Best Rearend Gear Option For tvs2300 E85

[Mikey_boosted_c]

As of now I have the stock ring n pinon in the car A6 . I'm Currently on 82mm 110 leaded octane or 91 oct with a jlt intake long tubes and opg . I was planning on going to 75mm pulley and convert to e85 . Now my question here is should I stay with stock gears (3.31) or should I go with 3.73s ? Would 3.73 be too low or should I go 3.55s ? I am on the et street pro 275/60/15 I want something that will make me go 1.55 60' at least and low 10s at least and not blow the tires off . On 110 oct best time was a 10.600 on 8.5psi @ 131mph with a 1.65 60' .

Any advice would be greatly appreciated .

 

[vortecd]

Stock gears in a A6 are 3.15. I would stay with them

 

[Vert]

What he said or its spin city.

 

[oldstv]

What they said. Makes tuning of the trans easier too.

 

[Scott8583]

75mm pulley on E85 is too much for a stock motor. E85 on your 82mm will pick up power. I run a 3.55 and like it, but like others said its harder to hook and tune. I think it helps on the big end.

Last year I ran 10.60's on heavy 18" NT05r's with 1.54 60' times on 3.55's. 79mm pulley

 

[Mikey_boosted_c]

Folks out here in Cali run 75mm and there cars last for a good while till they sell them .... But that was my major concern in dropping pulley size . I don't want the rods to give out on me ... Is there a tq difference in from 110 oct to e85 ?

 

[corepwn]

I've had pretty good luck with the stock 3.15s. As you make more power I know that Justin over at VMP would suggest going even lower, believe he's running 2.73s in his wife's car now.

 

[Scott8583]

I've had pretty good luck with the stock 3.15s. As you make more power I know that Justin over at VMP would suggest going even lower, believe he's running 2.73s in his wife's car now.

I believe they'er running 2.73's is because they are running a loose converter in that car. I know someone with a 3c converter that was hitting the limiter going thru the traps at 149mpg on 3.31's.

I have a couple theory's on gears. Most people swear the 3.15's are the way to go. Most TVS guys that run more gear, can't hook up in first, so they see no improvement in ET. Century guys are running looser converters and see higher trap rpms then us stock converter TVS guys. My car has been trapping more then I expected and I believe it's because I run 3.55's. At 146mph I go thru the traps around 7200 compared to if I had 3.15's I'd only see 6300 ish. My car makes roughly 80whp more at 7200 to 7500 then it does at 6300.

A 3.15 car might hook and 60' the same as me, but after 2nd gear is where the benifit is. My car will spin to a 1.40 60' (best of 1.38), and like I said the 3.15 might dead hook to a 1.40. Need to compare the 3.30's and 1/8th ET's.

I plan on doing more testing come spring. I bought my Pro's used and they were shot at the end of the year. I was spinning on a cool track on the gear changes losing ET. Best of the year was [email protected] with a Roush case making 15 psi on E85...