Looking for some opinions on my up coming exhaust purchase for my '01 SC. I already know I'm going with a Ravin R33 (Yep, minds made up, no opinions needed there). Question is do I go with 2 1/2" (stock diameter, right?) dual or 3" single (3" from cat back)?

 

3" is too big. Why would you want to make it bigger than 2 1/2"!!?? You only go bigger if you have made enough modifications to the engine to where a 2 1/2" pipe is no longer enough. And there would have to be some major mods to accomadate a 3" pipe being ran all the way back. 2 1/2" is plenty big enough. There is a huge difference between a 2 1/2" pipe and a 3" pipe. You lose way too much back pressure.

 

This is only my experience with it and all I can tell you about is my "before" and "after" Seat 'O' the Pants impressions......

"Before" was the stock setup with the tiny P235/70/16 tires that were bald BTW.... On dry pavement, it would barely get a scratch out of them. Got some new tires, P255/70/16. No scratch at all, but the wet traction was much improved!

"After", I got a K&N drop in filter and a Gibson Swept Side 3" exhaust (the only pipe that's 3" is the tailpipe). I was able to get a little bit of a scratch out the the new 255's with just those two additions..... I then got some 265/75/16 tires because the 255's were still too small...... After getting VSS gear changed to make the speedo correct, it still was able to get a scratch out of those big 265's....

Started towing a #4500 travel trailer.... Had pretty good performance, but downshifted into second a lot on the hills. I never did tow with the stock setup, so I can't really say how well it would have done..... After a year of towing, the Gibson started to rattle, so I got it replaced with a Flo-Pro muffler. Still used the same tail pipe. Wow, I noticed a big difference in the low end right away. On hills that normally caused a downshift, I was now able to stay in third gear. Same deal while towing the trailer.... Going over the same route that I had gone before, the hills that caused a downshift before I was able to stay in third. I felt a lot more throttle response too.

Oh, and now with 140,000 + miles on it and another new set of 265 tires, it will still get a scratch out of them on dry pavement... However, I don't try it very much anymore....... I'm getting too old to care and tires are getting too expensive!!

Anyway, going to a single 3" should not kill your low end. The type of muffler seems to make a difference that way too..... I would not go to dual 2.5" pipe however..... That might open it up too much for the low end side..... Folks here tend to get 2.25" for the duals and run 3" or larger tips......

Your milage may vary!!

Good luck!

Mitch

 

2 1/4 for duel and 3" for single is my advise

 

The pre-engineered single cat backs that I've seen are 3". I recommend a single exhaust system over duals on a heavy vehicle with small displacement.

 

hi,ive had two trucks(1999 f150 with 4.6 ) and 2001 chev with(5.3 auto) and went with the raven 3" in and out with a single kickdown and had NO PROBLEMS at all with either one.but awsome sound.and i am waiting for my shop to get my mufler in for my 04 f150 to put the same thing on it.

 

I'll echo that..

2.5" for duals, 3" single.

The SI/SO would be better.

 

3" SI/SO it is! Scheduled for install next week at Randys exhaust in Marysville, WA. Any locals have any feedback on his shop? He's about 100 bucks less than Midas.

 

for the 4.6L use 2.25" pipe and on the 5.4L use 2.5" pipe if ur going to run true duals. true duals will have the greatest performance. but if u want a single exhaust pipe 3" is fine for both the 5.4 and 4.6L

 

3"s is not too big! It's not about performance it's aesthetics....IMO. Whatever size pipe comes from the headers into the cats is the primary factor concerning performance...whatever follows is of no consequence.

 

I pu i n a Magnaflow Catback and I have a friend that has the dual exhaust and he does not like it. He says he has lost some torque for some reason ever since he installed it, and it has gotten so loud he has to crank the stereo.

 

i went with 2.5" true duals and love it, sounds wicked

 

You couldn't possible be more incorrect with this statement. Try doing some research before you start advising others on how to make performance.

Everything single component of the exhaust system has a direct affect on the amount of air flow the system will produce.

I would challenge you to provide some creditable proof to support your statement.

 

Lets say you have 2 1/4 pipe directly after the headers going into the cats...it's going to flow whatever that diameter pipe can handle. Just because you put a larger pipe lets say 3"'s after the cats that dosen't give you better flow of exhaust gases do to the fact you can't overcome the limitations of the preceeding 2 1/4 pipe and it's bends. Magnaflow and other exhaust manufactures achieve better flow over stock because of their mufflers and mandrel bending techniques. Maybe this is a better analogy for you too chew on........water flows through a 1" pipe at 20 GPM further down the line the pipe widens to 2". Does the flow of water increase....NO it's still 20GPM however the pressure decreased inside of the 2" pipe. Pressure and flow are not the same. Pressure could be equated to exhaust back-pressure and decreasing back-pressure too much in an exhaust system will decrease your bottom end, HP and overall performance.

You know Dawg there's a way to ask questions, make statements and debate ones opinions or facts.....and I have to say your way off the mark and as ignorant as I care to see again on this forum. Don't ask for my "credible proof" WITHOUT providing me or others with the same. You have NO idea what my qualifications or backround is outside of what I cared to list apon registration and I won't discuss or debate this point with you any further....consider yourself squelched and a non-person in my world. Reply if ya want but I ASSure you I won't be wasting my time reading your reply.

For your reading pleasure:http://www.magnaflow.com/07techtips/faq/question10.asp