tell me what i am doing wrong
09-09-2009, 02:20 AM
#23
I've been battling the same problem you are. Except I'm on 325/50/15 mt drag radials. My best 60ft is a 1.65 on those tires, but I heated the clutch so much it wouldn't let me into 2nd. I've gotten a 7.28@99mph with a 1.75 60ft. I'm usually right around 7.30's-7.35's. It's so hard on a clutch trying to get these radials to hook. Like you I usually run around 18psi in the tires. Next time out I'm going to try 12psi with either a clutch dump or REALLY fast slip.
It's hard to get good times with a six speed and radials. Easiest way to get a low time slip is slicks. I borrowed a buddys set one weekend and cut 1.5 60's all night. With a best of 7.16@99 on motor, and 6.75@104 on a 100 shot. You've just got to practice a lot. Good luck!
It's hard to get good times with a six speed and radials. Easiest way to get a low time slip is slicks. I borrowed a buddys set one weekend and cut 1.5 60's all night. With a best of 7.16@99 on motor, and 6.75@104 on a 100 shot. You've just got to practice a lot. Good luck!
09-11-2009, 01:12 PM
#24
Your trap speed is only indicating about 510 HP at the crank which would normally show up as approx 425 or so at the rear wheels. I would like to see the car on a different dyno and verify what its actually making now. Its almost impossible to trap that low with 480 at the tire unless you were racing in Denver. I based my calculations on 3900 pounds (raceweight with driver).....figured that would have to be close.
ET can vary alot but a light trapspeed is usually indicative of lower power.
Assuming your shifting reasonably quick and arent shifting ridiculously early, my guess is your not making the power you think you are and/or something may have gone astray in the tune or potentially the engine but that is doubtful.
Hit a dyno day with a couple of buddies you know that have some previous known baselines and see how the car performs on a different dyno and a different day. Make sure they datalog timing and A/F ratio while your there as well.
Just my .02 on the situation....Good luck!
-Tony
Your trap speed is much better though.....a 99 MPH car in the eighth would easily trap low 120's in the quarter.....what does your car weigh and how much RWHP are you putting down?
ET can vary alot but a light trapspeed is usually indicative of lower power.
Assuming your shifting reasonably quick and arent shifting ridiculously early, my guess is your not making the power you think you are and/or something may have gone astray in the tune or potentially the engine but that is doubtful.
Hit a dyno day with a couple of buddies you know that have some previous known baselines and see how the car performs on a different dyno and a different day. Make sure they datalog timing and A/F ratio while your there as well.
Just my .02 on the situation....Good luck!
-Tony
Your trap speed is much better though.....a 99 MPH car in the eighth would easily trap low 120's in the quarter.....what does your car weigh and how much RWHP are you putting down?
Last edited by Tony Mamo @ AFR; 09-11-2009 at 01:19 PM.
09-11-2009, 01:22 PM
#25
Something is wrong. My sled, off the footbrake when it was still weigh'd 3650 went 10.5 to 10.6 at 126 to 127 all day long in 2000+ da with 470 rhwp (dyno graph in my photo album for referance)
I was running on a goodyear drag radial too, which is a POS compared to the m/t, hell probably no better then running the 17 inch size you are even being a 275/60/15
Something is very wrong, your mph is a good 10 mph off where it should be if it makes even close to the power you think it does.
I was running on a goodyear drag radial too, which is a POS compared to the m/t, hell probably no better then running the 17 inch size you are even being a 275/60/15
Something is very wrong, your mph is a good 10 mph off where it should be if it makes even close to the power you think it does.
09-20-2009, 12:59 PM
#27
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mine at the track weighted 4k on the nose.. and made 484/462 i will take it to another dyno and see whats up.. i figured it was the bad launch and the weight that was causing my problems
