2012 national level autocross

[shrddr]

some of you are aware that i compete with the NSX nationally...

last year started really well, and then i blew the head gasket on the car (the temp sensor got disconnected, and thus the radiator fans didn't come on, causing the engine to overheat and blow the head gasket) while i was unemployed and thus not in a position to spend the big bucks to fix it. i spent the rest of the 2011 season driving various s2000's in B-stock... and an F-prepared porsche boxster. i won the pro solo finale driving an s2000, and finished 3rd in the autocross national championships in the boxster. but all that is history...

my NSX had its motor completely fixed up earlier this year, and it has been a very good start to the autocross season so far! i have won nearly all the local autocross events, and finished third in first national event of the year (the TX national tour) despite struggling mightily with a heavily oversteering car.

i compete in the B-stock class so the ONLY changes i can make are to use any front sway bar (i cannot change the rear), and use any shocks (spring must stay stock... cannot use zanardi, type-r, etc). i have been running the daliracing 1" front sway bar and koni shocks. as my driving (and driving style) has evolved and i have been getting more aggressive, it has been exposing the holes in my setup. while the car handles GREAT on low/medium grip surfaces... it oversteers heavily on high grip surfaces because the car ends up lifting the inside rear wheel! i am working with a race fabricator to try to build a custom front sway bar for me which will not only help settle the rear end down, but also cure the inside wheelspin issues i have been facing on corner exit (stock diff... i cannot upgrade that based on the competition class rules).

coming up this weekend is the mineral wells pro solo! this is the event that i won last year by over 2.5 seconds despite only being able to take 5 out of my 12 runs (this was where my car overheated and blew the head gasket).

i guess the point of all of this is to, first of all, announce that the car is back in a big way! and that i am gunning for a national title in september

more immediately, you can follow along with all of the action from the pro solo this weekend, if you are so inclined, at http://sololive.scca.com

and you can follow along with my entire season at http://nsxftw.blogspot.com


and videos for those who care...

this is from our last local autocross, which i won
<iframe width="640" height="360" src="http://www.youtube.com/embed/duSyBDDmPpc" frameborder="0" allowfullscreen></iframe>


this is from the TX national tour last month. the surface is very high grip, and i was struggling massively with oversteer... so you will see me driving much more conservatively than is typical.
<iframe width="640" height="360" src="http://www.youtube.com/embed/QWX2obV343Q" frameborder="0" allowfullscreen></iframe>

 

[shrddr]

oh, as an FYI for those who care... my current alignment settings are:

FRONT
camber: -1.1 (maxed out)
toe: 1/4" toe out

REAR: camber: -2.0 (maxed out)
toe: 1/4" toe in

for tires... i am running the hoosier A6 compound... 245/45/16 in front, and 295/35/17 in the back.

 

[docjohn]

good luck! You should get some help from the bigger bar.Also nice to see you opitmizing tire sizes.Have you thought about a higher end double adjustable shock( I'm assuming you use the single koni yellow)?

 

[shrddr]

yup, currently using the single adjustable konis. i have certainly considered higher end shocks (moton/AST, etc), but i tend to make changes to the car one at a time to fully understand what that change does and how i need to adapt my driving to take full advantage of it. so once i get the big front bar in and get comfortable with it... at that point i might look into either getting higher end shocks, or revalving the konis.

 

[Hapa88]

Good luck man!

Few suggestions though...I think you'll benefit greatly by:
1) Putting the Targa back on. There is a huge benefit in chassis rigidity (which is well documented). This may even help solve your oversteer problems.

https://www.google.com/search?q=nsx-t+chassis+rigidity

2) Getting a STMPO rear strut tower brace (if it's allowed). NOTE: This increased rigidity significantly, but i think it also increased the car's tendency to oversteer slightly.

 

[shrddr]

Good luck man!

Few suggestions though...I think you'll benefit greatly by:
1) Putting the Targa back on. There is a huge benefit in chassis rigidity (which is well documented). This may even help solve your oversteer problems.

https://www.google.com/search?q=nsx-t+chassis+rigidity

we are going to have to agree to disagree on this. there is no doubt that the targa top NSX's lose rigidity compared to the coupes, but keeping the targa top in place is going to make MINIMAL (if any difference) compared to taking it off. the targa is no longer a structural component connecting the A-pillar to the back. it is just held in by pins... there is no way that 4 pins are going to make a noticeable difference in structural stiffness. all we have so far is anecdotal evidence. for what it is worth, i have tried autocrossing with the top on, and i noticed absolutely no difference.

like i said, we can agree to disagree. both of us are going by what we "feel", neither of us has any real, hard, calculated data

2) Getting a STMPO rear strut tower brace (if it's allowed). NOTE: This increased rigidity significantly, but i think it also increased the car's tendency to oversteer slightly.

i can't do that.

