Ok-So basically my setup consists of nismo headers, mrev2, 5/16 spacer. As of now, I do not plan on getting a full exhaust system, but I have recently acquired a nismo y-pipe.

I know that there is a bottleneck issue of airflow if I use the nismo w/ the stock mid-pipe back, b/c the connection to the midpipe is 3 in. instead of 2.5. But, given this, would it still be beneficial to have the nismo y-pipe instead of stock for my current setup?

In other words, will the change in airflow w/ the nismo y-pipe completely cancel out any gains it might otherwise achieve (or will there still be some minimal gain).

Since I already have the nismo y-pipe, I want to put it on (Even if only minimal gains), but not if it will result in a performance decrease or adverse effects.

What do you all think?

 

search. its been discussed many times. ypipes generally do nothing, and tend to hamper performance.

 

^^I did search, but did not find a definite answer on whether installing an aftermarket y-pipe w/ stock from the y-pipe back will result in WORSE performance than the stock y-pipe. Does "tend to hamper performance" means worse performance installed than not installed, or minimim gains/no difference?

 

The consensus seems to be that when running headers & cats an aftermarket Y-pipe will cause a significant loss in low-RPM TQ. After my headers/cats, I'm a little more inclined to believe it. Of course, I'm sure there are those running headers, cats, Y-pipe and aftermarket rear-section that might not agree.

But if you'd like to try, I still have my *new* NISMO Y-pipe that I never installed. At this point, I'd be willing to work a real good deal for anyone interested in it.

FWIW, I would have installed it if I hadn't changed to the Crawford cats.

 

bumpy bump

 

Sorry man, just read it again.

You can get a reducer cone to taper the transition. Dr. Gas was where I got the one I was going to use with the Y-pipe. It's about 6 inches long, so the transition is smooth. He made a big run a long while back, but he might have some remaining. Otherwise, a muffler shop can get something together for you.