Did anyone time themselves at Sebring at NSXPO '06?

[dquarasr2]

I just came from a Chin event at Sebring today. I've been having some arguments with my NSX recently (it's been "oversteery") so to eliminate one of the variables, I bought a set of Kumho Victoracer V700 in '91 stock OEM size. I am very familiar with this tire from my '94 Miata, so I wanted to start with a known quantity.

In the first session it was still not as buttoned down as I would like. Particulars: car is just shy of 80k miles, stock everything except bespoke tires, aftermarket exhaust, Cobalt GT-Spec pads, SSS brake lines and Motul 600, medium aggressive alignment with a modicum of rear toe-in and negative camber. If I braked even a little late, or experienced even a little fade such that I needed to start turning in before I was done braking, invariably on exit the car never settled back down. It always felt as though it was "up on its rear haunches", ready to rotate. I wonder if the shocks have given up the ghost and need to be replaced.

In the last session I vowed to brake earlier, in a straight line, to be even throttle on turn-in, and more gentle on the accelerator as I approached the apex, managing weight transfer to the rear tires much more conscientiously. I also concentrated on carrying more speed in the turns are relying less on the loud pedal to propel me down the ensuing straights.

Using this technique the car was SO much more stable and did pretty much what I wanted it to do. So maybe it was me all along.

But after all this, and starting to congratulate myself on how I "fixed" my car by just driving it better, a friend who was timing me during these sessions told me that while I was faster than the other sessions where I was throwing the car around a little, I ran only 2:53! I'm fairly embarrassed by that time. All of my laps were encumbered by slower traffic (on my two best laps I easily lost 2-3 seconds following cars, never got a clear lap), but I've done 2:54 in my Miata (Kumho, Cobalt Spec Miata pads, Motul 600). I know Spec Miatas get deep into the 2:4x range.

So, I ask, what is a reasonable time for a mostly stock '91 NSX? I cringe when I think of what the answers will be.

Caveat: I REALLY enjoy bringing all my aluminum home with no wrinkles! But even still, I thought I should have at least been in the mid 2:4x range at Sebring.

Comments from the Prime brethren most welcome. I'm just not nearly as comfortable in the X as I am in the Miata, and I'm starting to wonder if the car needs some serious development / maintenance, or if that's the nature of the mid-engine configuration. Or if I just suck! :biggrin:

 

[GreggMarkarian]

I did some 2:38s and one 2:37 in the last session on the last day (stock '91, zanardi suspension, stock size ra-1 proxes, motul rbf 600 and XP-10 pads). Felt great to finally hammer the brakes in the braking zones instead of babying them like I had been the previous two days. But it was my first time at Sebring and I wanted to make sure the car lasted till the end.

Because of the mid-engine layout, it is more critical in the NSX than most cars to plant the rear end through the corner. You've got the right idea - overbrake going in so you can get to full throttle earlier in the corner. Slow in, fast out. The car will love you for it. The uncertainty you're feeling mid-corner is simply not having enough weight transferred to the rear tires. I know it feels like you're going as fast as the car can go already, but believe me, the more gas you give it, the more weight you'll transfer to the rear and the better the car will feel. Its a very difficult lesson to learn because it requires a certain leap of faith, but you'll be rewarded with so much traction it'll feel like a whole new car.

-Gregg

 

[tonynsx]

I did some 2:38s and one 2:37 in the last session on the last day (stock '91, zanardi suspension, stock size ra-1 proxes, motul rbf 600 and XP-10 pads). Felt great to finally hammer the brakes in the braking zones instead of babying them like I had been the previous two days. But it was my first time at Sebring and I wanted to make sure the car lasted till the end.

