cdemot02

I got off the phone with Lentech and Alternative auto, and our Auto's are basically handcuffed....so my next project would be to look at how hard would it be to put a different type of automatic transmission in this car? Any info would be a great help...

Thanks....

sranger

What exactly does "handcuffed" mean in this case?

cdemot02

Depends on how much horse you want....450 max with very soft shift points...

Koval

street or strip? im sure a built 4r70w could be done rather easily...then it's on to a c-4. there were a couple 05 bodied cars at wfc 8 with different autos.

StangFreak

With the torque management and the trans being controlled by the PCM I'd be carefull about swaping out the trans. Not to rain on any one's parade but swaping out the trans may screw up the computer as it can no longer match certain engine parameters with the trans, ie throttle position and shift points. It would stink if this was the case but it's some thing that should be considered. Swapping out the trans may also require going to a manual trans ECU as the computer wouldn't be as "married" to the manual as it would with the auto.

I'd check with companies like Lentech Automatics and Alternative Auto before doing a trans swap. Also consider how much power you want out of your car. I'd say that 400hp is prob the limit for the stock short block as it uses cast internals and not forged.

cdemot02

Planning on changing the block too. What exactly would the manual computer do to support the change over the automatic computer?

JST4FN

I would ride it out first and see what ACTUALLY happens. I haven't seen any cars out there yet to even judge anything. Right now everything on this car has been called weak and I've seen no evidence yet (still might be true). I still remember the days when they said the AOD was crap. I made over 700 hp and 700 lb's of torque with one and drove it daily.

Thanks Mike

StangFreak

I personally don't plan on changing the block but if the motor is pushed to over 400hp, especially if some one plans to use a supercharger with over 8lbs of boost, your prob asking for trouble. . Just my opinion.

As far as the manual computer vs the automatic goes the manual ECU doesn't have all the electronic controls in it that control the transmission. Specifically the torque management part. Basically an automatic car has two computers, the ECU and another which controlls the transmission. The two "talk" to each other and relay important information such as throttle postion, speed, and rpm among others. As a result you can't just swap out the stock trans and expect the car to run properly. Some thing would have to be done to trick the computers into thinking that the orig transmission is still there.

The easiest thing is to switch to the manual ECU which doesn't come with all the electronic crap so you could put in any automatic trans you wanted. Only downfall to this is you loose the benefit of having the 5spd auto.

Koval

well put man, that is exactly how i understand it after talking to lentech. im still going to try and talk to some other's about this but i really think i should take his advice.....start with a manual car and then install the auto when im ready. seems like it will be less aggravation, headache, time and money in the long run. plus you save your self a nice chunk of money not having to pay for the auto! im a pretty good manual driver anyways :bowdown:

cdemot02

Will the new transmission with the manual computer still automatically shift?

Koval

no...it will need an aftermarket stand alone to do that

Koval

and im talking for a 4r70w...who knows if thats even posible with the new one

cdemot02

All these problems....my head is spinning from all this...

Koval

me 2 but i just killed a bottle of merlot

StangFreak

With the manual computer you have no computer control over the transmission. You could, don't quote me on this, basically put in any transmission you wanted. You could use a C4, 4r70w or a built AOD trans. My choice would be a Street Terminator Plus AOD trans from Lentech. It can take 500 plus hp and be driven on the street with no problem. I currently have just the Street Terminator in my 90 GT vert and I love it.

cdemot02

Is it possible to just convert my car to a manual since I am getting a new comp anyways? If the computer won't shift it for me what's the point in having an auto....

StangFreak

I guess my question to you is why would you want to go through all that trouble. Sure you could swap out the ECU for the manual version and install a 5spd.

According to Lentech the stock 5spd auto in the 05/06 GT's is good for 450hp. That's enough to get you well into the 12's in the QM. Check out Alternative Auto, they have an 05 GT with the stock automatic trans that's running 12.90's.

Are you planning on making this car a race car or is it going to be driven daily on the street???

cdemot02

Daily driver, but supercharged with a lot of Torque...I'm worried about the transmission holding together.

StangFreak

Hmm, with a blower I'd say you would be better off with a built AOD or some thing along the same lines. Just for clarification, the Street Terminator I have in my car does shift by itself. It's just not controlled by a computer, that's the only difference. I also have the ability to shift manually if I want but I just put the thing in drive and leave it. Switching to a manual may actually require more work than changing to a different auto. Not sure if the automatic GT's already come with the cut outs for the clutch in the floor pan.

Also, using a blower on a motor with the stock bottom end is like riding a ticking time bomb. You may get 5000 miles or 10000 miles but eventually the motor will blow. The cast rods and pistons can't handle too much boost. You would need to get a forged rotating assembly (ie crank, rods and pistons) to safely put a blower on one of these cars. I wanted to do it myself but have settled on a combination of ported/polished heads, CAI, long tube headers, catted h pipe and a tune to make it all work once the car gets here. Should give me about 400hp at the crank. More than enough for what I want out of the car.

cdemot02

I have no problems with the AOD if it shifts on its own. Sounds like that is the road I will go. Not worried about the motor right away. I have some connections on that issue....