Hey guys, I ran my car friday and it was my first time ever being at a track. I got in a total of 4 runs because I was not there for long. Everything happens so fast at the tree that I couldn't even get a steady rpm to launch from, I just kept spinning and spinning.

1st run - 13.6 @ 103 2.20 60'
2nd run - 13.6 @ 104 2.19 60'
3rd run - 13.7 @ 104 2.28 60'
4th run - 13.8 @ 101 2.3 60'

For my first run I was at the top of third and getting close to the traps and I didn't know whether I would need to shift or not. I hit the rev limiter right before I hit the traps. So I shifted to fourth for the rest of the runs.

So my question is that I'm looking into getting some drag radials eventually and wanted to know whether I should go with a higher diameter tire than my 255/45/18 street tires so I dont have to shift to fourth or should I just get tires with less diameter so I have to shift to fourth. I have a few sizes in mind for going with a higher and lower diameter but I want to know what others recommend and overall what would be the best way to go.

edit - i have 3.73 gears

 

Well first off, good job getting out to the track, second, with a decent launch your car will easliy be a low 13 second car, and with a great one maybe even high 12s. My question is, what rear gears do you have? I'm not to sure on this but stock geared 3.31 or 3.55 S197 GTs should go through the traps in 3rd. If you're looking to stay in 3rd while crossing the traps I'd suggest going with a taller tire. I'm no good with figureing out how tall tires are from that size style, but something like a 28" tire would give you room to up your rear gear ratio, if it wasn't already.

 

sorry i thought the gears were in my sig. i have 3.73 gears. i found a calc online to figure out what size to go with but i just wasnt sure whether i should get a shorter tire so i have to go into 4th or whether i should get a taller one so i dont.

 

Naw, a stock 3.55 geared S197 bounces off the limiter just like the OP did just before the 1/4 mile. OP, your tune should have your rev limiter bumped up enough for you to pass in 3rd. What RPM do you hit the limiter?

Good job getting out there. Your runs are very impressive for a first timer. A lot of people can't get out of the 13s first time around.

 

IMO go with the taller tire if you can stay in the effective power band. The 3.73s are a tough gear to make that call with, with 4.10s I'd say go with a tire that'd make you shift to 4th if you've got the hp.

 

Yeah I was pretty excited to run a 13.6 my first run but then I started doing worse and was a little dissapointed.

My tune has the limiter at 6500 i think and i have 3.73 gears.

Oh btw, does anyone have a link to the excel spreadsheet that is on one of the forums that tells you your speed in each gear with different tire sizes and gears. i found an online calc that has all this but i just want to save the one on the forums.

 

I don't have the spread sheet, but like I said, you drop that 60' to 2.0 or better and your car will definitely be in the low 13s. It's generally accepted that for every tenth you drop in the 60, your E.T. should drop by about 2 tenths. .2 in the 60' should be good for .3-.4 on the big end and you'll be looking at a 13.2. Just an observation though.

 

Found it. its under other in the how to section. there are two of them.

http://www.cherod.com/mustang/HowTos.htm

Thanks for the info projectquick. hopefully next time i get out there ill get a better 60'

the calcs say 106 mph at the top of third with my tires and gears. maybe i need to check and make sure my redline is at 6500 because im pretty sure i redlined before the traps.

 

Not being able to make a pass in 3rd at 6500 sounds about right with 3.73s. I'm pretty sure anyway.

 

With practice you'll definetly bring it down. I've probably said this in every first time at the track thread, but my first time out in my 89 I was running 15.2-15.4s, with 2.2-2.3 60's. With nothing more than practice launching, and when and how to shift, I brought it down to low 14s with 2.0 60's. Practice, practice, practice, once it starts paying off, the strip gets addicting seeing how much time you can shave off with mods and technique.