Torque conv, stall-flash,low pull rpm from stop.

[82camo401j10]

Will a 2500 flash, 2100 stall, still pull away from stop at low rpm(1000)or less?
450-500hpish, 401, pulls Hard from 2-2500rpm-6000rpm , 727, 3:55 gear, 4800lb pickup.
Trying to buy a off the shelf budget TC.
Don't want to be slipping at 2000rpm! (45-50mph).
I know this subject has benn beat up!
Looking for some real world experience.
Thanks (building a jr version of farm truck?).
It will be quicker than it looks!

[Full Size Jeeper]

Hughes Performance Street Master Torque Converters GM25HD
Torque Converter, Street Master, 2,500 rpm Flash Stall, Heavy-duty Sprag, Chevy, TH350, TH400

I have this converter. On the foot brake(brakes suck) I can hold it to 2,200 rpm. I bought it to help alleviate having to set the idle up a little and the Wagon jumping forward when putting in gear. Think I might have 375HP. What you are worried about, I have not noticed with this converter. I my opinion, this is a very mild converter.

[Ristow]

i ran a 3500 rpm stall in my low rider chevy. at the time of install it still had the I6 rear gears in it. 2.94 or something. it was in stall rolling 55-60 mph. i could hit a hill and lose 10 mph or more and rpm would remain unchanged.


it would not drag you thru a light at idle. i think a 2100 will still require some brake pedal to prevent creep in drive.

[82camo401j10]

I'll check into Hughes!
The 1 that's in it now(p.o. install?), I can power brake to 1800rpm, flash unknown?
It won't start to move truck until bout 1000rpm.(mild 360 ,300hp ish).
He had local b-grade shop rebuild tranny the year before I got it.(had receipt).
I can't imagen they used anything but stock?
It almost feels like a RV TC? With trailer behind it spins up 12-1400rpm before moving.
I may just chance it with the big motor

[Ristow]

the stall speed goes up as horsepower is increased. or weight. any rated stall speed is the speed for whatever power/weight baseline it was rated at.



put a four cylinder dodge caravan converter behind a 502 chev and see what it stalls at. lol.


cruising speed will have about the same behavior,your car will require the same amount of power to rioll down the highway regardless of motor or tune. when you punch it it will stall/slip a little higher in the rpm.

[82camo401j10]

I have contacted Hughes for recomandations.

[Carnuck]

If you have the newer 727, get it done with parts from a lockup trans and use the 6 cyl torque converter. High stall gets you moving then lockup at 55 mph under throttle with load. Then newer converter uses a squared off drive and pump instead of the notches that crack under extreme load.

[Ristow]

If you have the newer 727, get it done with parts from a lockup trans and use the 6 cyl torque converter. High stall gets you moving then lockup at 55 mph under throttle with load. Then newer converter uses a squared off drive and pump instead of the notches that crack under extreme load.

same pump and drive between the two. 727's are not known to break the pump drives off the converter.


the 727 lockup system was a real pos.

[Carnuck]

The later Jeep 47RE trans has a much better pump, converter and lockup. The early ones were indeed a PITA.

[Ristow]

are you suggesting he put a electronic valve body from a 4 speed into his TC727? or do you have some other way to control this upgraded lockup converter?

[82camo401j10]

Mine is non-lockup.
Already have shift kit. Planning on a VB clean, new gov spring(5-5500rpm) shift
, adj bands,filter and run it?
Still ant heard from Hughes?
May just call them when motor comes out.
Probably use as is? May have other bugs to work out?

[Ristow]

i had a 5600 rpm gov spring in my 727. i loved it. i think that is the best performance mod to do after a decent intake and cam.




nothing to really clean in the VB,i'd leave a well operating transmission alone.


does it have a bolt in sprag yet? it will! lol.

[82camo401j10]

Bolt in sprag?
I've re clutched and seals, shift kit install, governer kits, adj basnds. a AT!
But never replaced any hard parts, I'm a engine man, know minimal bout AT?
But ant afraid to learn!
What bout the sprag? Weak link I take it?
How expensive?
How hard to swap?
Should I rebuild kit while I change sprag?
And last, what kind of abuse breaks sprag?
Thanks!

[Carnuck]

A speed controlled lock solenoid should do it. That’s what I put in my 999 in the mighty Elmo. Used the early pressure controlled valvebody 32RH (AKA 999 lockup) with the S shaped tube on top and added a flow solenoid with some help from a now retired Mopar trans tech at Sea-Tac transmission we used a ‘97+ 42RE pump and converter with input shaft after measuring depths carefully and matching input shafts as well.
He said it should work with the same with 727 as long as the case was designed for lockup (post ‘78) and you used the higher speed lockup spring which increased the line pressure.

Definitely bolt in sprague because the friction fit into the rear of the case design was bean counters idea. You can get real crazy and get lower first and second gears as well which only takes money. I hear some of the 47RE transmissions had them stock.

[Ristow]

the sprag is a roller one way clutch for the rear drum. it is pressed into the trans case. high power,traction in "breakaway" low gear. (in first gear with selector in D") can tear it loose. in manual L gear the rear band is applied which takes the abuse rather that the pressed in sprag.


bolt in sprags are pressed in,then they use longer bolts for the governor housing,which is behind the sprag,the bolts go thru the housing,thru the tranny case and into the sprag.