Was curious, what kind of hp numbers are you guys making out there with a street/daily driven car and a 4L60E? I keep hearing people debate about going to a 4L80E, but at what point is that really necessary?
I am sure traction may have a lot to do with it as well.

 

i know mine was slipping on the dyno with the stuff in my sig.

 

Power isn't necessarily the most telling rating.

You could have a 400hp turbo motor that makes 600 ft-lbs at 3500 rpm and runs out of breathe up top, still maintaining that 400 hp rating. Compared to a new LS2 making 400 hp & 400 ft-lbs, the trans wouldn't last nearly as long.

Traction is also very important. 2wd using street tires or AWD using R-compound tires (think Typhoon or Syclone) will be radically different. AWD is incredibly tough on trannies. Tires aren't the only factor, suspension design certainly affects how much shock the trans sees.

Usage is of great importance. Is the usage a 7,000lb truck that hauls a 8,000 lb trailer every day? Probably not, but the trans will certainly live a shorter life under those kind of conditions than if you put the same engine and trans in a 3000lb camaro.

Temperature management is certainly an important consideration. If you keep it cool, it'll have a much better chance of holding up.

Maintenance / condition is important. If you beat on it daily with a 350 hp motor, the trans may not live as long as a well maintained 500hp application that is driven less aggressively.

What is your idea of holding? How long a life are you expecting? Are you figuring on freshening up / rebuilding the trans every year? Because at that point, it'll likely "hold" a fair bit more power (but you'll also have it out of the car / truck regularly, and maybe not at predictable intervals)

And lastly, it seems like luck of the draw alot of times. Similar thing with the 7.5" 10-bolt that is in the F-body. Some last at ridiculous power levels, some fail catastophically at stock power and low miles. Who knows what goes wrong there. Maybe they were built on a monday.

'JustDreamin'

 

I am just trying to get some real life accounts of what people are doing as far as power, kind of vehicle, daily driven or track, and what they have had done to the transmission. I figure if some people can tell me actual accounts of their trans lasting 5 years with 450hp, or breaking after 2 weeks with 350hp, along with what they were doing when it broke, a reasonable idea of what tthat transmission will withstand in different applications can be created.
I've been around long enough that I already know all the things you mentioned about vehicle weight, maintenance, traction, etc. I want to get beyond the paper and hear what people are doing in real life.

 

What good is a 25K car if you cant drive it? Spend the money and take the extra 60lbs and get the 4L80E

 

How heavy of a car are you looking to put it in, and what are your plans for it?
My car is a low mile car but it sees daily driving and plenty of track time. The tranny is stock except for the shift kit. I would put $1,500 into a 4l60 before considering the heavier 4l80, but that's just me.

 

It's not really that I am concidering it, I am wondering because I deal with a lot of people that are doing work to the Ls1 engines, and I am hearing a lot of them talk about whether or not to install a 4L80, or a TH350, or TH400. I just want to hear from people with all sorts of stories so I can get an idea of whether to recommend if they should or shouldn't. These engines and 4L60E combos are in everything from the original Camaro and Corvettes to full size trucks, Jeeps and S-10's.