Expectations from a Torque Converter Swap

[solarguy]

I'm looking for feedback on doing a converter swap and want some butt dyno results especially from small block guys.  My combo 340 steel crank, cam is 484/284, HiPo ex manifolds, 2 1/4 pipe into turbo mufflers,  carter 625, tTF2 shift kit, 3.73's, 255/60/15 (26.5") tires, stock converter.  Car runs great but looking from more low end grunt.  Considering stall in the 2800-3200 range.  What can I expect for performance gains?  I think with that cam and rear gears, the stock stall is my weakest point.  I don't want to change to headers.  Thanks for any input.

[GoodysGotaCuda]

Are you running a 904 or 727?

I went from stock to a 3500stall dynamic, while the converter runs VERY well, within 2 years or so it's developed a crack which I am not happy about. The 904 has a 'weaker' design for the pump drive, so be careful with that if you do.

I've gone 13.6 on 30.5" tall slicks with my 318, really woke up the low end. Had I run some 26" slicks or so, and got my final drive back..it'd definately go faster! With 3.73s i'd go with 3000-3200rpm stall range. I'm not a fan of 'off-the-shelf' converters, my custom tweaked one runs awesome...but i guess the characteristic of the 904 is what hurt it.

[solarguy]

Hey Goody,

sorry to hear about your converter cracking.  that probably explains why I saw your post looking for 4 speed parts.  I'm running a 727.  How was your highway cruising with that converter?   

[GoodysGotaCuda]

I turned about 68mph for 3500rpm. 28.5"tall tires with 3.91's. Which makes the converter about 85-90% efficient at that speed. If i nailed it from there, it'd flash up to about 4000-4100 and pull. ...pretty nasty little converter for this setup.


edit: a 5spd would get me 2000rpm at 68mph (about 120 at 3500), man that sounds nice for cruising down the highway...

[Chryco Psycho]

changing the converter will make  big difference , especially in a small block , even a 2400 stall is good , , it will allow the engine into the powerband before putting load on the engine & wiull feel like a different car

[tactransman]

changing the converter will make  big difference , especially in a small block , even a 2400 stall is good , , it will allow the engine into the powerband before putting load on the engine & will feel like a different car

   http://www.ptcrace.com/index.php

[solarguy]

Thanks for the responses.  I think I'm on the right track then trying to maximize the hp and tq I'm already making, what ever it may be.   I've been looking at PTC, Dynamic and Turbo Action, they all seem to have good reps.   This is going to be the next thing on my list

[71chally416]

I have the 9 1/2" 904 Dynamic vert in mine and it works awesome. 

Like everything else automotive, you get what you pay for. If you try to save money on this very important item you will later regret it.