Time Trial Shenanigans.

Discussions related to SCCA Road Racing, Time Trials, and PDX.
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Wheelman_13
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Time Trial Shenanigans.

Post by Wheelman_13 » Wed Mar 27, 2013 9:27 pm

After quite a few years of HPDEs, track days, and a couple of Chump/LeMons races, I set a goal in 2012 to get a Time Trial license. I cut it close, but got it done in time to run an event at the end of 2012.

This year, my goal was to see where I stacked up, and optimistically win an event. Well, I won the first event of the season vs. a shallow field, so optimistic goal: complete. However I know I have a lot of work to be legitimately competitive.

That's where I'm hoping I can get some input along the way from my Autocross "family", lol.

My plan is to deposit data and video here for critique and/or a frame of reference for questions I may have about "how do", "what would you", etc.

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Re: Time Trial Shenanigans.

Post by Wheelman_13 » Wed Mar 27, 2013 9:27 pm

So: Where do I sit now?

I'm competing in TTB and will be running at venues including Carolina Motorsports Park, Road Atlanta, Roebling Road, and VIR.

For reference when talking about mods, here is the NASA classing chart for TTF-TTB (TTA+ now follow a different criteria).

The NSX base-classes as TTC** (the ** = +14 starting points).

As my car currently sits, I have ~4 points to play with before I hit the ceiling in TTB, although I suspect I'll actually have considerably more cap space once I get the car on a dyno to be reclassed based on power/weight ratio.

Vitals: (As of 5/15)
1992 Acura NSX 5MT

Weight: (now probably slightly less than after headers/cat delete)~3030 (including ~162lb driver & ~1/3 tank of gas) although I'm claiming less than this to allow some margin of error with track scales, so I'm taking more points here than I could just to be safely with in the rules for now.

Corner weights:
LF: 642
RF: 627
LR: 902
RR: 859
(that's 50.5% cross-weight, 41.9%F 58.1%R)

Power: ~267whp (based on DynoJet dyno)

Mods are currently limited to:
Engine:
  • ARK DT-S Tailpipe
  • TopSpeed Headers
  • Pride Resonated Test Pipes (Soon to be high flow cats for noise considerations)
  • Poly F/R motor mounts
Suspension:
  • KW Variant 3
  • Dali Type Q adjustable swaybars
  • Delrin bushings (front only)
Chassis/Brakes
  • STMPO front bar
  • ABS Update to 2001+
  • Hawk HP+ pads in OEM calipers
Wheels/Tires
  • 17x8 +37F / 18x10 +35R Advan RZ
  • 235/40 17F / 275/35 18R Nitto NT05
Last edited by Wheelman_13 on Thu May 16, 2013 8:10 am, edited 4 times in total.

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Wheelman_13
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Re: Time Trial Shenanigans.

Post by Wheelman_13 » Wed Mar 27, 2013 9:27 pm

Event 1: CMP (Starting 2/9/13)

Prologue
My last time here (November 2012) I ran a PR of 1:48.690 on 215/255 Dunlop Star Specs. The tires are the only thing I've changed at this point.

For reference, the TTB track record is 1:46.05. In November I finished runner-up to a now-banned-from-class Corvette which ran a 1:47.272.

Optimistically, I think 2.7 seconds should be do-able in the car as-is, but that's no margin for error IMO. That 1:48.7 was pushing the limit of how fast I could take the Kink on those tires (I actually spun there the lap after trying to carry a little more speed).

Here is some video from my last trip to CMP including a nice 110mph spin through the kink (according to phone GPS). The lap before the spin was my PR.
http://www.youtube.com/watch?v=MoQLel7YFAo


Event Summary/Results

Well, the good news first:

Saturday: 1st Place in TTB!
Sunday: 2nd Place in TTB (to a SC Miata :oops: )

Now the bad news:

Compared to November, I slowed down.

Best lap from November: 1:48.690 // Lap Average from weekend in November: 1:51.458
Best lap from February: 1:49.604 // Lap Average from weekend in February: 1:51.690

Weather conditions were largely similar (cold, dry, typical CMP light breeze both days).

The only thing I changed with my setup was the tires.

