My NSX AutoX Clip

[Binh]

This is my sixth AutoX. The car is stock with the exception of Tein Flex coil-overs. I am running the 15/16's with the OEM tires. At this track I could run the whole thing in first. At the limit the car under-steers, anyone know how I can get it to over-steer some? I am planning on getting some R-compounds for the next event. Enjoy the video and feel free to comment on my driving, I am a sponge. Also please ignore the video after I pull into the pits, forgot to turn off the camera.

Binh


http://www.candelaappraisal.com/files/MVI_0977.AVI

 

[VBNSX]

soften the front + stiffen the rear = your desired oversteer

although I must say... oversteer is not a usual complaint for the nsx...

x

 

[EIFFEL]

Oversteer can be requested on demand with more throttle opening, or earlier application of throttle. Make sure TCS is turned off. :smile:

 

[PaulL]

Please decribe the understeer condition more thoroughly.

Is it upon corner entry?
Do you complete your braking before turning in to the corner?
Does it occur mid corner?
Corner exit?

When you say "at the limit" do you mean during the fastest turns that you encountered?

There are different ways to fix each segment of understeer.

 

[Binh]

Please decribe the understeer condition more thoroughly.

Is it upon corner entry?
Do you complete your braking before turning in to the corner?
Does it occur mid corner?
Corner exit?

When you say "at the limit" do you mean during the fastest turns that you encountered?

There are different ways to fix each segment of understeer.

Understeer occurs in at mid corner and upon exit. I nornally brake hard before the turn and should be on the gas at the apex and throughout the corner. When I say at the limit I mean the limit for the corner that I am in. Any application of the throttle causes the car to push/understeer.

Thanks in advance.

 

[PaulL]

Understeer of that nature can be improved with some changes to the suspension. You basically need to improve front grip or reduce rear grip (if that wasn't already obvious!).

You can try some/all of the following;

- adjust tire pressures to give more grip in front or less grip in rear
- change tire sizes to give more grip in front or less grip in rear
    > since you're getting some new tires anyway,
      you might consider something like 225 front, 245 rear
      to improve the front bias.
      I actually squeezed 245 front, 275 rear once (on 16/17's)
- create a better alignment
     > reduce rear toe in (but don't go so far as zero toe or toe out)
     > maximize your front camber
- stiffen up the rear end (less rear grip)
     > stiffen compression damping if your shocks can do that
     > stiffer rear sway bar
     > stiffer rear springs
- soften up the front end (more front grip)
     > soften compression damping
     > softer front sway bar
     > softer front springs
- change corner weights on the car
     > create more weight on front / less in rear

One of the challenges is that your course was so tight and low speed. If you were in a 2nd gear a/x course, for example, the car might handle nicely. But get into some really tight turns, and the car is more likely to push.

Also try getting on the gas before the apex, or do it more abruptly so as to break the rear end loose (like in that one turn in your video!)

 

[loNfastNSX]

Nice!!!! :biggrin:

Man, I detailed that car for 3 days one weekend. I think about 2 weeks before you picked it up. Hope your enjoying it!

 

[Binh]

Nice!!!! :biggrin:

Man, I detailed that car for 3 days one weekend. I think about 2 weeks before you picked it up. Hope your enjoying it!

Thanks for the detail, it looked great when I get there. If you see Nick, tell me thanks for everything.


PaulL,
At the AutoX school the day before we had a chance to drive a rather larger figure-8 in which I could get into second gear and the car still pushed. I am currently running 40/35 pressures. I will try your other suggestions. Do you think I should get adjustable sway bars? Also what do you think are the largest R-compounds that can fit on the 15/16 OEMs?

thanks,
Binh

 

[GO X]

Thanks for the detail, it looked great when I get there. If you see Nick, tell me thanks for everything.


PaulL,
At the AutoX school the day before we had a chance to drive a rather larger figure-8 in which I could get into second gear and the car still pushed. I am currently running 40/35 pressures. I will try your other suggestions. Do you think I should get adjustable sway bars? Also what do you think are the largest R-compounds that can fit on the 15/16 OEMs?

thanks,
Binh

We run the KUMHO ECSTA 710 F-225/50/15 R-265/45/16 grips awesome, and were fast too. -Paul

 

[Binh]

We run the KUMHO ECSTA 710 F-225/50/15 R-265/45/16 grips awesome, and were fast too. -Paul

Paul,

Do you guys drive there on the Kumho's? How many miles are you guys getting out of them? Also do you have a picture of how they fit on the rim?

thanks,
Binh

 

[PaulL]

FYI - That's actually a different Paul that answered about the tires.

But the 710s are well-known to be the fastest tire available for autocross.
They will last an entire season, gradually getting harder and slower with each heat cycle.

I would not recommend driving to the event with them, as they wear out quickly ... usually lasting only about one hour on the a/x courses.

Plus, if you have an aggressive alignment, it will wear tear up the tires on the street even more quickly.

Before you start to do bars or camber bolts and other such mods, you need to decide what class you want to car to run in. If you run typical SCCA classes, and the car is close to stock, it runs in AS. You are only allowed to replace the front bar in stock classes, though, which really doesn't help with the pushing problem.

Once you mod beyond stock allowances, it goes to ASP, where modified Z06es will eat it for lunch. You'll never beat 'em.

One other route is to simply do whatever mods you feel like, and run the car wherever it ends up. It won't be competitive at a National level, but will be fun at local events none the less.