Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big question

Bruce H.

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Sept 3, 2014 – '14 Viper TA at Canadian Tire Motorsports Park (Mosport)

My last track event was here just two days ago, and the last on the original front Corsa tires. They had worn very well over 10 track days and 14,000 kms (~8000 miles). Today I was on new fronts that were just installed, and the original half worn rears. I had expected that the new tires would be a bit slippery until the tire’s release agents burned off, or a bit squirmy due to full tread and no heat cycles. That wasn’t the case, and was able to run them at my usual pace, logging in excess of 1.50 g’s in corners, and 1.48 g under braking, which is just shy of the 1.5g braking grip on the old fronts in their final laps. So these tires are terrific when brand new, half worn, and actually at their absolute best even as they are cording… and recording their fastest laps!

Previous day's peak g's prior to resetting for today
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Lining up in the hot pits
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Last day a track buddy and I started to use data-logging as a tool to compare various laps in my car against those in his race car in an effort to identify possible areas for improvement. This is the day that Kuno Wittmer was going to be doing some personal coaching with me and he wanted to use data-logging as well, comparing laps he would run in my car to laps that I would then do. Unfortunately the expected delivery date of his son was moved ahead, and a little too close for comfort for him to be several hours away at the track. Kuno’s day will be rescheduled.

Pretty decent resting stance with just 3 1/2" clearance under front splitter, and surely less with me it!
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...and under throttle on the front straight
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The data-logging and pointers from my track friend had lowered my lap time to a personal best 1:35:41 two days ago, and as I became more practiced with those slight driving changes today I was able to further reduce that to a new best 1:34:67. This is a phenomenal lap time at Mosport for a bone stock production car by any high-end performance brand, and while I’m not pushing the car, I continue to drive within my comfort zone. I’ve been conservative in that regard all season as I’ve watched lap times consistently fall from having the extra seat time, rather than pushing beyond my comfort zone. I’m sure there’s another few seconds to peel away with better driving, and that will happen as I find improved techniques, competence and confidence with more seat time. The challenge and reward is in improving my driving as measured by lap times, and there’s no short cut to getting there other than seat time, training and on-going analysis.

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It became obvious that the car’s on-board G meter can only record up to 1.5 g under cornering since it reads that “peak” after most days on this track. I find the G display useful in that it generally indicates or confirms how confident I am on any given track, with 1.5g indicating I'm on it. Since a peak number doesn’t really tell you very how you're doing all around the track I checked the QRacing data-logger which records and displays g forces continuously around the track, showing them above 1.5 regularly in level (non-banked) corners on this track which I've run over many years. The Corsa tires really do get sticky when heated to track temps, and they really do maintain incredible grip lap after lap. SRT made an excellent choice for a fully streetable tire…but there’s no doubt in my mind that the Michelin Pilot Sport Cup 2 tire offers superior grip on track, and would be an even better streetable choice, at least in the warmer weather.

Here’s a short video that captures some of the action, including passing a few very nice cars. I'm using a lot less brake now than I used to, and trying different lines. At the end of the long back straight I'm trying that corner as a double apex, entering on the inside to brake later and deeper which the car seems to like. In this clip is the new 2014 911 (991) Turbo Sport that did run an even quicker lap time of 1:32:2 using lighter after-market wheels and a tire change to the MPSC2’s, which were a huge improvement he claimed. He’s highly trained and skilled, and I’d suggest the quickest of these two cars would be whichever one he was driving! He has the new 2015 GT3 RS on order, and I have a feeling I’m going to need a LOT more seat time and better tires if I hope to keep up to him in that! And you'll hear why you should always disconnect your cell phone's blue tooth when heading out on the track ;) Enjoy!

https://www.youtube.com/watch?v=yos9iTxyhhs

What seemed different today was the frequency that I had the rear stepping out. The first few times it happens you wonder how far out it will go, will you catch it, will the car spin, etc…and then why did it come out. Since I’ve taken the time to work my speeds up slowly when the rear has come out it has been pretty gentle and easily catchable with a little opposite steering input and usually staying on the throttle…and in some cases doing nothing and it tucks back in. So today again it was a non-event each time, and I could mostly anticipate it rather than simply react to it. Data logging showed how just a couple of mph greater entry speed into a corner was enough to loosen the rear at mid corner. That doesn’t necessarily mean that was as fast as the car could go, but rather perhaps the fastest it could go with the amount of throttle I was using, and the weight that I was keeping transferred onto the rear tires at the time. In most cases I had induced the slide with throttle-on over-steer exiting a corner, in another it was while dropping 100 feet down the infamous T2 without enough throttle to keep the weight shifted rearward to maintain rear grip. That’s a corner that requires a solid commitment, and an extra 2-3 mph entry speed was enough to remind me of that. The lesson isn’t to enter slower, but rather keep your foot in it enough to keep the car balanced.

