went to the track for the first time in almost 3 yrs today, having never launched the car since its been single turbo, on street tires (255 falken ziex's) and pump gas (93 octane). heres my slip, my times were pretty conistent all within 3 tenths of this one

R/T 1.006
60' 2.063
330 5.322
1/8 7.898
MPH 97.40
1000 10.096
1/4 11.931
MPH 121.34

i thought the E/T was good considering the street tires, but i'm not gonna lie i'm dissapointed in the trap. i was really thinking 125+, i run even with cars that trap 130 from a roll on the highway, does that seem right?

also that time there was done slipping the clutch at 5000 rpms, it BARELY spun at all in 1st...... i tried launching higher and it just smoked the tires (and my clutch lol) so i came to the conclusion that wasn't the best way to go. with the lower launch, it'll spin a lil off the line, hook and kinda bog for a second, THEN boost hits and i take off. i know i'm losing alot of time there, would i be losing alot of trap speed there too? also i'm shifting at 8000 rpms.....with a big single (gt40r) should i rev higher?

any tips are welcome! thanks

 

anyone?

 

Did you get a dyno number? What brand of dyno ? How much does your car weigh?

There are soo many factors in this. My friend dyno'd 455 whp and was only trapping 119 mph. Althought it put that down that much on the dyno, it wouldn't put that much down at the track. Cars can act completely different on the track than they did on the dyno.

How was your boost acting? Any ignition break up or anything weird going on that normally doesn't?

Reving past 8,000 won't help unless your still making power past 8,000.

You usually expect to pick up 25-30 mph between the 1/8th and 1/4 so that looks normal.

 

The car was dyno'd on a dyno jet on 15psi on 93 octane, it was 420whp.... i've since bumped it up to 20psi on 93 with some meth/water using the coolingmist kit. i'd GUESS i should be up near 500 now? but i can't say for sure.

Car felt great, wasn't breaking up or anything strange like that, it was pulling as hard as it usually does..... i can't say what the boost was hitting because i honestly didn't pay attention ( my first time at the track in a car this fast haha), but i know on the street i get a steady 20psi on my autometer (probably actually a lil bit lower then its reading).

Reason i was thinking reving higher would maybe help, is because when i'm going thru the traps i have to shift into 4th and i have some lag, the car is still accelerating but not pulling as hard as it would say...... ~700 rpms higher. Would that skew my trap #?

thanks for the reply Lupe

 

With a 121 trap speed, you are nowhere near 500RWHP. You definitely have some gains that can be made with a better 60 foot time and by practicing your shifting. Not bad for street tires.

Andrew

 

thats what i don't understand....... how can i be running even from a roll with cars that trap 130, yet only trap 121 in the 1/4. i know for a fact i dyno'd 424whp @ 15psi on a dynojet w/12% correction, and on 20psi it definitily pulls harder. i'm so confused right now.....

 

i ran my car at the track on 14 psi and trapped 120mph then i turnend the boost upto 19 and trapped 125mph!
on 15 psi i made 417whp
0n 18 psi i made 463whp
this is on full weight 93 touring with 2 jl 12s an amp and a 1/2 tank of gas so it probably weighs 29** lbs

 

Get some slicks or drag radials, Leave the street tires for the street. Once you feel a 1.5 60' launch youll never want to go back

how did the run feel? did is feel the same on the"but" dyno?

 

Because not all chassis dynos are the same. The only true measure of power is either an engine dyno or the drag strip. Chasis dynos are great for tuning and evaluating changes. They are terrible for evaluating one engine against another on different dynoes.
Trap speed is a very accurate measure of HP. With a 121 trap, my guess is that you are at about 380-400 RWHP.

Andrew

 

next saturday i'm going to another dyno to see what numbers that spits out at me...... i'll run my 15psi map to compare to my old dyno numbers, then run the 20psi map. altho its an autometer guage, i think the actual is 18 not 20