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3" or 4" exhaust?

1995Chevy3500

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1995Chevy3500 Enthusiast

1995Chevy3500

Posted
Posted

I have a stock 6.5 diesel, 1995 3500 HD series...Im looking for my hp/tq and im not sure what to go with, 3" or 4" exhaust....it will be straight pipe,muffler,then the end tail pipe. I will not be running ANY other mods on this truck whatsoever.....just want a lil more power....The muffler fell off anyway,so replacing is in order no matter what. Any ideas???

F117ewo Enthusiast

F117ewo

Posted
Posted

I am running a 3" Banks downpipe to a 4" BD cat-back exhaust. You can't go wrong with the 4" exhaust pipe. The difference from stock was so good that even my wife noticed how much it had improved. The cost difference should be minimal, so go with the bigger pipe. You won't regret it.

 

Jake

96 K2500 6.5TD

Cranky1 Enthusiast

Cranky1

Posted
Posted

On my 6.5 TDI I first did the exhaust off the Y pipe, I had 4" pipe to a Magnaflow muffler with dual 3" pipes exiting out the side. This made a big difference in power.

 

About 6 months later, the 2nd exhaust work I did was the 4" down pipe, the difference was massive! I think the stock down pipe is 2 1/2" with a crease in it that would restrict it to 1 1/2". It had a nice rumble at an idle, when putting your foot into it you will here the turbo spool up... Sounds really nice..

1995Chevy3500 Enthusiast

1995Chevy3500

Posted
  • Author
Posted
On my 6.5 TDI I first did the exhaust off the Y pipe, I had 4" pipe to a Magnaflow muffler with dual 3" pipes exiting out the side. This made a big difference in power.

 

About 6 months later, the 2nd exhaust work I did was the 4" down pipe, the difference was massive! I think the stock down pipe is 2 1/2" with a crease in it that would restrict it to 1 1/2". It had a nice rumble at an idle, when putting your foot into it you will here the turbo spool up... Sounds really nice..

 

 

 

 

 

Ok, im starting to feel torn on what to do. I have a 95 chevy 3500hd flat bed tow truck, its a ramp truck. So im a little heavier than you guys as far as weight, so obviously im feeling a little more underpowered than you guys. I do have a manual 5 speed which helps but ......help me decide

 

* I need RELIABILITY more than anything,so if I only need a bit more power,then im ok with that

 

* I would like an exhaust to help optimize my gas mileage

 

* I dont really want a loud exhaust, I dont mind a loud turbo tho!!!

 

* Where do I find this 4" downpipe if I decided I wanted to go that route?

 

* Is there a muffler that can honestly keep it somewhat quiet with a 4" pipe?

 

 

 

Ok so right now im running stock 2.5 exhaust, my muffler fell off, so its straight pipe to about where a normal trucks rear axle would be. Its right about at the level of loudness that I could with stand if anyones ever heard it....lol Any answers would be greatly appreciated.....

Thanks

1995Chevy3500 Enthusiast

1995Chevy3500

Posted
  • Author
Posted

Ok, I actually got under my truck, its parked at my bros....but anyhow,I was over there and I thought, let me take a look at whats really going on....well what I saw was a 3" downpipe and after that, some moron put a 2.5"pipe to a 2.5" stock style muffler and 2.5 the rest of the way out the back.....lol...how could you choke down the diesel like that!!! It doesnt make sense, but anyhow,the pipe looked pretty darn new,specially after driving her home 2500 miles...so some moron really thought long and hard about that exhaust setup, probably why it fell off in utah coming home from Tennesse....

 

I think im gonna go with a step exhaust, 3" downpipe to a 3.5" pipe to a 4" muffler to 4"s the rest of the way out and see what happens...gotta be better than choking it with a 2.5" pipe...

  • 2 months later...
FH-Leader Enthusiast

FH-Leader

Posted
Posted

ok so you whant a real fuel saver. put a 5'' on it the diesel needs room to breath. then go spend 370$ on a k&n air intake system and you will add power and be geting better fuel milage out of it.

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