I have just blown my 3rd 700R tanny. The trans was built with all of the right stuff shift kit the works. Blew away from the light and the shift into 2nd and nothing. There is nothing but a faint whine, I can run through the gears, nothing. I have not opened the tranny up yet to see what went, but I know it is not going back in. The engine is right at the 400 RWHP level and I want to know if anyone has converted a 6L80 into a c4 and what did it take. There is nothing I could find in previous threads. I have slightly more power than a standard corvette which has the 6L80 trans, so I suspect it should hold up. I am so sick of breaking 700Rs, and I am really not interested in a turbo 400. I suppose one could fab up a connection to the "C" beam, purchase a controller etc.

 

You will be the 1st to install a 6L80E trans into your C4.

We will all be watching here on C4.

Go for it.

 

I am reading that there are some very special electronics in this trans. I am not so sure it can be done without someone building a controller.

 

If you want bulletproof, go with a 4l80e. Just need a conversion tailshaft, shorter driveshaft, a controller, and 50 extra horses to lug the thing around. It's been done many times.

 

Check out Rossler Transmissions in Ohio. They build some strong tranny's. I have quite a bit more hp and recently had mine rebuilt after 3 years of punishment.

I went with Rossler after blowing up 700r4 tranny three weeks in a row!!!!

 

There are some C5's with 900+ centrifugal blown horsepower running around with with a 4L60E I have been told last year.

Not sure how many full power passes they get out of them though.

I built my 87 trans to take an honest 650 HP.
When I hit that power level I will find out how good the trans really is.
I built it myself.

Maybe you should rebuild yours instead of relying upon others workmanship and what they tell you they did for you.

Many of these aftermarket trans companies build them near stock & charge $3,000- $5,000 with a converter I am told by more than 1 trans builder that has seen a High dollar trans come into their shop for a repair or rebuild.
Some lasted than 50 miles those guys tell me.

So I went about rebuilding my own 700R4 trans.
The older cousin to your 4L60E.

brian

 

No room for a T400/gear vendors OD? Wont break that may suck some power up though.

 

I have read in the past that a Gear Vendors Overdrive unit is very efficient, very little parasitic drag present even at 1,000HP. only a 1% power loss through it.
So if you feed an honest 1000HP into it, you will have 990 HP coming out to the driveshaft in Overdrive mode.

I think a Turbo 400 trans uses up around 50 HP at 6,000 RPM's.
But it has been years since i seen the that Hotrod or Carcraft article.

I was researching a G/V overdrive unit last year also.
Stardard model good up to 1,000HP.
They make a Heavy Duty racing unit good up to 2,000HP.

Neither are cheap to buy.
It is a high end $ overdrive unit but a very good one if you can afford.

 

The parts needed for the conversion for 4L80e can be purchased here http://www.transmissioncenter.net/4L...4L80E_Swap.htm
Scroll down until you see:
Attention C4 Corvette Owners
C4 Corvette 700R4 / 4L60E to 4L80E Conversion Kit

 

The 6L80 / 6L90 has a extra bolt hole that mounts the transmission to the block, also no one at present makes a after market controller for 6L80 / 6L90 transmission. See the links below, I have been waiting for a stand alone controller to hot the market myself.
http://www.ls1tech.com/forums/automa...ler-6l80e.html.
http://www.cadillacfaq.com/stsfaq/ts...-07-30-023.pdf
This guy was able to get it in a Camero
http://www.ls1tech.com/forums/conver...o-does-go.html

 

I have quite a few people tell me with the right components that the 700R should easily handle my engine. RWHP 400. I am wondering if I should rebuild it using the right heavy duty parts and wait until there is a controller for the 6L80/90.

Anyone out there lead me to the proper parts. and or let me know if this is feasible.

 

patc which is the transmission center 2 posts up has all the parts you need,also pete k. can tell you what to get.

A lot of people have been taken by tranny shops promising the best parts only to find out they have stock stuff.

You can rebuild it yourself and there are videos and books to help you out plus do a search on this forum and you will find lots of info on doing it yourself,thats what I plan on doing when I rebuid mine.

good luck

 

Find your self a Know good trans shop to build you a good trans.
The one now is a POS it's been done 3X's now by athe same local shop I put a Preforma trans on layway I should have it paid for here soon.

He makes a 700 H/P rated trrans 2 years warranty.

 

Sounds like the builder may not be that good. What temp has the tranny been running at?

 

I know the feeling.
You put your trust in a shop and they hand you back junk.

 

My last trans build...

http://forums.corvetteforum.com/c4-g...-kit-pics.html


I'm still on this one... number 3 and it seems to be holding up well.

 

Dana @ Probuilt transmissions is my 1st choice for parts & live tech advice online at his website forum,
I called him at 11:00 PM(California Time) on a Sunday night last year & he picked up for me.
I helped him find some special 700R4/4L60E Extra High Torque capacity input sprags that he was long searching for too.
He knew it was me calling from Illinois.
I found the input sprag from a transmission shop in Chicago area.
That trans builder specialized in C5 up to 900HP+ HP builds.

So Dana took a little extra favoritism towards me.

He walked me through all difficult assembly & shared all his Blue- printing tips with me over many hours on the telephone.
We likely talked for 7 or 8 hours total over 2 or 3 nights.

I have shared some of my lessons learned from Dana with you guys & gals here on C4 Tech in the past.
The sticky that used to be at the top of the page here on C4 tech but has been moved.

CorvetteMike2004 his 1989 Vert 700R4 build.
Everyone contributed including myself.

It is one of the best Sticky Do It Yourself Right the 1st time around here on C4. Likely Ever.

I made sure the "HUMAN FACTOR" is accounted for.
For I struggled at times myself on my 700R4 build for my 1987 Vert.

Take a few hours to read at your convenience sometime soon.

You can successfully rebuild your 4L60E or 700R4 yourself if you have the motivation to begin with.

Brian R.