe to stock or zero cause AutoX tires can get costly. And if you are not doing so.... remember to brake only in the straights. Too much trail braking is evil for cars that are RWD also.

 

[docjohn]

The nsx dose'nt like 0 toe in the rear.

 

[apapada]

The nsx dose'nt like 0 toe in the rear.

you are right for 95% of the time. But, I'm pretty close to that and my rear end stays planted until *I* tell it otherwise

 

[Tank]

you are right for 95% of the time. But, I'm pretty close to that and my rear end stays planted until *I* tell it otherwise

With zero toe in the rear, what are your other settings (shocks, sway, and springs)?

t

 

[apapada]

With zero toe in the rear, what are your other settings (shocks, sway, and springs)?

t

Let me just say first, that I always felt uncomfortable about two things in my NSX: 1) very aggressive suspension setup that would make my garage stink tire fumes just by driving 10 miles home at a normal pace. 2) most importantly, tricky oversteering at the limit. Ok at the track, but not ok in other circumstances (i.e. accident or obstacle avoidance). Oh yeah, that first point about very aggressive suspension setup has some consequences for tire wear, but that's never really been a problem

So bottom line, I wanted for my NSX to have a "normal" suspension setup without compromising handling and vice-versa. Oh, and if tire wear would become better, that would be a nice bonus too...

Anyway, here are details of my setup:
to be exact, total toe in at the rear is 0.5*. Rear Camber is -1.3* for each wheel. I have the stock springs and shocks, and the DALI adjustable bar set on the middle hole.

In the front I'm running stock stock springs and shocks, and the DALI adjustable bar set also on the middle hole. Camber is a nice positive 0.3* per wheel (better, easier and more precise steering feel), total Toe in is 0.25* , Caster is 7* per wheel.

Two important factors that I must disclose however is that my rear track is widened by aprrox. 30mm by the use of adapters and that I'm running BFG G-Force Sport 215/40R17 in the front and Pilot Sport 2 255/35R18 at the rear. And yeah, 99% of the time it is a very bad idea to mismatch tires between front and rear axles. The remaining 1% of the time is for times like these, when one actually knows what he/she's doing.

I'm very happy with this setup which resulted by starting with later-model suspension setup and after extensive trial-n-error (as in 8 sets of tires, 4 levels of pressure adjustements and multiple suspension setups). I'm not saying this would work for any application, just that it does for mine. The car is very predictable at the limit, with tons of warning and will have a tendency to understeer before switching into a 4 wheel neutral drift. Every time it went into oversteer, it was become I wanted to induce it. I feel my NSX is now very predictable, very drivable at the limit and still fun (read "tail-happy) when and only I decide to. No more tire smell in my garage and I'm predicting that tire wear life just doubled or tripled. Plus I'm not sacrificing (excessive) tire wear for handling anymore...


edit: for spelling

 

[Tank]

to be exact, total toe in at the rear is 0.5*. Rear Camber is -1.3* for each wheel. I have the stock springs and shocks, and the DALI adjustable bar set on the middle hole.

In the front I'm running stock stock springs and shocks, and the DALI adjustable bar set also on the middle hole. Camber is a nice positive 0.3* per wheel (better, easier and more precise steering feel), total Toe in is 0.25*, Caster is 7* per wheel.

Interesting set-up. In my earlier post I left out the decimal point in the toe reading, so I hope that didn't throw you off about what I was running. But I have to say total rear toe of 0.5* is still a little agressive. Specified range for the NSX-R is 0.2 to 0.3* total which is more still than the standard stock settings. At my low point in tire wear I had each rear wheel at 0.5* and that really ate tires. I'm now at 0.25* per wheel, for a total of 0.5* like you, and as you say the rear stays planted until I tell it otherwise. My front toe is 0.25*total, same as yours, also.

Where we really depart is front/rear camber. I'm running a -3.0* both front and rear, but our applications are different. I'm doing mostly autox and I need a really sharp turn-in. I'm also lowered by my H&R springs. My sways are Comptech - softest setting in front and middle in the rear. My Konis are about a half turrn in front and 3 quarters in the rear. And for what I'm doing, that makes for a fairly neutral car that can rotate on demand.

Oh, yeah, tires. I'm running Kumho Victoracer V700s 225/40/17 front and 275/40/17 rear. And so far, they're wearing pretty evenly as are my street tires. But with the neg camber, I won't get maximum wear out of the street tires but I accept that to be more competitive. I don't put a lot of street miles on the car anyway.

Thanks for sharing your data and insights.

t