Scott was the issue with daves turbo just the port shrouded compressor cover. I talked with john craig and he said at some time you would see all compresssor covers with port shrouding. So if the cover had not had the slots in it would it have been ok.
The GSCA asked for Dave to change his PT71-GTQ (same as a GT-70?) because of the larger inlet bell diameter...basically because they were of the opinion that he was getting more air into his turbo. The inner inlet bell measured out to be less than 71.5mm with the turbo plug, but the inlet bell is more like 74+mm.
Lonnie and I have spoken with Harry Hruska, John Craig, and Rick Head. After I make some follow up calls AND I dissuss the matter with the registered TSM racers - an announcement will be made.
I feel that it should be legal. We do not want to discourage any vendor that is still willing to do research and developement on new parts for our 17 year old cars.
Race Jace
I do agree we dont want to discourage a vendor who is willing to do R&D. We also do not want to change the rules. This allows the racers to have time to grow into the rules. Leaving the rules alone is one item that makes the class more competitive. This GT-71 is a big jump for the class. The fast guys will go faster and the guys that are growing into the rules will be forced again to drop the coin for another turbo or fall futher behind. My opinions aside as Scott stated we are following up on this turbo ruling and will have an answer in the near future.
as long as the 71mm gage does not fit then how could it not be legal?
The 71.5mm gauge does not fit the compresser housing. The housing does not have a tapered inlet there for the ported shroud is the largest air inlet area to measure from. That area is around 74mm or maybe a little more. The other issue not even posted is the availabilty issue. These are all issues for 2003. If you do not consider the ported shroud the turbo inlet at the compresser inlet fit the turbo plug like a glove.
The PT71-GTQ will remain disallowed for the 2003 race season as it was not readily available at November 1, 2002. This turbo, and all ported shroud models that otherwise meet the TSM rules, will be allowed beginning in 2004.
Lonnie and I polled the registered TSM Point Series racers about this turbo issue. The majority of responses that we received stated that they would like to see the above "ruling" stand.
If it so happens that our Buick turbo dealers (Limit, Precision and Innovative) come out with something newer...it needs to be readily available by November 1, 2003. Same rule, new year.
And BTW, anyone trying to run a 72mm or larger compressor wheel in a necked down inlet bell (i.e. an hourglass shaped inlet) will be disqualified for trying to "deliberately break the rules." The rule is that the inducer side of the wheel cannot exceed 71.5mm. The turbo plug is just one of our tools to measure this.