Heckeng Posted May 31, 2007 Share Posted May 31, 2007 Hey guys, I was just curious if any of you have ever broken a standard sprag and drum. I have talked to ATI, and they claim that this is the most common break on a th-350 and they claim that if the transmission is in good shape, and you replace the sprag race ($40) and upgrade to a 36 element sprag and drum assy ($260) that a th-350 should be good for around 900hp. I'm just curious to hear any experience you might have! (and I wanted to get a current thread up on the new board!) Quote Link to comment Share on other sites More sharing options...
Guest Posted June 1, 2007 Share Posted June 1, 2007 Blew 3 pro built th350's with 36 sprag in less than 4 runs each! Don't see how it could hold 900hp! I was only at an honest 650 back then! First one just surged forward made a loud pop then quite pulling. Second one did the same as well as cracked the case near the tail housing. Third one was a $1400 without converter deal with a T-brake, When I released the button the front wheels came up about 6"'s then the case split down the casting seem along the top center of the case almost from bell to tail. These were all by on top trans/converter companies for racers in the country. They swapped me a top of the line 400 for the grenaded th350, It's been freshened 3 times in 10 years and still works like a swiss watch! Don Quote Link to comment Share on other sites More sharing options...
Heckeng Posted June 1, 2007 Author Share Posted June 1, 2007 Wow, that's not what I wanted to hear Don! I guess I can dream huh! When you got your th400 going, did you keep engine braking ability? Quote Link to comment Share on other sites More sharing options...
Guest Posted June 1, 2007 Share Posted June 1, 2007 No, Mine is not a street setup at all. T-Brake reverse shift pattern and freewheel decel. I had it do that way on purpose as its hard on a all out drag engine to be used as a compression brake. You can however make a basically bullet proof th400 that works like stock! Don Quote Link to comment Share on other sites More sharing options...
mc71454 Posted June 23, 2007 Share Posted June 23, 2007 I run a 36 element Sprag and Drum in mine. The parts alone ar e$600 to $700. I do not think most Montes under 800 HP will need more than a 34 element Sprag. Just make sure your burnout procedure is correct by starting in 2nd gear and NEVER Shift from first to second while doing a burnout. When the car starts to grip and roll forward let out of it immediately. I just installed an Ultra-Bell on my trans after cracking the case at 130 mph a few weeks ago. Quote Link to comment Share on other sites More sharing options...
Heckeng Posted June 23, 2007 Author Share Posted June 23, 2007 I thought you were NOT supposed to let off suddenly in a burnoff for fear of converter damage? Quote Link to comment Share on other sites More sharing options...
Guest Posted June 23, 2007 Share Posted June 23, 2007 Souldn't the plate read 1/4 MPG? Quote Link to comment Share on other sites More sharing options...
mc71454 Posted June 23, 2007 Share Posted June 23, 2007 Let out as in when you are moving forward so the rpm's come down as you move forward. Don't let it grab and jerk the car. Quote Link to comment Share on other sites More sharing options...
Heckeng Posted June 23, 2007 Author Share Posted June 23, 2007 Cool, that's what I thought. But what does shifting while doing a burnoff do though, I haven't heard that one before. I'm guilty of that on occasion, although usually not with slicks! Quote Link to comment Share on other sites More sharing options...
mc71454 Posted June 24, 2007 Share Posted June 24, 2007 Cool, that's what I thought. But what does shifting while doing a burnoff do though, I haven't heard that one before. I'm guilty of that on occasion, although usually not with slicks! While I am not a trans expert, basically when you shift from 1st to 2nd, the direction of the rotating drum changes instantly and the sprag is what takes the brunt of the load. From what I have been told it is the No-Load action of the burnout that makes this a problem when it is not a problem when accelerating with a load on the trans. Always start in 2nd gear shifting from 2nd to 3rd is OK. Hope this clears it up..Have a good one ! Quote Link to comment Share on other sites More sharing options...
kc8oye Posted July 6, 2007 Share Posted July 6, 2007 hah, I couldnt' get my tires to spin from a standstill in 2nd gear if I wanted to Quote Link to comment Share on other sites More sharing options...
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