feedback to improve handling (for you track gurus)

[whatisreal7]

Alright guys, I probably could do a search that will probably answer 1/2 of my questions in individual form, but as with every case, everyone's setup is unique, and needs to be looked at holistically as a total picture. So here I am, still filled w/ adrenaline, writing this email. Don't tell me to do a search since I'm still excited from the event!

Situation:
* Track day at California Speedway in So Cal.
* Ran with a few friends, who had a new M3, the older 1994 M3, and Mercedes C230.
* I ended up with the slowest lap times
* Driver skills aside (most important aspect, but for the sake of tuning the car, let's table this conversation).

Setup:
* 1998 lowered on HypermaxII "35-click adjustable"
* Front type-R chassis bar (two bars)
* Rear wheels not cambered to spec as to save tire life (i dont track often, so I chose tire wear over performance). Probably -1 degree, as opposed to -2 or -2.5.
* I had the front coilovers set ~medium, and the rears a few clicks on the softer side.
* Front tire pressure at 30psi, rears at 35.
* Running 17" 2002+ OEM rims, with GSD3's. Plenty of tread (thanks to the camber)

Result:
* Tail-happy as hell.
* Spun out once and did at 540 ended up facing traffic!
* Not a lot of confidence going through turns as the rear just felt unstable.
* Little to no understeer, whole lotta oversteer.


Questions:
* Given the above, what 1-2 things are the largest contributing factor to the overwhelming oversteer? Will the camber have the greatest impact? The chassis bar did me in?
* HypermaxII's are the greatest track coilovers. But if I had to live with them, how should I set them up? Crank up the stiffness in the front, and medium in the rear?
* Should I remove the R bars to give the body some roll so my softer suspensions can allow the tires to contact the pavement a bit more?
*more to come

 

[NSXGMS]

Result:
* Tail-happy as hell.
* Spun out once and did at 540 ended up facing traffic!
* Not a lot of confidence going through turns as the rear just felt unstable.
* Little to no understeer, whole lotta oversteer.


Questions:
* Given the above, what 1-2 things are the largest contributing factor to the overwhelming understeer? Will the camber have the greatest impact? The chassis bar did me in?
* HypermaxII's are the greatest track coilovers. But if I had to live with them, how should I set them up? Crank up the stiffness in the front, and medium in the rear?
* Should I remove the R bars to give the body some roll so my softer suspensions can allow the tires to contact the pavement a bit more?
*more to come

If you're "tail happy" (losing your back end) you're experiencing overwhelming oversteer.

First, the Type-R chassis bars are not causing the problem. They don't really affect understeer/oversteer and if anything would produce understeer. Also, your camber or toe settings aren't going to be that significant in changing understeer or oversteer, particularly for a driver who's not pushing the car to it's limit. If you are looking for a massive change in the handling characteristics of the car camber isn't going to do enough.

No mention of what sway bar setup you are using so I assume OEM sways front & back. If so, try replacing the front OEM sway with the Type-R front sway. That will significantly increase understeer and help dial out the oversteer. There are other great sway options out there but the Type-R is cheap, simple, plug and play and fits your needs.

If you're not running the OEM rear sway I'd recommend it. Make sure you know exactly what sways you're running. If you are running the OEM front sway but a Zanardi rear sway this could be the entire cause of the problem.

You could also try bringing up the front tire air pressures and/or bringing down the rear tire pressures.

As far as coilover stiffness obviously stiffer in front is going to help you dial out your oversteer. On the track I keep mine at 100% firm front and 80% firm rear. The Type-R & Type-S, most AM springs and several of the more popular coilover kits use higher spring and dampening rates in the front. This approach would tend to produce understeer.

I run ZEAL coilovers with the Type-R chassis bars and front sway and I have understeer city. It's very hard for me to break the back end loose. I've been thinking about installing the beefier rear Zanardi sway to balance it out but am also planning on more power and wanted to see if more power does the trick or changes my needs before buying something I just end up removing.

 

[DrivingAmbition]

Make sure you have a stiffer springs in the front. Most of the Japaneses built suspension systems run a stiffer spring in the rear. I do not know why they think this works, may be they just like drifting? Invest in the non compliance rear beam and toe links. It will help make your rear tires last longer and make the rear of the car much more predictable in corners. Also make sure you run about a 1/2" of rake at the jack points. This means if your front ride height is 4" at the front jack point then the rear should be 4.5". Give us a call we can help you with the parts and getting everything set up. Cheers, Shad

 

[docjohn]

What are your spring rates? If you spun you need more instruction/practice.Never start your track experience in a vacuum.Take rides with other experienced drivers,let an experienced nsxer /intructer drive your car.As I always say untill I know how you drive I can't blame the oversteer on the car.Shad jumped in between us but yes to what Shad has offered that is why I asked about your spring rates.

