With the new hp box out (TST and soon to be released Edge) is an aftermarket 4" exhaust still a good option or is a 5" exhaust a better option?

 

Does the 1" larger diameter translate into a different exhaust note on otherwise similar systems?

 

you will have less air velocity with the smaller pipe therefore likely less of a note sound.

JT

 

[quote author=jt link=board=49;threadid=24107;start=0#msg227953 date=1072144393]
you will have less air velocity with the smaller pipe therefore likely less of a note sound.

JT
[/quote]

Think you have that backwards, you have more velocity with smaller pipe. Don't know about the sound

 

oops yes You are right thats what I mean't.

JT

 

[quote author=jt link=board=49;threadid=24107;start=0#msg228361 date=1072219495]
oops yes You are right thats what I mean't.

JT
[/quote]

I knew it had to be

One nice thing about the diesel world is that you don't need to worry about the velocity thing really. In the gas world bigger isn't alway better, have to worry about the scavenging thing and try and get the best of both worlds. :-

 

I also own a 71 firbird which will eventually need a new exhaust. In the pontiac forums, people talk about putting a 3" exhaust pipe after the headers and 2 1/2 after the crossover or the muffler. This is done for the scavenging effect.

I read in the earlier post how diesels doesn't really need the scavenging effect. Why does the stock exhaust go from a 3 1/2 to a 4"? Would seem to be more efficient going from a 5 inch near the turbo to a 4 inch at the end.

I am sure this has been discussed before but I cound't find anything about this.

 

RamRat,

Like the memebers said stay with 4 inch unless you're going over 500 RWHP. Check our site and see what is available, we even have dual systems if you want the dual 5 inch tip look from the rear! It really confuses the rice burners too when you nail it near them and they hear the sound exiting from both sides!!!

Mark @ DPPI

 

Forced induction systems have different needs/requirements than NA systems.

Our 4" exh is only the tailpipe (from behind the muffler and back). Probably some performance effect from it, but mostly appearance. Would a full 4" be better? I think so, but it would have cost DC more to put it on in the first place. The good news is that 4" comes standard on the new 600.