Just like the thread title states. I want to know why the major tuners out there can't provide us with power without all of the smoke. Don't get me wrong here, I love my 6.4 and the 275hp tune I am running. I cannot believe how powerful the truck is. It is actually scary at times how fast! I have been running my 250hp tune lately for two reasons. 1) it shifts much smoother than the 275, and 2) it still smokes, but not as much as the 275. I want all of that power, but when I get on the throttle I don't want to blind the driver behind me in a cloud of poison, as well as letting that poison make its way to the upper atmosphere.

Now I realize that you need some extra fuel when tuning, but from the information I have read, proper tuning would not smoke that much. So maybe this question goes out to the guys at Spartan, the guys at Banks and all the other tuners. Is there a way to make efficient tunes without smoke, is there a way to make a big HP tune with no smoke? These are the tunes that I want to run!

 

The smoke is a byproduct of throttle response. Stock tuning does fueling proportional to boost, so if you don't have the airflow, it won't over fuel. Custom tunes eliminate or reduce this because more fuel makes the turbo spool faster and reduces lag. If you get a true custom tune, you should be able to get the tuner to keep fuel proportional to boost. You won't eliminate smoke, but it could probably be reduced. At highway speeds, it would also help to unlock the TC and shift down easier, so you don't have as much smoke when you get into the throttle cruising at low RPMs.

 

So Cartman, in your opinion, there is no reason we can't run big HP tunes with little to no smoke? I don't mind a light haze of smoke while I am pushing it... it is the huge plume of smoke when I lay into the throttle from a stop or on a roll on the highway.

Here is a piece of an article that I quoted directly from a Popular Hot Rodding Magazine:

 

Yeah, its a trade off though. Less smoke means waiting for it to build boost before the power comes on.

 

Are you sure this is correct? I've always understood that if you can burn x amount of fuel with no smoke, you will spool the turbos just as fast as if you burned x amount of fuel with a ton of smoke(the smoke is extra fuel in addition to x). There are some limitations to the holy grail of a perfect burn which is why you generally see huge amounts of smoke(again, this is just my understanding not what is actually correct).

I suppose you could take the exhaust density into account, but I'm not sure if that's enough to make a big difference, and wouldn't it also slow the exhaust down slightly?

Maybe the tuner guru's can chime in.

 

Ya, I would love to see this thread gain some momentum! I am extremely curious about tuning, and would love to know more about it.

I think I will try to call some of the guys over at Spartan and see if I can get some info on tuning, and why these tunes smoke so much. I def think there are a lot of people out there who feel the same as me... in that they love having these huge HP tunes but feel extremely guilty billowing huge amounts of smoke into the air when we step on it. Don't get me wrong it's pretty cool when you first see it, but that novelty wears off pretty quick once you realize what you are actually doing. It is pretty disgusting when you come to think of it.

Sometimes I actually miss running the DPF, because the smell of the exhaust is sweet and non intrusive. You can literally stand right next the exhuast and the ordor doesn't make you sick.

Thanks again guys for chiming in... keep it up!

 

I talked to someone over at Spartan.. and the gist of it is that when you initially hit the throttle it smokes because you have more fuel than air. It takes time for the turbo to spool up. So the added fuel actually aides in getting the turbo to spool up as fast as possible. So as soon as the boost and the amount of fuel begin to level out that is when the smoke clears up. So Cartman hit the nail on the head.

So the guys over at Spartan don't know a way to spool up the turbo fast without adding fuel... Does that mean it can't be done? I would say it can't be done without adding something else to the motor to force the turbo to spool up.

However, I think I have a solution. Instead of waiting for the turbo to spool up, why not force the turbo to spool up?? I wonder if you electronically control the turbo to build boost without dumping all that fuel.

Another idea would be to use a supercharger for instant boost! Well wouldn't you know... it's been done! I had no idea about this though. Here is a quick read a Duramax with a supercharger on it.

Super Turbocharged Duramax Diesel Engine - ProCharger Supercharger - Diesel Power Magazine

So what do you guys think??

 

They are controlling the turbo, but it still takes time to spool. I have noticed this on my 6.0L just recently. I was running the free spartan tunes that smoke more and they had great off idle response. I just got custom tunes from Eric at Innovative and they hardly smoke at all, but the turbo is more laggy. I'll take the lag over obnoxious smoke any day. I can still make them smoke when I want to, but in normal driving it is well controlled.

 

I'm not buying that excess fuel helps the turbo spin up quicker. It might make the air a little more dense, but I don't think that would amount to much.

Smoke is just wasted fuel. If it was burned it would increase the velocity of the gasses and make the turbo spool quicker but it's not. It sounds like they just map the fueling to the accellerator and when you floor it you get X amount of fuel. Then you get a bunch of smoke until the turbo can spool up and provide enough oxygen to burn it all.

If the fueling was matched to the boost, it would smoke much less. Granted you would probably still have some as you do need some excess to accellerate.

Mike