Engine/Transmission (1998.5 - 2002) exhaust question straight pipe?

[danieljones]

A friend oh mine was wondering if it would be better to straight pipe a stock 2002 or should he just leave the muffler. He heard from somebody at the muffler shop that it would affect timing and boost pressure resulting in poor fuel economy?? I have a 93 CTD and told him I felt a difference in mine lost 2 psi in boost but gained about 50 in fuel mileage over all but I didn't know about an 02?!?!



Any help out there guys??



Thanks from the first gen crowd

 

[rashwor]

Here is what I did.

I had a muffler shop cut out the muffler, but leave the resonator in. The resonator keeps the droan to a minimum, but lets the truck exhale better than with the muffler. The only difference I noticed in the truck is a sweet, but not irritating, sound out the tail pipe. I did this before adding the EZ so I don't know if it helped with EGTs or not. I did drive it daily for about 3 months between the time the muffler was removed and the EZ and gauges were added. During this time, I never noticed any improvement or difference in performance or mileage. :-{}



I did what I wanted the way I wanted and I am very happy with it. Here is my explantion. I wanted the muffler removed, but the resonator left. Around here, the younger crowd (which I am not part of any more ) seem to like the with no nothing but open pipe. I have to agree they sound sweet passing on the road this way... but riding in one for extened times is a little less cool IMO. The muffler shop guy where I have my work done said, "Yeah, we straight pipe about 5 CTDs a week and 90% are back within two weeks wanting some kind of muffler back on the truck. " It pays to know what you want. Ride in someone's set up the way you think you want yours set up if you have the chance. Think... "Can I stand this sound for N hours at a time?" Nothing against the loud crowd! I like them that way... but not for N hours a day in my truck. Sorry for the long post.

 

[danieljones]

Thanks for the responce, he took out the resonator and the muffler didn't know there was both, my bad. So other than the sound no diff eh?

Thanks Dan:--)

 

[Ncostello]

I gutted my system and went total straight. I've been this way for about a year now. I sure sounds good... but... I think I'll be going back to the more "refined" tune of a good straight through muffler. I'm leaning heavy towards the Rip Rook 4" Diamond Eye system. I'll still get the loudness I like but without the raspy-ness and cackle.



Straight 3" is good dont get me wrong because I like the straight pipe sound. It will help with the EGT's somewhat I'm sure. I dont really think it will hurt boost or timing much if any. But its starting to sound a little obscene now after a year. You really have no idea how loud it is until someone drives it for you and puts the pedal down between buildings in a downtown setting. Its really loud!! Ticket Loud!! I want the big rig sound with just a touch of mellow smoothness. Thats why I'm going back to a muffler and 4".

 

[danieljones]

Thank you all, I will give him this URL and let him make his own opinion. I sure like the straight pipe in my 93 but I haven't heard his yet.



Thanks again

Dan

 

[TPlasek]

I'm 28 and I only lasted strait piped for 10 months. I installed on of those strait through Napa mufflers. Those long road trips are much more pleasant now.

 

[TomGolden]

I have the Pinnacle Performance 4" exhaust, by Jerry Jardine. Have had it on since April 2001. In May 2002, I removed the straight through muffler myself. I have seen exactly zero difference in boost, EGTs, fuel economy, anything... because of going straight piped. Except sound. It is soooo much better sounding. But, as said by someone else above, in the cab the drone is



Oh well...

 

[Truckie]

I have a 2001 and have had it straight piped since April of 2002 and love every second of it. I also drove big rigs for 7 and half years and all my trucks were straight piped, if I did not get tired of that for 7 and half years I don't think I will get tired of hearing my Dodge. The sound dose not brother me at all I like the way mine sounds, and there is not to much cab noise. I need to get someone to drive my truck while I stand out side to here it.

I wish I could find some more of the stickers I had on some of the other trucks I drove they said " Straight Pipes Save Lives"

Oo.

 

[Scrappy]

straight-piped

I bought my truck in may 0f '01, straight-piped it in Aug. of '01, and stacked it in Jan. of '02. It sounded good with the stock exhaust straight piped and it had very little drone. With stacks, the sound is the same just closer. My first try with 4" exhaust and stacks droned real bad. I reworked the stacks and there is no drone that I can distinguish in the cab. The truck is really loud

 

[MCummings]

Originally posted by danieljones

... ... He heard from somebody at the muffler shop that it would affect timing and boost pressure.....

