to anyone who has made this change,
i have a 2001 ho 6-speed which is stock. i am considering a straight pipe (losing
the cat converter and muffler) and a less restrictive air filter. my question is what will i
can i expect to gain (power and mpg) other than just more noise?
thanks, randy smith

 

Mostly it will lower your EGT's. Thus allowing you to buy bigger injectors to get more fuel, which in turn will give you better power.

 

My truck is stock and I had it straight piped but I just finished putting the muffler back on. Could not stand the noise, it seemed the closer it got to 2000 rpm going down the highway I could not stand it in the cab.

 

I've been straight piped for close to a year now. It not that loud... Very little drone... Straight piped you will notice that EGT are lower, turbo spools faster, and you might just gain about .5 to 1 MPG...

 

ON the tip if you go straight piped but a turn down so the exhaust outlet is pointing towards the pavement and it will sound quieter. They have actually done tests, and if you look at most of the new cars they all do this and this is so they get extra free muffling. I think that a lot of the drone people complain about after straight pipe would be cured by this.

 

i am also considering the straight pipe, because it will be cheaper than a 4inch kit.

 

There is no cat on a 2001. That thing before the muffler is a resonator. It takes the drone out. It is crazy loud straight piped with a heavy load

 

4" straight pipe, turbo back here, and I love it!

Had an MBRP muffler for a week and was way too quiet for me!

 

Straight up 4" turbo back with nothing but pipe and a tip!!! It sounds freakin awesome and wouldn't have it any other way. It was originally a dynomax turbo back system and after about a month of not being able to hear nothing but the motor I decided to kick the muffler to the curb, haven't regreted it since!! Although my neighbors sure don't like it at 4 in the morning They just don't know what COOL is!!