Cummins vs. Cat

Scania v8 cab noise is 59 db, European volvo only breaks that when the fan comes on! I'm 37 but I feel so old around a noisy truck

 

Brilliant good man!! Lol

 

Last I knew some sort of back pressure is good. I was told that a Cat motor straight piped you drop 20-30 HP. You are better off with some sort of back pressure.

 

I also have also heard some back pressure is good.
When I ask why I have never got a satisfactory answer.

As for wearing ear plugs they can also block out some things you need to hear.
I drove an old 6 cylinder Mack with a short straight pipe , it was surprisingly civilized.
The V8 Mack however would leave your ears humming for hours after driving.

 

Well one thing would be that you get a bit better turbo spool with some back pressure. How big difference it is on a diesel I don't know but my m20 2,7l with a hx40 and exhaust 19 spools 4-500rpms faster with the exhaust mounted than just a down pipe.

 

I hear you and am not arguing but I don't see why this would be.
It does not make sense given what I know about fluid dynamics.
Why exactly would the turbo spool quicker with a bit of back pressure?

 

Would love to explain my theory but it's just to difficult in English + I can't promise I remember it corectlly, so long since I reed about it.

 

By slowing the exhaust out of the turbo it will retain more heat in the exhaust housing whichs helps with a quicker spool up, but I doubt over all horsepower will be increased.

 

And there you go, nope the top hp will probably be reduced a bit but how is actually looking for the peak hp (other than dyno queens) ? loose say 50hp of say 600 in the top of the rev band and gain a lot of drive ability.

If we take a truck engine, is there actually anyone revving the engine to the 2000rpm where the peak hp is.

 

Once had a DS14 Scania motor rebuilt by Scania ZA. The truck had a straight pipe at the time. One of their warranty conditions was that it had to be fitted with a silencer aproved by Scania, to meet their warranty terms. So i.m.o a bit of backpressure is good for a motor. Some motors can deal with no backpressure better than others. A Cummins is definatelly a motor that needs backpressure, CAT not so much, ran a 3406 with straight pipes with no issues. Scania DS14 no issues, except for warranty. What would the effects be on a Detroit S60 DDEC111?