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I primarily do 6th Gear lapping days when at Mosport. They only accept advanced level drivers so there is no need for run groups. You simply drive for as long as you like, or until your tank is empty. Great bunch of guys driving the best of the best. Every day looks like a Lightning Lap comparo about to happen, although probably half are gutted out race cars, and many others are trailered and running slicks. Usually one very well driven ACR-X there to remind us all of which car can ape-**** whatever you might bring, and sometimes a local Comp Coupe racer in his stock '08 ACR. This would be the stock and road legal car that was running quicker times this day.

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Now for the big question: Is the TA better on track than the SRT or GTS with Track Pack?

Answer: How would I know….I’m still so far from reaching this car’s limits that I‘m sure I wouldn’t have reached their limits either :) The one who would really know is the driver who is comfortable somewhat gently sliding the car around every corner, balancing it on the limits of adhesion from corner entry to exit. A 10% tire slip angle is supposedly when the tire achieves its greatest grip, so unless you are holding it on the edge of sliding it you’re just not there yet. That's what a pro driver like Randy Pobst can do when testing cars, and what many racers do in their own for their fastest lap times. And I suspect it’s mostly when driving at those lofty limits that any differences would become very obvious. So unless you’re that driver, I would suggest that most of us could take any Gen V on the track and run similar times, and have just as much fun while improving our driving skill behind the wheel of one very impressive exotic!

And for this we can thank Ralph Gilles, and the entire Viper team of enthusiasts who make Track Rat’s dreams come true!

Bruce
 
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Bobpantax

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Terrific post Bruce. Thank you.
 

VIPER GTSR 91

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Great post and info. That Vette painted up like the GM Tudor car sounded great but looked like he had some issues or just plain slow?
 

pathoguy

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

I don't drive fast and obviously do not race my G5 which makes me appreciate even more guys like you that do. Besides enjoying the videos that you share, you are using the car for its designed use and I suppose testing it along with your skills. Do viper owners that race in this way provide technical/mechanical/driver feedback to the SRT team? I would think that your input about the car being raced in this controlled manner would be important.
 
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Bruce H.

Bruce H.

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Thanks guys.

The Vette was likely on a cool down lap as I'd never catch him otherwise. He and the ACR-X run in the 1:26 range to my 1:34's. It's actually a tube frame race car with full carbon fiber body weighing 2600 lbs and has 700 plus hp!
 
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Bruce H.

Bruce H.

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Pathogy,
Thanks, and these lapping days are really mostly about car guys more fully appreciating their high performance cars in a legal and controlled manner that's much safer than anything you can do on the street. It's a cooperative as opposed to a "race" competition. You make life long friends here, and I'm just as happy to follow another well-driven car as pass it...well, unless it's a 911 GT3;)

The Viper Team does see and appreciate these threads but legal doesn't allow them to respond. Ralph was very interested in my input when we met at Mosport, but they also have broad and deep talent in-house that push the car to the limits regularly.

You should come out to a track and meet some Viper track guys...maybe ride along for a few laps :)
 

zim32

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Great job Bruce!!
 

FLL-B/W-GTS

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Told ya Bob how bad ass the new 991 Turbo S is with the Pilot Sport Cup 2s(That's why I got them).....Good weather tonight ,bring that TA to Palm Beach tonight and do some passes(Fun)....The TA is the best Viper yet and it is great the Germans have some direct competition from a Great American Machine....

Excellent Bruce H......
 

Bobpantax

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

And I told you no cheater tires - only OEM. You have a short memory my friend. LOL

Told ya Bob how bad ass the new 991 Turbo S is with the Pilot Sport Cup 2s(That's why I got them).....Good weather tonight ,bring that TA to Palm Beach tonight and do some passes(Fun)....The TA is the best Viper yet and it is great the Germans have some direct competition from a Great American Machine....

Excellent Bruce H......
 

FLL-B/W-GTS

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

I remembered, it will have Pirellis on it for ya.....
 

emericr

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Thanks for sharing.
Good info and feedback
 

Twister

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Re: Track Attack #11, New tires, best lap time, max g’s, 991 Turbo S…and the big ques

Excellent post
 
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