What do you guys think gives more hp/mpg ... exhaust or intake?

[2broke2smoke]

guy who works at the hospital with me bought a cummins ...



asked what i would do to improve the truck ...



i answered straight pipe and gutted cat, or mbrp and gutted cat for the more noise sensititive types



than an afe intake system ... but i'd do the exhaust first because there is more bang for the buck ...



(450$ for the afe !?!? i was gonna buy one for fall brawl, untill i saw how much the system was, thought it would be the same as my buddies '03 that he purchased at indy ... but dang, apparently the '06 intakes are made outta gold)



any who ... he asked me how i know that the exhaust would give more improvement than the intake and i just looked at him with one of those looks ...



so i thought i'd ask you guys ...



we all know that tdr members know everything and are never wrong :-laf

 

[PC12Driver]

My feeling has always been exhaust then intake. If you're gonna stuff more air into the engine, it would be nice if it has somewhere to go once the engine chews on it.



And since neither really add any power to a diesel, and considering the psychological effect of more noise = more power, I'd suggest going with the pipe first.

 

[Hammer]

1-A Big Bolt under the fuel pedal to restrict throttle movement.

2-Place ALL credit cards in a safety deposit box and never,ever visit them again.

3-Stay away from you because your full of bad ideas which will hurt his wallet and his fuel milage. :-laf :-laf .



Seriously. .

You didn't say what year the truck is so I will say this. Any improvement to air flow is a way to help improve efficency of the motor and fuel milage. With that said and you know it also,the only true way to better fuel milage is moderation. All the fueling enhancements,exhausts,air boxes etc etc etc in the world only help if you have the ability to moderate your fat foot on the loud pedal. Moderation,hmmmm,no wonder why my fuel milage sucks right now,I can't do it,I just can't... ..... Andy

 

[Coalsmoke]

On a relatively stock truck, a clean stock air filter will be about as good as anything else you put in its place without changing the entire intake system (filter through plenum. I have an AFE and love it, it sounds great, but when you look at hard factual test data, you see the numbers all within ~1mpg. The exhaust will offer some small, albeit direct savings right out of the box, and should continue doing so.

 

[wcjp]

What year is coworkers truck?

 

[2broke2smoke]

new '06 ...



and yeah i told him to keep it at 1900-2000 for the ultimate mileage ...



but we all know how that goes

 

[Hammer]

If its a 06 then there is no need for exhaust as they are already 4" stainless from the factory. Upgrade the air intake to one of his choice and go from there. Do remember though the electronic motors LOVE rpm's to be efficent. S&B Intakes are the newest rage out on the show fields right now due to their clear lids and their free engraving of your box lid. Airboxes are like ice cream,many flavors available and each will have their own little cult following. The way I see it after my own little test with my 12v on a Mustang recently there is little or no difference in power between any I had available to me,just color design and name so have him pick the one he likes the lookof the best and ride with it... ..... Andy



http://www.sbfilters.com/index.php

 

[2broke2smoke]

i dunno ... the muffler/cat combo are pretty restrictive ... i gutted the cat and put on a free flow muffler and it really seemed to make a difference ...



we'll see in a couple of weeks at fall brawl

 

[Extreme1]

More FUEL!!!

 

[GIT-R-DONE]

I would go with the intake. Exhaust isnt THAT restrictive IMO, get more air to it, then add FUEL, as suggested above.

 

[Cummins Pilot]

More FUEL!!!

Beat me to it.....

 

[pwerwagn]

Id say save the money spent on an exhaust and intake and get a fueling box with some timing. (TST CR or something like that. . ).

More power and mileage. And probably close to the same $$ as an exhaust/intake combo.



--Jeff