oliver foster

I am surprised you can't get it to smoke.
Just 1 3/4 turns on my fuel screw and I am thinking about backing it out a 1/4 turn to lower EGTs and smoke a bit.
I still have the collar in place and have a turn or so more before it even bottoms out on the collar.
This is a NON I/C ed motor, so it has the bigger stock injectors...
It smokes pretty hard if you floor it in any gear until boost comes up.
It will leave a big puff of black smoke, ever gear shift [5 speed], that you can see in the rear view for hundreds of feet.

taterfarm

what is your max boost and pyro temps? it doesn't smoke at all, even when starting out? I have the same settings but turned the smoke screw out and it still has too much smoke and thats with my crappy torque converter that shifts like a CVT. Wonder why your not getting any more fuel?

ClassA4x4

Max boost is 31psi at wot. Pyro varies depending on load; it will go beyond 1300, if you let it, at sustained climbing steep grades. Egt goes down once in lower gear.

During starting all I get is a split second puff of smoke, but that's it.

cougar

31 is good, more than that your are just producing wasted hot air. The 60mm compressor would be good. I think I saw a 62 somewhere, But I'm sure that will require some machining. If your still running your stock injectors, that might be a place to improve. Your other option would be to build a bigger dog house. Got room for a belt driven supercharger?

BILTIT

I have my fuel collar removed, screw in ??? turns, smoke screw out, star wheel all the way up, dennyt1 and i smoke enough if i am hard on it or at too low of an rpm and floor it. I think some of the difference can be contributed to 5spd VS auto. We have to work to keep our boost up due to shifting. I max at 40psi and 1250F up a hill in 4th to the floor with my camper in tow. I accelerate as i climb the hill VS most trucks slowing down.

How much smoke is too much smoke is also a subjective term.

taterfarm

sounds like your in a good place for what the turbo can do efficiently, but it seems like there should be more fuel available.

Can you tell if the fuel pin is getting full travel on the cone part, maybe its not getting full travel? I guess I did cut mine so maybe thats where the extra fuel is coming from. Any idea what your fuel pressure is?

with my 92 5sp, it had the fuel screw maxed out, star wheel most of the way down, smoke screw up several turns, 4" exhaust, big air filter, 3200 spring and a ground pin. i hit 273 hp on the dyno, that was on 100% home brew biodiesel which has less btu that #2. there was plenty of fuel available, if the smoke screw was down at all then it could black out the sun.

ClassA4x4

Yes, the cone is making full travel, I can see it from the dragline. My fuel cone though, is custom ground (by me) based on the stock shallow position (not deep side) - it's like a DennyT-s1 or M3, just not as deep. I'm scared to make it deeper, I don't want to get any fuel pin leaks. I did try the stock deep side but the motorhome wouldnt run well with it, at lower rpms.

Fuel pressure from the stock lift pump ranges from 8psi to 2psi depending on load.

I think I'm very close to max power at the optimum stock/free mods for the stock IP, stock turbo and stock injector capacity, that if I give it more fuel it will smoke and need more air, that if I get bigger injectors it will need more air and more fuel pressure, and so on and on. . .

taterfarm

strange, guess your getting enough fuel to it then. its funny how different these are from one truck to another.


was there a thing about some of the later pumps not putting out as much fuel as the rest? not the non intercooled ones either, thats a different deal. i remember reading about this a long time ago with some people just not able to get any power on a maxed out pump, seems like it was on the later engines or at the time of that pump recall or something? I remember reading about it but cant recall the answer or reason why it was that way, seems like it was when i was looking into runaway situations with some pumps hitting it with a few turns and others never reaching that point.


edit: the fuel pin oring isnt too bad to change.

archer39

A 11,000# motorhome weighs the same as a 5,000 (loaded) trailer and my truck, just saying.

I don't have a problem controlling the smoke. Don't get me wrong, it will black out the road if i have to floor it from a stop but its not like i am fogging out the highway at 55 going up hills.

BILTIT

Yup but a motorhome has much different aero-dynamics vs truck/trailer. This will change the load on the motor.

As many have seen the weight doesnt effect these engines nearly as much as aero-dynamics at highway speeds+.