Thanks for visiting Team ZR-1 Motorsports and hope the information was useful to you.
By: John Rovner, Team ZR-1
Written for Vette Magazine
Team ZR-1 at Buttonwillow
With less then two weeks before Rodgers Ward's Pony Express, "Team ZR-1" changes hats once more. We decide to tune up for the 84 mile high speed race held on Nevada state highway 305 by attending a closed road course event put together by Guldstrand Racing Association and by Team ZR-1'er Pat ( PJ ) Leonard's American Auto-X Series. This was an Inaugural event at this fairly new racetrack and "Team ZR-1" was glad to be part of it.
The event was limited to 125 cars maximum and was held over 2 1/2 days of the Memorial Day weekend. This allowed each driver to get at least 5 runs per day plus some fun runs each afternoon.
Buttonwillow Raceway Park
This race track is located in the town of Buttonwillow Ca, about 20 miles from Bakersfield Ca. Buttonwillow is a town you'd only stop at if you are flat out of gas or just cannot drive any father and need some sleep. In trying to find a battery for my camera, I find there is no place to purchase one in this town and am forced to drive the 40 miles round trip to Bakersfield to buy one.
I live about 600 miles, round trip from this track. By leaving Friday mid-morning I was able to miss most of the traffic and allowed the ZR-1 to breath at speeds we do not want to be public about. Since this ZR-1 has been setup for drag racing, with the exhaust modifications ( 3 inch pipes from cats through mufflers, no reasonator, and a crossover ) and re-calibrating the ECM E-prom, the ZR-1 still got about 23 MPG even with the air conditioner on. The gas in CA sold these days not only costs more ( $1.83 a gallon ) but causes the MPG to drop by two to three MPG.
The track is fairly new, thus the pavement is error free of pot holes or ruts and is smooth as glass. As can be seen by the drawing, the course is a fun to drive, but can be a little scary at first with the hairpins, doglegs, and blind turns coming off of hills.
There are no guardrails, so if you misjudge a turn you will end up in the weeds. And weeds it is, the land may have been farmland at one time, no trees, only weeds and soft dirt. This event was held on the east track, which is one mile in length and most Corvettes were able to do at least 85 MPH plus on the straight's in second gear.
Only one word describes it, HOT !
It was in the mid 90's and most of the time. There was no wind to cool anything down including the track, so by mid-day the track became slippery. There was a short time when wind came into effect but it was the type that produces wind shears and little funnels. At one point the wind picked up all the awnings and trashed them so bad the metal legs were bent beyond repair. By Sunday afternoon everyone looked like lobsters. Since there were no trees, none of us had any shade when doing our course workers duty or staging our cars for each run.
Every type of Corvette you can thing of was there. From mid year to present and from stone stock to highly modified for Auto-Xing only, non street driven.
" Team ZR-1 " had 8 ZR-1s present, two of them were lowered and configured for Auto-X duty and ran lap times under 54 seconds.
Between the 8 ZR-1s the lap times ranged from 53 to 69 seconds. Those running with tires like Hoosiers ran the lower numbers and those of us on stock GoodYear GS-Cs turned laps in the 1 minute 5 second time and those running with BFG's ran a little quicker times of 1 minute 2 seconds.
One Modification Does it All ?
As I have stated, my car is slightly modified to compete in drag racing. The few changes allows this 1994 ZR-1 to turn ETs of 12.6s at 117 MPH all day. The changes made allowed this ZR-1 to break the street tire class of National Auto Sports Association's record. The suspension, alignment and tires are bone stock, which is fine for the drag racing but when it came to a Auto-X, it became clear leaving those areas stock is a real negative to this type of event.
Since I will be running the Grand Sport Division of Pony Express from 130 to 160 MPH, I took this Buttonwillow event as a learn / tune event. It also became clear that making modifications for higher horsepower, means nothing, if not a negative, for high speed cornering. With the higher HP, I could get through the straight's real fast, but then was forced to do much more hard breaking then cars with less HP. With the LT-5 engine being 200 lbs heavier then a base Corvette engine, the car had way too much understeer.
I have been pre-testing a FX3 processor chip being designed for Lingenfelter for drag racing. The stock FX3 module has this chip soldered in and to do this type of change you either have to purchase a FX3 module that has a chip socket or have the OEM unit de-soldered and solder in a chip socket. LPE were nice enough to send me another version of the chip to test at this road course track.
