I posted this in 5th gen but got no results, so I'm trying this forum.

I am looking for info on the inner diameters for the exhaust piping on the 2000 (VQ30DE-K), e.g. the ID of the B-pipe, muffler, catalytic converter and the Y-pipe inlets/outlet. I haven't had any luck finding this info via search.

 

Don't know about the DE-K, but I suspect it is not any different than the DE. The inner diameter of the 4th gen b-pipe is about 1.88". I'll have to check my y-pipe at home tonight.

 

IIRC, the cat is a 2.5" flange and the rest of the exhaust is 2" or 2.25"".. at least on the 5th gen.

I've got a stack of 5th gen exhaust gaskets in the garage, but I don't remember which one is which now.

 

gotcha. I'll be upgrading my DE-K to a 2.5" Y-pipe outlet and a 2.5" resonated B-pipe, but with the stock muffler. I'm trying to predict if I'll see any issues (besides it hopefully being close to stock quiet) due to the stock muffler having a smaller size... (e.g. backpressure buildup in the rear piping due to the exhaust cooling down and then hitting the 2.5->2 or 2.25" restriction)
As a side note, I've ordered the Y/B-pipes from WSP, and they won't ship until later this week at the earliest. I'm thinking if I really want to, I could change the B-pipe order...
I called WSP back last Friday inquiring about fitment of the B-pipe, and Lynn (I think that's her name) talked to Dallas and he said the 2.5" resonated B-pipe will bolt up to the stock muffler.

 

2.25" iirc........

 

yeah, they'll bolt up no problems.

I did an install on Mike Hill's 2000 model with a full Cattman 2.5" exhaust, and we ended up putting the stock muffler back on. fits just fine on the cattman. the WSP should as well...

If you're looking for quiet power, I definitely say stay with the factory muffler. the WSP and the Cattman and frankencar are all just too loud if you're not looking for the noise... Of course, that's all relative and there will be 20 people telling me I'm full of ****, but those are my personal experiences. they may think they're not that loud. I heard a full cattman exhaust.. from two blocks away. when Mike backed up to my garage door one day, the pictures on the walls were rattling.

 

Yeah, I like the stock muffler. I bitterly detest the annoying-azz noise I have coming from the cracked muffler pipe right now. I laugh at ricers with loud exhausts all the time, especially around my hometown which appears to be a local center for ricers. Now I know why I hate it. There aren't many things that are more annoying than hearing this constant "hummmmmmmm" noise over your stereo AND road/wind noise which changes with RPM/load/throttle position. I mean, I don't want to announce to the whole world that I just increased my throttle position by 25%... I'd rather keep that to myself

As far as performance... using 2.5" with a 2000 and a stock muffler, should I pretty much expect to see my low-end utterly trashed (especially with the recent addition of the PR CAI including its midpipe, where I've already seen a slight difference)? I'm wondering if using a 2.5" B-pipe rather than 2.25" is a mistake... because I can probably change the order before it ships...

 

Well, not exactly presented in the way I was hoping (an analysis of each pipe's diameter and the effect of changing each one), but the overwhelming suggestion is that 2.5" is the best for 2001, which is identical to the 2000. e.g.: http://forums.maxima.org/showthread....light=2.5+2.25

Catalyst is 2.5", Y-pipe will be 2.5", might as well keep it consistent throughout. I'll stick with the 2.5" setup with stock muffler and see how it runs.

 

yeah, you'll like the 2.5" gains all over the place.

 

Cool. Reassurance is good

 

Question:

Can the stock muffler be adjusted to become 2.5" from a 2.25" inlet?

 

It would be neat if you could cut off the stock muffler's inlet pipe, cut the hole out to 2.5" and have a custom replica pipe made in 2.5" mandrel bent (then welded on)...

too much work for me though