I was wondering if there was any way to clear up some of the smoke on my truck. I don't really care if it blacks the sky in the low rpm's, but I don't like the smoke I get in the upper rpm's (2200-3000) I can turn the starwheel back & clear up the smoke down low, but as soon as it starts to rev & the power comes on it starts to smoke again. I like to look at the smoke as much as the next person, but I don't think that the black stuff in this rpm range is very healthy for the ol' cummins?????? I always thought that after the turbo spooled up most of the smoke should clear up, is this correct???? is there any way to fix this w/out killing alot of power?????? thanks for any replies, Dusty

 

I can only take a guess at this one.<br>As I understand this, (...and no way am I saying I understand it correclty), As the boost from the turbo increases, the smoke should decrease.<br>Thus, I can only take a guess and say maybe take a look at a bigger turbo, or perhaps increasing the boost?<br><br>I think you are correct... the star wheel is only effective under low rpms (Pre boost). So adjusting this will have no relation to higher rpm smoke.<br><br>Good luck. Perhaps someone else can provide a better, far more accurate explination and help.<br><br>Rich.

 

Thanks for the reply,<br> I know my timing probably needs adjusting, &amp; a bigger turbo would help too, but unfortunately I can't afford either one right now. ??? I'm pushing 38 pounds of boost, so one would think there should be plenty of air, but I guess there's still more fuel than air??? dunno what to do, I hate to slide the plate back, but I'd hate even worse to melt my truck, we'll see if anybody else has any idea's, thanks again for the reply, Dusty

 

Sorry I couldnt offer anything else.<br><br><br><br>How high are your EGTs?<br><br><br>Rich

 

not sure about the temps I seem to run out of numbers on the pyrometer [undecided] I don't run my truck this hot for very long periods of time, but I wish it wouldn't run this hot at all, most of my temp problems are found in 5th gear (empty) and some in 4th gear (mainly loaded) like I said I'd hate to lose ay power after having it, but don't know what else to do????? thanks again, Dusty

 

More air is the only way to solve that. Running your turbo at 38# of boost ain't helping you. You're creating more heat running that much boost. The little HX-35 turbo can't handle the fuel you putting out so the unburnt fuel comes out as black smoke.<br><br>A PDR-40 would sove most of that problem.

 

i had my AFC gutted for lots of smoke (yeah, the pump strained from a dead stop with full throttle). it also smoked on the top end 4th locked WOT. i was making 40 pounds of boost and pushing the egts over 1200*. now i made it so my truck barely smokes (reinstalled AFC rack and adjusted it--had enough of showing the smoke), i'm only hitting 35 pounds of boost 4th locked WOT with egts only hitting 1100*. now a full forward star wheel wont be close to a gutted AFC so there's a difference. but all in all, you are overboosting at 38psi. 35 is max before you start turning the air into heat. timing might help, i know that i definately need timing. hmm, smoke at 2200 rpms? lemme think...

Tom

 

what about upgrading to a 16cm housing? it should help a little...

 

98rammer<br>I had my akc housing gutted and after I put it all back together it ran better with it than with out it. Also you said something about adjusting rack travel. How do you do that and what does it do.<br>thanks<br>Aaron

 

rammer,<br> I'm already running a 16cm housing, as well as an open element filter,(not quite a scotty, but surely better than stock) so 38 psi isn't as good as say 30-35 psi???? Is there no adjustment in the pump other than where the plate is that can cut the fuel back in the higher rpm's???? <br><br>can anybody give me a # as far as in mm's or something as to how far forward you're running a #10 plate, I started out w/sliding my stock plate &amp; didn't know to mark where it was????? I figure I've probably got my plate a little forward from stock, but even w/ a stock plate my truck it would blow a little haze when wound out, I just figured w/the more fuel from the plate the smoke just went up w/the difference in the plate. &amp; it seems that no matter how far back I slide the #10 the top end seems relatively close to the same( smoke wise) i just mainly lose bottom end power? any ideas?? thanks again, Dusty

 

I was once where you are only with a #11 plate and 370 injectors w/ the 16 CM2 housing on my stock turbo. I was making up to 44 pounds of boost and smoke way bad :. With this set up I made 392 HP, with the 4000 RPM gover spring kit and the rocker adjustment.<br><br>I installed a Pier Super HX-40 and didn't change any fueling and to my great surprise all the black smoke was now just a slight gray haze and with only 38 PSI of boost ;D When you run a turbo out side it's map all that happenes is the air gets extreemly hotter and even though you are at a high boost level there isn't as much O2 as keeping it with in it with in it's map. The HX35/16 goes out of it's map anything over 34-36PSI.<br><br>Sorry to tell you dude you need more turbo, and if you are like me soon you'll need another one to go along with it also. <br><br>Oh also that gray haze didn't stay gray for long I think only a week or so I added my #10 and then the #0. I got that black smoke back again...... : 8) ;D <br><br>

 

thanks drawson,<br> i'm slowly realizing that what you're saying is the cold hard truth, I definatly need more turbo! in the meantime(until funds allow the turbo) should I slide the plate back a bit or just be very careful w/my right foot? also would I be ok w/a hybrid turbo ( a 40 compressor side on my 35??) and last but not least what kind of temps are you running w/your setup, #0, 370's,gsk, etc., w/the hybrid should I be able to run my #10 safely, &amp; possibly add some 370's in the future???? thanks for the help, Dusty

 

I can put the EGTs over 1500 deg if I stay in it too long(high rpms 3000+). What I'm finding is that since the #0 plate I don't go full throttle all that often, I don't need to. With the Super turbo and the Scotty Air 2 the rise of the EGTs are alot slower than I was with the stock turbo and the Scotty 1. I can tow my TT at 70+ MPH with the cruise on and all but the steepest hill is all I have to kick it off and slow some to keep the EGTs under 1250(my towing limit)<br><br> I would just hold off on the hybred unless your sure your done adding fuel and the thinking of adding the 370s. I am very pleased with the set up I have now but I know that it is starting to get the old weak feeling again and I know I'll be adding some more fuel here shortly... 8)