Every time I set the FX3 to stiff on all four wheels, car had a understeer with these stock GS-Cs and lap times were lousy, about 1 minute 10 seconds. Switching the FX3 to fronts soft and rears stiff up to 75 MPH, the tires quit crying, the car had a little oversteer and lap times came down to 1 minute 4 seconds. These results were reproducible, by flipping the FX3 switch on console. I switched back and forth on 8 different laps to assure what I was observing was correct.
If anything the tests show you can improve how a Corvette performs by spending about $40 for these type of chips and using a vendor like LPE that is working with Bilstein directly in designing the hard code installed in these 8 bit processors.
Event Lap Times
Friday night was used for getting the 100 or more cars fully tech'd and signed up. Gates opened both Saturday and Sunday at 7am. Saturday, the course was run clockwise and being the course is a one miler, they had a parade run, so all could drive slowly around it to learn the course and see where the pylons were added to slow cars down into some corners.
Sunday, they pulled a switch on us, and we had to run the course counter -clockwise, which made it even tougher, but most thought the track was more fun this direction.
Cars were broken down into four run groups. Being my ZR-1 had the exhaust changes and E-prom change, I had to run in the ASP group. This is where the big boys are with all the Auto-X changes to their cars. This should be a warning to others, if your making any changes and it causes you to move to another class, is it enough to compete with others in that new class ?
Since we would like to run this track again ( not wanting owners of the track to 86 us ), the rule on Saturday was, if you got four wheels off the track, your next run would have to be made with an experienced driver in your car to see what you were doing wrong and help correct your driving habits. With several drivers getting too hot into corners ( none of them ZR-1s ) and spinning out, on Sunday they made it tougher. If you went into the weeds you were done for the day. Remember once off the track you were in soft dirt that would be sprayed all over the track surface, making it even more slippery for those running behind you.
Early on it became clear that the extra weight of the ZR-1 was a negative on its lap times, but the higher horsepower helped gain some time back at a high cost to the strain of the front tires.
ZR-1's Lap Times
All " Team ZR-1'ers " were within the A-Street Prepared or Super Stocks groups. Following are lap times For ZR-1s and shows that making modifications do in fact shorten those times
Model Year Saturday Sunday Driver
91 54.62 53.65 PJ Leonard
90 56.82 55.49 Ron Kern
92 54.23 53.71 Grant Byers
92 62.87 63.21 Sean Irby
92 65.66 62.01 Mike Thomsen
92 65.93 63.25 Bill Staebell
94 67.25 65.20 John Rovner
How other Corvettes Performed
Clearly the ZR-1's modified for Auto-Xing took top times.
My times on Saturday were switching FX3 to firm all the way around and leaving tire pressure at 35 lbs.
My times on Sunday were switching FX3 to soft front / firm rears and leaving stock tire pressures at 35 lbs. As can be seen, the others got better by about 1 second from one day to the next, but my times got better by about 4 seconds with just the FX3 processor chip change.
One other test point, leaving FX3 in sport mode, Lap times were as high as 72 !
Lastly the rule, " Drive slower and go faster is " is a true statement. What makes you a winner in drag racing, may not be so in Auto-Xing.
Grant Byers is a professional driver for Monroe shocks, he does this type of thing everyday. His lap times show that the driver experience can make up for spending big dollars for modifications.
Here shows a mix of different Corvette model years lap times. This is not a complete list of all 100 drivers or there best lap times. This only shows that there was about 10 seconds spread from all the Corvettes lap times.
Model Year Lap Time Driver
66 55.77 Don McWilliams
67 60.06 Speedy Knudsen
79 61.27 Mark Costello
90 65.12 Geri Smith
90 66.26 Becky Tonkin
95 54.81 Gary Thomason
88 55.11 Jeff Clorioso
94 55.18 Tom Hasslinger
72 54.73 Brett Egen
64 56.20 Mike Baker
70 57.32 Lynn Anderson
All in all I got out of there without hitting any pylons, having a Did Not Finish (DNF) or harming the ZR-1 in anyway. I simply dusted off the car, turned the air conditioner and stereo on and uhh.. cruised the 280 miles back home.
June will be another busy month for "Team ZR-1". We will be at the Pony Express, drag racing at Sears Point, Auto-Xing at Mather Air Force base, car shows and more.
You can contact me by E-mail: John _Rovner@Novell.com or calling
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5/3/98 9:21:41 AM