Is my converter just too tight?

[Randy 406]

I'll try to explain my problem without writing a complete novel.

I've got a TH400 in a 3300 lb S-10.Smallblock 400,1050 dominator,2 stage Wilson plate.The converter is a 10" PTC.When I first got this converter it was a 10TH03 SL .090.This configuration stalled 4500 against the brake and flashed to 6500 on the spray.I sent it back to tighten up the flash,it came back 10TH00 .090.Ever since then I've had the following problem.Accorcing to PTC the change should have only taken out 600 to 800 rpm.

I run against a pro tree.When I apply the transbrake,and go full throttle,the rpm's come up real slow.Sometimes the playback shows it going to 3000,then climbing after the release of the brake.It doesn't seem to "flash",just slowly climbs.Other times,if I can stay on the brake long enough,it will hesitate at 3000 then climb to 3800.Again no "flash",just a slow climb after release.No chip in the 3 step,revving against the brake.

I have all the symptoms of a broken,or hurt sprag.The problem is my converter is spragless.I checked the stator tube,and have no movment.So,I can only assume it hasn't turned.

Just finished installing another converter,a 10" Midwest,that's also on the tight side.Stalled 4000 behind a buddies 540,certainly not the optimum converter for me but,it was available.Testing it on jackstands,the motor lugs to 3000,then seems to clean up and go to 3500.

I've put as much slack as possible in the rear accelerator to lessen the "squirt",as it seemed like it was flooding,with no real improvement.Nitrous is delayed (drag radials),when it hits seems to run fine.If I take out the delay,it blows the tires away with as little as a 100 shot.No spray feels like I'm dragging an anchor.

I've checked everything on the motor side,everything seems normal.Any help will be greatly appreciated.

[Hutch]

The converter is just too tight and that big dominator is not happy at 3000 rpm. The borrowed converter is the same as it was built for a 4.25-4.500 stroke motor and has similar characteristics.

Hope this helps, Hutch

[Randy 406]

Thank you Hutch.

[ericandkayti]

why a spragless????????????? that just slows you down!!!!!!!!

[Randy 406]

Because a sprag WILL break.

http://www.transmission-specialties.com/catalog/index.php?cPath=22&osCsid=cbba57c9d7c78cc633a9b3b3790a3386

[ericandkayti]

there are 2 sprags out there that will not break. it a mechanical diode. one of them has 10 struts, and the other has 5 struts. i think neal chance is the only ones to offer it. i beleive hutch will back me on that one.
eric(just my thoughts)gray

[Hutch]

The Neal Chance MDX diode has worked flawlessly so far.

Hutch

[Rick Crawford]

Which model 1050 are you using? You may need to lean out the intermediate curcuit to keep it from loading up. I run a 1250 Dominator against a 2800 stall with a low compression 466 so it can be done, the carb just won't like it.

[Bellman]

why a spragless????????????? that just slows you down!!!!!!!!

I've heard that is a thing of the pass.. The newer spragless converters don't slow you down...

Or so I've heard..

[Stroked-Z]

Using a spragless PTC here....a little on the loose side for me but i'll have it tightened up this winter as it was built for my last car.......as far as slowing me down.......i dont think so.

-Carm

[n2oracer]

We've had similar problems with a Dominator and a tight converter before. We put larger intermediate air bleeds in to lean it out when going up on the brake. I can't remember how much of a change it was, seems like about .008-.010". This was a couple of years ago on a friends car so I don't have any logbook info to look at.

[Randy 406]

Which model 1050 are you using? You may need to lean out the intermediate curcuit to keep it from loading up. I run a 1250 Dominator against a 2800 stall with a low compression 466 so it can be done, the carb just won't like it.


I didn't see this earlier.
I'm running a 9375 1050.Had PTC loosen the converter up,it's going to 4000 against the brake now.I'll be trying it out tommorrow.