i'm getting ready to make a custom exhaust system. i would like to have it exit in front of the rear wheel. i'm alittle concerned about soot build up on the wheel and exactly how to make the exit so that it looks clean. if anybody has some pics of a system that exits infront of the rear wheel, i would greatly appreciate it if you could send them my way.

i'm getting ready to make a custom exhaust system. i would like to have it exit in front of the rear wheel. i'm alittle concerned about soot build up on the wheel and exactly how to make the exit so that it looks clean. if anybody has some pics of a system that exits infront of the rear wheel, i would greatly appreciate it if you could send them my way.

Might want to check on the legality of it - IIRC MI says you can't do it :confused:

I had that on my old '94 Dodge, I had 3" straight pipe with a 90 degree turn down pointed slightly back. It would still coat the tire some, but not nearly as bad as when I had a slash cut installed. Suprisingly the gunk on the tire sprays right off very easily. You might not like this though if you use a 4" straight pipe, I had that on my '01 Dodge for a very short time, the resonance in the cab was absolutely unbearable around 70-75mph. But,that was with a Cummins of course, maybe the V-8 in our trucks won't resonate. I will tell you on my '01 with about 8 feet of 4" straight pipe which had only 2 gradual bends, the turbo spooled unbelievably quick. I put a louvered muffler on it with the same exit, took care of the resonance but I couldn't believe how bad it choked the truck down. I switched to a regular old 4" system with a perforated core muffler. Not as good as the original straight pipe for performance, but way better noise wise.
Good Luck!!

If you like it loud on the cab go for it, but if not shy away from it. I know two guys that have straight piped Cummins with exits before the wheels and they are annoyingly loud. You have to holler at each ohter to carry on a conversation.

Thanks for the info. Is a straight piped Cummins even a fair comparison to a straight piped Duramax?

man, i guess no one has any pics available. i've been trying for a couple weeks now without luck. thanks to you all that provided feedback.

later

I tried a staight pipe on my LB7 and it sounded just like a 350 chevy w/ straight headers....loud as hell, so then I decided to custom make my own exhaust since the magnaflow muffler was only $250 and 4' of pipe was only $75. My buddy welded it up for me and I ran mine in front of the rear tires. It was tricky since it can only exit between the leaf springs and frame, but I had it come out at a 45 degree angled back w/ a angle cut on the end. Looked decent and sound resonance wasn't bad...I'd never do it again though. My rim was always black or gold colored from the exhaust and I'm not the type to wash my truck every weekend, so that is a major factor...If you like to wash your truck then go for it. Sorry I don't have any pics for you though...

thanks banchetta, that was the best feadback that i've gotten so far. you may just have changed my mind. exhaust sound is so subjective that you really can't tell until you try it yourself. some people say that their truck wasn't much louder than stock after straight piping it, and your opinion is that it sounds like a small block with open headers. i definately don't want that.

i still think i'll try the straight pipe, but run it over the axle. it will be extremely easy to add a muff later on if i don't like the sound.

Here's kinda what your looking for as far as pictures.

http://www.streetpro.us/PowerMasterPics.html

http://www.streetpro.us/images/DuraMax_Diesel_012_edited.jpg

go to an exhaust shop and have them straight pipe the stock exhast. i got mine done for $70. its a cheap way to see if you like the tone. personally i think it should be way louder. just my thoughts.

thanks Bassin, that gave me an idea of what the side exit looks like from the exterior of the truck, even though it is a dually. at this point, i don't want to chop up the stock system incase i don't like the noise and want to put it back stock. i did some measuring and planning over the weekend, and i know exactly how i will run the pipe.

its going to take:
3' of 4" tubing
2' of 5" tubing
qty 1 4" 90deg elbow
qty 1 3.5"x4" adaptor
qty 1 4"x5" adaptor
i should be able to get that all for under 100$. i'm going to start at the 4 bolt flange and use the adaptor to go from 3.5" into 4". it will then jog down to clear the crossmember and make a 45 deg turn in front of the forward spring hanger towards he side of the truck. a 8" section of 4" tubing to clear the frame, and then the 4"x5" adaptor with a 5" slash cut tip.

Where are you getting 4 inch pipe that is already bent. I can not find anyone local to bend 4 inch pipe.

the only good supplier for mandrel bent elbows that i have found online is http://shop.airflowonline.com (http://shop.airflowonline.com/). my dad gets this stuff for me through his work. the system will not be one continuous pipe. i will piece it together using elbows and straight sections. i only need two 11deg elbows and one 45 deg elbow, which i will cut out of the 90deg elbow. all of this is easily accomplished with a chop saw (old mitre saw with a metal cutting wheel) and a mig welder if you have some fabrication skills.

If you just want to know how loud it is, then just unbolt it in front of the muffler, thats what I did to determine how loud the straight pipe is to the front of the rear tire..of course it might calm down a little if you went to the rear, but you'll have an idea and won't cost you anything...I went w/ a 20" muffler and liked it...was a little too loud for highway and found myself raising my voice to talk to others and had to turn the radio wayyy down when I got to the tolls, I got an exhaust for my new truck and went w/ the 24" HOG performance exhaust... I absolutely love it. Louder than stock, but not too loud and has a nice exhaust note to it...Only cost me $500 for the 304 stainless and comes w/ a 22" x 6" polished tip...

that's not really a fair comparison because all the sound is then dumped under the truck versus being directed to the side and out to open air. the bed acts like a big resonator and some of the sound energy is reflected back up into the cab. it would be quite a bit louder than with a side exit tail pipe. i've already decided to do it because it is not going to cost me much for the parts. if i don't like it, i don't know what i'll do at that point. it depends on how much mileage increases, if any. i'm not that worried about egt's.

banchetta - did you have a side or rear exit tailpipe installed with the 20" muffler?

Side, just like the pic of the dually....It barely fit. I only had enough room to fit it between the flange and where it turns before the rear springs....If you don't care about loudness then get the 16" muffler and that'll make it easier. Of course I wanted to keep the exhaust flange and welded the tailpipe to the muffler so there was only one break on the whole exhaust system like stock....

well, i finished up my side-exit straight pipe last weekend. it turned out really well, and i'm pleased with how it looks. but . . . its alittle too loud for my tastes. i'm not sure what i'm going to do now.

Add a muffler.