ET questions

[bigpappy33]

So i went to the track on my 20s, the last time i ran on them i had my old bfg kdw2 tires that were pretty bald and ran a 12.46 @118. since then i have gotten a new belt tensioner, Mcleod RST, and taller 315/35/20 NT05s rear tires (28" vs the old 27") and could only muster a 12.46 @116, with a bunch of 12.5s-12.7s at 115. One thing i did stupid was run on a full tank of gas, do you think this could be the reason for the loss in MPH? Or maybe the taller tires are hurting my top end? I have 4.10 gears too. the best 60' i could cut was a 2.0, spinning 2nd bad.

p.s. next purchase is going to be some jegs wheels and 275/60/15 Mickey thompsons hopefully i can get well into the 11s.

Also both times I ran was on a bigger pulley than what i dynoed with, so im prob seeing 470-480 rwhp vs the 505 i made with the smaller pulley.

 

[GrnBullitt08]

Your car is very capable of running those 11s you desire. Im sure the loaded tank didnt help but I would think going from the bald KDWIIs to the NT05s would have helped a little....the 2.0 60' time tells it all, the the jegs wheels and tires that should drop, you have all the needed mods minus a smaller wheel and tire combo to be cutting low 60' times and ETs.

 

[psfracer]

16 gallon tank--so if you normally run about 6 gallons, then the extra 10 gallons cost you roughly 63lbs. (1 gallon of gas = approx 6.3 lbs)

Was there any DA difference between your previous runs and these most recent runs?

A 1 inch taller tire will effect gear ratio somewhat, your 4.10 ratio with 27s dropped to a 3.95 with the 28 tall tire.

The good news is 118 mph is good for 11.50s easy if you can sort out the 60' time.

 

[BlownAway05]

It's def gotten alot hotter out since the last time you ran plus a lot more humid. In the heat, my 93 tune from VMP will not run strong if I don't give a lot of cool down time. With the weather differences, loss of gearing, gas weight, and probably some extra weight from the bigger tires themselves, I wouldn't be too worried about the mph difference, seems reasonable. Right now, it sucks to drag race in Florida.

Did Justin right you a mild race tune as well? He wrote one for me, it doesn't have any more timing, but it will let my motor run a little hotter before it starts to pull timing. I use a 50/50 mix of 93 pump and 110 leaded when I run it. It gives me pretty consistent 120+ trap in 90* heat, as long as the air isn't too bad.

 

[bigpappy33]

16 gallon tank--so if you normally run about 6 gallons, then the extra 10 gallons cost you roughly 63lbs. (1 gallon of gas = approx 6.3 lbs)

Was there any DA difference between your previous runs and these most recent runs?

A 1 inch taller tire will effect gear ratio somewhat, your 4.10 ratio with 27s dropped to a 3.95 with the 28 tall tire.

The good news is 118 mph is good for 11.50s easy if you can sort out the 60' time.

Yea the gas hurt me, and the both times i ran at Gainesville Raceway, although yesterday was a good bit hotter than last time. Really need to get those tires, got a bad itch to break into the 11s.

It's def gotten alot hotter out since the last time you ran plus a lot more humid. In the heat, my 93 tune from VMP will not run strong if I don't give a lot of cool down time. With the weather differences, loss of gearing, gas weight, and probably some extra weight from the bigger tires themselves, I wouldn't be too worried about the mph difference, seems reasonable. Right now, it sucks to drag race in Florida.

Did Justin right you a mild race tune as well? He wrote one for me, it doesn't have any more timing, but it will let my motor run a little hotter before it starts to pull timing. I use a 50/50 mix of 93 pump and 110 leaded when I run it. It gives me pretty consistent 120+ trap in 90* heat, as long as the air isn't too bad.

I know what you mean about the heat, the last 2 passes i ran were 13.0s... It was raining around the track so the air was pretty humid too. Tried to get some cool down time, but even after 20 min my iats were about the same. i'll email justin about the race tune, sounds like its right up my ally. Thanks for the heads up. I'll prob be at speedworld a good bit more in late June and July, so maybe i'll see you out there