Compare this video from last year (up to where I spin anyway):
http://www.youtube.com/watch?v=MoQLel7YFAo

To this video from this event:
http://www.youtube.com/watch?v=pLha8tShxJc

My racer excuse is that I didn't have confidence in the tires. All street tires "squidge" a little on a track, but these NT05s definitely squidge differently to the Star Specs.

Here's a lap graph comparing my PR lap vs. my fastest lap this weekend:

Image

So basically, I tip-toed through the Kink (between ~65&71 on x axis), and also appear to lose time through the carousel (Ts5/6/7 between ~25 & 37 x axis). That's marginally retarded considering the extra contact patch I was working with, but like I said......squidge.


Some other data:

Tire temps:

I took a pyrometer with me and took some measurements throughout the day:
(I don't have "crew" and have limited laps/session, so I couldn't pull in hot to take these. As a result, these are about 1-2 minutes after parking following a cool-down lap)

Session 1: (cold, morning, pressure = 35psi all the way around at the time measurements were taken...so close to "hot" pressure)

RF:
Inside 101
Middle 97
Outside 85

LF:
Inside 98
Middle 96
Outside 92

RR:
Inside 125
Middle 119
Outside 103

LR:
Inside 119
Middle 113
Outside 110


Skipping to Session 3: (~15 degrees warmer ambient, full sun, ~37psi)

RF:
Inside 115
Middle 110
Outside 100

LF:
Inside 119
Middle 119
Outside 112

RR:
Inside 137
Middle 137
Outside 133

LR:
Inside 140
Middle 140
Outside 134

For those who haven't been and/or haven't watch the videos, CMP is a significantly right-handed track, so really the LF/LR numbers are the ones that matter. The Nittos seem to like higher pressure than the Star Specs that I ran previously (which felt happiest ~34-35 hot).

Lastly, my weekend ended by cracking a brake rotor. My first on this car. Thanks to some lucky foresight I'd started carrying some take-offs around as spares, so i was able to swap it out in just a few minutes to drive home.

Image
Last edited by Wheelman_13 on Wed Mar 27, 2013 9:44 pm, edited 1 time in total.

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Re: Time Trial Shenanigans.

Post by Wheelman_13 » Wed Mar 27, 2013 9:28 pm

Event 2: Road Atlanta (March 9-10)

Image

Prologue

I've been to road Atlanta a few times, but only once previously in the NSX. At the time I managed a ~1:45.xxx lap trying to chasing a 944 Cup car.

You can see that here if you can deal with the drunken helmet-cam view: http://www.youtube.com/watch?v=NGP9xlOF2R0

I fully expected to get destroyed at this track having looked at past season's TTB results. The track record for TTB is somewhere in the 1:36 range....9 seconds/lap is a bit of a gap.


Event Summary/Results

Unlike CMP, I got significantly faster vs. my last visit.....but (as expected) I got utterly destroyed in-class.

I managed a 1:42.599 on Saturday, lap seen here: http://www.youtube.com/watch?v=A6n4KJn6x5A
That was in spite of some pretty atrocious rev matching going into 10A. I got close, but could do no better the rest of the weekend.

The winning time (in class) was a 1:36.xxx (close to a lap record), so like I said: nowhere close, and exactly as I expected going in.

Take-Aways:
  • The Nitto NT05s still seemed happiest ~37psi hot or maybe a little higher. That said, I seemed to only have really a three lap window during a session in which I was quickest. I'm not sure if it was tire/car/or driver, but outside of that i was shedding time.
  • -I was giving up either a lot of horsepower, a lot of weight, and/or a lot of tire to my competition, so everything with a grain of salt at this point.
  • -On balance, I'll take a 3 second improvement having made essentially no changes to the car, and then see about getting closer next time after making some modest changes.
  • -Also, cracked a rear rotor this time. Apparently my car wears rotors out pretty evenly front/rear.
Unfortunately, I hadn't discovered the wonders of data logging the last time I was here, so I don't have any graphs to overlay and see where I made up the time I did. That's ok though because last time didn't involve a concerted effort. I have video of an entire session I'll upload at some point, but if anyone cares to critique based on the short video above, feel free.

Next Round will be either Roebling Road if I can make it work for a 5-day weekend 'cause that's a pretty good haul from Knoxville, or CMP again if not.

