cfr865

How many have around 550 or more rwhp as a dd? I know of some that see mostly track use with this much and more that have held up quite well. I was thinking about going with a forged short block with about 550 rwhp but I don't have the money for a built trans. Just wondering if I should hold off until I save enough for the trans also.It'll be all street driven with an occasional all out run.

graygt07

good question.......looking to do the same and leave the tranny alone.

JM05

I should be around 650 in a few weeks on mine I bought a billet input shaft and beefed up the jumbo and intermediate servos that is what Tci recommended I should do for now. I just hope it will extend the life of the tranny till my wife gets over the shock of the $14,000 I just dropped into this car.

ChiDiddy

im actually in the exact same boat as you are. 5k including labor for a forged block and 2k including labor for a built transmission. Decisions decisions. Shop says i should go with the engine first and upgrade the ranny later. Just need a new stall converter which i was told was the weak point

teedub

I'm at 505 to the rear wheels on my DD. It's been about 18 months and 15K miles since the install. Stock bottom end and A/T. No issues at all so far.

antonio1988

The car should be fine assuming you don't mash the gas every chance you get, and also, the tuning of your car is what makes all the difference in the world. I've seen 450rwhp cars blow up and 550rwhp ones run fine on stock tranny's and bottom ends, only difference was the tuning. Also, ChiDiddy is correct, I was told the same thing by numerous places of the torque converter being the weakest point in the transmission, I now have a TCI 3000 stall TC and I have absolutely no regrets in the 8 months I have had it in there.

Never2mucHP

Something else to consider is traction. With that much power, the more traction you have (ie big sticky tires, suspension components to help you hook) the more stress you will put on the drivetrain. If the wheels are slipping, then the drivetrain takes less of a beating. Of course this doesn't help with E/Ts, but it might prolong the lifespan of the tranny

ChiDiddy

Wow who tuned your car? Any slippage in the auto trans? What are your other mods? Gear ratio?

teedub

a local guy here in Naples tuned it. I can PM you info if you want/need.

Other than my Whipple @10psi I do not have any other mods and I've never noticed any slippage from my trans at all. I still have the stock 3.35's in the rear end. BTW it is putting down 530 ft/lbs of torque as well.

AKRA

I had my 9 psi supercharger pushing around 500 flywheel hp on my 07 Mustang for about 1 year before my automatic tranny went out. It hurts it worst when you mat it and it down shifts into 3rd gear. 3rd gear is the weak link in these transmissions.

My brother has a 06 Mustang with a Roush TVS 2300 pushing 17 psi (Forged Bottom End) and it took him 3 days before his automatic tranny went out.

I recomend the TCIi 5R55s Super Streetfighter Transmission is listed as being able to handle 1200 lb-ft of torque.

Good luck,

Al