 

[shrddr]

well... the race did not go so well. here is the report, copy/pasted from my blog (http://nsxftw.blogspot.com/)

----------------------------------

the "mineral ring" (as us TX folk call it), is a giant slab of asphalt that once upon a time used to be a military helipad or some such. the surface offers high grip for what you would expect from asphalt, but is extremely abrasive so the grip comes at the cost of very severe tire wear.

i came into this event on 16 run tires, and with a codriver. my experience with hoosiers has been that they are fastest on runs 1-15, plenty fast on runs 16-35, and fall off more from runs 36-50 until they die. i generally do not get more than 50 runs out of a set of rear tires on my car. anyway, given all that... i figured we had plenty of tire to get through this event. the first few runs on saturday felt decent. i was dirty on the left side, but the raw times were in the hunt... and considering the car was being loose (manageable, but not confidence inspiring) and that all my runs had mistakes, i was feeling good about where i was and was confident about making a serious upward move.

on this particular surface, with a slightly uphill start, my car was getting 2.0 60 ft times, and 4.8 200 ft times compared to the 5.0-5.1 second 200 ft times for the s2000's. it's REALLY nice to get a 2 to 3 tenth lead in the first 200 feet of the course.

that didn't seem to help me though, as the car got looser in the afternoon and i spun out once on each side. my codriver (who is the DP national champ, is a car setup wizard, and has an incredibly well built STR legal s2k as his daily driver) was also struggling with what he described as a car that was not just very loose, but very unpredictable, and not at all confidence inspiring. he said the car shows potential, but needs significant thought to be put into the setup... starting with a BIG FRONT BAR.

there is only one person/company that i know of that makes a somewhat big bar for the NSX (the daliracing trophy bar), and given that the NSX is a slightly rare car, they dont keep them in stock. i asked him about wanting a bar in early february when this problem was first discovered... and he still does not have any available. so last week i took the car to professional race engineer/fabricator andris laivins (http://www.laivins.com/), and he is going to build a custom bar for me. i should have the bar by early may, which means i should have it in time for the big spring nationals prosolo/tour in lincoln.

while getting the car ready to take sunday morning runs in the beautiful morning sunshine, we saw cords starting to emerge on the outside shoulder of the right rear tire. 32 runs is all it took to get there... which is just astounding, and speaks to how abrasive this surface was! i usually get around 50 runs out of a set of rear tires. my previous "low" in terms of how quickly i wore out a set of rears was 44... so this completely shattered that mark. as you might expect, fabric does not grip as well as rubber, and by the end of my runs, the rears were corded on both outside shoulders, and were starting to show cords on the inside as well. it was an epically disappointing way to get dumped out of contention.

several people have pointed out over the last few weeks that the bright side of all of this is that the car will likely be plenty fast when i finally get the big front bar in. but to be totally honest, i am a bit tired of "looking on the bright side". i have been lazy about car setup for too long, and it is almost shameful for me to keep bitching about the same setup problem and not really doing much about it other than trying to drive around it.

all of that is changing though, and mr. laivins is up to the task of building me a custom one off bar!

 

[dquarasr2]

Just a hunch:

That sounds like a ton of toe on both ends.

Front: I know toe out front gives great turn-in. Could it be it's turning in TOO well? What kind of oversteer are you getting? Entry, apex, or exit?

Rear: toe in provides good stability. But . . . is it possible you went too far? I'm used to toe settings about half of what you are reporting. Do Hoosiers work with what might be a high slip angle?

Not sure I know why these sound extreme, I can't necessarily explain it, just sounds higher than I'm used to using or seeing. Where did you get these specs?

Sorry if I'm barking up the wrong tree. I might be grasping at straws.

Great showing, BTW, hope you continue to have success and can bring home a championship in September!

 

[shrddr]

Just a hunch:

That sounds like a ton of toe on both ends.

Front: I know toe out front gives great turn-in. Could it be it's turning in TOO well? What kind of oversteer are you getting? Entry, apex, or exit?

Rear: toe in provides good stability. But . . . is it possible you went too far? I'm used to toe settings about half of what you are reporting. Do Hoosiers work with what might be a high slip angle?

Not sure I know why these sound extreme, I can't necessarily explain it, just sounds higher than I'm used to using or seeing. Where did you get these specs?

Sorry if I'm barking up the wrong tree. I might be grasping at straws.