 

[NSXDreamer2]

In memory of nsxtasy, tire pressue!!! make sure you have them set at HOT, ideally, as soon as you come off track. I found 32front 35 rear to 35 front 38 rear a good starting point.

If you just started tracking, slow in, fast out, build up your confidence... take your lines smooth, with slow hands, take notes your entry speed and then focusing more your car's position at the track out. Once you are getting the track rhythm and getting comfortable, starting to increase your entry speed by braking less, (step on the pedal with less force but you could start slowing down earlier, instead of late-braking.)

Hope this helps.

 

[CL65 Captain]

Result:
* Tail-happy as hell.
* Spun out once and did at 540 ended up facing traffic!
* Not a lot of confidence going through turns as the rear just felt unstable.
* Little to no understeer, whole lotta oversteer.

Just a wild guess here.... drop throttle oversteer? No confidence going through turns and when the rear starts to feel unstable he lets off the gas and around she goes. It sounds more like driver input than setup.

I ran my NSX on Goodyear F1GS3D (which I hate on the track) with no front bar (sway bar link had broke) and a Dali Track bar on the rear and still managed to control the oversteer (well, except for that one spin) and chase down a C6 and Z4 M Coupe running on R888s. So I think that since he was slower than his buddies including a C230 that he wasn't pushing the car to the limits but was making novice mistakes in a mid engine car causing the spins.

 

[NSXGMS]

Just a wild guess here.... drop throttle oversteer? No confidence going through turns and when the rear starts to feel unstable he lets off the gas and around she goes. It sounds more like driver input than setup.

I ran my NSX on Goodyear F1GS3D (which I hate on the track) with no front bar (sway bar link had broke) and a Dali Track bar on the rear and still managed to control the oversteer (well, except for that one spin) and chase down a C6 and Z4 M Coupe running on R888s. So I think that since he was slower than his buddies including a C230 that he wasn't pushing the car to the limits but was making novice mistakes in a mid engine car causing the spins.

I agree that there's nothing about his setup which would seem to induce oversteer. I of course assumed that he knows what he's doing out there. The drving style of the OP may very well be to blame. You or I might drive his car and discover it's wildly understeering.

The NSX really wants to understeer generally and it takes some serious countermeasures to really get it to want to oversteer.

 

[whatisreal7]

Thanks for all the input guys. Does it make a difference that the car is lowered ~1.5 - 2"?

Driver experience is definitely a factor here. I've only tracked 1-2 times w/ this car, and this time was the only time I tracked w/ a transponder that clued me in how consistently bad I was driving =) The time I spun out, the car didn't give me any warning/feedback; it just snapped and gave out. Two laps prior it slid out and I was able to counter-steer and bring it back. The second time I wasn't so lucky.

Shad, since I am local (kind of, I live in the Peninsula in Mountain View), I just might take your invite and pay you a visit. Hope there are some christmas specials coming up :wink:

 

[asylum]

First check your rear toe. Be sure you have a decent amount of positive toe.
Front and rear stock sways ?
TCS off (this shit made me make a spin once).

A stiffer front sway front sway bar could be a solution, as well as stiffer front or softer rear suspensions. But it is strange that just stock sways + aftermarket coilovers lead to such uncontrolable oversteer. Also, talking just about the fact that spring rate should be higher front as on the NSX-R is BS, as we should talk about spring+damper bound and rebound rates together. For exemple Tein have stiffer rear springs and I never met oversteer, even with the Dali race sways.

Start with the softest damper setting rear.

I also did not like the F1 GS-D3 on the track.

 

[Coz]

Right on Shad...
I use a simular set up on my Green NSX & Red NSX
Stiffer springs up front. 12k/10k
Stiff dampener settings on the front and soft on the rear.
Stiffer sway bar up front 1", 3/4" rear
Rake 1/2"
Rear Beams, Toe Links, Front Piviot Clamps.
But I run more negative camber, 2.4 on the rears.
Helped a great deal for the money spent.

Seems most of us agree on one thing for sure.
Stiff front end and soft rear end.

Make sure you have a stiffer springs in the front. Most of the Japaneses built suspension systems run a stiffer spring in the rear. I do not know why they think this works, may be they just like drifting? Invest in the non compliance rear beam and toe links. It will help make your rear tires last longer and make the rear of the car much more predictable in corners. Also make sure you run about a 1/2" of rake at the jack points. This means if your front ride height is 4" at the front jack point then the rear should be 4.5". Give us a call we can help you with the parts and getting everything set up. Cheers, Shad

 

[nsxnut]

I ran my NSX on Goodyear F1GS3D (which I hate on the track) with no front bar (sway bar link had broke) and a Dali Track bar on the rear and still managed to control the oversteer

I suspect you have the Front Frame Type-R Stabilizer Bar?

