Slow Z28

iTrader: (19)

what size tires are you running for bolt on combo? i'm trying to decide if i'm gonna have enough tire so that i'm not shifting to 4th before the traps. got choices for tires coming up soon since i am purchasing a set of rims. is there a way to work out the formula for an automatic car with a loose converter to see what i'll be crossing the traps at? looking at either the ET Drag 28x9 which actually measures 27.3" height or the Hoosier slick which is a true 28" tire. or even the Hoosier QTP at 27x10.5 which is a true 27x9 tire. But will that tire hook at all on my converter/gear combo?

3200lb raceweight car
bolt ons
TP4400 w/ 2.86 str
4.10's

anything else you need to know?

also, for the bolt on guys, where were your shiftpoints(rpm, not hypertech settings)? i'm just looking for a good starting spot. and i know it shouldn't be shifted above 6300 or so, correct?

thanks

<small>[ September 24, 2002, 05:33 PM: Message edited by: z28kid98 ]</small>

Mike Hoffpauir

Last Christmas I was still bolt-on and gave the 4.10's a shot (from factory 3.23's). I still had the vig #7 at the time and was on 26X8.5 15 et drags. I was shifting the car pretty high around 6300-6400, and going through the traps even higher (6500?). I bumped the 3-4 shift as high as I could to keep the car from shifting into 4th.
I personally felt the car was revving over its powerband for that short tire and 4.10 gear.
Maybe those 27.3" tires would set you just right.
I do know that the car seemed to sixty foot about .02 quicker on the average, and it took a higher foot brake to get the car there. The change was from 1.62-1.65 with 3.23's to a whole bunch of 1.59-1.62. The et changed about .05, as I was running 12.0's at the time.

I'm curious to see how the 27.3's would work out with 4.10's. Probably good <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

<small>[ September 24, 2002, 07:57 PM: Message edited by: Mike Hoffpauir ]</small>

Slow Z28

iTrader: (19)

that's what i was thinking. i mean, i'm 1.70 60's right now, so anything in the 1.5's is awesome with my lighterweight car. I was thinking the full slick would be needed to hook this combo(as have other people recommended) and the 27.3" when it grows on the top end might help keep the rpm's where i want them, or atleast lower than the 6500rpm you were crossing at.

Chris

Anti-Streetability Member Hopeful <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

JS

iTrader: (4)

The 27.2 grows more than u think..Going threw at 122 w/4.10 on a 26 slick = 6500rpm

U wont go threw at 122 so I think your safe....
Or u could just do it this way....

MPH X GEAR X 336 DIV. BY TIRE HEIGHT

JS