Because of the mid-engine layout, it is more critical in the NSX than most cars to plant the rear end through the corner. You've got the right idea - overbrake going in so you can get to full throttle earlier in the corner. Slow in, fast out. The car will love you for it. The uncertainty you're feeling mid-corner is simply not having enough weight transferred to the rear tires. I know it feels like you're going as fast as the car can go already, but believe me, the more gas you give it, the more weight you'll transfer to the rear and the better the car will feel. Its a very difficult lesson to learn because it requires a certain leap of faith, but you'll be rewarded with so much traction it'll feel like a whole new car.

-Gregg

Well said, Gregg. If I have read your message before I went to Willow Springs this past weekend, I would have done much better. Oh well, it's never too late.

Tony

 

[1BADNSX]

My best time at Sebring in a stock class E36 M3 was a 2:33.5, but that is with a lot of laps there and Hoosiers . Gregg’s times seem pretty reasonable for a slightly modified NSX and also achievable in a stock NSX with Yoko’s. Mark Hicks would know best.

Bob

 

[dquarasr2]

Gregg, thanks for the tips.

I think I would have been around 2:50 on a clear lap. This is with my friend on board, and he goes around 260 lbs. I don't know how much time penalty that equates to.

I did try braking what seemed was ridiculously early to be able to start feeding throttle as I turned in. I also noticed that it did provide a lot of rear grip doing so. I am a little shy with the gas pedal as it is so much stronger than what I'm used to, and I guess I still don't trust the car yet. The first time I tracked the car it had around zero toe in the rear, and tires that were toast. It was EASY to go sideways using the throttle. Fun, but in a nervous kinda way. The last two track events I've had a much better alignment on it.

Yesterday I started feeding full throttle earlier and earlier and it did plant quite nicely. In turn one I even got some understeer, which allowed me to add nearly 10 MPH through that turn.

I figure that on a clear lap, with the passenger seat empty, I can get into the 2:45 range.

One other thing that I will look at is the rear brake bias. Yesterday I noticed that when at threshhold braking sometimes the only way to get the car whoa'd down all the way was to heel-toe very early in the brake zone and get some engine braking involved.

Regardless, comments most appreciated. Next time I'll change my driving style on my first few laps and see how it goes. As it was, since I was instructing yesterday, I didn't have a huge amount to track time, only about 45 minutes total on the new Kumho's (which were barely heat cycled before I used them on the track).

Bob, Mark was jetting outta there early yesterday, so we didn't have time to hook up for some laps. I was hoping to have him or Maria drive the car and see what they thought.

Thanks both for your comments.

 

[RacerX-21]

I rarely ran alone... that both helps with weight and my willingness to hold the edge. But my data acquisition showed a best time of 1:19 and I think Wei Shen clocked me at 1:22 with him in the car.


I asked Peter Cunningham (At the bar) what a GT car should run... he said 1:10. Nice... just kick me in the balls why dont you:smile:

 

[dquarasr2]

I rarely ran alone... that both helps with weight and my willingness to hold the edge. But my data acquisition showed a best time of 1:19 and I think Wei Shen clocked me at 1:22 with him in the car.


I asked Peter Cunningham (At the bar) what a GT car should run... he said 1:10. Nice... just kick me in the balls why dont you:smile:

I'm sure you mean 2:19, 2:22, and 2:10, unless you're talking about the club course.

If you're doing 1:19's on the long course, you're defying the laws of physics!:biggrin:

Your car is obviously nowhere near stock, right? (If it is, talk about being kicked in the balls! )

 

[John McCain Racing]

I rarely ran alone... that both helps with weight and my willingness to hold the edge. But my data acquisition showed a best time of 1:19 and I think Wei Shen clocked me at 1:22 with him in the car.


I asked Peter Cunningham (At the bar) what a GT car should run... he said 1:10. Nice... just kick me in the balls why dont you:smile:

Have you run your Miata's at Sebring yet?

 

[VintageracerNYC]

well just to be off subject I ran 2:10 at Daytona this weekend at the HSR event!

