I am ordering a ford 9 inch tuesday (used) and it will come with 4.11s.

I plan to abandon my blower and go turbo in the not so distant future. The kit i have found comes with a T76 turbo.

I dont know at what rpm the turbo will spool up at nor what would be the best gearing you guys think for best quarter mile time???

thanks guys

 

You need to know your tire size, estimated trap speed, and rpm you want to go through the traps. Then it is simple math to decide what gear you need. If you are running an automatic, you will need to add an estimated percentage for converter slip, typically 5-8% for a high stall (5,000rpm+) and a bit less for a lower stall conveter. Depending on the tire used, you might want to add an 1" for tire growth to the diameter. There are on-line calculators to make it easy, if you don't care to do the math.

Rich

 

Rich is right, you just have to calculate it based on your expected trap speed. Since alot of turbo guys wind up running high mph and turbo motors don't generally rev high, we end up with tall gears. I'm using 3.00's and hitting 146 mph at 6200 rpm with a 26" tire.

Mike

 

I am gonna stay with my t56 (i will get g force internals). Any idea where a t-76 turbo will spool up at???

 

3.42 - 3.55 is a good gear for M6 tranny.

 

I agree. With your power and boost level likely with that sized turbo, anything more than a 3.42 will be useless in the 1/4 mile, and will probably be useless on the street as well. (Useless meaning you will spin your tires every which way, or on the track you'll have to shift into 5th gear)

 

3.42's with ~800rwhp work good for me with an M6. More gear would be bad and require shifting into 5th in the quarter with a 26" tire.

Rich

 

thanks so much you guys!

 

how much boost you guys think i will make with the t-76?
on a 396 stroker with afr 210 ltf heads and a blower cam???

 

Depends on a lot of things... one being the design of the kit. What kind of hit is it (headers, logs, etc.)?

 

it is the ohio boost kit... headers.
http://www.ohioboost.com/p_lt1fbody.html
just a ball park guess would be fine.

I will be getting the 4" down pipe and the air to air 3" upgrades as well...

 

Realisticly, I'd say 750-800rwhp with an M6 tranny and pushing the turbo pretty hard (18-20psi).

 

sickness. just a matter of time and money : )

i might spray it a little off the line until I let the boost take over.
depends where she spools up at.

 

Remember though, I can rattle off 15+ ls1 vehicles on ls1tech.com that arent hitting 800rwhp with their T76 and nice turbo kit. You will have to push that turbo, have agreat tune, and need some serious heads. Ask engineermike what it takes to push a T76... he has made 700rwhp thru an auto and log manifold kit.

 

i want only the top of the line stuff on my car. I am going to have a billet bottom end and the best heads available... i hope that it will remain streeteble though and the tune will affect that I am sure. 91 octane of course/