Now that I eliminated the EGR valve on my 97 Cummins (california edition) I want to ditch my Cat but I don't want to have alot of drone in the cab as i drive the truck alot. I am just trying to increase the efficiency of my exhaust as i am adding a #10 plate and a 3k GSK. If I fully Strait pipe the exhaust (eliminate the cat and muffler) is it going to be excessivly loud in the cab at highway speeds. Would i be upset with myself if i leave the muffler in. I live in Idaho so emmissions or the legality of exhaust is not an issue.

 

Do it , I love the sound, but have no idea if it will have a lot of in cab drone.

 

erik, with the mods you are planning IMHO you really should have 4" or bigger exhaust.

They can be had very reasonably. (under $300 if you shop around)

 

if you keep the tailpipe out behind the rear wheel the drone is low. mine is terribel and loud in the cab. it dumps right at the end of the cab. and at hiway speeds it almost unnoticed unless i accelerate

 

i couldn't stand mine when i had it straight piped. about 2100 rpms it just killed my ears. like doc said, with the mods you are planning you should just head straight for the 4" exhaust. i'd do that before your planned mods because the exhaust will help with the added exhaust temps your mods are gonna produce.

 

Thats is a good point....I strait piped mine too (12V) and found that it was a waste of time and effort. The drone was terrible, and it sounded like a tractor (which is ok if your a farmer). Drove its like that for a few months and then went to a 4" with muffler. Its awesome now.


This is an exhaust from one of our sponsors (I just picked one at random) and its pretty hard to beat:

http://www.vulcanperformance.com/ser...minized/Detail


Here it is in SS: http://www.vulcanperformance.com/ser...ainless/Detail

You can get a 5" for a little over $300

 

does anyone have any experience with Vulcan Exhaust. Would there be that much of a reduction in EGT's if i go with the 5in. over the 4in. Is the 4in. adequate.

 

4" is really adequate. You really only NEED a 5" if you are getting over 500 hp....but the 5" DOES look way cool (to me at least).

 

3'in straight pipe is terrible! 4'in straight pipe is awesome! I recommend the Donaldson 10'in resonator. You keep the sound but loose the drone.

 

you got a PN to share with the rest of us????