I just want to get some feed back on anyone with a five inch exhaust installed on their rig. I'm thinking about getting the SUMMIT RACING 5". It's turbo back, 4" off the trubo down to 5" all the way out. It's all aluminized..rather be stainless...but the price is pretty hard to beat. Do the DMAX's need a certain amount of backpressure??? If so, does the 5" affect that?

Thanks all!
J-HEFF

http://dieselplace.com/forum/showthread.php?t=19999&highlight=jegs ...This started about the Jegs, but contains some info on the Summit 5"

You have a turbo and need no backpressure. Actually you want as little as possible. the 5" tail pipe probably dosnt help perf anymore than a 4" but it looks and sounds better. I have a system simmilar to what you describe and like it. I yanked my muffler too. She sounds gooooood

I have the same system as ratlover. John Kennedy's 4" to muffler and 5" the rest of the way out. Unlike ratlover, I have not performed the mufflerectomy...YET!!!

MaxRock

I have the DPPI 5 inch system, no complaints!!

:iamwithst

DPPI 5 incher here too. Straight pipe is LOUD:ro) My only complaint is the tailpipe could have been bent a little better, it was a ***** to get lined up. But I would do it again.

Thanks guys for the imput. DId anyone noticed EGT drops from 4 to 5 inch? Or is it too little to notice?

I just installed the Summit 5" system. I installed the muffler instead of straight piping it. I was afraid the straight pipe would make it sound like a jet plane all the time. So far I'm happy with the sound. It has a nice turbo whistle/deep throaty rumble to it.

Are there any issues as far as noise ordinances (sp?) when you straight pipe a turbo diesel? I think I heard somewhere that they feel that the turbo quiets the exahust noise enough?

Sure there are noise ordinances, it depends on what city you're in. The turbo does quite the exhaust down alot! My truck is loud but it's not as loud as my '01 8.1 gasser with 3" duals and with cats. Loud diesels make a low rumble/roar instead of the (sometimes obnoxious) kackling noise of a gasser with glasspacks that are burnt out.

Alot of it depends on how you drive though. Drive like an idiot and you're gonna get attention from the fuzz, neighbors. Drive normal when you in residential areas and I don't think you'll have a problem.

Has anybody figured out if 6" will fit all or most of the way for an exhaust? I wanna go sort of different if I could.

I have the 5 and I think you will find its plentiful, trust me on that one.

Has anyone driven through a tunnel with their straight 5 inch? I did the other day let me tell you it rocks :ro)

To re ask this ? Has anyone gone from a 4" to a 5" was there a EGT reduction between the 2? Do you assume there would be a EGT reduction? I pulled my 03 Z71 on the gooseneck the other day about 35 miles through the hills of WV and the EGTS where way up there I had plenty of RPM left but kept having to back out of it cause the EGTS were getting way to high IMO. I am still running stock exhaust right now and the Pred was on the 40 tune do you guys think a 5" would be any better than a 4" in these circumstances? I know I asked the same ? about 3 times in this post I am just curious before I lat down more $$$$$ I really wanted Stainless because of the weather but the summit 5" is only in aluminized. Decisions Decisions

To re ask this ? Has anyone gone from a 4" to a 5" was there a EGT reduction between the 2? Do you assume there would be a EGT reduction? I pulled my 03 Z71 on the gooseneck the other day about 35 miles through the hills of WV and the EGTS where way up there I had plenty of RPM left but kept having to back out of it cause the EGTS were getting way to high IMO. I am still running stock exhaust right now and the Pred was on the 40 tune do you guys think a 5" would be any better than a 4" in these circumstances? I know I asked the same ? about 3 times in this post I am just curious before I lat down more $$$$$ I really wanted Stainless because of the weather but the summit 5" is only in aluminized. Decisions DecisionsSometimes if your EGT's are higher than you are comfortable with, Floor it to force a downshift and they will usually drop, especially with a "tuned" motor.
On edit: I don't think there would be any difference in a 4 or a 5 in pipe. I think John Kennedy has a stainless 4 to 5 exh. He would know for sure if there is any diff in EGT's as well.

I notice about 200 deg drop from stock to the 5 inch, but I only had my truck for about 2 weeks before I made the switch. Hopefully someone that has had more time to watch will chime in.

How has the aluminized stainless held up in winter conditions anybody? I know I'd be paying alot but if I could get something that would hold up to Ohio weather and still look o.k. What happened to that one guy that posted about he thinks he saw 6" on a Duramax in a parking lot or something? I wanna know if it wolud fit, I know five would be enough but just curiously wanna know.

I just noticed I said aluminized stainless. I meant aluminized 5".

Someone on here has dual 5`s with 6" ends. I think it is Blueox, but not sure.

:ro) here in texas the only way you can get a noise violation with your truck is if you are stupid and drive around racking your truck out. with normal driving even the loudest trucks are still legally noise safe? don't worry about sound unless you plan on bing dumb because they will pull you over trust me i had a powerstroke with a 5" straight piped before my d max

Just bringing this back up to see if anybody has figured out if six inch exhaust will fit under the truck? If it can I want it done to mine.

It would fit but I don't recommend it. The pipe allready goes under one of the crossmembers. Five inch hangs down low enough. Not to mention that snaking it around the shock, spare tire, and mudflaps (if you have) is tough enough with the five inch. If you want to be different stay with the five incher - how many guys are running five inch anyway? 95% of the guys on here seem to run 4" mbrp.

There is alot of Dodge and others running 5" around where I live. All from flex pipe to whatever. I wonder if I could have 5" up so far and then run 6" up over axle and out. Or just go with good rust free 5" w/ 6" tip

Like I said, it'll be tight to go up and over the axle, around the shock, miss the spare tire, clear the leaf spring and end up behind the rear tire. My five inch is touching the spare, I had to modify my mud flap to clear it. If you want to be original put dual 6" side pipes on it - that'd be cool. Just buy stock in a car wash to get all the soot off your truck. I had to put a chrome turndown on mine because in one week the entire rear quarter-panel was BLACK!