JASON 77

iTrader: (22)

buyin a 9 inch, what would be the best gear for a street/strip car with a 28 inch tall tire? options are 3.73's, 3.90's or 4.10's

jmm98LS1

iTrader: (28)

Need more info.....M6 or A4? How much rwhp and what rpm do you want to be at through the lights?

JASON 77

iTrader: (22)

it does say A4 in the topic. not really sure, still want it to be streetable.

jmm98LS1

iTrader: (28)

lol, my bad....I'm blind.
With a 28" tire I think you could probably get away with 4.10's. You'd still have decent cruise rpm in OD (2600rpm @ 70mph) and you'd have enough gear for ~120mph in the 1/4.

Greaseymec

iTrader: (9)

4.10s with a 28" tire would work out well. I'm running 3.89s (Ford 9 inch) with 26" tires and it seems to be a good combo. A4 here also. Trapping 118 on a mail order tune.

Mec

WAHUSKER

iTrader: (4)

3.70s took me thru the traps at around 6k with 27" QTPs.....

EPP

iTrader: (22)

It depends on rwhp, tire size, converter slippage and rpm limit. We have 3.70's in mine and we're about out of gear. Bob

WAHUSKER

iTrader: (4)

What Bob said is the key.....what is your setup? I ran 4.10s with cam-only & NA setups & they were about right. But with a S/C (or NO2) they were too deep, I ran 3.70s & now have 3.50s. With a redline of 6500 here is where you'd top out in 3rd gear with each ratio:

4.10s = 127 mph
3.90s = 133 mph
3.70s = 141 mph
3.50s = 149 mph

Conventional wisdom says you don't want to shift into 4th with an A4 at WOT unless you like rebuilding your tranny. So how much power are you making & how fast will you be going? And how much does gas mileage matter & how much highway driving do you do?

daniel6718

iTrader: (36)

yeah depends on converter slip and trap speed

bad2000z

iTrader: (4)

I went with 4.11's. I'm running 275/60/15's (28").