Need suggestions for track dilemma

[jjjferro]

Ran my PB of 11.74 @ 116.9 mph. Shifting into fourth just before the finish line. What do I need to do to get the car not to shift?
(I do have the TCI Ratchet shifter. Can I just leave it in 3rd???)

'08 GT Automatic with Procharger, PI 3200 converter, MT Et Streets 275/60/15 (28" tall). Shifts at 6200 rpms.

THANKS!!!

 

[stkjock]

two things come to mind

taller tire
up the rev limiter and leave it in 3rd

it's a stock 5R55s? and you manually shift it during the run?

Edit - looking a gear spreed sheet I have tells me that your 3rd should run out at around 88-90 @ 6800, how is it you're shifting just before the line?

 

[jjjferro]

Overdrive is off and it's shifting so must be 3rd the 4th??? Car rev's to 6200 and then drops to around 5200 before the line.
Yes stock 5r55s and no I'm not shifting it.

 

[stkjock]

Something is not making sense to me.

3rd gear on your set up should shift around (based on your 6200 shift point) 82mph, so well before the traps and 4th would go to about 125, well beyond your traps.

I would have thought that the car would shift to 4th just after the 1/8 and take 4th all the way to the line.

 

[19COBRA93]

What's the ratio for his 3rd gear? I have 4.10's (and a manual), but there's no way in hell 3rd gear would take me anywhere near the finish line. Even with 3.55's I could manage about 113 in 3rd.

 

[jjjferro]

Ok then I need to find out why the rpms are dropping???? I figured they would be dropping for a shift. Is there something else I should be questioning?

 

[classix_stang289]

can this rpm droppage be checked on a dyno and would it be a tune adjustment to rid of the issue?

 

[stkjock]

What's the ratio for his 3rd gear? I have 4.10's (and a manual), but there's no way in hell 3rd gear would take me anywhere near the finish line. Even with 3.55's I could manage about 113 in 3rd.

1.55

Ok then I need to find out why the rpms are dropping???? I figured they would be dropping for a shift. Is there something else I should be questioning?

any video of your passes?

 

[jjjferro]

1.55



any video of your passes?

Just the burnout. I'm going again tonite and will pay closer attention to the rpms and shifts. Thanks for your time.

 

[stkjock]

if you can, get video and data log your runs.