MIKE I AM THE ONE WHO BOUGHT THE 18" WHEELS FROM PPC FOR A STOCK BODIED PANTERA AS DISCUSSED BY JACK A WHILE BACK. THE BACKSETS FOR MY CAR CAME CORRECT FROM KINESIS. I DID TALK WITH KIRBY ABOUT THE WHEELS FOR HIS CAR BUT HIS CAR IS A GTS AND THE WHEELS ARE A LOT BIGGER. I HAVE 18X9 AND 18X12'S. I RUN HOOISERS ROAD RACING TIRES AND ALSO RUN GOODYEARS FOR LONGER TRIPS AS I DID NOT WANT TO MAKE ANOTHER RUN TO VEGAS WITH THE ROADRACE TIRES AGAIN AS I DID LAST YEAR DUE TO POSSIBLE FLAT PROBLEMS.
THE FRONT OF THE CAR HAS BEEN CUT AT THE FRONT RIGHT OF THE FENDER DUE TO THE IMPERFECTION IN THE CAR AS MANUFACTURED. I DID CUT THE LIP OUT AT THE TOP AND SLIGHTLY PULLED THE FENDERS OUT. THIS WAS NEEDED FOR THE HOOSIERS AS THEY ARE ABOUT 1/2" WIDER THAN THE GOODYEARS DUE TO THE VERTICLE SIDEWALLS SIZE IS 245/40ZR18 HEIGHT IS 1" TALLER THAN STOCK BUT I CAN BUY A HOOSIER THAT IS ABOUT 1/4" SHORTER (NEXT TIME WHEN THEY WEAR OUT) I PROBABLY WOULD NOT HAVE HAD TO PULL THE FRONT FENDERS WITH THE GOODYEARS BECAUSE THEY ARE NARROWER. THE BACKS ARE P335/30ZR18 13" WIDE AND 1" SHORTER. I ALSO HAVE PPC ADJUSTABLE SHOCKS SO I JUST LOWERED THE FRONT A LITTLE AND RAISED THE BACK. STANCE IS A LTITLE HIGHER BUT THE LOOK OF THE 18" ARE WORTH IT. I DON'T HIT THE UPPER FENDER WELL BUT I DO HIT THE INSIDE BACK OF THE FENDER WELL IF YOU TURN REAL SHARP AS BACKING OUT IN A LOT. NO DAMAGE AND MY OTHER TWO CARS DO THE SAME. THE SUSPENSION WORKS FINE-REMEMBER IT GOES UP AND CAN ALSO GO DOWN FOR TRAVEL OR MINOR BODY ROLL. I WILL TAKE THE EXTRA TIRE AND LOWER PROFILE WITH A LITTLE HEIGHT GAIN ANY DAY AS THE HANDLING IS ENHANCED GREATLY. I HAVE GONE FROM 15" TO `16" TO 17" ON MY FIREBIRD OVER THE LAST 14 YEARS IN THE AUTOCROSSING WORLD AND THE CAR NOW SITS 1" PLUS HIGHER AND HANDLES THE BEST IT EVER HAS WITH 17" SIMMONS RACING WHEELS AND HOOSIER AUTOCROSS TIRES. MY SUSPENSION EXPERT JOE AT CUSTOM ALIGNMENT TOLD ME YOU WANT THE GEOMETRY RIGHT ON THE A-ARMS AND THE HEIGHT IS NOT THE BIGGEST FACTOR. I DID NOT BELIEVE HIM UNTIL MY FIRST AUTOCROSS WITH THE AJUSTMENT. I JUST WATCHED AT GT2 PORSCHE WITH 18" AND 19" HOOSIERS RUN AT THE SCCA CROSS AND THERE IS A REASON THE GERMANS ARE USING THE BIGGER WHEELS AND LOWER PROFILES. THE VINTAGE CARS ARE NOT ALLOWED TO TAKE ATVANTAGE OF THE TECHNOLOGY AND AN UPGRADED CAR CAN SMOKE THEM IN MOST CASES.
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Originally posted by Mike Dailey:
There is a very interesting article in the Spring 2003 Pantera International quarterly magazine about wheels and tires. The article is written by Goran Maimberg and is mostly focused on wheel and tire combinations but integral to the discussion is some information about how important the Pantera ride height is to the performance of the car, e.g. actual calculations on the impact of height. The article is very well done and easy to understand.
I did not want to go to 17� and 16� wheels to get good Z rated tires and planned carefully to keep the car as close to the ride height I had with the 15� stock wheel as possible. With a bunch of work on wheel and tire selection I was able to keep it very close to the 15� wheel Euro ride height. At the time I didn�t understand what I was doing I just wanted the car to have the same stance as it had with the 15� wheels because I liked how it looked. Now I know there is much more to it than how it looks! The car was at the 15� wheel and tire ride height for very good performance reasons.
One puzzling part was a contribution from Kirby Schrader about the performance problems with 18� wheels that I did not understand.
Can anyone shed some light on what�s going on with the 18� wheel problems, custom machine work, more negative offset, lack of room between the top of the fender and the top of the tire, can�t get the wheel to go high enough up into the fender, etc. Does this same problem exist with 17� front wheels when using the correct tire side wall height for a Pantera? I guessing the tire must hit the flat underside of the fender?
Mike
