KATOOM

Well I finally had the opportunity to install my new 4" Magnaflow exhaust with no muffler. For those who dont know, I have been battling excessively high EGT's while towing my 5th wheel during summer getaways in the mountains, and new exhaust was the next move in trying to reduce them since my stock exhaust was already straight piped. First off, the 4" system sounds very nice. Since they're both without a muffler the overall noise is about the same "loudness" as the straight pipe 3" but just deeper and not so raspy now. I also took the time to incorporate one of the stock mid pipe exhaust hangers which MF opted not to use in hopes to keep drone down. Although it does drone a bit while towing but not nearly as bad as I anticipated. I'll deal with that later if it becomes a problem since I dont have enough time behind the wheel listening to it in order to determine if what I'm hearing is annoying or not. I'm still in the passenger window down faze.

Interestingly enough though the turbo is much happier with a free'er flowing exhaust. Spooling is faster and it seems I even gained a couple psi of boost, and the pressure sits more solid at max boost whereas before it tended to waver and drop a few psi unless the RPM's and amount of throttle was perfect.

The real test though was while pulling my 5th wheel..... Remember, its kinda heavy at 14k lbs and I had the chance to get out in the summer heat this weekend and pull some long grades to see if did anything or did I just waste more money. Well good news is that the difference was very noticeable and very considerable. I can honestly say that I dropped a 100* and the overall drive-ability of the truck pulling grades while watching EGT's showed that they were cooler and less apt to spike at any given time I needed to press it hard. End result was I am VERY happy with this addition and after experiencing it for myself I can say without a doubt that a straight piped 3" is NOT the same as a 4" without the muffler. Clearly the 4" mandrel bent pipe with less aggressive bends flows much easier than the stock 3" straight piped and will lessen EGT's and increase spooling time and HP.

Why did I say increase HP? Well generally HP gains with a diesel exhaust is minimal since all exhaust is really supposedly doing is releaving EGT's to allow more fueling, but after cutting off the stock exhaust pipe I can clearly see where I had to have gained some power. Obviously 4" is going to be larger around but mandrel bending compared to the stock exhaust which is smash bent indicated that in many locations the 3" exhaust is around 2.5" at best. And the bends on the stock system are tighter as well. And.....to add insult to all that, the stock exhaust pipe clamps were even tightened to the point of collapsing the pipe a bit. For an engine that's pulling the kinda weight I'm pulling at 26-28 psi boost, the stock straight piped exhaust was tapped out. See what I mean in the pictures below.

4" sitting next to 3"



3" is the largest diameter of the stock exhaust pipe.



Smash bending the stock exhaust pipe resulted in some locations being 2.5".



Look inside where its smashed from clamps.



Now for the real indicator of HP gains.....
While pulling those long grades I was able to keep the EGT's down so therefor was able to also hold the throttle harder and for longer periods before having to downshift. That was an obvious improvement. BUT..........along came a problem with this "gain". While charging up a few strong uphill pulls, all of a sudden the clutch slipped. I thought to myself, was that what I thought it was, but unfortunately was able to re-slip the clutch on demand as the throttle neared WOT and boost levels maxed. So not only did I reduce EGT's and increase boost but I obviously gained a few more ponies as well.....and seemingly producing just enough more HP than before whereby the stock clutch cant hold the power while pulling 14k. Next up on my "cant afford" list.....a new clutch before I destroy the flywheel.

Oh yeah.....I also had the strangest dead pedal experience too, but I'll start a new thread about that since this is supposed to be about the positive results of aftermarket exhausts. But sadly the overall excitement of a new exhaust system quickly was overcome by a multitude of "potentially" costly things during my weekend getaway. I just wanted to go home.....

I just keep trying to tell myself that all the hassle I may be going through is cheaper than new truck payments, but the sour taste does get hard to swallow after awhile.

patdaly

Don't think of it as additional expenses, look at it as being on the ultimate quest for the perfect truck....... and Hp begats double disk SB clutches which begats twins for towing, which begats............

That's why I am scared to break the seals on my P7100......lest I start the race to empty wallet.

drc5900

Well, you got me convinced to move on to 4" exhaust, that'll be next on the list.
I already done [most of] the other necessary upgrades, please see sig, just wanted to do things in the right order, before the power upgrades I'll install a KDP kit.

nkennedy

I had replaced my clutch before the 4in exhaust, and I also went with the muffler; however, the EGT drop was about the same. I also liked being able to give it a little more fuel without excessive EGT's on the hills. Able to keep my speed up going up the hills now.

