So here is my dilema.. I am going to be making a gear/tire change soon. Right now the truck makes 410rwhp / 365ftlbs on the motor. This is through a 4L80E, 12 bolt with 3.73's and a 26" tall tire. I'll be putting the 2 stage on it soon set for a 200 hit.

Right now the truck traps at 110mph unlocked in 3rd at 6k rpm. I think there is 3-4 mph in it with some adjustments to the tune on the top end, adding the pulley, moving the filter around, lowering the front 2 inches and some other minor things. So I'm using 115mph as my basis NA.

I think with the 200 shot that is planned, 130mph is a good N20 basis.

I don't mind running 2 different tires, one for NA one for the jug..


NA (unlocked figures are based on actual slip % I am seeing with this verter)
A 4.88 gear with a 26" tall tire puts me in 3rd locked at 7,250 NA 115mph
A 4.88 gear with a 28" tall tire puts me in 3rd locked at 6,750 NA 115mph
A 4.56 gear with a 28" tall tire puts me in 3rd Unlocked at 6,950 NA 115mph
A 4.56 gear with a 30" tall tire puts me in 3rd Unlocked at 6,500 NA 115mph



N20 (Slip percentage might be different but assuming the same as above)
A 4.88 gear with a 30" tall tire puts me in 3rd locked at 7,100 N@0 130mph
A 4.56 gear with a 28" tall tire puts me in 3rd locked at 7,100 N20 130mph
A 4.56 gear with a 30" tall tire puts me in 3rd Unlocked at 7,300 N20 130mph


Now to my questions

Will the 4L80E hold that power regards to stock clutch packs?
If so, will it hold that power with a locked verter?
If it was your setup, what would you do?


Thanks for the help

 

The 80 with just a shift kit will hold 800hp or something like that. I would do 4.56s with 28" tire.

 

I would go with a 4.10 and a 26" or 28" tire. The slippage on the nitrous will be higher and with your cam I'd think that you're peaking well before 7100. Just my opinion. Having the 80E in there will allow for a little less tire which is where the high first gear is nice.