 

[ChopsJazz]

All good advice. Listening to the OP it sounds to me like a beginner's tire pressure mistake.

I love this advice:

Also make sure you run about a 1/2" of rake at the jack points. This means if your front ride height is 4" at the front jack point then the rear should be 4.5".

:biggrin:

 

[stuntman]

I read somewhere that HKS Hypermax comes with 8/9KG (f/r)


No one asked about his rear toe?

 

[whatisreal7]

Thanks for all the great advice:

Yes i'm running type-r stabilizer bars up front

I don't know what the rear toe is, but will consult w/ Shad next time I'm in sacramento.

Chopjazz...30/35 f/r tire pressure when tires are cold is too high or low? I didn't measure it when I started tracking yet.

 

[Hrant]

........ I didn't measure it when I started tracking yet.

I guess you may have diagnosed one of the more contributing factors. Running on OEM wheels and OEM size tires, you can put as much as 10 psi on the track if pushed hard.

Irrespective of the infamous old debates that proclaimed 33/40 cold was the ideal psi (shish), if you ran the rears at 38 or 40 cold (assuming that is what you run on the streets) then you probably got to 46-48 psi at the track and that would make the car VERY bouncy and slippery - hence oversteer too in the hands of a novice. Try to run them hot at no more than 33/40 psi and then tell us what you find before major changes :wink:

 

[stuntman]

Thanks for all the great advice:

Yes i'm running type-r stabilizer bars up front

I don't know what the rear toe is, but will consult w/ Shad next time I'm in sacramento.

Chopjazz...30/35 f/r tire pressure when tires are cold is too high or low? I didn't measure it when I started tracking yet.

You've been PMed...

 

[NSXDreamer2]

Chopjazz...30/35 f/r tire pressure when tires are cold is too high or low? I didn't measure it when I started tracking yet.

Not trying to beat the dead horse, but since you are in sunny california, I would supposed the track temp would be around 68-80 degree?? 32/35 is my favorite tire pressure when I still daily drove my car. But at the track, I'd bet you are probably running more than 42psi at the rear after couple warm up laps.

What I would do normally is that right after you get to the track, (assuming you have a 30-60mins commute to the track from home) I would check the tire pressure right away, adjust 2 degree less than what you would otherwise set up. Then adjust it between sessions.

Even with R comp. tires, when the rears got more than 45 psi, the rear end was getting a little out of control.

 

[ChopsJazz]

Chopjazz...30/35 f/r tire pressure when tires are cold is too high or low? I didn't measure it when I started tracking yet.

Those are pretty high pressures for cold tires. We may have found the culprit.

 

[whatisreal7]

Inside of the door panel says 35/40 f/r, so I just thought 30/35 would be safe. But if it adds another 6-8 w/ the tires getting hot, it would've put me over 40 in the rear...

Anybody here track w/ Hypermax II's? I'm thinking I should swap that out since I've heard from a few folks that it is not a good set of coilovers to track with.

 

[NSXDreamer2]

Inside of the door panel says 35/40 f/r, so I just thought 30/35 would be safe. But if it adds another 6-8 w/ the tires getting hot, it would've put me over 40 in the rear...

Anybody here track w/ Hypermax II's? I'm thinking I should swap that out since I've heard from a few folks that it is not a good set of coilovers to track with.

It's not the best but it's a better set up than OEM and many others out there. It's actually one of the best in the $2000 range.

Make sure it's not leaking then just adjust the tire pressure, start with the softest settings front and back.

FORGET ANY OTHER MODS. focus on the tire (over) pressure. Then focus your driving... Seriously even Schumacher can't beat me in a C230 if I'm driving a nsx, Period! :tongue:

 

[titaniumdave]

Inside of the door panel says 35/40 f/r, so I just thought 30/35 would be safe. But if it adds another 6-8 w/ the tires getting hot, it would've put me over 40 in the rear...

Anybody here track w/ Hypermax II's? I'm thinking I should swap that out since I've heard from a few folks that it is not a good set of coilovers to track with.

Tire pressure and alignment. Swap springs, heavier to the front.

Get some instruction.

Get lots of time behind the wheel.

Then spend some money on rear beam bushings and rigid toe links, like Shad said. Either he or I can help you there:wink:

Dave

 

[stuntman]

Tire pressure and alignment. Swap springs, heavier to the front.

Get some instruction.

Get lots of time behind the wheel.

Then spend some money on rear beam bushings and rigid toe links, like Shad said. Either he or I can help you there:wink:

Dave

What you need to do is:

Buy some springs from Factor X
Buy the rear beam bushings and toe links from Shad
Buy a Brembo F40/Lotus BBK from titaniumdave
Buy yourself some instruction from me
Buy yourself a beer

lol, jk :biggrin: