4 " exhaust

[hammersley]

If you aren't pulling and just driving - will you gain anything from the 4" exhaust? I installed a K&N filter and not sure I noticed anything except that I wanted to believe I did. Is this the case for the 4" exhaust as well?

 

[ACoyle]

https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=21346&highlight=word



For what it's worth, This is what I think.

 

[TXRam]

IMHO - it's not needed unless you have significant modifications. Just getting rid of the resonator and stock muffler and replacing them with a Walker or Magnaflow straight-thru will give you pretty much the same gains, and better sound/tone.

 

[JIM S.]

It boils down to your personal opinion..... if your not seriously bombed its not NEEDED. . but it sure is cool to look under your truck and see that big OL' pipe and I think the bigger pipe gives a better tone. but if you cant spend the money, get a straight through walker muffler from NAPA (cant rem the part #) (271468 maybe?) I have the 4" one and like it but you would need the 3" one. anyway whatever you do it will be better than what it has from the factory ... jim

 

[Cooker]

If you are not heavyily BOMBed (over 300 rwhp) and/or you are not towing much, the 4" is a waste of money IMO (BTW I have a 4" exhaust). As the others have suggested get youself a good muffler (Walker 3" 21468) and drop the resonator. This will yield good results for minimal $$$.



When I went to the 4" on my 96, which had 100% factory exhaust, I noticed maybe a 75* (on my unfortunately still stock truck) drop in unloaded pre-turbo EGT's while cruising at highway speeds. If my truck were BOMBed maybe I would have seen more and maybe towing I'd see more?



I agree it sure looks cool to see that big a$$ pipe under the truck, and I also think that the 4" pipe has a slightly deeper tone than the 3".



-Ryan

 

[EMDDIESEL]

I have a 4" exhaust and an EZ, i never tow or haul anything either. But the 4' lowers ET's and the sound and power improvement alone are worth it in my opinion.

 

[Batman]

I can't give you figures (lower EGT's, helps with HP... ) However, there is a huge difference between a stock system and a 4". I had the muffler removed and replaced with a straight piep for about a month before I installed the 4". BIG DIFFERENCE. can't beat the sound, and take a real good look at the stock system, alot of cripping in the front half, mine actaully looked to me as if it was reduced down to 2-1/2" in certain bends.

just my two pennies, good luck with your decision.

 

[DAWG-1]

I did the same as Batman, straight pipe. THERE IS a BIG difference between stock and 4". I noticed the turbo spooled up faster, Jardine has a deep tone, exhaust temps cool down much faster at shut down, lower wot exhaust, simple installation using the Jardine, others need welding to install, 5" SS tip looks . I met Jerry @ Timberline get together and he was a very nice gentleman.

 

[Archive]

Hey Batman... cool avatar! LOL.



Back on topic... I think any time you plan to pump up your engine, you should allow it to breath better. 4" exhaust helps that.

 

[tntway]

ABC's

being a nurse, i hafta say that the keys to life are the ABC's

A-airway

B-breathing

C-circulation



this means: K&N filter, 4" exhaust, injectors. in the O. R. we use monitors--this means gauges, gauges, gauges!!



LOL



p. s. do i need mine? i dunno, but i sure do like it...

 

[drawson]

I am bombed alittle and was running a stock system w/o cat and muffler replaced w/ a dynomax bullet. The Jardine 4" exhaust lowered my EGT towing 125-150deg and empty 50-75. The exhaust note was loader w/ the stock system, But it now sounds much COOLER with the 4" system. Be above 300 HP sounds about right and it does allow us bombahaulics to add more fuel and get more POWER Isn't this what it's all about????

 

[mediccummin]

4"

Just installed my 4" JRE exhaust today, going to muffler shop tom. to have joints welded and hangers moved. Took it out for a test run, sounds real good, much deeper but quiter at highway speeds. When you stomp on it the growl echos through my neighborhood, my neighbors will love my in the morning. In the short distance I drove I did notice a little difference in the EGT's, they dopped about 50 so far. I will have better results when complete, and I really take it out for a longer test. There is more power and spool up is faster. My EGT's also cooled down much faster. I think it is a good investment. Tuesday my DD1's and boost mod go on. Dwayne... .....

 

[Ninearrow]

Good posts on a topic I'm very interested in now. I was all ready to spend the $s to go 4" and asked a diesel mechanic his advice.



He said, "As long as your turbo is smaller than or same size as your exhaust pipe, a bigger exhaust gives zero improvement. " He said it was like dumping a 1/2" water hose into a 10" water main. The big pipe does nothing to decrease pressure on the smaller pipe.





Please say it ain't so!

 

[EMDDIESEL]

Tell you Diesel Mechanic friend he is wrong. I have been a diesel mechanic for almost 10 years and anyone with a half a brain knows his analogy is incorrect.

If you doubt it, Right before you get your 4" installed, find the bigest long hill in your area and floor your truck going up and time yourself and remember your top speed, now, try again with your 4" exhaust and you will see a substantiall difference. I saw an almost 40degree EGT drop and alot more acceleration and spoolup. Ted Jannetty did this towing a trailer and it made a huge difference. It does not matter how small the turbo outlet is compared to the exhaust.

Think of it this way, if his theroy were true, then if you took a pressure nozzle which has a large VOLUME of water going through a small opening, if you attached a hose the same diameter as the nozzle it would flow the same volume?, No, you have 6 cylinders feeding a turbo, that exits through a 3" outlet then has to travel all the way to the rear of your truck and over the axle. As the exhaust cools it gets more dense, therefore it slows down, so a larger exhaust will flow MORE volume. If your entire exhaust were only 1 foot long, his theroy would be ok, but he is not taking into account the length of your exhaust. Without a large exhaust, the turbo will have backpressure which slows down how fast it spins. And that means LESS POWER.

I guess your Mechanic feels he is smarter then Banks, Jardine, Stans, Jannetty, and all the other performance diesel exhaust companies.



I would stay away from that Mechanic, the next thing he will tell you is to put a Fram oil filter in your truck

 

[mediccummin]

4" rules

Just got my truck back after having my install welded. JRE 4". Looks great sounds real good and has improved my power, EGT down, spool up faster, turbo cool down in half the time. I agree with EMD again, your mech needs to pound sand. If biger exhaust did'nt help with power etc then there would'nt be such a thing. Dwayne, oh ya good luck, go with JRE great product.

 

[RottnDogue]

My 4" is going in this weekend, Can't wait. .



Darren

 

[EMDDIESEL]

I should hopefully have my muffler out by the meet on the 12th, you putting it in your truck when you have your kit installed?