Pwnage1337

WARNING: **** POOR FABRICATION PICTURES AHEAD

Here's my first half assed mockup. Lots more cutting and welding and grinding to go lol

rklessdriver

Not bad at all. Looks like it will work great.
Will

Pwnage1337

Thanks, I still need to cut away the section behind the tail shaft on the top and bottom. I'm planning on welding another bolt support on the side in the 3 o'clock position, and underneath it as well for good support. I think the adapter should have enough strength, it doesn't have very much flex. I can stand on it without it moving very much

Still need to get a Yoke.

rklessdriver

I wouldnt cut it too much shorter unless there is physical interference.... the more contact surface you have the less it will flex. Can also build a nice safety loop easily by welding a strap in open side of the adapter.
Will

Pwnage1337

I was thinking the same thing with the hoop. I have about 3 hours in this so far with cutting/mocking up. I think I did 20 test fits before drilling lol

Mike Holmen

I cut my C beam like you indicated. I welded on a chunk of aluminum at the 12, 3 and 6 o'clock positions. I used 6066 aluminum plate for the 3 o'clock position. Used 6066 flat bar 3/8 thick for the top/bottom, approx 10 inches long. Worked out good. Welding only took a few hours.

Was harder finding time to actually do the welding.

Awesome build. Your gonna have to let us know what you think of the 4L80 vs the 700r

Pwnage1337

I don't have the skill or equipment to weld thick aluminum but I wish I did so I could do something like what you're talking about. I already know I'm gonna like the not so massive RPM drop from 1st to 2nd a lot more!

rklessdriver

Absolutely going to love the close ratio....
Will

Pwnage1337

With my rear gear and tire size, 1st gear is basically 10 mph for every 1000 RPM. Leaving 1st at 60 sounds fun to me! Lol

Pwnage1337

Got the Cooler mounted. I had to cut a piece of angle iron and weld the two pieces flat together to get enough rigidity so it wasn't droopy.

Currently i'm considering robbing power from the racetronix positive red wire from the battery, part of the fuel pump hot wire kit. It's a 10 gauge wire, which should be good for like 30 amps. I run a single Walbro 255, the fan has a current draw of 4.8 amps. Thoughts?

The RXP255 pulls 8 amps at 43 psi, at 13.5 volts. I run underdrive pulleys on my car, March power and Amp series, so I maintain 14.2 volts even at 800 rpm idle. I'm gonna give it a shot and if my car burns down to the ground we'll all know why

1993C4LT1

Awesome work man. Sucks that the 700r4/4l60/4l60e trans don't last long with power.

Pwnage1337

Thanks!

I would probably would have just built a 700 if I wasn't planning on building for more power down the road. The 80E gear ratios are definitely more attractive. Weight is kind of a downside, but my car will sit lower so I won't have to buy coil overs! Converter prices were pretty shocking and almost turned me away from it. Circle D, Yank, etc were all basically $900. Add in the cost of the controller and its a $1600 swap, without driveshaft shortening, and adapting to the C beam

Pwnage1337

After select curse words, the use of two giant pry bars and about 10 attempts, I've got this pig in place. Right now I need to drill the bolts for the C beam to the trans adapter. I figured I would get it in place, then drill them right where it sits.

Does anyone have any recommendation about how to measure for the shortening of my drive shaft? What I've come across on the internet is two ways:

1. Put the car on the ground, or load the suspension somehow so that you can account for suspension travel and the slip yoke travel.

2. Bottom the Yoke out in the transmission, pull it out 3/4" and measure.

Thoughts or input?

Thanks!

C409

..... Ask the folks that will be building your new driveshaft . There is no suspension travel in a C4 Corvette ... C-beam and Batwing prevent that ... measuring method #2 sounds good but the driveshaft guys will need to know if you're measuring from the centers of the U-joint trunnions or not .....

C409

..... From what I can see in your pics , the C-beam is not a snug fit on your adapter ... you might want to weld on some appropriately sized spacer plates before you drill .....

Pwnage1337

​​​​​​Close eye, there's about .25" of play and I intend to cut a piece of flat steel to take up the wiggle room. Probably slide it on the top side, clearance to the tunnel is pretty tight

qwiketz

great work. Thanks in particullar for the pic of the cooler. That is on m to do list.

For those of us without the fab skills, just a reminder, they have the 65 and 70 variants of the 4l60 these days. Probably lot of cash unless you can find one off someone though.

Jealous of the 1st/2nd gear ratio!

Pwnage1337

Took my driveshaft to get shortened, the place said they won't touch it because it's aluminum.

There's a place 50 miles away that will do it, so I'm headed that way tomorrow.

Going to run the cooler lines and start the wiring of the TCU. Yay! Lol

89L98TPI

For those who are following I recently swapped a 4L80 in in place of my built 700R4. BUYERS BEWARE! Even with the Billet tail housing we needed to shorten the driveshaft and cbeam to make it fit. Loving the results so far. Good luck with your swap

Benny42

When i did the T56 swap, my driveshaft was 1" too long. A local shop custom made a 100% new steel shaft cheaper than any shop i could find to cut my stock aluminum shaft. Just tossing that out there. Nice project.