What makes glides so different that reaction time can be .022 slower and .04 slower in ET?

Compared to?? Are you comparing 2 powerglides? Same 1st gear ratios?

valve bodies and number of clutches

Pump pressures to converter assuming same converter is being used?

Sorry guys, I have 2 transmissions, my spare is a FTI I believe them both to be pro brakes 1.80 low gears pressure is within 5 lbs of being the same, I have now put my spare in, The FTI and it is slower eta wise and reaction time is slow as well, I was wondering what things could be different for one to be slower than the other, yes same converter.

quote:

Originally posted by coop5140:
Sorry guys, I have 2 transmissions, my spare is a FTI I believe them both to be pro brakes 1.80 low gears pressure is within 5 lbs of being the same, I have now put my spare in, The FTI and it is slower eta wise and reaction time is slow as well, I was wondering what things could be different for one to be slower than the other, yes same converter.

Take the pump and input shaft out of the old transmission and put it in the new transmission - reset - endplay. If both transmissions don't run identical, it's not the converter.

My guess it's the torque converter operating slightly different. Any data? Log converter pressure? Run replay?

There is many things that it could be.If you are not monitoring charge pressure this is probably where the difference is. I always recommend to monitor this. Call me at the shop and lets go over a few things and get ya fixed up.

Greg

quote:

Originally posted by 1320racer:
valve bodies and number of clutches

I agree with this. Number of high gear clutches can make a good difference in ET.

quote:

Originally posted by TORQIN:
Pump pressures to converter assuming same converter is being used?

Each case could be different but I borrowed a friends trans (PG), same converter, the stall rpm was a 175 tighter at the launch, all else was pretty much identical through out the run. The car ran exactly the same with either trans! Could not tell one trans from the other by looking at the time slips, only the saw the differences due to the data logger.

Curious, the high gear clutches clearance for reverse clutch release? This affects reaction time? Curious how?

Just attempting to learn.

quote:

Originally posted by TOP38:

quote:

Originally posted by 1320racer:
valve bodies and number of clutches

I agree with this. Number of high gear clutches can make a good difference in ET.

quote:

Originally posted by DaleH:
Curious, the high gear clutches clearance for reverse clutch release? This affects reaction time? Curious how?

Just attempting to learn.

That would be cleaning up static friction, drag.

I was pulled into a 370 Pro Tree index class for the reason I was told the tree was impossible 3250 lbs. So it seemed like a decent performance challenge. A lot of really good local Super Pro racers have bombed out of this class because of the quick tree. It's an odd set of rules, heavy slow cars on a quick tree 6.50 index.

It would be like running NHRA Super Street 10.90 on a 370 pro tree.

I had it solved in a handful of runs. Transmission, shock, chassis adjustments at 3250 lbs on a 10 x 28 tire.