SS346

Huge congrats!!!! are these the same guys that ran 9's a few weeks ago?

that's motoring bud, congratulations.

ok if its a torque management issue, why is it not eliminated from the tune? or is just not "worked out" yet? this issue seems to rob mph.

that sounds like more of a torque management issue.

I guess the best way to find out is do some of your own testing. sure it may cost you a bit, but imagine the wealth of knowledge you will gain. Its not general lag im talking about, its lag between gear shifts, a bov will not get you full boost earlier in the rpm, but it will get you better response between gear shifts.

I read in an earlier post about average power being the key. that's spot on. peak power means nothing, eg if car A) makes 280rwkw @ 6000rpm and car B) makes 260rwkw @ 6000rpm but makes more down low torque, I can assure you car B) will drive around car A). torque gets you going, horse power keeps that momentum. for the manual guys, I would look at changing your BOV, in between shifts, when you back off the throttle, the BOV opens and vents boost to the atmosphere, an incorrectly sized bov can slow the turbocharger speed dramatically, so a larger/efficient BOV would be beneficial by venting more boost pressure to the atmosphere and not slowwing the turbocharger down, this will result in better boost response when you snap open the throttle. another way around boost response is flat changing, (hold throttle flat and shift gears) this is what the auto guys do !! lol!!! Plazmaman have a new bov, I read it in a thread they posted up, I would really be looking into changing the bov, same goes for the auto cars. From my drag racing experience, if you were to drop a tenth off your 60ft time, double it and subtract it from your et you will get a very good indication of your future et. (this will only apply to cars that dont 60ft very well. eg if a car runs 1.51 60 ft and runs 10 sec et's, if you go faster in the 60 ft then your et wont change much, though your trap speed will drop a little.) eg. if your car ran a best of 12.4 with a 1.87 60ft, and if you were to run a 60 ft of 1.63 your et will be very close to 11.92 1.87 - 1.63 = 0.24 x 2 = 0.48. 12.4 - 0.48 = 11.92

that explains it! if boost drops off in the top end, obviously so does power, hence the low top end charge. you may not see a dramatic drop in boost on the dyno, but on the street you will notice its worse. I'll bet that if you had a flat boost curve, your car will run about 117mph easily, that being said your power would be about 290-300rwkw.

ok "assuming" your car weighs 4000lbs , for the given best mph of 111, it works out to be 426hp @ flywheel (317kw) and about 330rwhp (245rwkw). that power was on the day you raced the car. you seem to have a low top end charge, generally on a perfect et you will get about 23-26mph, depending on 60ft. with your 2.xxx 60ft you should be seeing at least 26mph, your best half track mph was 88 and best trap speed was 111, there is only a 23mph top end charge. does the car feel as though it drops off power in the top end? you may have an incorrect diff gear ratio. I got the data from one of (literally) 100's of timeslips with notes I have.

What is your 660ft mph and your top end speed??? also what diff gears do you have? actually probably better to post your time slip.

I hope that virgin racers are well eduacted from this thread. people seem to be very hung up on dyno graphs. remember that at the track your mph is an indication of power ....... at the temperature relative humidity etc you raced at.

just from experience of other 9 sec cars, they normally see low 1.3's

thanks. it actually not my car, I just "look after it" it has a 2800rpm converter, the 60ft times are pretty bland, compared to the 9 sec et. 1.45 60 ft at best.

this is the only one I can get my hands on, you will see the car had an argument with the tyres lol! hence the reason with the slow time and mph. VXSS turbo

lol! a good example of power loss due to in-efficient converter would be an NA engine that was making 338rwkw with a stock converter, the made 289 with a high stall (5500rpm) that ran 126mph with the stock converter and 120mph with the hi stall.

yes they do, but that depends on the converter efficiency, the car in question has 96% efficiency so really the power is not effected that much so the figure maybe should read 420 rwkw?