Martin S.

Splash of gas, my fat *** and all racing clothes in the car...here is the final outcome.

Driver side front: 609 Passenger side front: 610

Driver side rear: 1064 Passenger side rear: 942

Total weight on the car, 3,224. In my weight to HP class @ 255 HP, my car with me and a splash of gas needs to weigh 3,267.


I'll just start with 3/4 of a tank to be safe...see the enclosed EXCEL pdf

k722070

seems like you are cutting it too close.
let's say you come in 1st, pull into impound for weight and you end up 5 lbs shy.
is it worth giving up the tires, pads, oil and what ever other contingency forms(MCS $350 cash) you filled out to not bolt a 25lb plate in the passenger footwell?

the other strategy would be to get another dyno, this time leave the decklid closed, that should bring you below 250hp. dropping the pizza box from lunch on the closed decklid could get you down to 240hp.

Martin S.

I may just do that, bolt a 25 Lb plate to the passenger floor. Juts to be safe, I will start the day with a full tank, and then off to the scales....

Dyno with the deck lid down, lose 15HP? Would that mean that I really don't have 255 out on the track, as my deck lid is down? I wonder what is the science behind this open lid/closed lid. I am not much of a science guy...

Thanks for the response.

race911

Which is the fallacy of the power/wt classes. The dyno operator at Thunderhill had his two shops next to our garage, so I'd talk to him a lot. He just did whatever he needed to do for the various NASA requirements + SCCA SSM. Disgusted him to see guys pull on with their radiators blocked, ECU swapped to a stock unit, etc etc etc.

A friend who's at the pointy end of things on prep, but still 100% legal and continually pulling down the lap record, exploited the loophole by massaging and massaging and massaging the torque curve for his GTS class. Wholly unintended when they wrote the rules. I think he gave up about 10% on HP, but the engine makes torque like a diesel. Was good for 1-1.5 sec/lap at Thunderhill when he got it max'd out.

k722070

while moving forward the engine bay is filled with air, lots available to be sucked into the airbox. some even say the air in the engine bay is ambient temp while driving.
while sitting on the dyno there is no air moving over the top of the car and into the grill and engine bay, which is why a shop that deals with 911's will open the decklid. some will even point a fan at the back to add air.
as ken points out lots of wiggle room here. let your car get hot and don't point a fan at the front cooler and you'll get even less hp.
I get a good laugh when a guy with a 997.2 3.8 GT3 says his dyno shows 330hp.

Martin S.

I know there are lots of tricks, especially upping torque...."Homie don't play that way:; I guess I don't want to win that badly.

k722070

to your question, you might even have more than 255hp while on the track. I heard a funny story from an old guy, well older than me, about race support in late 90s florida. they used a gt2 wing on a na 993 and routed the side intake(normally used for the intercooler) directly to the airbox. said it gave them an extra 3mph on a medium straight. that type of system would never show up on a dyno.
the wt/hp class system does a good job of making the drivers start out equal, but there are always going to be people that figure everyone else is cheating so they should get away with whatever they can. but in the end as the cars get close it should come down to the driver. more track time, better data analysis, better coaching, or just a more committed driver should beat someone spending time and money on sneaking in a few extra hp.
but I'm probably naive. my track is less than 10yrs old and we are just making the transition from having fun with street cars to realizing we should be trying to win. it was only just this season people with big pocket books had cars built to a spec class so they could win. sadly they have just made the track more dangerous because they don't have the skills and/or experience to drive a car built that way. and they don't win, they don't even come close.

ToSi

More importantly, why 120lbs of wedge?

Martin S.

You have hit the nail on the head...I want to win, but not bad enough to cheap. I am trying to refine my driving using the AiM system and some coaching. And my car is prepared to the max, no shortcuts. If that isn't good enough, then the drive can always get better.....there is no status quo in driving, if you are not gotten better, relative to those that are, you are getting worse....