'Looking like CMP at the moment...which should allow time to tweak the car a little.....and make it to an Autocross :rockon:

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Re: Time Trial Shenanigans.

Post by EliseAutoXr » Wed Mar 27, 2013 10:42 pm

Looks like fun, thanks for the update!
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Re: Time Trial Shenanigans.

Post by SilverMaxima » Wed Mar 27, 2013 10:54 pm

EliseAutoXr wrote:Looks like fun, thanks for the update!
x2

I like your used of the word "squidge" in describing street tire movement... Didn't know you'd snatched up a set of NT05s. Was that just due to timing during the off-season...? I went from the original Specs to RS3s and I much prefer the feel of the Z1s. Granted, my only experience in the RS3s was a cool December day at CMP East Course, but they had several characteristics I didn't like, and were downright disturbing at triple-digit speeds when hard on the brakes. :? I'm hoping they'll be much better when it's warmer out (managed mid 50s back at CMP after a cold, foggy, damp morning).
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Re: Time Trial Shenanigans.

Post by thrdeye » Thu Mar 28, 2013 7:00 am

A question I have, not necessarily relevant to ETR, is why NASA TT instead of SCCA? Just curious...it was a hot topic at the national convention. You can PM me if you want or post it here. Either way.

Now, my opinion on the slowness on the Nittos is that the Star Spec is probably the most forgiving tire known to man. Pound for pound, if you had to run 1 tire that needed to do everything, that's it. It doesn't care about conditions or temp...it will work. Almost any other tire is more particular about conditions and setup. As such, you probably have a little work to do to setup the car for the tire. Now, what "setup" means on a fancy-pants poor-man Ferrari, I don't know :D
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Re: Time Trial Shenanigans.

Post by steverife » Thu Mar 28, 2013 7:25 am

Does SCCA even have a viable TT program?
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Re: Time Trial Shenanigans.

Post by integra55 » Thu Mar 28, 2013 7:38 am

I can't speak for Richard, but in my case... the ease of entry... the availability of events ... prep levels ... no medical .... no school required ... no novice license required ......

even though my car meets the TT 3/4 requirements of the SCCA, and I do have a physical twice a yr, all I had to do was run the different HPDE levels asking for a check ride as I wanted to move up ....

and even bigger Chris ( assuming, as is my case, you aren't attracted to the idea of hill-climbs) just how many opportunities are there to participate here in the SE ( within ... say a 5 hr tow/drive ? ) .... 1 at RA, 1 at CMS ... can't think of any others

just with NASA-SE ... (granted RR is a bit out of my comfort range, distance wise, but so then would be Little Talladega, which is the only other "close" SCCA" event ...

Feb 9-10 Carolina (CMP),
Mar 8-9-10 Road Atlanta,
Apr 13-14 Roebling Road,
May 18-19 Carolina (CMP),
Jun 14-15-16 Road Atlanta,
Aug 3-4 Road Atlanta,
Sep 13-14-15 Road Atlanta,
Oct 11-13 VIR Full,
Nov 2-3 Carolina (CMP),
Dec 6-7-8 Road Atlanta.


then you have the pissing contest going on between NCR & ( I'm guessing CCR/SCR) over the Carolina Cup Pro Series that has driven lots of drivers away from the Mar. event at VIR which used to have a 1 day PDX ( and even then .. no TT)

SCR was the only region that tried to support the TT level 2 events ( basically a TT3 event with PDX level prepped cars ), which none of the level 3/4 licensed drivers would attend (so it died a quick death )

I've had this talk/argument with Steve E ( CCR ...RE) many times, and he is very typical of the "old school" SCCA cadre that isn't about to change ... "that's not how we've always done things" ( though if you talk to him you'll get a different story) the SCCA claims they want to increase the participation level at TT's but won't budge when it comes to the largest target group they have ... namely the a-x'ers and the PDX'ers that are looking for a chance to get timed track time
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Wheelman_13
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Re: Time Trial Shenanigans.

Post by Wheelman_13 » Thu Mar 28, 2013 11:07 am

Yeah, the tire decision was more of a timing thing. I questioned whether the set of star specs I had on the car (and still have) would make another couple of track events. I also wanted to try a slightly wider front tire. By the time I started shopping, the Z1 was sold out of any size I could use, and the ZII wasn't (and still might not be) out in those same sizes.

