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View Full Version : HPDE Observations: Car; Groups; Other Cars; Tires; Temps; etc.



Stealth
08-09-2015, 03:24 PM
This thread addresses my HPDE with SpeedVentures (“SV”) at CA Speedway yesterday and attempts to touch on some issues that relate to both Gen Vs and HPDEs. My car is a 2014 Viper GTS and is stock except for Castrol SRF brake fluid, MGW shifter, Arrow PCM and Corsa Cat-back. I have OEM Corsa tires and 4,700 mi.

First, SV was just excellent. Well run, good track time, addressed feedback from drivers, etc. They also had NICE cars. Too many HPDE Club groups i SoCal now do NOT have nice cars in the upper run groups, and also have too many low-budget race cars running with street cars. My run group had a Ferrari 458 and 430 Scuderia, Porsche Turbos, Mercedes AMG SLS Black Series, M5, M4, M3 and M2s, F-Type Jaguar Coupe, Porsche 911S, Cadillac CTS-V, Audi S5, etc.

Second, CA Speedway (Autoclub Speedway) is a professional, high speed track which includes part of the high-banked oval and the infield. It has a few heavy braking zone.

Third, I chose to run in the highest, non-open passing group: passing unlimited on the various straights and point-by in other areas. This was a downgrade from my usual open-passing group but was really perfect and safer. We all got to go as fast as we chose and were not really delayed. The open passing groups, on the other hand, attract more race cars (homemade) and other cars on race tires. These drivers push their cars harder, take more chances and throw more rubber, all of which increases risk and wear and tear on your car. If you want to approach racing conditions with your street car, then this is a different matter. I just enjoy lapping time on a great track.

Fourth, a bit about heat and its effect on the cars, including my Gen V. It was about 85F at the track and this was actually cooler than forecast. Many cars had heat issues. A C7 Z07 owner told me that yes, he did have loss of power/heat issues after several laps but that he was ok with this for an OEM car. We were not in the same group and I did not see him run so I do not have further input here. An F-type Jaguar Coupe (supercharged) owner indicated that he experienced loss of power after the heat build up. A MacLaren MP12-C had a “Transmission Failure” message after 4 easy laps. A modded Mitibushi something (500hp+ at the wheels, race tires., etc.) overcooked it brakes and had engine heating issues, etc.

My Gen V saw its highest Oil temps yet. In May at this track with 72F temps, I saw Oil temps of 224F or so. Yesterday I saw 261F briefly but mostly around 225—242F. Temps cooled even a corner or so later. Admittedly, I was going relatively fast and pushing at times. When I aggressively heel-towed down from 120mph or so for low speed corners (and consequently had the rpms singing), this definitely elevates the temps (vs. clutching, using the brakes and then rev-matching). The car quickly cooled down to low 230sF when I backed off a bit, and temps quickly dropped on the cool-down lap. I am on factory coolant and have 4,700 mi. on the car. There were no signs of any degradation of the car’s performance. The car also did not appear to burn a drop of oil. I was in “Safe” oil measured before and after the event. As a precaution I added a ½ qt. before leaving home. I am running factory fill (0-40w?).

Fifty, tire pressures were very interesting. My car has factory Pirelli Corsas. I started at 29psi cold before I left home. After my first session I was as high as 36.5psi, depending on the tire. I let the air out to around 32.5psi after my first session. The wear was generally going down the tire to the edge of the Tread and did not continue to the sideway so it appeared to be just right. In my two afternoon sessions, when it was hotter and I was definitely moving on track, twice I received a “Low Pressure Warning” and it showed I was at 28-29psi. I thought that this was a bit unusual but verified my post-session temps as 31.5psi or so. So, I was likely a bit under-inflated the last two sessions. Has anyone else experienced this?

Sixth, the MGW shifter is AWESOME! I have laguna leather and the stock shifter had a very nice feel so I was reluctant to change. I had a MGW shifter with the Viper logo even before I purchased the car. It has a long cylinder shape. It was just awesome for shifting at the HPDE.

Seventh, a comment about some of the other cars. The AMG SLS Black on Michelin Sport Cup 2 tires was fast! It was a beautiful car and well-driven—carbon fiber and alcantara everywhere. I think it runs around $300k. My car has Corsas and TA Exterior Aero. My appeared to be very evenly matched with the SLS Black. Neither car pulled the other on the front straight or other comparable areas. I can see why the Magazine comparison was close. There were areas of the track where the AMG’s double clutch appeared to provide an advantage. For example, I could see that car shifting and I would lose just a little bit of ground as I clutched and shifted (I do not "speedshift").

