I am about to buy a 06 solstice as my new toy and will be swapping in a LSx engine and adding a turbo. My main concern is what is the strongest 4 speed automatic transmission with overdrive I can fit and how much work with a sledge hammer or sawzall is required to achieve the fit. I am looking for 7-800 horsepower with this build but I am limiting the power to what the transmission I can put in will hold. This is a daily driver type car, so no powerglides ect.

So can I fit a 4l60e or a 4l80e? if so how much clearancing?

if not how much power can the 5l40e be built to take?

thanks in advance for help with this.

 

I'm pretty sure any of the mentioned transmissions can be built to handle the power you are talking with no problem.

 

im not worried about building the trans to handle the power, im worried about fitting the trans in the car. everyone seems to be doing either low power v8 swaps with the stock auto or going t56 or 5 speed manual. I want to stay auto and need way more than the stock trans

 

Can't really help you myself.. but Suggest you do more research both on here and Internet..

I know that mallettcars.com does a package or conversion.. other are out there.

https://ls1tech.com/forums/conversio...tch-setup.html

general info on the stock trans from Wikipedia:
5L40-E The 5L40-E is available in either "M82" (rear-wheel drive) or "MX5" (all-wheel drive) versions. It is engineered to handle the stresses from vehicles up to 4000 lb (1814 kg) GVWR. The final drive ratio is 3.42:1, 3.73:1, or 3.91:1. The 5L40-E is designed for 1.8–3.6 L engines with a maximum of 250 ft·lbf (340 N·m) of torque. This transmission is very known for failing between 150,000km and 200,000km in the 5 series E39 and X5 BMW'S and BMW will not repair this type of transmission, only offering replacement at a high price

 

I have been doing alot of looking online and have only seen stock trans or manual transmissions. There was one thread here on Ls1tech that listed a ls2/4l80 swap but with no pictures or details on the transmission install.

 

ah, sorry, misunderstood. I can't help there. you might be able to check dimensions between the 2 transmissions and if you can get in there check how much clearance you have with the stock tranny. I'm sure some of the guys on here wouldn't care a bit to take a few measurements for you.