Great showing, BTW, hope you continue to have success and can bring home a championship in September!

nah, this is definitely not a toe related problem. 1/4" toe in is ~6mm toe in, which is what the spec was for the early NSXs, so it is certainly nothing extreme. the car is loose throughout the corner... and we (think we) know why...

from having other take high speed pictures/video of the car while it was going around a corner, it became apparent that when entering a corner aggressively (trail braking, etc), i am lifting the inside rear wheel off the ground. this is happening because the hoosiers A6 (autocross compound) provide an overwhelming amount of grip for the stock springs and the outside front is compressed to its max and the car is very diagonally loaded with the braking and turning. consequently, the inside rear runs out of droop and is lifted off the ground... hence the corner entry looseness. for autocross, i LIKE corner entry looseness, so if this was the only problem, that would have been fine. but...

the stock NSX has less roll resistance in the front than in the rear... so once again... with the amount of grip the tires provide, in the mid corner phase the inside rear is more unloaded (even if it is still on the ground) more than the front. this is not so great, maybe just for my driving style, but i want the rear to start settling down from it's entry rotation at this point.

on corner exit, as i start rolling onto the gas, given that the rear is still unloaded from the mid-corner phase, i end up getting a fair bit of inside rear wheel spin. apart from the loss of acceleration, this also means that i am not able to transfer the weight to the back of the car to settle it down.

ideally i would cure ALL these problems with reworked spring and damping rates that are much more appropriate for the grip level of the tires, but given that the rules of the class prohibit me from doing that... i can bandaid the problem with a BIG front sway bar. it will make it much harder for the car to lift/unload the inside rear wheel... and i will be happy

 

[Hapa88]

like i said, we can agree to disagree. both of us are going by what we "feel", neither of us has any real, hard, calculated data

All i'm trying to do is HBO!!! (Help a Brotha Out). :biggrin:

Here's my experience:
First one was the 11th of 12 runs. I had been running the Targa On this whole day and the day before.
http://www.youtube.com/watch?v=Bhht2y2kjXk

Here's the last run, 12 of 12, where I decided to try out with the Targa Off. I noticed the difference after very first set of corners. The feel was so different that I completely missed the last cone in one of the rear chicanes and hit a cone shortly after that. The car felt much more dull and less precise..
http://www.youtube.com/watch?v=ccuA38_D83A

Here's the experience of other Primer's (4 of which seem to think the same as I do):
http://www.nsxprime.com/forum/showthread.php?t=149732

Anyway, you've already learned your car in this configuration. I guess the worse thing to do is to mess it up. And you are correct in that I do not have any hard calculated data...

But I honestly believe, however, that if you learn the car with the Targa on and are able to practice that you'll ultimately run faster... I mean, i would never suggest you switch it up during a competition. I'd do it during some practice runs.

Regardless you seem to be doing something right that's gotten you this far! Good work!

Lastly, what are the rules of running Bilstein Struts on the lower perch? You stated that you can run any strut.. the Bilstein offers a lower perch that lowers the car 7/8"... Are the Type R Front Chassis bars outlawed too? Can you run different Springs from different years? I know the dampers are different across the early years, but the springs may be too..

 

[shrddr]

All i'm trying to do is HBO!!! (Help a Brotha Out). :biggrin:

don't get me wrong, i appreciate the feedback

Here's my experience:
First one was the 11th of 12 runs. I had been running the Targa On this whole day and the day before.
http://www.youtube.com/watch?v=Bhht2y2kjXk

Here's the last run, 12 of 12, where I decided to try out with the Targa Off. I noticed the difference after very first set of corners. The feel was so different that I completely missed the last cone in one of the rear chicanes and hit a cone shortly after that. The car felt much more dull and less precise..
http://www.youtube.com/watch?v=ccuA38_D83A

there are too many variables in this "test" . first, you have a passenger with you in the second run. not only does that change the weight in the car significantly... if you are anything like me... when there is a passenger in the car i drive a bit differently. second, up until the point you missed the chicane, you were noticeably more aggressive on course.

point being, both you and i are going by what we feel. and that's perfectly fine either way

Lastly, what are the rules of running Bilstein Struts on the lower perch? You stated that you can run any strut.. the Bilstein offers a lower perch that lowers the car 7/8"... Are the Type R Front Chassis bars outlawed too? Can you run different Springs from different years? I know the dampers are different across the early years, but the springs may be too..

i can use bilsteins but i have to be on the "stock height" perch (cannot change ride height. i cannot run any type-r parts because they were never sold as "factory options" in the US market. and i cannot mix/match parts from different year NSXs. the rules are VERY restrictive, and i am ok with that. i am not much of a tinkerer with the car... i just like to drive it hard!

by the way... your car sounds GREAT!