The Jaguar F-Type Coupe (550hp?) was also impressive. It was OEM stock except for the tires according to its owner and had an automatic transmission. The owner was a relatively new driver and did very well. He had larger-than-OEM Pirelli Corsas mounted and was quite fast. As noted, he did have some minor heat issues, but was not aware of any of his guages

Finally, I need to find an alternative to Blue Tape! My car has clear bra protection, but this will not always stop a rock, etc. and you may need to replace the clear bra and/or repaint which is something I want to avoid. The blue tape works, but looks silly any needs constant maintenance. Blue tape is also a bit dangerous—I had a fist-sized ball of tape come off the center of the hood, swerve toward the windshield and then hit the driver’s side rear-view mirror at high speed. The broken MacLaren had sloppy Trac Rap (which still looked much better than my blue tape) but it was unclear how it would hold up since the car went down after 4 easy laps. Does anyone have any good solutions here other than just hope for the best?

Overall, the Viper was again just awesome. From the street to the track and back again without incident. Dodge definitely has built a great machine! :United_States:

VetteFish
08-09-2015, 03:58 PM
Great post and glad the car performed well! What were your times? And also, what octane were you running with the Arrow PCM? Thanks!

VENOM V
08-09-2015, 04:45 PM
Glad you had a great time!

Speed Ventures is my favorite HPDE group to run with. With transponders, the cars line up in order of time, which means less slow cars in front and improved safety. Plus it's kinda fun to be competing with the others and trying to move up the ladder.

Ever run Hoosiers? You would absolutely love them.

Stealth
08-09-2015, 07:29 PM
My car was running 91 octane pump gas--nothing special, on stock tires with stock alignment. I do not run with a transponder as I really do not what the timing to be a contolling element of the experience. The parties running similar speeds were 1:54/1:55 on the Roval so I was somewhere around that with plenty of room for improvement on several corners. When I went to line up they did ask the time and I just said faster than most, and not as fast as others, but that I did not care where I started--and I did not. There were probably around 25-30 cars and it was not crowded on that track. It was very easy to get around other traffic. Usually I only had to wait a corner to pass.

With some previous cars (a built C5 Z06) I towed a small track trailer with Hoosiers. For me the added logistics, storage in the garage, etc. was not worth it. I have just as much fun on street tires. The Pirelli Corsas seem very good. They do not get very slippery. I stepped out a bit a couple of times when cooking, but otherwise grip seemed good.

Next time coming off the turn 2 highspeed corner exit (120-130mph?) into the tight, slow 90 degree turn 3 I plan to clutch, brake, and then just go from 4th or 5th to 2nd rather than heel-toe down to 2nd. This alone should keep the car 10F cooler.

AZTVR
08-09-2015, 08:41 PM
I need to find an alternative to Blue Tape! My car has clear bra protection, but this will not always stop a rock, etc. and you may need to replace the clear bra and/or repaint which is something I want to avoid. The blue tape works, but looks silly any needs constant maintenance. Blue tape is also a bit dangerous— Does anyone have any good solutions here other than just hope for the best?

One of the regulars (instructor) at the West Coast Racing events uses and sells the following, I believe.
http://www.trakktape.com/
I have no experience with it. Looks better than blue tape, though !

Stealth
08-09-2015, 09:17 PM
Thanks for the tip on the Traktape. If this is the same as Trac Wrap, this is the one I saw. I may give it a try next time.

LmeaViper
08-10-2015, 09:04 PM
My car was running 91 octane pump gas--nothing special, on stock tires with stock alignment. I do not run with a transponder as I really do not what the timing to be a contolling element of the experience. The parties running similar speeds were 1:54/1:55 on the Roval so I was somewhere around that with plenty of room for improvement on several corners. When I went to line up they did ask the time and I just said faster than most, and not as fast as others, but that I did not care where I started--and I did not. There were probably around 25-30 cars and it was not crowded on that track. It was very easy to get around other traffic. Usually I only had to wait a corner to pass.

With some previous cars (a built C5 Z06) I towed a small track trailer with Hoosiers. For me the added logistics, storage in the garage, etc. was not worth it. I have just as much fun on street tires. The Pirelli Corsas seem very good. They do not get very slippery. I stepped out a bit a couple of times when cooking, but otherwise grip seemed good.

Next time coming off the turn 2 highspeed corner exit (120-130mph?) into the tight, slow 90 degree turn 3 I plan to clutch, brake, and then just go from 4th or 5th to 2nd rather than heel-toe down to 2nd. This alone should keep the car 10F cooler.

Interesting about your observation on the heel and toe downshifts and temps. A week or so ago, I found a long road out of town and went up and down the gears repeatedly for maybe 10 mins. Mind you I never really went full throttle up, just 3/4 or so and full downshifts from 4th. I was surprised to see my coolant and oil temps go up into the upper 190's...never got those temp increases form repeated runs through 1st - 4th otherwise.

