Single VS Twin turbo

The twin turbo setup on c15's are called ACERT. The purpose for it is less emission. I don't see difference with rpms. It all depends with ecm file, the way it was built, engine timing, and compression from pistons. acert turbos are not that powerful than the 3406/earlyC15/c16.

 

the cat twin turbo from 08 to 2011 has a class action lawsuit against it. my friend bought 1 & if it were not for MR. Haney he would of been in a world of hurt, cause he could not give that truck away as beautiful as it looked. cause no one wanted that engine too many problems.

 

Your correct that is how it works. The reason behind this setup is for emissions. You get constant boost at all rpm ranges so the fuel is burnt no matter your rpm's. Black smoke is too much fuel not enough air( aka epa nightmare). The other option was a single vgt turbo. Up until here recently this option was very very troublesome and expensive to replace. Because you cant fix it properly without the proper parts like days of old because manufactuers wont sell the rebuild kits. Crying shame!!!! Twin turbo would be much better if cat could have gotten thier act together n the hardware surrounding it.

 

Mr Haney wrote a good report on the twin turbo. It's on here somewhere

 

Based on the Miller Cycle I believe from the 30's/40's. With the ACERT you have VVA's that work similar to a Jake except on the intake side. At the bottom of the intake stroke they open the valve again to get another gulp of air when conditions are met to gain a more efficient burn and less pollutants. Obviously turbo lag is real, not imagined with these engines but they still pull good if driven correctly.

The 2007 EPA engine were also compound turbo's and like has been said, the base engine was fine....the aftertreatment not so much.

 

and too much sensors.

 

........,..,,I was wrong. Here it is.

http://www.thetruckersreport.com/tr...actuator-defined-kind-of.170500/#post-2442847

Brings a tear to my eye. I miss reading that kind of stuff....

The twins aren't bad... Update the studs tho.....

 

I've heard it said that the are actually not really twin but "sequential" turbos. I think the idea is one spools up quick and then the other takes over.