Effects of a TOO HIGH STALL converter

[Dusty Bradford]

what is ideal for rpm drop. im looking at around 7-800rpm

I like to see around 1000 but more doesn't seem to hurt them.

 

[Dusty Bradford]

Yes that is correct. A quality converter like the PTC i have is very efficient in all aspects. Cruising (about 5% slip), top end (under 5% ), but when the converter is loaded the stall is increased dramatically. I see about 3100 with zero boost/vacuum. Flashes to 4700 at 24psi. The converter works so well its like magic. Its without a doubt the biggest improvement ive seen from a single part in years of playing with these cars.

Well over a year spent developing the 9.5 To see it come as far as it has is a great experience. Then to have it work well enough to own the Fastest V6 Regal pass, TSO, TSL, TSM et and mph records is just icing on the cake

 

[TURBO 6]

Stop bragging!!!


No research, you got lucky.........Over and over again and again.

 

[oldguy]

Rpm drags on 2-3 shift

on 2-3 shift, rpm stays constant for 2.5 secs. then it takes off. is this a way too tight converter?

 

[Dusty Bradford]

on 2-3 shift, rpm stays constant for 2.5 secs. then it takes off. is this a way too tight converter?

How much did the rpm drop on the shift? As long as the car is accelerating and gaining mph your good.

The rpm holding is very common. Alot of pro-mods will actually drop rpm from the gear change to the finish line in the 1/8 mile.

 

[oldguy]

rpm drops 1300 then stays for 2.5 to 3 secs. car leaves @ zero boost on 150 hp spray[1.7 60']. spray off at 12# boost

 

[GNVYUS 1]

I'd attribute some of the 3rd gear staying to HP in that area of the band, we don't have much vs some turbo import etc.

 

[Dusty Bradford]

rpm drops 1300 then stays for 2.5 to 3 secs. car leaves @ zero boost on 150 hp spray[1.7 60']. spray off at 12# boost

If you have the power turned up where you'll be racing the car, the converter could stand to be 200-400 rpm looser.

 

[bison]

on 2-3 shift, rpm stays constant for 2.5 secs. then it takes off. is this a way too tight converter?

So whats the rpm and the combo? If you increase the boost it will drop less. Mine drops around 1300 at 18-19 psi. It drops 1000 at 24psi. It still hovers for a couple seconds on the shifts but its pulling a very high g-force in 3rd for the mph after shifting.

 

[Chevota]

Got any FAST logs you can send me of a good clean pass?

With the weight of your ride I bet the converter is working very well. Obviously by the e.t's it's hauling ass The 9" doesn't work so well in the heavier cars with a limited rpm range. That's why's it's so easy to blow the a/c's away with this 9.5. If you turn over 6k at that weight, there may not be much to gain. If I can look at some logs I'll let you know though.

Thanx for the reply Dusty. It currently sees 7100rpm shift points with a 3.42 gear, 28in tire and a PG. I'm getting a 600rpm drop from low to high and 6300 thru the traps. By your standards is that acceptable?

Scott Wile

 

[tomard]

Looks like I got over-taken

Anyway - footbraking test shows my stall just about 3K (28-3200 rated converter, so I guess I am right in the middle).

My only issue now, is that when I put the car in OD, with the 4th gear pressure switch active, it wants to lockup when I am not yet high enough in the rpm band, and it jumps, sputters and barfs

So I cruise around town, in 3rd ...... until I can get problem resolved.

I happen to have a vacuum switch that was in car for the TH350c, that I just jumpered, but maybe thinking that I should put it back inline to avoid lockup attempts at too low vacuum - any thoughts there? Maybe my vacuum switch is going to activate too soon as well?? Attached picture of how I am currently setup!

 

[Dusty Bradford]

Thanx for the reply Dusty. It currently sees 7100rpm shift points with a 3.42 gear, 28in tire and a PG. I'm getting a 600rpm drop from low to high and 6300 thru the traps. By your standards is that acceptable?

Scott Wile

Sent you a PM