 

[Kip Olson]

Best timed lap @Sebring was 2:21. Tried to hang with Rob Morrison with his 2:19lap, but he was just to fast with that race car. Kip Olson

 

[dquarasr2]

Best timed lap @Sebring was 2:21. Tried to hang with Rob Morrison with his 2:19lap, but he was just to fast with that race car. Kip Olson

:frown: Sigh. :frown:

Anyone want to by a '91 NSX, cheap?

No, just kidding. Sheesh, I need to work on my confidence in the car.

 

[docjohn]

Practice-seat time,and please take advantage of Chins' great instructers,esp those with mid-engine experience.I was doing 2:48 0n day 1 and 2:36 day 3.My car was on ra1 and I have the r susp and bbk up front.

 

[dquarasr2]

Practice-seat time,and please take advantage of Chins' great instructers,esp those with mid-engine experience.I was doing 2:48 0n day 1 and 2:36 day 3.My car was on ra1 and I have the r susp and bbk up front.

This is why this self-inflicted shame weighs so heavily on me.

I AM one of their volunteer instructors! I am good at identifying basics to HP driving, I feel I have good communications skills, and put newbies at ease. I know the line, I know car control, so I think I am pretty effective at being a decent instructor.

But the times I ran have me totally baffled. My approach speeds to all the braking zones were 20-30 MPH higher than I do in my Miata. I know I was braking earlier, partially due to the higher approach speeds and partially because the Cobalt GT-Spec aren't nearly as good as the Cobalt Spec Miata, and also the fact that the Miata is nearly 700 lbs lighter than the X.

But I thought I had carried reasonable speeds through the turns, certainly enough to be somewhere in the mid-2:40's.

I can't tell you how much this is bothering me. I just can't get a good handle on this car. I don't knkow if it's the car's brakes, swaybars, shocks that make it uncomfortable for me to drive, of if it's just me being too tentative with it.

I think next time I will participate as a regular entrant rather than an instructor so I'll have more time to devote to getting comfortable in the car. Instructor days are somewhat of a fire drill and I really don't ever get a chance to put my head into it.

Thanks to all for the comments, suggestions, etc.

 

[docjohn]

You just need to track the nsx more!BTW if your shocks are original I would get a new set.That will help somewhat with the feel of the car.Have you had a ride around with Wei Shen? That often will help you get on the thottle sooner.I have had other front engine instructers drive my car and I can tell you that most have almost looped the car trying to drive it like thier cars.

 

[dquarasr2]

You just need to track the nsx more!BTW if your shocks are original I would get a new set.That will help somewhat with the feel of the car.Have you had a ride around with Wei Shen? That often will help you get on the thottle sooner.I have had other front engine instructers drive my car and I can tell you that most have almost looped the car trying to drive it like thier cars.

So I guess I shouldn't think about buying a mid-70's Porsche 930, eh? :biggrin:

 

[GreggMarkarian]

I AM one of their volunteer instructors!

Then you should know that how good an instructor you are has little to do with how fast you can drive. And also that just because you are an instructor doesn't mean you can't still learn a lot from the instructors around you.

After hearing more of your backstory though, it sounds like you are simply treating the NSX as the expensive exotic that it is. Its a lot easier to run at 8/10ths or 9/10ths in a little Miata than an NSX. I mean, if you have both, why risk it? Little voices like that in the back of your head will cost you many seconds on the track and make everything in the car feel wrong.

I think the little voices have the right idea - push yourself and you technique in the Miata and enjoy the NSX for the expensive exotic that it is. You can still track the NSX, but leave the stopwatch in the Miata. :wink:

-Gregg

 

[docjohn]

Gregg,,stop giving GOOD advice!:biggrin:

 

[the nsxnut]

Great thread, Doug... BUT, remember that timing at Chin Motorsports events is unofficial - AHEM - that being said...

First, note on Kip's times above, his NSX is the heavily modded 'Comptech Special'... still a street car (kind of), but it's got pretty much every thing from the CT catalog on it. And, of course, Kip's a very experienced driver.

