4" exhaust and HP

[ISurvivedNMU]

OK,
On a fairly stock diesel truck.. maybe an addition of an air filter... Can a larger exhaust make any more HP?

On a chipped truck.... More HP with a larger exhaust?

And My guess on an extreamly chipped truck with pane or nos, it would make a difference...???/


Can a larger exhaust on a diesel slow you down, like with gassers... but there is no backpressure needed on a diesel ....right?



ISNMU

 

[waterdonkey]

I know with the Cummins that there is a difference. Hard to say if there are HP gains but my turbo spools a lot faster. I feel that my truck is more responsive on the throttle. My EGTs' have dropped by 50 to 100 degrees. The tone is the best of all. Diesels do not need the back pressure required by a gasser.

my .02

 

[Camstyn]

I found the exact same thing as waterdonkey. It feels more responsive, like the turbo spools up faster. Lower EGT's are a nice side-effect too. Others have dyno'd and found no gained horsepower but I bet if a load type dyno was capable of capturing accurate 0-1500rpm readings it would show the power curve improvement there.

 

[ISurvivedNMU]

Come on guys, with all the diesel knowledge here..... There has to be more info.... Help

 

[RAF]

ISMNU, I could tell a difference right away by adding the AFE and 4"...more responsive throttle,quicker turbo spool up, from the SOP meter. The engine breathes better.

No,a diesel doesn't need backpressure like a gasser. The general rule is you probably get about 1/2 of what the manufactures claim on HP gains.

 

[Roland_Jenkins]

I noticed no performance difference.

I have read comments where people felt they had lost some low end by going to a 4" turbo back exhaust.

Trucks TV did some mods on a dodge diesel awhile back. With a 4" Banks turbo back they gained 2 horsepower

I consider a bigger exhaust as a necessity for bigger and better things to come. Like that hot chip, injectors or what ever.

If a bigger exhaust was the only mods I was going to do, I'd say save your money.

BTW I put co-phased deer whistlers on and now my turbo spools up faster.

 

[morepower02]

Originally posted by Roland_Jenkins
[B
BTW I put co-phased deer whistlers on and now my turbo spools up faster. [/B]

, try the tornado intake

 

[ISurvivedNMU]

The reason I am asking everyones opinion.... Is because a buddy of mine told me on a stock truck you will lose HP... On a truck with a small chip... 70 HP you will lose low end... and the only way to make it work for you is to have a high HP chip, Pane and lotsa air coming in....

Just wanted some real world experiences....

 

[Camstyn]

I can see losing power on a naturally aspirated engine that needs exhaust back-pressure but with a turbo I don't see how it would be anything but better for it.

 

[Strokin_A_Duramax]

Exhaust & Hp

From what I found they are right a diesel dosen't need backpressure like a gas motor. I've been told by people that a 4" downpipe will cause you to lose bottom end. If it does it is not enough to notice. What you will notice is about around a100-150 degree drop in EGTs from cutting off the muffler, and about a 50-100 degree differance in the 4" downpipe. Alot of people were going to a 3.5" downpipe because of the alleged loss in low end. Like I said though in my experiance you can't tell any loss in low end stock or chipped. One thing you need to remember is that a diesel engine is essentially a big air pump. The more air you can flow in and out with less restriction, the more power you will make with less heat,,,,,,,Just my .02 though.....

 

[Geno]

Brian
Tell yo buddy he is full of it. Mine wasn't a ball of fire but to me it was noticable. UNI cone an Flowmaster
Geno

 

[Geno]

Strokin
I have not herd of a 4" down pipe for a Duramax, Have you?
Geno

 

[ISurvivedNMU]

Originally posted by Geno
Brian
Tell yo buddy he is full of it. Mine wasn't a ball of fire but to me it was noticable. UNI cone an Flowmaster
Geno

Geno,
I will let aaron at edge products know.....

ISNMU

 

[Geno]

Brian
Don't start no trouble, Im in enough trouble as it is on the Page.
Geno

 

[Strokin_A_Duramax]

Originally posted by Geno
Strokin
I have not herd of a 4" down pipe for a Duramax, Have you?
Geno

I have a 4" exhaust system for Duramax's I will double check to see what size the downpipe is though.....