What is the diameter of the piping on these catbacks? Some say its 2.25 and others say its 2.5, so which one is it?

 

afaik its 2.25 on the obx dunno bout the other..... but 2.25 makes it not worth it to me bc stock is 2.25....

 

not sure about the obx. however, most japanese exhausts run 60mm piping which equals to about 2.3-2.33 inches in diameter. i believe the greddy and apexiws are both 60mm for the maximas.

 

man somebody really needs to make a 2.75 inch full catback for us..... or does someone make it already????????

 

why?

 

bc 2.25 and 2.5 are too restrictive for out 3.0 to breathe properly!

 

No.... Turbo/SC/NOS.... maybe, if not.... NO

 

I love my Apexi WS

Sounds nice and deep...

 

I wish someone had a sound clip of it, i would love to hear it!

 

i have to disagree 2.75 in my opinion is perfect for NA, some of the ppl here are more worried about how loud it will be and what not so smaller piping is better for that, but there is no exhaust for out cars that i know of that will gain more than 5 hp, now with a 2.75-3.0 exhaust i bet the gains would be closer to 10 hp....

 

that isn't true. 2.5 inch pipe will flow 250hp. Bigger isn't always better. Systems that are too large in diameter can actually hurt performance. Improved flow is what you need. We have 4th gen maximas trapping over 100mph on stock exhaust with other mods. piping that big can hurt your low end big time. Ask several of the F/I guys that took their blower off or weren't spraying nitrous and still had 3 inch exhaust, it kills low end. Area under the curve is what makes a car fast, not 1-2 more peak hp at 6600rpm. 2.5 inch is plenty big enough for a 3.0L engine N/A.

 

on my 240sx i had a 3.0 inch cat back on it and it was great, no problems loud yes power delivery was excellent tho, and i dont see how a 3.0 couldnt out flow a 2.4 4 cyl theres no doubt a 2.5 could flow 250 hp, but it could still be restrictive and not AS free flowing as a 2.75 - 3.0 inch cat back

 

I dont think you want anything larger than 2.5" diameter exhaust on a maxima. And i would guess that they are not made for a reason, Read this...

http://www.nissanperformancemag.com/...fthenerds2.php


Highlights from the article...
"Too big of an exhaust pipe causes power loss, especially low-end torque. This is because a big pipe has less exhaust stream velocity than a smaller pipe."

"If the exhaust pipe is too large, the flow will be sluggish with low velocity and the scavenging will not be good. Remember that a good exhaust has low backpressure and high velocity. The only possible exceptions to this rule are for turbocharged or nitrous motors."

I also found this...
"Some basic exhaust pipe diameter guidelines for non-turbo cars are as follows:

1500cc-2000cc motors- 2 inch
2100cc-2500cc motors- 2.25 inch
2600cc-3000cc motors- 2.5 inch"

 

hmm well based on that i guess i am wrong, but still i think we could benefit from 2.75 but theres no way to know huh?