Stangbanger3v

how much hp can our stock auto tranny take??? is there ne way to beef it up to take more???? around how much would it be for a auto to maual swap???? im gonna be running a lil over 600rwhp i know my engine is good but im a lil worried bout the tranny

RED121572

600rwhp? That is quite a bit of HP you got there. An no, your stock tranny isnt gonna last long with those numbers.

I think the best advice anyone can give you is to call to a tune specialist such as Brenspeed, JPC, etc.and ask them what they think a stock tranny can hold.

Good luck and report back what you find out.

zkiller

My tranny died after 3200 miles at 10 PSI. I think 450 HP is about the most these 5R55S will take stock. If you go above that the tranny is likely to fail. I lost third gear clutches on mine. I have since upgraded to a Level 10 Stage 3 transmission (and stall)which they rate at 800 HP (crank). It has held up well to my abuse.
You can swap to a manual for 5000-7000 dollars including labor. It would require a PCM and harness changes etc. My dealer has even done it on a customer car.
Your TCI converter is just a reworked stock converter so I would consider upgrading that too. I have seensome TCI converters fail at high HP too.

modaddict

You want to go for 600+ hp and skimp on the tranny? Not wise, my friend...

If you search around, you'll find the majority of guys who make that kind of power consistently have gone to 4r70's.

Sure you'll hear about this shop or other that has made such and such amount of power on their car but I garuntee you that these 'shop cars' get their tranny replaced every month or so and are constantly breaking them. It is an investment for them and well worth replacing the parts - you just never hear about.

Why do they do it? Simple - to show so and so amount of power and what the average joe will use and have so you will be more inclined to buy their blower or other product...[]

I will go out on a limb and say that 90% of the 'regular guys' making over 600 rwhp are doing it with a 4r70 set-up. This is what I believe anyway.

Stangbanger3v

where can i find the 4r70 and or the level 10???

zkiller

Yes modaddict is right. Most people are reverting to the 4r70w which is 4-speed auto used on previous generation Mustangs. Talk to Lentech for their 4r70w package w/ a transbrake. It is like 6500 and includes a stand-alone computer to control the tranny.
Level 10 sells the upgraded 5R55s for a total package cost of about 5000 (I paid 5500 shipped to my dealer). The 5r55S has a 5/8 input shaft so that would be one reason to use a 4r70w if you are going to extreme power levels the input shaft could be a weak point.
I am not going to be going over 600RWHP ever so I chose to keep the stock transmission type and have it beefed up by Level 10. I also wanted to keep my tranny controlled in the tune.
I have a Lentech tranny in my fox body and it rocks!

modaddict

Awesome advice Z!

He is 100% correct. The weak link on the 5r55 no matter how much you beef up the internals is the input shaft and I know a half dozen guys who have destroyed it.

I think with a good build, yes, you can keep upwards of 600 rwhp on a beefy 5r55 (like the level 10) but if you are ever going to surpass that or are plan on using serious torque off the line, then a 4r70 is mandatory IMO.

forensicsteve

Another company is FB Performance out of Bay Shore, Long Island. I bought their 4stb-e. It's based on the aode/4r70w. They have different options. Mine has full-manual valve body,transbrake, electronic overdrive and TC lockup. Also about $6000.While changing short blocks, I decided toupgrade the turbo,so I also had the tranny further strengthened by FB. Still a few weeks from being track ready, so cannot comment on results. On the street, it's like driving a clutchless manual.

Grabber

The engine durability is measure buy HP. The tranny durability is measure by torque. Currently, they were tested at 400, but are suggested to have less torque then that. I have over 400 Torque and have driven 2K miles, an zero problems as of you. Just thought I'd give my .02

modaddict

What vortech set-up (pulley) are you running now with how much boost to make over 400 ftq?