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Low boost & black smoke with ATT

Dan,
Take the truck to Metro Diesel injection service in Agawam. They said they can time the OBD2 trucks. He quoted me 60$ a year ago when I spoke with him but that might have been a discount as he knows the fleet manager where I work really well.
 
Matt, I'm in SE NH right near New England Dragway. Haven't had a chance to open the hood and check for any air leaks yet, too busy with two kids starting preschool and kindergarten this week.
 
Slim Shady said:
That is why I think, the problem with the the smoking on this truck and the ATT turbo is related to the exhaust or some other problem, not the turbo. Slim, are you referring to my truck here? I didn't mean to insinuate it was smoking due to the new turbo, I think it's more related to the computer or the IP not being on exactly the same page. I'm sure I'll get it worked out once I can get it timed, and maybe get a gl-4, and check for intake leaks. I don't think it's an exhaust problem.

If you get a notion call and talk I love talking to people from different parts of the country. I am glad you like the turbo, it definitely a turbo made for heavy towing
Click to expand...
I think Mr. Bucbuck might have a slight gear ratio advantage over me. I was at 4;10 before I started upsizing the tires. I actually was considering getting a small set just for trips, but screw that. If Joey D can tow 10k with 35s, then I'm keeping my 33s
 
Detroit Dan said:
I think Mr. Bucbuck might have a slight gear ratio advantage over me. I was at 4;10 before I started upsizing the tires. I actually was considering getting a small set just for trips, but screw that. If Joey D can tow 10k with 35s, then I'm keeping my 33s
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I have upgraded the gears, 4.56. I will report after towing with them. I did it more so for air locker installation as it was all apart and nows the time. I am sure it will help withthe towing but it's not a huge jump.
 
Joey D said:
I have upgraded the gears, 4.56. I will report after towing with them. I did it more so for air locker installation as it was all apart and nows the time. I am sure it will help withthe towing but it's not a huge jump.
Click to expand...

What were you before?

With my 235/85's 4.11's I'm turning 2k doing 60mph. 65 is around 2200 or so.

When I had my 225/75's I was 2200-2300 doing 60.

Hows HIghwy RPM?
 
Matt Bachand said:
What were you before?

With my 235/85's 4.11's I'm turning 2k doing 60mph. 65 is around 2200 or so.

When I had my 225/75's I was 2200-2300 doing 60.

Hows HIghwy RPM?
Click to expand...

Me too same rpms with same tires an g/r. I am planning on 255/85's or maybe going to 19.5's not sure yet.
 
I had a really bad streak of black smoke when trying to climb the rocky mts. And I had low boost. I was only getting like 5psi and was leaving a super thick dark trail of black smoke, and EGTs were flying up. This was when I was at a mile elevation and higher. Before that the low boost wasnt an issue and I wasnt flooring it at all anyway. So I had to down shift and slow to 40MPH to stop that, and I was running with just some junk in the bed, nothing heavy.

Before this the truck ran great and never had an issue hitting 17psi even with the GM4. So when I got where I was going I had ripped off the Banks 3.5" exhaust with Cat included and straight piped it. Truck came alive then, saw 12psi on acceleration now, but was extremely loud, so I put on a chambered 4" muffler and lost a couple psi boost, and it was still loud.

On the way back over the mts it was much better, but I still got more smoke on acceleration at a mile high, even on light acceleration, it just wasnt prolonged smoking. My barometer was reading correctly, and I would stop and start the engine and it didnt adjust enough I guess.

So the ATT requires much more exhaust flow to work well, compared to a GM4. However my backpressures were around 28psi when the GM4 was pushing 17psi and the ATT feel about same power around 15psi and there is only like 17psi backpressure. The ATT uses just like +2psi on the turbine pressure the whole time, compared the GM4 which was always like +5 to +12 psi over the boost pressure. So if the turbo generates all that heat to compress air just 10psi how much work and heat does the engine have to do to compress it to 20 or higher?

I tried my stock and Engh chip and both smoked the same amount up in the mountains.

I need to make a TM and put my GM4 back on with the more free flowing exhaust to make any real comparisons, because with that Cat restriction it must have been hindering the GM4 too, but the smaller turbine would spin up faster.

I still get smoke now when I put my foot into it, even with 5" muffler and 6" tip on the exhaust. Sometimes it fun, but I enjoyed no smoke from the GM4 before. Once I replaced the IP and injectors about a year ago my truck didnt put a bit of smoke out anymore, even with the power chip from Engh, and it gives a lot of power, much higher fuel rates.
 
The 4.56's will put me about 50rpm lower at 60mph with the 35's than I was with the 30in tires and 4.10 gears.
 
But you did say you were pleased with how it towed before you pulled the 4:10s, right? Hey, what's this I just noticed in your sig, CV shafts?
 
Also, finally got five minutes to pop the hood today, found that the clamp on the turbo end of the new intake hose was loose. Well, it wasn't loose it was tightened all the way down, but I could still spin the hose back and forth by hand. I think the new hose is much thinner than the factory hose, so the factory clamp does not tighten down enough to seal it tight. So I thought about it for a minute, then took the clamp off, ran a couple layers of Joey Ds magic rubber stretchy tape around it, the put the clamp over that. Seemed to take up the slack, got the clamp as tight as it would go and now I can't spin the hose at all. I can't imagine that there could have been a great deal of sucking wind there, but maybe it was and that's where I was losing the extra boost I think I should have been seeing. BTW, what kind of boost numbers should I be seeing, anyway? I had the old GM-X with a TM set at about 10-11, now I'm only working at about 5 lbs, with the occasional jump to 7lbs. I think I may have seen 9 once for a second.
In fact, normal driving for me on back roads, I don't get any boost, I'm running at zero where I used to always have a couple lbs going.
 
Matt Bachand said:
What were you before?

With my 235/85's 4.11's I'm turning 2k doing 60mph. 65 is around 2200 or so.

When I had my 225/75's I was 2200-2300 doing 60.

Hows HIghwy RPM?
Click to expand...

Ive been thinking of going to 235/85s. Right now I have 225/75s and drivnig down I 75 Im doing 70- 75 and the rpms are around 2400- 2500.
 
That's typical boost, has smoke cleared up, you are moving cfm not building a lot of psi to overcome inefficiences of the turbo which is a good thing, at 100 mph I'm only 10 psi, turbo will build to 18 psi but then you are going really fast, or working really hard, my normal highway boost @ 70/75mph is about 3-4 psi.
 
Detroit Dan said:
But you did say you were pleased with how it towed before you pulled the 4:10s, right? Hey, what's this I just noticed in your sig, CV shafts?
Click to expand...

It did tow better with the ATT and the 4.10 gears than it did stock.
The CV shafts are in the front axle. I don't run U joints in the knuckles I run a set of CV joints. Much smoother operation and better turning radius.

https://www.rcvperformance.com/stor...id=48&osCsid=3d209d2f82c0078828339a5738036ccf

They also sell CV shafts for the IFS trucks that will not break or pull apart.
 
IFS Independent Front Suspension.

Brooklyn I have ? for you.

What size rims are on your truck?
And how many lugs?
 
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