straight pipe or muffler

[dmaxmathis]

I am buying an exaust, i have been looking at the mbrp exhaust sysyems, getting a turbo down pipe and full turbo back system. Is it better for a dmax to get a 4" or 5" exhaust and then is it better to straight pipe it or get the muffler with it. I have heard that it needs backpressure and i have heard that it doesnt need backpressure to run better. What do u guys think, 4" or 5"? and muffler or straight pipe?..thanks

 

[lotsofmiles]

straight pipe it!!!!!

 

[LBZ]

Straight pipe 4" from the downpipe back.

 

[Kat]

X3 Moved here :thumb:

 

[SgtKilroy]

4" straight pipe

 

[TeaBagger2006]

If it's a Lly or newer straight pipe it with 4" and if it's older lb7 throw a muffler on her

 

[JoshH]

I've always had a straight pipe 5" on my truck, and I always thought it sounded good. I have also had twins on my truck for the past 20k miles, and I just recently put a stock motor back on with a single stock turbo. After going back to a single, the exhaust sounded kind of loud cruising at 70 MPH (the extra turbo on the twins acts as a muffler). I threw a muffler on it, and I think it sounds a lot better. It is still loud when I get on it, but it kind of toned it down under cruising conditions. Sounds a little more mellow to me too.

 

[whitetrash21]

Straight

 

[hondarider552]

4" donaldson :thumb:

 

[LBZ]

If it's a Lly or newer straight pipe it with 4" and if it's older lb7 throw a muffler on her

Why??

I will say if you go to a larger turbo your going to want a muffler. After putting my S464 on, I had to install a muffler as it was way to gay-sounded like a set of blue bottles on an '85 Ford farm truck!!

 

[coldLBZ]

Straight :thumb:

 

[Tayler]

I have a 5 inch straight on an LLY. I would go with straight pipe with either 4 or 5 inch. I think the 5 inch gives a deeper tone to the exhaust, but that might just be my opinion.

 

[dmaxmathis]

thanks guys..its a 2007 new body style, i want it loud but dont want it so loud that it gets on my nerves cruising down the road and i will prolly stay with stock everything.. all im going for is intake, exhaust, chip, lift, wheels and tires, whats a good intake for it?

 

[sha4910]

no muffler

can I just take my muffler out and run my duramax without tuners? will it hurt the truck in anyway or is it safe ?

 

[sha4910]

and how do I get the whistling sound of my turbo? ive never heard it whistle

 

[fast03]

what year truck?

 

[cdbright]

i ran 5" on my 08 LMM, same engine you have and it was awesome. I had the MBRP muffler on it just so i could creep through town and not keep the neighborhood up at night , but when you are on it you would swear the muffler is not even there. My new 09 truck came with 4" Gibson, but i may change it to the 5" just cause it does seem to sound a little deeper, i think louder the better:woott::woott:

 

[sha4910]

engine light

hey guys I got another question.. I just took my air box cover and tube off and revedthe truck a few times. now the engine light is on.. y would that happen? I have a 03 gmc duramax 2500hd

 

[cdbright]

the MAF sensor is not picking up the air flow since it is prob laying next to the cover you removed

 

[sha4910]

does that damaged anything or does it just leave the annoying engine light on ?