beerme

Hey all,

I just wanted to let everyone know I picked up a new 700R4 with a 2.84 carrier. I am truly impressed with how my car drives now, my 1st gear shift is delayed a bit more which is making the car more fun to drive.

The reason I went to this setup is because I upgraded the engine to 383 and rear-end to a 3.73 which resulted in 1st gear shifting very quickly.

I was unsure about doing a different carrier but this seems to have been a good move, about 500 miles on the tranny so things could change but all in all I am very pleased.

Just thought I would share in case someone is considering this for their car as well.

eutu1984

just saw this video on it, looks good.

odxr

The 700r4/4l60e was originally designed as a 1/2 -3/4 ton truck trans -the reason behind the deep 1st gear.Just in the last few years the aftermarket has came out with the new 1st gear set.Before you had to build up a 200r4-to get a good car type gear spread.

WVZR-1

I believe there's little validity to that "generalization". I believe it likely an EPA thing.

The shorter 1st gear allowed certainly taller rear axle ratios to get the vehicle "in motion" and still produce the #'s required. The trans never saw "real 8600GVW" 3/4 ton applications as the higher GVW applications got much shorter rear axle ratios. The 4L60 did well considering the applications it was used in and the generally thought "higher heat" generated through the 1 - 2 wide spread.

OP - with your rear gear choice there's absolutely no doubt that the change improved your driveabilty. Do you notice the 2 - 3 split also or just paying attention to the 1 - 2?

byynow

What is the source of the 2.84 carrier? Is it aftermarket only or can it be adapted from an OEM transmission?

rklessdriver

Sonnax manufactures the 2.84 planetary. PN 77284-K

http://www.sonnax.com/parts/3734-2-8...ut-carrier-kit

Will

BOOT77

A powerglide has the same ratio change percentage on the 1-2 on a 700r4, so if you know the why & how a pg works then

BOOT77

Read the youtube comments and watch it again. My TPI only drops to 4k shifting at 5700, but wait TPI can't make power up there???

five7kid

The video is a bit deceiving. The original 1-2 shift is about 5700 RPMs. The new ratio 1-2 shift pegs the tach before the shift occurs.

Not saying there aren't benefits to the modified ratios, just saying their demonstration was not apples-to-apples.

beerme

My greatest attention has been on the 1 - 2, but the seat of pants feel is the 2 - 3 is more delayed as well but I really haven't been watching that shift point.

All in all I am still really happy with the way the car is driving now.

Tom400CFI

I noticed it too. I DO think that a taller first gear is better for applications like the OP's...but yeah, I saw the same thing. Second vid was probably shifting at 61-6200 RPM

856SPEED

They don't...

Have you seen your dyno sheet at 5700 RPM? W/O a miniram or other after market shorter runner intake you are falling flat at 4500 and dropping power quickly at 5000RPM. Sure you can rev it to where you want.....

BOOT77

They do if you know what your doing

Tom400CFI

Let see your dynos sheet then.

No "TPI" looking intake that I've ever seen is making meaningful power at 5700 RPM. Some people think there is some "black magic" that can make it work...but the length of the runners and properties of harmonics say that it won't. Dyno sheets pretty consistently show that, too.

pologreen1

Well you could make a mint to post and share your info, because the world is full of knowledge and proof that states otherwise.

BOOT77

edit: not worth my time

Tom400CFI

A pretty common response when fact checking is brought to the table.

Pologreen is right; if you've unlocked the "secret to high RPM TPI's"...you're sitting on a GOLD MINE!

eutu1984

http://image.superchevy.com/f/914656..._induction.jpg

856SPEED

Absolutely! Because

You are working against the law of physics.....


Been there and done that myself with Edelbrock hi flow base and runners and going to miniram......night and day...

Tom400CFI

What is ^this? Context, please?