Lost 1/4 mile time

BigDutch · Post by **BigDutch** » Mon Sep 21, 2009 12:16 pm

Hello,

Thought I would discuss this here. I went up to the track this weekend to test the car out again. It was alot of fun, however I could not get the times I did the last time.

My modifications are as follows:

SRT-4 Cat-back
Injen CAI
MPx 60mm TB
MSD 8.5mm wires

The best time I could get was a 15.9. My 60ft time was decent 2.3 but still not the same as I did a year ago. (15.7 last sept)

The difference is the 60mm TB. I think that it slowed me down the 2 tenths...?

The butt dyno shows that the car feels quicker, better in the top end as well. Gas milage is substantially improved as well. But that was not the intention of getting the TB. I wanted to be FASTER.

So I am a little lost on my next performance investment. I would appriciate some guidance.

Thanks
Jordan

Post by **racer12306** » Mon Sep 21, 2009 12:32 pm

What was your 60' last year? a half a tenth in the 60' is a couple tenths on the big end.

BigDutch · Post by **BigDutch** » Mon Sep 21, 2009 12:33 pm

2.18 last year, that could explain it

Post by **occasional demons** » Mon Sep 21, 2009 12:38 pm

The 60mm will slow you down, if you go WOT too soon. I'm assuming you just had the stock 52mm one last year. Too much air/low manifold vacuum for not enough rpm will cause the engine to bog. Put a 65mm TB on there, and you will have a more noticable effect. You really have to watch how much throttle you give it. With the 65, I could be closing the throttle, and start accelerating harder. The 60 is just not as noticable, but it is still there. You have to make yourself roll into the throttle at a more controlled rate. this is one area, where I hate to admit, that e-throttle will out perform your foot. (if someone had all the right values plugged in)

Post by **racer12306** » Mon Sep 21, 2009 12:39 pm

BigDutch wrote:2.18 last year, that could explain it

Bingo. Problem solved

get back to 2.18 and you will see your 15.7 or 15.6 if not 15.5

BigDutch · Post by **BigDutch** » Mon Sep 21, 2009 12:43 pm

Yeah I think that it now may have been technique. I was just going WOT with the TB, not being sure how to fully use it to its full potential. Next time I believe that I will feather the gas a bit to get the time down for the 60'.

I was launching at 3700-4000 RPM, would that be too high for this set-up?

Post by **occasional demons** » Mon Sep 21, 2009 12:46 pm

Yep, if the extra cfm is causing you to bog a little at the start...

You should be able to hear it with a CAI. Maybe not as well as a ghetto IM, but the sound should be there, provided that rear section isn't drowning it out.