 

[shrddr]

The season has been interesting... very up and down with car handling struggles.

But a few weeks ago, I got the car handling better than it ever has! The sway bar is in a happy place, and the shock settings are as good as they will be. I'm very happy with the way it rotates through corners.

We are currently in the middle of the national championships week! The Pro Finale was this past weekend, and the Autocross Championships are on Thursday/Friday. I finished in 3rd place in the NSX at the Pro Finale. Here is the event report: http://nsxftw.blogspot.com/2012/09/pro-finale-2012.html

Stay tuned for the Autocross Nationals report this weekend, or feel free to follow along with the action on Thursday/Friday at http://sololive.scca.com

 

[shrddr]

The 2012 National Championships are over, and I finished 9th out of 25 in class. That is not good enough for me. I have been working to make the NSX a nationally competitive car for a couple of years... and as much as I love the NSX... I have to admit I love winning even more, and I finally concede that I have failed at making it catch the s2000 CR. Having driven the CR a few times and experiencing what it can do at an autocross course, I am forced to admit that an NSX cannot keep up (in the B-stock class).

Here is my full write-up of the event: http://nsxftw.blogspot.com/2012/09/national-championships-2012-i-love-nsx.html

My car is not going anywhere. It will just be returned to "normal" duty, and I will be co-driving something else for autocrosses from this point on.

 

[TURBO2GO]

I think you did an awesome job. Hey a CR is still a Honda. Just an uglier one... So it's like losing to your uglier cousin. At the end of the day it's a faster auto cross car but we all know where it's at.

 

[docjohn]

I also applaud your determination and resolve to bring the nsx up to competative levels in the parking lot.I knew the car would be tough and i know just how good the s2000 is in the cones,oh well.

 

[R13]

'Grats on the podium finish in the Pro, and kudos for developing the car to this point. I recon if you threw a damp surface into the equation, you'd eat the S2Ks for lunch, but they are definitely fearsomely capable on these tight courses.

It's been fun watching. Best of luck with your future endeavors. Meanwhile I may try and schmooze the NSX a slot in the STR class so I too can get killed by S2000s .

 

[dquarasr2]

One thing that may have been lost in the focus on NSX the car is the contribution of The Driver.

To be competitive at the national level, not only does the car need to be highly competitive and prepared to the limits of the rules, The Driver must be top-notch, especially in some classes.

In the mid-90's I was doing fairly well in local autocrosses in my Stock-prepared Miata, even had a couple of second-place finishes at what I realized later were poorly attended Pro Solo events, but I got my clock absolutely cleaned at Nationals. In 1996 I finished near the bottom of the class b/c I coned out day two. But even on my fastest run, if it had been clean, I would have finished only mid-pack. The skill level at the top of nearly every class is very, very high.

Nice going, Shrddr, not only for car development but also for driving.

 

[shrddr]

'Grats on the podium finish in the Pro, and kudos for developing the car to this point. I recon if you threw a damp surface into the equation, you'd eat the S2Ks for lunch, but they are definitely fearsomely capable on these tight courses.

It's been fun watching. Best of luck with your future endeavors. Meanwhile I may try and schmooze the NSX a slot in the STR class so I too can get killed by S2000s .

i have been trying for 2 years to get them to put the NSX in STU . it doesn't stand a chance in STR when limited to 255 wide tires, but on 285s it could get interesting!

 

[shrddr]

One thing that may have been lost in the focus on NSX the car is the contribution of The Driver.

To be competitive at the national level, not only does the car need to be highly competitive and prepared to the limits of the rules, The Driver must be top-notch, especially in some classes.

In the mid-90's I was doing fairly well in local autocrosses in my Stock-prepared Miata, even had a couple of second-place finishes at what I realized later were poorly attended Pro Solo events, but I got my clock absolutely cleaned at Nationals. In 1996 I finished near the bottom of the class b/c I coned out day two. But even on my fastest run, if it had been clean, I would have finished only mid-pack. The skill level at the top of nearly every class is very, very high.

Nice going, Shrddr, not only for car development but also for driving.

absolutely, racing is more about the driver than anything else... and when i maintained my nsx/autocross blog, i always emphasized that the NSX is nothing more than a tool i am using to improve my skills.

i have done well nationally in other cars. i won the pro finale last year in an s2000 CR, and finished 3rd in FP. this is not to say i consider myself "good", far from it. i have tons to get better at... i'm just tired of trying to do that in a car that is not capable of a top level finish in autocross. from the perspective of driver development especially, it helps to be in similar machinery to the competition because it allows you to ignore car differences and hone in solely on what you are able to do as a driver