Optimal Race Trasmission Setup

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DuSpinnst

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Does anyone have an opinion on an optimal Race Trasmission setup with regards to the physical transmission and the torque converter? Currently we have the A999 Transmission and we are looking for as much information as possible on how to race this transmission.
 
Pull it, throw it away, and install a 904 worked over, or 727 (but I think they rob to much horsepower).
 
krabysniper said:
Pull it, throw it away, and install a 904 worked over, or 727 (but I think they rob to much horsepower).
Click to expand...


999 is a heavy duty version of the 904.
A 727 will be about 1 - 1 1/2 tenths slower than a 904/988/999 if the trans and converter are built to the same extent. The difference is due to the internal rotating and overall weight.

A 2.71 low gear is available in '80's & later 904-type transmissions, but they had lock-up converters. How much it helps depends on the rest of your combo. Ideally, you can put the 2.71 low gear into an older trans because the lock-up style trans. and converters are not good for racing.
 
We where looking at this car as strictly a dragster. MOPAR offers some rebuild kits for the 904, I know the 999 is the same case but I assume the "Race 904" MOPAR kit is not the same as 999. Has anyone bought these kits from MOPAR?
 
The A999 is a truck and van transmission. I am "assuming" he is refering to using the 999 in a A body as this is an A body forum. Pull the 2.74:1 low gear and the 1.54:1 second from the 999 and put in a 904, do the other basic hot rodding things to the trans (shift kit, performance rebuild, maybe swap in a 5.0-ratio second gear lever to really make it hit ya in the arse, find a 5 clutch high gear drum out of a newer lock-up style 904) whala race tranny suited for an A body.
 
Thanks for the replies. Justin left out some of the details. We are using a 4.10 rear, engine should make max power at 6000RPM which is also the redline, we are projecting a race weight around 3300 lbs, and we are going to be running slicks.

I guess we are trying to find out more of the detailed differences between the transmissions. From what we have read, the 999 and 904 share the same case. If that's true, can we swap parts from the 904 easily into the 999? Then, we really are looking for opinions on the way to build it. I have always had manuals, and while I understand how an auto basically works, I don't know how we should set it up. I know we want a loose converter to keep our engine in its powerband. I don't know how loose though. I also don't know about the valve body. We could go auto or manual on the valve body, but what are the pros/cons of each?


The other thing we need to consider is that car has to able to drive on the street to cruises and shows without boiling the trans fluid out. We will install a dedicated cooler, but will that be enough if we are running a loose converter and no lockup?

Lots of questions, and I will call the trans experts, but I wanted to post these details because others probably have the same questions but might not want to ask them.

Thanks
Ken
 
Absolutely no sense in swapping the guts from a 904 into a 999. The 999 has the 5 disc front clutch and should have, depending on the year the low gear set. What it may have that you don't want is the lock up torque converter. What you need to make it a non lock up is a non lock up input shaft from a mid to late 70's non lock up tranny. If possible get the reaction shaft also. You can convert the lock up reaction shaft by removing one of the balls that seals a passage but you can't convert the input shaft.
 
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