So wondering why heel and toe downshifts would increase temps over regular hard driving?

Russ Oasis
08-10-2015, 11:53 PM
For you East Coast guys, come to the HPDE at Viper Days. It's Oct. 15 & 16 at Pitt Race near Pittsburgh. The track is brand new and awesome. If you do well in the school, you can register and stay for the Time Trial group in the NARRA series which is Oct. 17 & 18. Skip Thomas is teaching the school. You can't have more fun than this with your clothes on. Go to http://narraonline.com/racing/uspde-performance-driver-education.

Simms
08-11-2015, 10:57 AM
For you East Coast guys, come to the HPDE at Viper Days. It's Oct. 15 & 16 at Pitt Race near Pittsburgh. The track is brand new and awesome. If you do well in the school, you can register and stay for the Time Trial group in the NARRA series which is Oct. 17 & 18. Skip Thomas is teaching the school. You can't have more fun than this with your clothes on. Go to http://narraonline.com/racing/uspde-performance-driver-education.

Just registered!

Stealth
08-11-2015, 03:15 PM
Interesting about your observation on the heel and toe downshifts and temps. A week or so ago, I found a long road out of town and went up and down the gears repeatedly for maybe 10 mins. Mind you I never really went full throttle up, just 3/4 or so and full downshifts from 4th. I was surprised to see my coolant and oil temps go up into the upper 190's...never got those temp increases form repeated runs through 1st - 4th otherwise.

So wondering why heel and toe downshifts would increase temps over regular hard driving?

HPDE spirited driving for successive laps goes beyond what you are likely to duplicate on the public roadways. There is generally constant acceleration and braking for 20 minutes. This is not abusive to the car in any way but does generate heat. Heel-toeing from 5th or 4th to 2nd from 130mph to 25mph increases the rpms and likely engine heat; braking may also decrease airflow. My point was that the car cooled quickly (in a corner or so) when I short-shifted, etc. Accordingly, in heavy, sustained braking areas, it may make sense to use more braking and less rev-matching, and then just rev match at the desired gear. E.g., from 5th or 4th to 2nd, rather than 5th to 4th, 4th to 3rd, and 3rd to 2nd. I used this technique in some areas of the track and it was effective.

Russ Oasis
08-11-2015, 03:41 PM
Guys, heel and toeing is to match revs so as not to upset weight balance when you are breaking or cornering. It has nothing to do with using the engine to brake. Also, remember that when rev matching from 4th to 2nd or 5th to 3rd (as Stealth was describing above), you need to rev a bit higher to accommodate the lower gear that you're going to from the higher gear. Rev matching is only necessary when you are at the threshold of braking or don't want to upset the car as you are asking it to turn.

Leslie
08-11-2015, 05:47 PM
You could use 3M defender to protect the paint. $40

Arizona Vipers
09-08-2015, 02:24 AM
They also had NICE cars. Too many HPDE Club groups i SoCal now do NOT have nice cars in the upper run groups, and also have too many low-budget race cars running with street cars.

Does this really matter? If the cars that are "not nice" are too slow for you, then it's time to move up to the next group, or am I wrong? I run a VERY fast Gen 2 and love running against everything that's out there... One of the only times I've ever been passed was by an old, 80's, crusty Honda Civic and I loved it. You gotta cheer for the engineering and/or driving skill involved in that... Thanks for the great information by the way! I've been hearing about Speed Ventures and you've sealed the deal on trying to get out there with them! Send me a PM on the next even with them you plan on going to and let's hook up!

Stealth
09-14-2015, 04:52 PM
Does this really matter? If the cars that are "not nice" are too slow for you, then it's time to move up to the next group, or am I wrong? I run a VERY fast Gen 2 and love running against everything that's out there... One of the only times I've ever been passed was by an old, 80's, crusty Honda Civic and I loved it. You gotta cheer for the engineering and/or driving skill involved in that... Thanks for the great information by the way! I've been hearing about Speed Ventures and you've sealed the deal on trying to get out there with them! Send me a PM on the next even with them you plan on going to and let's hook up!

You are correct to an extent that it does not matter what type of car is running. Good, courteous drivers respectful of the rules and other vehicles could be driving any type of machine. Point acknowledged. That said, people who care about their cars tend to drive them different than those who view the cars as disposable racing machines. Race cars, for example, get damaged from time to time and have major failures more than OEM street cars. They talk about replacing engines and transmissions and fenders; OEM drivers talk about brake pads, tires and oil, etc.

In any event, they have different run groups for a reason--each party can go where they are most comfortable.