AUTOGON350

iTrader: (8)

Ok. How neccessary is this stupid 3.5in catback that I bought? I have been trying for months to find a way to install this thing without having to ristrict pipe diameters to 2.25 or single 3in y-pipes. Isnt it a waste to have a 3.5in system with a 3in cat and y-pipe? Im beginning to think that some hooker 2055's and a single 3in high flow cat and catback might be money better spent.

I am just pissed because I bought the mufflex 3 billion dollar 3.5in catback and I just dont want to restrict any part of the system to 3in unless enough of you guys say "yeah Im running 12's with single 3".

Is this 3.5in overkill for 350-400hp street applications?
any suggestions? or dual cat 2.5in y-pipe companies I dont know about?

ksrammstein

I would recomend going with the Hooker 2055 headers and their Y pipe for it. I believe it is the biggest Y pipe out there, other than custom made. I think you should be okay. Just get a reducer for after the cat.

AUTOGON350

iTrader: (8)

that was the biggest diameter y-pipe I could find. Im just wondering if its worth keeping the 3.5in. I could sell that 3.5 catback and my 2 cats and probably get enough money to buy the headers and a 3in catback. I just dont know if my application requires that 3.5in.
Thanks for the reply.

CrazyHawaiian

Are you using the Mufflex Y-pipe? I asked about it once but was scolded for not doing a search on a company I didnt know existed. Mufflex also has a 4" system and I think they also make a bigger Y-pipe. I'm gonna do SLP 1 3/4ths" headers and Mufflex 4" system with Mufflex Y-Pipe on my 91 Z.

Akshay

Here's my take on exhaust piping.

Exhaust gas flows better in smaller pipes than in bigger pipes.

This is because smaller pipes keep gasses hotter and lighter (also reducing weight). So hot gasses flow better than cooler gasses.

Bigger pipes create cooler gasses, which adds weight to an already heavy pipe, which slows down flow, which creates backpressure.

For dual exhaust, If you're using a straight-thru muffler, I would say use the same diameter pipes as muffler's inlet.

If you decide to use Flowmasters-type (chambered muffers), then go with 3" piping.

AUTOGON350

iTrader: (8)

[QUOTE]Originally posted by CrazyHawaiian
[B]Are you using the Mufflex Y-pipe?
No I am not using the mufflex y-pipe cause it is only for long tubes as far as I know.

That makes sense about the pipe diameter and temp relationship. That must be why so many companies offer such small diameters on thier Y-pipes.