KATOOM

I think its worth me noting that I ordered this Magnaflow kit through XDP (Extreme Diesel Performance) because they were priced the most competitively. What I found out was that this is a great company to deal with..... When my exhaust system showed up with missing clamps and I had to contact Magnaflow to try and get them to send me more, I was pressed to find a clamp in order to make the kit work so I could get the truck going. I let XDP know about this issue with Magnaflow's exhaust system and they not only wanted to pay for the $15 clamp I purchased, they issued me a $50 gift card if I used them in the future. AWESOME customer service..... Why cant every vendor be this way?

SIXSLUG

When I got my truck the exhaust was the first thing I modified, mostly from reviewing threads on here before I even had my truck.

I didn't plan on hot rodding it but rather building a steady eddy tow rig for two construction trailers, an 18' enclosed tool trailer and a 14' dump trailer.

My first concern was the fifth wheel hitch in the bed on a totally stock truck with 43K original miles and a carfax report that showed it had only attained 2000 miles in two years. Basically my truck made 41K miles in two years towing a fiver around the country. I had all service rec'ts and was not too concerned about the condition because it appeared very well taken care of. However, the factory exhaust had been accused of being minimal in many threads I had read so I attacked it first.

That was a good move, Katoom. An upgraded clutch should give you the peace of mind to keep on truckin.....

KATOOM

Thanks SIX. I appreciate the kudos.

wilderness

A methanol injection system is one of the best ways to keep egt's down around 900 or less in 5th gear on steep hills. Along with the exhaust you will never have to even watch the gauge anymore. They have progressive spray kits that work in conjunction with your throttle and easy control panels to turn off when not towing. You can use "heet" or below freezing windshield washer fluid to make the gas. It's not twins or a bigger turbo but you will drive it like an auto once you get into 5th as you'll never have to shift, unless you have a 6 speed... Just throwing it out there.

WesHawkins

I just ordered a Banks 4inch system for my 2000 Dodge Diesel. I'm curious what intake system you are using, I assume you upgraded from stock. I'm looking for suggestions if anyone has any.
Thanks,
Wes.

KATOOM

I did upgrade from stock. I have an aFe Megacannon. Basically the same as the BHAF but with a metal shield bracket which gives a place to mount the air filter. Is it better than stock?.....well yes and no. Its been proven that the stock airbox will deliver enough air but the filter size/area is too small. So guys go and get a K&N OEM replacement which is worse since the media is to light and allows oil and debris to pass into the intake. Also, the OEM airbox is notorious for cracking which will allow debris to enter after the filter. Point being is that an aftermarket intake system is better than stock but not for airflow but for filtration for that added airflow. There's plenty of versions out there from you to choose from too. And no dig on Banks either but they're not the best just because they're the biggest. Banks is the premium name and generally means you just pay more for their stuff, which is the same or better made by someone else.

WesHawkins

I ordered the banks exhaust system because I put one on a friends truck a few months ago and it was a snap. My factory exhaust has pretty much had it anyway. He also had me put on a Banks intake system he had bought at the same time as the exhaust but I wasn't impressed with it very much, especially for the money he paid.

SIXSLUG

I run a NAPA BHAF and a heat shield. I got the template for it on here years back and used it to mock up a cardboard one before finalizing the design and cutting it out of 3/16" aluminum plate.

I drilled the top of the filter to accept my meterminder off the
stock box, which I was horrified to find cracked on the outlet side!

Airflow isn't a problem. My mod list includes an ATS intake horn and exhaust manifold someday....

Don T

well I started of with 4" MBRP cool duals then mod after mod later I`am getting real close to MY truck. You can`t pry that 12 V away . some have tried at 14000$ offer for a 95 2500 .Power I don`t think I could find (( TO MUCH )) . Well the race is worth it . Just know when to stop .

Don T

I think a better head manfold off the head to run away exhaust temps would be the answer. But WHO makes a great exhaust system from the head ???

KATOOM

Oh there's plenty of aftermarket exhaust manifolds available ranging from something which looks like OEM to various versions of that OEM style, and then there's ones which are flipping amazing looking tubular header systems.