Twin Troubles

ShaferDiesel

Way To Small!
Joined
Nov 3, 2012
Messages
159
I'm building a truck for a customer, a work/tow rig. F350/5.9/Allison. I just got the twins set up and finally started the engine and can't build boost. I've got a S472 (83/1.10) over a S300g with the 12Cm housing. Got it timed at 16 deg, has a Colt Cam, and when I put it in gear I can get maybe 1400 RPM stalling the converter and maybe 5-6 lbs boost if I'm lucky. I have not had it out on the road yet where it may do better but this does not seem right from my experience.

I've ruled out the obvious like wastegate, boost leaks etc, and she's got plenty of fuel, couldn't see in the shop afterwards lol. I did all the piping with 3", has the stock 01 7.3 intercooler and it is not plugged. I also made a very nice tube intake for the head, cut the intake off the head etc. Did I choose a **** set of twins for this job? Should it be boosting better? WTH am I doing wrong?
 
What is the stall of the converter? Mine use to do that.. Flat line at 1400 And 5 psi. I had to crank up my pre boost fuel. Now I can stage.. I can burn out.. Rolling burn outs. I have a tight converter with a 64.5/73/14
 
Its a stock duramax converter, 2200 stall? But I even tried launching it on the lift, pedal to the floor 3000 rpm and then bring on the brakes, never could get over 5 lbs and she's dead weak and smoky like it has no turbo at all. Even pulled the whole AFC/Fuel plate and still nothing. This thing should scream IMO.
 
Is it a ally 1k? I have a customer with a 12v with a ally but I don't think it's from a dmax. It doesn't have a tcm.. Another one of my buddies had a 12v with a tq shift. And he couldn't get the trans tuning down to save his life and he ended up selling the truck
 
It is an ally 1K, I've got the tuning on those down, have done many conversions and love 'em! I'm running DDP stage 3 sticks.
 
BTW how come I'm looking at a f[]cking 6.0 in your avatar lol! I love those damn things! 2 to 3 sickos a week makes the back pocket happy!
 
Because I'm not brand loyal. I've owned one 12v a 6.0 a 7.3 another 12v and I have a 6.4 as a shop truck that with a s366/s480 duel fuelers, stage 3 Rcd cam, 75% nozzles. That hooker hooks and books.
 
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