Tires & Gears

[Geos05GTvert]

How do I figure out the best combination of tires and gears for a quarter mile? Anyone know?

Here are my specs:
Car weight 3970 with driver
RWHP 480
Gears 3.55

I was told that the Power House kit runs best with 3.73 for the quarter but not sure what size DR's I need.

 

[Kevin@PMP]

G - A lot will depend no how serious you are about racing, 6k RPMs in 4th with a 27" tire (stock height) and 3.73s allows for a 129mph trap speed, with 4.10s you will be at 117 at 6k. So with 3.73s you would still have a lot of room to grow and great street manners. Ideally on the track you use all of your power band in all 4 gears so you want to go through the traps at the top of 4th.

Here is a good calculator http://www.csgnetwork.com/rearendgearcalc.html enter the target RPM as the max you want to go through the traps at and play with tire height (most common drag tires are 26" or 28" tall), trans ratio for 4th is 1.00.

Don also has a good calculator that I am sure he will link to.

 

[travelers]

G - A lot will depend no how serious you are about racing, 6k RPMs in 4th with a 27" tire (stock height) and 3.73s allows for a 129mph trap speed, with 4.10s you will be at 117 at 6k. So with 3.73s you would still have a lot of room to grow and great street manners. Ideally on the track you use all of your power band in all 4 gears so you want to go through the traps at the top of 4th.

Here is a good calculator http://www.csgnetwork.com/rearendgearcalc.html enter the target RPM as the max you want to go through the traps at and play with tire height (most common drag tires are 26" or 28" tall), trans ratio for 4th is 1.00.

Don also has a good calculator that I am sure he will link to.

Thats what I was looking for. The one I have is basicly the same.

 

[Geos05GTvert]

Thanks Kev!

G - A lot will depend no how serious you are about racing, 6k RPMs in 4th with a 27" tire (stock height) and 3.73s allows for a 129mph trap speed, with 4.10s you will be at 117 at 6k. So with 3.73s you would still have a lot of room to grow and great street manners. Ideally on the track you use all of your power band in all 4 gears so you want to go through the traps at the top of 4th.

Here is a good calculator http://www.csgnetwork.com/rearendgearcalc.html enter the target RPM as the max you want to go through the traps at and play with tire height (most common drag tires are 26" or 28" tall), trans ratio for 4th is 1.00.

Don also has a good calculator that I am sure he will link to.

 

[06GT_Vert]

Geo - The bug has gotten you!!!

 

[94tbird]

im using 4.10s now and all of my shifting is done before the 1/8 point. im riding out 4th gear for the remainder of the quarter mile haha

 

[Geos05GTvert]

Kevin,
What tires and size are you running and would they fit on a 17x8 stock bullit rim? With our setups bieng so simalr you have all the work already done.

G - A lot will depend no how serious you are about racing, 6k RPMs in 4th with a 27" tire (stock height) and 3.73s allows for a 129mph trap speed, with 4.10s you will be at 117 at 6k. So with 3.73s you would still have a lot of room to grow and great street manners. Ideally on the track you use all of your power band in all 4 gears so you want to go through the traps at the top of 4th.

Here is a good calculator http://www.csgnetwork.com/rearendgearcalc.html enter the target RPM as the max you want to go through the traps at and play with tire height (most common drag tires are 26" or 28" tall), trans ratio for 4th is 1.00.

Don also has a good calculator that I am sure he will link to.

Geo - !The bug has gotten you!!

Dont tell my wife that. I've got a secret fun fund and it's draining quickly LOL. My immediate goal would be to run high 11's on street tires use the DR's at the track. So I'm thinking with a little added boost 13PSI and some 3.73's It's feasable. I would like to see a Mid or low 11 on the stock motor.

Sean: Are you powershifting to get your 11's? Or just shifting quickly. Your car was fast as hell on 11PSI. If you had the right tires you would have been running mid 11's if not faster.

I could concievably shave 3ths with good DR's and proper hookup, and another 3ths with some power shifting and another .1ths with the gears and still have a very streetable car. The bug has gotten you!
You could say that lol.

 

[Kevin@PMP]

Kevin,
What tires and size are you running and would they fit on a 17x8 stock bullit rim? With our setups bieng so simalr you have all the work already done.

I am running the M&H 275/50-17 drag radials (they are 28" tall) a lot of people go with the 275/40-17 Mickey Thompsons (they are 26" tall) Both will fit on the stock Bullits. I am very happy with the M&H's.

Shaving some weight off the car would help a ton also, a swaybar delete, k-member, a-arms etc would all help you get where you want to be.

 

[don_w]

Don also has a good calculator that I am sure he will link to.

It's here: http://www.2005stang.com/gallery/albums/userpics/10330/RPM_vs_Speed~0.xls

 

[Josh@PMP]

Geo, Work on that '60 time and you are all over high 11's. If I could have go mine down to what I have ran before I would have been them this weekend too...

 

[don_w]

im using 4.10s now and all of my shifting is done before the 1/8 point. im riding out 4th gear for the remainder of the quarter mile haha

Same here... and like I've said before, the first 1/8-mi is the most fun anyway.

 

[06GT_Vert]

No im shifting like im on a sunday drive...Cant powershift when im loosing the clutch...Clutch took a dump on saturday..Sunday it took all i had to get it gear.

 

[Hylander]

No im shifting like im on a sunday drive...Cant powershift when im loosing the clutch...Clutch took a dump on saturday..Sunday it took all i had to get it gear.

Just be honest here. You suck at driving!

 

[06GT_Vert]

Just be honest here. You suck at driving!

Maybe but im still faster than you...hehehhehehhe

 

[lostsoul]

who took a picture of me riding my bike to the store??!!?

 

[Hylander]

Maybe but im still faster than you...hehehhehehhe

No, you're faster than Joe... you have yet to beat me!

 

[Geos05GTvert]

My question is: So if I want to finish around 6K in fourth at the end of the track and I'm making 480RWHP and car weighs 3970 and gears are 3.73 I still dont know what tire I need.

I keep hearing that the M/T ET Street Radial is the best hooking DR's out there can I get confirmation on this? Do I get the 275/50/17's or 275/40/17's or should I get a bigger wider tire?

 

[06GT_Vert]

The more tire you can get to the ground the better - I will be running a 28" Tall tire - You can get away with a 26" Tall tire becouse of your gear size..

 

[06GT_Vert]

No, you're faster than Joe... you have yet to beat me!

you are correct!! Where are your pics from the weekend?????????

 

[Kevin@PMP]

My question is: So if I want to finish around 6K in fourth at the end of the track and I'm making 480RWHP and car weighs 3970 and gears are 3.73 I still dont know what tire I need.

I keep hearing that the M/T ET Street Radial is the best hooking DR's out there can I get confirmation on this? Do I get the 275/50/17's or 275/40/17's or should I get a bigger wider tire?

With 3.73s you will need a 26" tire, but then you run into the problem of not having enough sidewall. IMO 3.90s or 4.10s would be a better option with a 28" tire for your car G.