Well sorry guys, no update on my tranny tonight. The shop got a little behind on an SE in front of me, so I can't be mad at them. Now, if it was something other then a tour... well, Hell would come to see the light of day!! No not really...
But I did have a interesting conversation with a few felas about torque convertors and the effects in a high performance situation and would like to share some of the info that was shared there. This is from
CatMan, NECO member from Athens, GA on the subject...
A new higher stall torque converter will definitely help in your 1/4 mile times. However, you're failing to address the biggest problem with the CD4E: the drivetrain loss. It's not so much that we have a weak drivetrain that can't handle power. In fact, from what I've heard, a stock CD4E tranny can handle a lot more power than just about anyone is putting out right now. But it's absurd that a stock MTX cougar/contour can dyno at 130-140 fwhp whereas a stock ATX is only around 120. That's the biggest dissapointment I have with the CD4E that Ford uses. The sloppy shifts and shift points can be pretty easily corrected with a custom burned chip. But there's no way of reducing the drivetrain loss without rebuilding the tranny itself to perform more efficiently. The only place a torque converter is going to help you is off the line with your launches. After that, it's not going to do a whole hell of a lot when you're doing a 1/4 mile run. Reducing the drivetrain loss will. I'd much rather get back that 20 or so horsepower that our tranny makes us loose ALL THE TIME than get a better launch at the very beginning of the race. And if you can get both issues taken care of, then you're that much better off.
The only real problem I can foresee with getting a higher stall torque converter (like a 3000 stall converter), is traction. If you get a 3000 stall torque converter, it'll be like having a clutch and revving the car up to 3000 rpms before dropping it. This may cause some serious traction issues at such a high rpm. So if you get a converter that stalls too high, you won't get traction. And you can't launch at lower rpms because the converter won't let out the clutch. If you get one that's too low, you won't get the best launch possible. So if you're going to replace the stock torque converter, be sure and do some research to find out what the best stall would be to avoid traction issues but still get a good launch. This wouldn't be such an issue if there was an LSD for the ATX, but that doesn't look like it's going to happen any time soon. If I had to guess, I'd say somewhere between 2500-3000 would be the best place to start.
The other thing people need to take into consideration is driveablility. A new torqe converter won't necessarily cause any issues directly that I know of, but it'll definitely change the way the car drives. The main problem you'll be running into is gas mileage. You can expect this to go down quite a bit with a higher stall converter, just because you're car will be constantly launching at a higher rpm than normal. So you'll have to go higher in the rpms to get the car moving, which means lower miles per gallon. This kind of mod really isn't for the casual modder that just wants to get a few more horsepower, a better exhaust sound, and maybe knock .1 or .2 of their 1/4 mile time. It's really more for the people that just want to make their car fast.
I was going to try and shorting it a little, but since I am so wordy it all seems useable to me. Take from it what you want and research from there. Just wanted to share some more info.
I case you are wondering, I am staying with the stock stall convertor. Why? Well, I don't drag my car enough to see any gains from a mod that really cost that much. If my car was not a daily driver, well I would do it... maybe! I had made this decision before reading this response from CatMan, but he sure did make me feel better about it. Thats CatMan for sharing your knowledge on this subject.
If you haven't already noticed, my main goal with my rebuilt is the make my CD4E as reliable as possible and make some improvments in the shifting department. This rebuid will not fulfill all these requirments, but a chip will finish it off.
