Dimewise

Anyone over 900whp running the stock 6l80?

What all is done if anything other than tune and converter, cooler. etc?

How long did it last and what did you run after it broke?

Car is supposed to come out of the shop in a month or so and need to make the trans live until I can afford to build it.

4head

There is a guy who posted some videos on youtube on how to use the blue cat tool, he has great experience getting a lot of power to survive in gen 3 stuff, and seems to have good luck with the stock 6l80's

I know there are some heavy *** suv's and or trucks with stock 6l80's surviving but rarely any info on vettes.

I have a circle d level 4 kit I'm putting in mine, and a circle d triple converter. I just decided while I have my motor out, it would be easier to do the trans and driveline too. I was able to drop the rear cradle in like 5 hours with the engine removed. really quite easy.


The best thing you can do to keep it alive is get 1 the right pressures in there, 2 use as much torque management as you're willing to use, 3 make sure the rates after the shift aren't too aggressive

And super critically run a big *** trans cooler. Bypass the radiator. Janetty on youtube says to not bypass it. But that's for old men in heavy *** cts-v's who don't understand that fluids need to be at the right temperature to do their job.

Also the ctsv guys have made plenty of power 800+ on the 6l90 and i guess 6l80??? Not quite sure if they had one... and 1/4 them. Tuning is important for these transmissions. I recommend the ctsv sites and look around. There are some fast cars and they're heavy as hell too. Kinda stupid that the corvette guys didn't get into the 6l80.

Wheel hop in trucks etc will kill the rear planet, but the rear planet is actually pretty beefy. So avoid wheel hop, and don't punch it in Drive on the highway. As in DON'T LET IT AUTO DOWN SHIFT MULTIPLE GEARS. Downshift one by one using your steering wheel buttons. Apparently several 6l80's were lost to kickdown into a lot of power.

Dimewise

So there is an optimum trans temp? Not just the coolest as possible?

harleyreb1

I ran my stock 2010 6l80( stock converter) for around a year at 850. Did multiple Texas mile runs (WTO in 5th for several seconds) mine lasted but I didn’t beat on it hard everyday. I did add a secondary trans cooler. Tune is critical and don’t run it hot. Plus add an extra quart of oil.

high9s

I was always told the oil additive packages couldn't do their job until 180°. I never get on my engine or trans under that temperature. I am talking street, not track.

Dimewise

Guess I should mention my trans has a great tune, stall, external cooler/fan.....and 80k miles lol.

my plan was to not do more than a 3rd gear pull when I wanna blow the Cobb webs out. Maybe do a 2-3 run occasionally.

will suck not being able to make dig hits with the fancy new converter tho

VVVROOMTX

I know that the guy from Gforce, Marvin does a lot of transmissions and even tunes them, builds a good unit. I believe he did the 6L80 in Richie's blue vette and that thing got beat on. If i were to build it that would be my pick. I don't think circle D will do 6L80s or warranty them. I've been told by a lot of poeple with C6s and 6L80s that drag race, to just run them with a good converter and tune until they die, then buy a new GM unit with warranty and keep warranty trading them when they break.

Dimewise

Ya Marvin will be the guy that builds it, thats the plan.

Warranty trading sounds cool but id imagine they wouldnt like the motor combo the trans is attached to in my car lol

VVVROOMTX

What they wont know, wont hurt them

Aviator493

Not 900, but I’ve been 750 for 3 years on a reman trans that’s bone stock and has been flawless. It’s not very friendly until it warms up, but it shifts like butter when getting on it. It’s getting ripped out now for a manual swap. Lol

Skorppi

What is safe power level to lock stock converter at WOT? I have heard that stock converter lockup can´t handle much power.

4head

What will kill a trans is the shift power, shift rpm, and traction level.

I think if you launch in 2nd and aren't on stupid sticky **** it would be fine. Especially with like a bias ply, and avoid wheel hop with good suspension etc.

You said you have a good tune, so I think just send it.

It's a stock trans, if it pops a new one is what? Less than a grand? The worst part is the swap. I dropped my rear cradle in like 5 hours, on jack stands, with a long break and dicking around (couldn't figure out the parking brake stuff on the first one, ended up being easiest opposite how the tutorial I used recommended).

