Dyno pull after 4r70 swap

[TClark22]

Finally got around to getting it retuned after the 4R70 swap. before it made in the 650s with a t56 on 7lb gate springs (netted 8-9psi) on 91 oct. I swapped in a built 4r70, ptc converter and changed gate springs to 10lb springs (netted 11psi i believe). We came out with, i shit you not, 666rwhp with a little converter slip.

[video=youtube;7qR9sbtnJxg]https://www.youtube.com/watch?v=7qR9sbtnJxg[/video]

Obviously that seemed like a short pull. lol 4.10 gears on a turbo car with a auto will do that. Built rear is to come hopefully sooner than later as i can't really race it like it is since I'll top out 3rd gear well before the end of the 1/4. Seriously...105mph top speed in 3rd...i was speechless. I know the converter slip had a little bit to do with it but i was expecting it to top around 125ish. Also tire size, these tires are 315/30...also not helping.

So yay more money to spend...tighted up the converter, build rear end...turn up booooooost. lol even with my hoosiers on, in 3rd gear I'm roasting the tires from about any speed.

 

[F8L BYT]

Ugh That sounds so nasty! I love it! The numbers are fitting for it!

 

[GloomySVT]

You going to a taller gear? 3.55? 3.27?

 

[TClark22]

You going to a taller gear? 3.55? 3.27?

Yea probably 3.27. Maybe a 3.55 since i plan to run a 28" tire. My 315/30 25.5" tall tires didn't help.

 

[NasteeNate]

Gives me hope when I build my 4R!!!

 

[stangfreak]

nice man. car sounds wicked. I would love auto/turbo setup in my cobra

 

[TClark22]

Yea auto and turbo are like peanut butter and jelly.

I love it already and the setup isn't even proper yet! Just the seamless shift between gears is awesome...even if I'm ice skating around with those shifts. I have sprung a leak again at the fittings for my trans cooler so the car is not going anywhere until i fix that but I'll make sure to get the gopro strapped on and get some videos of me leaving black marks everywhere

 

[NasteeNate]

yeah, please do! Must feel like rocket.

 

[Mr. Mach-ete]

Thing sounds like it wants to suck little babies in, Jesus.

 

[whitedevil95]

Wow that sounds awesome!!

 

[PACIFICGREENSVT]

Nice. I'm going down to 355's when I can get some time out in the garage. I think it should be perfect with my 28in tires. Again nice! I love my 4r70w.

 

[SVTFastBack]

Sounded good, sorry I had to laugh though... Heard it spool then just as it was getting better
bam, a quick climax. You need some gear! Also I know they spool better on autos but yours was really smooth, what size and a/r? I have an friend down here with a 2014 he wants to go single with that's an auto just off gate spring and maybe eventually a controller, he wants 74mm Warner.

 

[gimmie11s]

Yea probably 3.27. Maybe a 3.55 since i plan to run a 28" tire. My 315/30 25.5" tall tires didn't help.

don't be nervous about going to too tall of a gear.

I went 3.27s from 3.73s and noticed nothing except for better cruising mpg, smoother drivability, and a 4th gear that doesn't stop until well after 145mph with a 28" tire.

Almost wondering if I should have gone 3.15s....

 

[whitevenum]

3.55 plus 28" tall tire is what I run. Works great.
Congrats on the swap

 

[GloomySVT]

I've heard of turbo guys going as low as 2.73. Their reasoning is more engine load to build boost faster, plus a nasty top speed. I think 3.27s are more feasible though. Car will probably feel super sluggish with a gear ratio in the 2's lol

 

[GloomySVT]

Ooo, forgot 3.08s existed. That might be a nicer option than the 3.27s, if you aren't running taller tires.

 

[wakebum2507]

i've got 2.73's in mine...

1000+hp and 2.73....still spins from 60. not sluggish feelin. lol

 

[TClark22]

Sounded good, sorry I had to laugh though... Heard it spool then just as it was getting better
bam, a quick climax. You need some gear! Also I know they spool better on autos but yours was really smooth, what size and a/r? I have an friend down here with a 2014 he wants to go single with that's an auto just off gate spring and maybe eventually a controller, he wants 74mm Warner.

lol i know, i laughed as well but more shocked, its over way to quickly. I knew the 4.10s would hurt but with the t56 4th gear pulls still went to 125ish...so i have some slip in the converter that will need to get tightened up.

I have absolutely loved my turbo selection so far. Its a Forced inductions borg warner S476R 87mm turbine wheel with 1.1 a/r, obviously 76mm compressor wheel.

A lot of people go with a sub 3.0 gear because they want to run things like half mile events and even mile races that need the extra mph.

Currently I'm thinking about 3.27 or 3.15.

 

[GloomySVT]

lol i know, i laughed as well but more shocked, its over way to quickly. I knew the 4.10s would hurt but with the t56 4th gear pulls still went to 125ish...so i have some slip in the converter that will need to get tightened up.

I have absolutely loved my turbo selection so far. Its a Forced inductions borg warner S476R 87mm turbine wheel with 1.1 a/r, obviously 76mm compressor wheel.

A lot of people go with a sub 3.0 gear because they want to run things like half mile events and even mile races that need the extra mph.

Currently I'm thinking about 3.27 or 3.15.

I'd say go 3.08. wakebum2507 is an absolute madman with those 2.73s :lol1:

 

[assasinator]

Consider a serious race setup for a turbo car...3.27's and a 1.85 powerglide. At a certain power level with a hard hooking car, you can only put down limited power with a set tire. At that point first gear ratio loses importance. I suggest gearing the car one time instead of the multiple times some do. 3.08 or maximum 3.27 is all you will be able to use. IMO.