im about to buy a Bullydog 4" exhaust
from turbo back including 4in downpipe/ elbow.

what kind of performance gain should I see, if any...

my truck is stock w/ AT.

i plan on adding BHAF, and minor IP tweaking untill I get gauges.

im getting a GREAT deal on the exhaust.
thanks for any imput..

 

Stock you'll see slightly decreased egt's and more sound. You will be prepared for power upgrades in the future if desired.

 

I have heard claims of HP and TQ. I did not see either even with some injectors on board.

Sounded better. EGTs were the same as the muffler delete I had previously done.

Dave

 

There is no real performance for exhaust changes in a stock truck. Like the previous statement, bigger exhaust is a compliment to more fuel and air.

Since there is no air/fuel ratio, the exhaust have no bearing on engine power until you have so much fuel that EGT's are too high.

Until you add more fuel, you will probably not make any more power.

Now, adding power is as easy as bolting on more parts. Do a search for "torque plate" or "TST plate" and you will see.

I do not mean to mean to damp your fire, I just want you to know what to expect.

Ronnie

 

yeah you will notice a drop in fuel milege until you get used to the sound.
mashing the throttle to hear the echo and what not.

 

so will adding this exhaust reduce my tq. at the low end because of no back pressure like it would in a gasser?

the only advantage of this would be sound even with a BHAF..?

i wonder why sooo many people always do these things first ( i read hundreds of times where people always say intake, headers, exhaust.. over and over..
and most that i read say they gained power.. so i dunno, i guess this is a reality check

 

Probably a small gain in power but nothing ull notice..

 

For me, it's in preparation for more fuel. My 97 got a full 4 inch exhaust, then my B-1 turbo, with only an 11 plate. It's way underfueled, but the 100 plate and injectors are waiting for time to get thrown on, maybe even 191's. I've watched many guys throw more fuel in the mix, then more air. To me, it's harder on the motor to overfuel than underfuel. Just my humble opinion.

 

its definitely a preparation for things to come. its almost the same as guages, you buy them but you dont get any HP increase but in turn they let you start adding fuel because you are watching your engine more closely. the exhaust will do nothing to a stock truck but once you start with the fuel you can flow air more easily.

 

Exhausts and intakes are considered "supporting mods." They allow you to get the most out of power mods. You will notice that your exhaust and turbo are louder, but probably not any noticeable power gains.

 

Rolling18,

You ask about backpressure. Roughly, for every pound of boost you make, you also make about that many pounds of backpressure between the exhaust valve and the exhaust wheel on the turbo.

The turbo does require power to drive. I have driven my truck without a muffler and did not have a loss of power. Most good aftermarket diesel mufflers are HUGE and will flow very well, considering the power levels you can attain with your truck.

I hope that helps,

Ronnie

 

Hi I put my truck on the dyno at work and checked exhaust back pressure it was 13 inch of mecury the max allowed is 3 and that is when my truck was stock max boost was only 18 psi and took a long time to get there after I put 4inch exhaust on the truck came alive it would make 21 psi of boost in very short amount of time.I did a dyno after the change and only gained 10 hp but it sure feels like more.

 

You have really only lowered your egt by increasing the flow directly out of the turbo w/ the 4" exhaust. This will help your turbo live longer so its not a bad upgrade. My stock system bent down to around 2 1/4 inches after the muffler and resonator at the bend over the rear axle. Cummins spec'd a full 4" system for the 5.9 ISB. Dodge/Chrysler saved a lot of $ going w/ 3" tubing and a 4" tip. It'll be a little louder, breathe easier and run cooler at the turbo outlet. You are only helping things along, especially if you are gonna add more fuel and air later on.

 

dont we all add more fuel and air later on?????

 

It will sound good. LOL