Just don't go back to that guy for anymore Diesel Advice. It will affect boost pressure, 24V's usually see a small increase of boost (unless you live in high altitude), and lower EGT. When Istraight piped my stock truck, There was a noticeable difference in turbo spool-up time, much quicker,, and in the 2,500 - 2,800RPM range there was a nice increase of power. I noticed alot of drone, and it was much louder,, Exactly (except for the drone) what I wanted.



Timing? It is adjust variably, by a few degree's, depending on the engine load, and RPM, by the ECM. The only way to change timing on the 24V (ISB) Cummins is to install a box specificly designed to change timing, or a power box, similar to the Edge EZ. (Not all boxes have timing,, be carefull)



Hope this helps.

Merrick Cummings Jr



BTW, unless he doesn't mind load and droney,, put a Straight through muffler on it,, or even a Full 4" exhaust from DPP, with a Chrome tip ;D

 

[WadePatton]

I took the muffler out and left the resonator. Sure seemed to spool better, but there was a bit of a drone at 70-72mph.



Then Big Exhaust comes along with the inexpensive 5" system. I put it on straight and it was super cool except for a WICKED buzz/drone right at 2150. I loved the sound, but it was a bit much as every mailbox and signpost kicked a LOT of sound back at me.



I put a 10x51 GUTTED muffler on and toned it down a bit. 9" would have fit better. Now I have absolutely NO drone, and just about the perfect sound.



I might try a smaller muffler later.



Now I just need a 7" tip.

 

[tgbol]

I ran a 3" straight pipe for about a year. Last week I put a Walker (Napa) straight thru muffler on. Quieted the exhaust, but the turbo just screams. I am going too try some thing else. What I was looking for was about 1/2 way between the straight pipe and the muffler.

 

[danieljones]

Thanks for the reply mcummins, very informative. I do have one question for you though what type of performance box would you recommend.



Thanks again

Dan

 

[MCummings]

Depends on your budget, and how much power you want.



A Power Edge EZ will advance the timing, Usually bringing up MPG a small margin, act as a boost fooler allowing you to get more boost without setting any overboost computer codes, and adds a small amount of fuel over stock. Adds about 60HP over stock. An affordable box, not REQUIRING transmission upgrades, or gauges. Gauges are Always recomended, but this box doesn't require them. As well as intake and exhaust mods, they are not needed.



A Power Edge COMP box does everything the EZ does, but adds 60 MORE Hp than the EZ, bringing the total over stock HP to 120.

This box is very adjustable, and will require upgrades such as a heavy Duty Clutch, a different Intake, exhaust work, and fuel system upgrades.



The COMP is the box you will want to go with if you plan on going even higher in the HP range later with bigger injectors, and turbo(s)



There are other boxes out there from TST, Blue Chip, Diablo, Western Diesel, SuperChip, Dyno Sources, Bully Dog, BD Power, Diesel Dynamics, and many others.



Sopme companies have a contract with Power Edge to buy the EZ, and private label it, and sell it as their own.



As of right now, I can only recomend the Power Edge COMP, because it is the only box I have first hand experiance with.



Hope this helps,

Merrick Cummings Jr

 

[WadePatton]

I recommend the Diesel Dynamics Ultimate Fueling Module. It is a PE Comp box that DD reworks a bit. It is recurved with the expectation that the end user WILL use bigger injectors.



I, however, am quite pleased with mine on the stock injectors and DO plan DD3's very soon.



DD lifetime warranties the box too. And it is the only unit I have owned, but I have tried an EZ and knew that I needed more!



Watch the used market for them as some are different for different years and you might find a deal like I did.

 

[Forrest]

7" tip? :--) gonna need a rodent & bird screen.

 

[MCummings]

Originally posted by WadePatton

I recommend the Diesel Dynamics Ultimate Fueling Module. It is a PE Comp box that DD reworks a bit. It is recurved with the expectation that the end user WILL use bigger injectors.

I don't think the DD module features timing. Which is great for running NOS and/or Propane.



Merrick Cummings Jr

 

[WadePatton]

Don't start rumors here.

The DD products have some degree less timing than the PE products they are derived from. And I'm sure that would be better for the druggies.

 

[MCummings]

I stand corrected.