How much power can auto tranny handle?

[Ragtop George]

My personal opinion on tranny coolers is that they are really for cases where there is long term stress on the transmission, for example, if you are towing, have a high stall torque convertor, drive in hot, high altitude areas, have lots of long hills, etc. Unless you are regularly drag racing, there is simply not enough time for the transmission fluid to heat up when you floor it for a few seconds. The only way to make the tranny live through the shifts when you have boost is to modify the valve body to shift faster so that it can't slip during the shift. This is what Level 10 is supposed to do, I am considering having my auto done by them at some point. I have been running full boost through the shifts for 3 months now without a problem, but I don't know how things will be in 3 years.

George

[ICUFG]

George how much boost are you running and whats your altitude where you live.

[Ragtop George]

I have the 2.75" pulley from Pulley Boys, which is about 6PSI. The altitude here is about 2500 feet, which according to the standard atmosphere calculator, gives about 13.4 PSI of atmospheric pressure.

http://www.digitaldutch.com/atmoscalc/

George

[ICUFG]

So with boost you are ar 19.4 lbs of pressure im kinda confused.

[Ragtop George]

The way I look at it, with the stock 4 PSI pulley you would have 14.7 PSI of atmospheric pressure plus 4 PSI of boost pressure, so the absolute pressure would be 18.7 PSI. With a 6 PSI pulley you would have 20.7 PSI of absolute pressure.

Now, when atmospheric pressure is only 13.4 PSI, not only is the non boosted pressure lower but the boost is lower too, since boost is a ratio of atmospheric due to the positive displacement supercharger. So a 4 PSI pulley would only generate 13.4/14.7*4=3.65 PSI of boost. So the absolute pressure would be 13.4+3.65=17.05 PSI. With a 6 PSI pulley, the boost would be 13.4/14.7*6=5.5 PSI. This would give an absolute pressure of 13.4+5.5=18.9 PSI. Consequently, my power output should be about the same as a 4 PSI pulley at sea level. I would need an 8 PSI pulley to match sea level absolute pressure. The problem with this is that the temperature of the boosted air starts to really rise at higher boost levels, which makes detonation more of a problem.

Anyway, my transmission is only seeing power levels that are generated by the stock supercharger system, despite my smaller pulley.

George

[Roysan]

I have a 2002 Camry SE V6 auto trans and had TRD install a SC in it. Anyways they're suppose to come out with an EBC for it in another 4 months if that even happens. I've ran wide open throttle and I believe my tranny slipped, the RPMS would jump up but the car felt like it was'nt pulling. Anyways I took my car to JMO USA in Fullerton,CA. and had them work on my torque converter. New internals and a trans cooler. Now my car shifts at higher rpms closer to torque, no slippage, shifts smoother, feel continuous pull and get this... I'm getting better gas milege.
It's expensive though... $1150 included labor and parts and the ceramic coated tranny cooler.