For the purpose of comparing a 'Street' NSX, most of the cars in question have, at a minimum, R compound tires, and some level of suspension and brake upgrades. For an NSX equipped thusly, a good time will be under 2:40; a great time will be under 2:35. Dr Chin's supercharged/bremboed/suspensioned/Hoosiered NSX goes about 2:30-31. I've gotten mine around (nat. aspirated) in 2:35ish. I've run the Chin Spec Miata around in about 2:46ish. And, for the record, Maria can almost always match my lap times!

I'd love to drive your car next time we're there, Doug. Sorry we didn't have more time on Saturday...

BTW, for DocJohn... I found a loose lower control arm bolt on the RF of the Spec Miata, and it had POSITIVE camber! It wasn't our imagination... the car was NOT turning in! Too bad it spoiled our ride...

 

[dquarasr2]

Then you should know that how good an instructor you are has little to do with how fast you can drive. And also that just because you are an instructor doesn't mean you can't still learn a lot from the instructors around you.

After hearing more of your backstory though, it sounds like you are simply treating the NSX as the expensive exotic that it is. Its a lot easier to run at 8/10ths or 9/10ths in a little Miata than an NSX. I mean, if you have both, why risk it? Little voices like that in the back of your head will cost you many seconds on the track and make everything in the car feel wrong.

I think the little voices have the right idea - push yourself and you technique in the Miata and enjoy the NSX for the expensive exotic that it is. You can still track the NSX, but leave the stopwatch in the Miata. :wink:

-Gregg

Gregg, yes, you're absolutely right. I didn't mean to come off all hoity-toity. I would welcome another's input, very much so. Every time I go out it reminds me how much I DON'T know. At least I'm cognitively ignorant!:wink:

I do hear the little voices in my head. Thinking back, I don't recall being very relaxed behind the wheel. I had a passenger most laps, and rather than stop and think about it, I kept reinforcing bad behavior until after the lunch break, after some time to think about what the h*ll I was doing.

Great thread, Doug... BUT, remember that timing at Chin Motorsports events is unofficial - AHEM - that being said...

First, note on Kip's times above, his NSX is the heavily modded 'Comptech Special'... still a street car (kind of), but it's got pretty much every thing from the CT catalog on it. And, of course, Kip's a very experienced driver.

For the purpose of comparing a 'Street' NSX, most of the cars in question have, at a minimum, R compound tires, and some level of suspension and brake upgrades. For an NSX equipped thusly, a good time will be under 2:40; a great time will be under 2:35. Dr Chin's supercharged/bremboed/suspensioned/Hoosiered NSX goes about 2:30-31. I've gotten mine around (nat. aspirated) in 2:35ish. I've run the Chin Spec Miata around in about 2:46ish. And, for the record, Maria can almost always match my lap times!

I'd love to drive your car next time we're there, Doug. Sorry we didn't have more time on Saturday...

BTW, for DocJohn... I found a loose lower control arm bolt on the RF of the Spec Miata, and it had POSITIVE camber! It wasn't our imagination... the car was NOT turning in! Too bad it spoiled our ride...

Thanks, Mark. I did hesitate to associate numbers with the Chin event, but when it was requested that the multiple transponder timing systems be taken down, with an offer for just the one to be used, I thought it to be an "unofficial" official sanction of timing laps. I understand that timers in the HPDE format is not encouraged.

My upgrades amount to Cobalt GT-Spec, Motul 600, and Kumho V700 R-compound.

And no apologies required for not having time. I know yours and Maria's time at events is limited as your first duty is to run the event and your second duty is to have some fun in the Chin Miata. Anything after that is pushing it.