Plus the Nittos were hella cheap and I got them with free shipping from discount tire.

I think I got used to the squidge, or had scrubbed them down far enough by Road Atlanta that it wasn't bothering me too much anymore. I suppose we'll see when I go back to CMP next time.

As for NASA vs. SCCA, I can sum that up pretty easily: Entry barriers, accessibility, and availability of concise information.

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Re: Time Trial Shenanigans.

Post by PushinTheLimit » Thu Mar 28, 2013 11:37 am

Richard, I know we've discussed this before and it looks like you've done well your first few times out in TT. Going to Hoosier A6's is the biggest gain you'll see on the track. And it's good that you're still in TTB and I know you wouldn't want to bump up to TT3 since that class is big $$$.

Since your base tire width for the class is 265mm, if you could run 235's all around, that would subtract 7 points toward a set of A6's or even R6's. A6's in that size would still be a total of 6 points (+13 for A6's, -7 for 235's) but R6's would work since they are only +10. I know you are probably trying to get around this since you drive your car to events.

Outside of tires, take advantage of as many of the "free mods" that you can do. Alot of those take away your streetability so if you're worried about that, pick the ones that don't mess that up. Lots of guys have gone to small lightweight clutches but for daily street driving... not as good. The competition is getting tough to where you can bring a total street car and go in and win in TT. Many of the cars are purpose built since TT has been around for a few years now.
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Re: Time Trial Shenanigans.

Post by Wheelman_13 » Thu Mar 28, 2013 12:22 pm

Yeah, the race-tire thing is basically never going to happen on this car. Trust me, I completely understand the hamstringing I'm giving myself there, but it is what it is.

My base tire (since I start in TTC) is 255, but there is really no way I could go any skinnier than that with the car at its current weight and still be able to put power down/maintain correct balance. I also can't do a square setup with this weight bias.

My plan for the near future is to install the headers that I have laying around already, along with some high-flow cats, just to gain a little torque/power.

After that, I need to get the car on a dyno to get a WHP figure because based on the power/weight limit for TTB, I'm Nowhere. I think it's 10.something. I'm probably at 12.something right now. That would give me a lot more room to drop weight, add power, or use points for aero/tire/etc.

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Re: Time Trial Shenanigans.

Post by PushinTheLimit » Thu Mar 28, 2013 12:35 pm

Aero was going to be my next suggestion for you... just wasn't sure if that was something you would be willing to do to the car. To get the full benefit of aero, you really need a wing and a splitter. The splitter isn't good for street driving (like speed bumps and inclined driveways). It would certainly help the car at especially tracks like Road Atlanta.

The headers should help you some. Would you ever consider replacing the seat with something lighter but still street legal? Could save a little weight and be much better on the track.
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Re: Time Trial Shenanigans.

Post by Wheelman_13 » Thu Mar 28, 2013 1:22 pm

Yeah, If I put the car on a diet that will likely involve seats, lightweight bumper beams, battery, and maybe some composite bits....but not too many of those. The body panels are already all aluminum, so not really much to be gained there for the expense.

The current seats actually keep my butt in place pretty well considering, but a "race" seat would still be better and would also drop the weight of the power motors and whatnot.

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Re: Time Trial Shenanigans.

Post by SilverMaxima » Thu Mar 28, 2013 4:03 pm

Wheelman_13 wrote:Yeah, the tire decision was more of a timing thing. I questioned whether the set of star specs I had on the car (and still have) would make another couple of track events. I also wanted to try a slightly wider front tire. By the time I started shopping, the Z1 was sold out of any size I could use, and the ZII wasn't (and still might not be) out in those same sizes.

Plus the Nittos were hella cheap and I got them with free shipping from discount tire.

I think I got used to the squidge, or had scrubbed them down far enough by Road Atlanta that it wasn't bothering me too much anymore. I suppose we'll see when I go back to CMP next time.

As for NASA vs. SCCA, I can sum that up pretty easily: Entry barriers, accessibility, and availability of concise information.
Gotcha.

And +1 to SCCA versus others... Even here, info is sparse and PDXs rare within a 6 hour drive. NASA TX has plentiful events though!

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