What am I doing wrong?

[mwinter501]

Gents, I need your help.

I have been going down the track for a few years now, so Im not completely new, but not really experienced either. I have been noticing other people getting much faster times with similar or even less performance parts than my car has. The more experienced people I race with have older and classic mustangs, so they don't really know the in's and out's of my car.

I have an '07 Shelby GT which came with the FRPP CAI, FRPP handling pack, Hurst short throw, and FRPP mufflers. Since then, I have added 4.10:1 gears, JBA longtubes, H pipe with racing cats, high flow elbow for the FRPP CAI, email tune from Bama at american muscle, Nitto NT05 drag radials and and a raptor shift light.

My fastest time on the 1/4 mile was a 13.29 a few weeks ago. I am seeing guys on here running mid 12's with similar mods.

Here is what the timeslip reads:

RT: .079
60': 1.833
330: 5.499
1/8th: 8.522 @ 82.60
1000: 11.119
1/4: 13.29 @104.40

I have been launching at ~4500rpm since thats the highest I can put the neutral rev limiter. My shift light is set at 6500 and my rev limiter is set at 6700.

Obviously I'm doing something wrong. can anyone help me out? All help is greatly appreciated.

 

[RedMustang]

what pressure in tires ?

 

[SteveP]

with the nittos, u need to run about 17lbs of pressure if not less and do a good 10second burnout. You need to get them nice and sticky. DO NOT do it in the water box. If you have skinnies, roll through it but if u have reg fronts, go around and back in so you can get them alittle wet. pull forward then do the burn out.

this will help your launch, the rest is up to you

 

[rojizostang]

what's the weather like? it seems to me your 1/8 times are a little slow, going from memory. your 60' times aren't that bad, but not that good either. with similar 60' times i was doing 12.9's and a little better on the mph. in both the 1/8 and the 1/4.

have you figured the da?

 

[mwinter501]

Ive been running 16-18lbs in the tires depending on temp. weather was in the mid fifty's at the time of the last slip, low humidity.

Steve, I have been doing exactly that for the burnout. I always go around the water and then back in before pulling back forward to do the burnout.

I guess I just need more practice, my shifts must be slow or ill-timed.

rojizostang, sorry for my ignorance, but what is the da?

Do i need to start launching at a higher rpm? It seems to squat and bog quite a bit at 4500. only reason i keep it there is the neutral rev limiter, I like to use it as it is easier to stay consistent.

 

[rojizostang]

rojizostang, sorry for my ignorance, but what is the da?

density altitude. there's a calculator somewhere. i'll look for it.

here 'tis
http://www.dragtimes.com/da-density-altitude-calculator.php

 

[Newman]

Not to thread jack . But I have the pretty much the same set up minus the suspension and long tubes. Before the gears I went

13.55 @ 105 with a 2.1 60ft on 20" drag radials.

This past weekend I went out with the 4.10 and 275-60-15 nitto 555r and went

13.28 @105 with a 2.00 60ft

I ran the tires a 24 lbs which I know was high .. I slipped out at 3400rpms
I figured that I would for sure be in the 12's. ( I did only run once due to retarded long lines)

WTF an I doing wrong

 

[mwinter501]

oh, ok....

DA shows 13.26 @104.5

 

[rojizostang]

i could never get drag radials to hook up consistently with the 5m. i went to mt bias ply tires and started pulling consistent 1.67's to 1.69's. 11.5 to 12psi, launching at 4.5k off the two step.

 

[circusboy]

where do you live? what is the alltitude?

 

[Steedman07]

How are you shifting? Power shift that fucker...

 

[mwinter501]

I live in the Dallas TX area, altitude is only ~650ft.

 

[rojizostang]

I live in the Dallas TX area, altitude is only ~650ft.

bout the same as it is here

 

[08gt4u]

you might need stickier tires than the nittos to take full advantage of the launch.

 

[fdjizm]

Where and how are you shifting?

 

[Noclutch]

Sweet Babay James! You have some issues to work out. LCAs if you don't have them, get them. Shifting must be killing you. Get a vid on your runs with audio.

 

[mwinter501]

Shifting at 6500 normal shifts.

 

[mwinter501]

I have LCAs on the way and will soon be getting relocation brackets to weld in.

 

[Newman]

I was shifting at 6200 . Cause I'm not sure where my rev limiter is.

 

[SilentScope]

BANG YOUR GEARS LIKE YOU STOLE THE BITCH !!!!!!

thats how.