I already decided that in 2007 I'll participate as a paid entrant so I'll have all day to progress at my own pace and enjoy it without having to divide my attention with a student (not that I'm complaining, the barter of track time in exchange for bringing along a student is way fair, and rewarding as well when I can bring along a newbie who doesn't know the track in the morning and is motoring along quite nicely in the afternoon; very rewarding indeed.)

 

[docjohn]

Thanks Mark for the followup.Amazing how a loose bolt can feel like the tire went down or worse!

 

[VintageracerNYC]

well I will be running the last HSR event of the year at Sebring the last weekend of this month and I will be thrilled to run a 2:25! Kips time of 2:21 is smoking fast as that is nearly as fast as some Porsche Cup cars I saw racing there this spring. Will let you know soon after. Racing Brakes BBK upgrade sure has helped the car dramatically fighting fade from high speed.

 

[Scin]

Your stock 91 shocks are shot, guaranteed. Replace them with Bilsteins and I bet you will easily find 5 seconds a lap+ and the car will feel way better.

The shocks on my 94 with 52,000 miles were worn out. I can honestly say that replacing them was my best mod!

 

[dquarasr2]

Your stock 91 shocks are shot, guaranteed. Replace them with Bilsteins and I bet you will easily find 5 seconds a lap+ and the car will feel way better.

The shocks on my 94 with 52,000 miles were worn out. I can honestly say that replacing them was my best mod!

Many thanks for this perspective. I'm was thinking this might be the case, but I'm trying avoid throwing $$ at it until I find it for sure. I think the best approach at this point is to have someone, who can help me tune it, drive the car and make an evaluation, or tell me it's the Nut That Holds The Wheel.

If it is indeed shocks, are Bilsteins the best answer? I've had good luck on other cars with Koni Sport. Is the consensus that Bilsteins are the best bang-for-the-buck for the NSX? (And if so, what kind of $$ would we be talking for all four (sans installation)? More of a rhetorical question as I'm sure I can find out quite easily. I'll poke around here on Prime and elsewhere.)

NEVER MIND! I just checked out the FAQ and found everything I needed!

 

[flyn2Lo48]

I've run Sebring 4 times in my stock 97 NSX and I can't say I've had an oversteer problem. One suggestion: though stock psi (for the 97) is 33front/40rear, I'll tell you that the car is more neutral (e.g., no oversteer/understeer) if you'll bleed off the rears to only 4-5# higher, when hot, than the fronts. My instructor suggested this after he drove my car and I routinely adjust the tires using this technique. Just for grins, run stock psi, get the tires hot after several laps, and check the psi again. It's likely climbed from 33/40 cold to 37/50 hot! Try it and see what you think.

 

[dquarasr2]

I've run Sebring 4 times in my stock 97 NSX and I can't say I've had an oversteer problem. One suggestion: though stock psi (for the 97) is 33front/40rear, I'll tell you that the car is more neutral (e.g., no oversteer/understeer) if you'll bleed off the rears to only 4-5# higher, when hot, than the fronts. My instructor suggested this after he drove my car and I routinely adjust the tires using this technique. Just for grins, run stock psi, get the tires hot after several laps, and check the psi again. It's likely climbed from 33/40 cold to 37/50 hot! Try it and see what you think.

On the recommendation of a long-time NSX tracker who also uses the same Kumho R-compound tires I was on, I ran 33 / 37 cold (which puts it pretty much where you suggested). Don't know how to equate that to stock PSI. I didn't check them hot since I almost always start with a cold PSI baseline, then just bleed / add 1 or 2 PSI from there depending on how the car is reacting. I know that after one session in particular the tires were nice and hot, as I had lots of rocks and OPR (Other People's Rubber) stuck to and in the tread.

Usually there's a 2-3 PSI split front/rear for rear-drive cars, and often 4-5 PSI split in FWD cars, but I imagine all bets are off for a RWD mid-engine car. Which is why I asked my NSX track buddy before I came out.

I'm very confident the jitteriness of the car is not the tires, but as always, thanks for the input and suggestion.