So I'd just start in 2nd, let torque management pull the timing on the shift to 3rd, and rev it out.

As for fluid temps I have only heard as cool as possible. I don't know about the 180 deg... I personally will wait for it to get to like 90 deg or something reasonable, and then let her eat. But I don't think 180 deg is actually necessary. Not sure. Dexron 6 is quite thin. I know some guys add a "little bit" of tractor fluid to lower the viscosity which should help out temps further. I don't know what "a little bit" means. But I rather run trans fluid than tractor fluid, so I bought 1 quart of the mercedes super thin ATF. Top Tec ATF 1900 for the Mercedes Benz 236.15 specification. It isn't officially rated to MB but liqui moly is probably reliable enough to trust their viscosity ratings.

My plan is to use idk half quart of it in the total mix when I rebuild the trans. And I plan on replacing fluid far more regularly. When I drained my stock trans (mind you I've only had the car 1k miles, no idea how the previous owners treated this car), the fluid was god awful imho for 24k miles. Slightly burnt smell, but dark as ****. I was expecting a lot better.

Then simply make some kind of access port setup on the lower area of the pan to easily vacuum out fluid and pump it in. Just leave the fill plug open to check the drip rate, but make it easier to pump. Not sure if the cooler line access ports reach down far enough to drain all of it. Probably all stuff I'll go over in a video.

4head

Or you could even rebuild the stock one, with stock parts/stock replacement upgrades. Sonnax just came out with an increased stock clutch count hub so you don't need to spend big money for an upgraded what is it... 4-5-6 hub? Can't remember. Too many details this far in the build to keep track of.

Or circle D trans sells their powerglide hub upgrade and clutches seperate, that costs about a grand... For around 2 grand you can get their complete clutch kit and their hub. Looking now they sell a sonnax part.

From what I've seen a 6l80 is not very difficult to build aside from that snap ring being a bitch. I'm going to build mine. Do I have any automatic trans experience? hell no. Just gotta do it. If I burn one up, I burn one up!

CI GS

Tune it right, keep the temperature below 200*, rpms below 7000, and gear it so it doesn’t shift into 4th during a run, and a stock 6L80 will last a lot longer than anything else short of a built TH-400 or PG.
Bear in mind that when you add aftermarket parts to it, it absolutely needs to be custom tuned by someone who knows what was done to the trans, because once you change clutch packs and do valve body mods, etc, that throws everything off.
BTW: the quickest and fastest 6L80 Vette I’ve seen on these forums is running a stock (albeit refreshed with GM clutches) 6L80, and he runs mid 8s @ 160+, iirc.

Turbo6TA

I would never lock a stock converter or an aftermarket single disk high stall converter at WOT.

If you are planning to actually lock the converter during WOT, you need to get a multi-disk converter.

Unless your C6 is mostly a race car, I would just get a quality single disk high stall converter and forget about re-programing the car's computer to lock the converter at WOT. Certainly not needed on a daily driver or a weekend joy-ride car.

VVVROOMTX

Link to this Sonnax rebuild? im interested

Omega Doom

im waiting for subfloor to chime in on this thread but great info being passed along

Omega Doom

not to hijack but im wondering whats the main differences between the A8, A8, and the new A10s other than the obvious which is extra gears so i mean can the A6 be made to shift like an A10 and which tranny will hold more power?

realcanuk

A stock trans can last a while at that power with the right tuning, but eventually upgrades are needed if you want it to last. I rebuilt mine using all the upgraded sonnax parts that are available, and extra clutch packs. The drums should also be welded while they are out. The only really expensive part was a billet intermediate shaft as mine twisted.
As mentioned, keeping it cool, an extra quart of oil. and most importantly, a good tune by someone who knows what they are doing is key.
its been probably 5 years since mine was built and the trans never gave any problems at all. I sold the car to a friend of mine and he also has not had any issues since.

VVVROOMTX

Do you have a list of all the Sonnax parts you used with part numbers? Also can you explain welding the drums?