www.neons.org

I often wondered how a 3" exhaust would work in a big cam N/A setup. Found this browsing honda tech...
http://www.honda-tech.com/showthread.php?t=2341715

I would think this wouldn't apply to mild n/a motors. So no bolting one on your sohc with a pacesetter header and an iceman

sounds about right.

i ran 3" on a bunch of my 2.0 and 2.4 setups for a few years.

i never saw a lack of torque or power b/c my exhaust was too big.

it's been proven that open header makes best power on cammed n/a setups.
the exhaust is only a way of having the exhaust leave the rear of the car, being street legal'ish, adding weight, and reducing sound.
you'll never make more power through a full exhaust compared to a correctly designed open header setup.

I found the 3" was also the best (212whp 169tq Dyno Dynamics). I forget the power gain from 2.5" to 3".

And as stated previously, open header will get you more (but I need an exhaust for "street nights" at the track).

MB

I just wished I had found this before I bought all my exhaust stuff

just put a cut-out after the header.

3" exhaust is quite heavy.

exactly what i was gonna say.

the difference is hardly worth selling what you have and upgrading.

if starting from scratch, yeah why not. but he only gained what? 9WHP?


i just use a cutout.

I can't find the article, but I read one a while ago about tuning with the diameter of the exhaust piping after the collector. I don't think it's a matter of eliminating a restriction as it is a matter of tuning, just like with primary diameter.

Perhaps someone has the article, a link to it, or at least remembers more than I do about it.

If you aren't running a header with a good collector, or if you're running a cat I'm not sure how big of gains you will see.

anyone have any vids of these setups running 3"?

for something thats gonna see the track somewhat regularly i would agree, but for someone like me who hardly ever goes to the track (why when i have the interstate to myself at 4am 5 days a week), 9 or even 5 WHP i could really enjoy. and the guy in the honda forum made a good point, the 3" sounds MUCH better.


however, an electronic cutout wired to a throttle switch to come on just before WOT, that would be fun... pull up next to the ricer and drop the hammer:grin:

this is the only video i have of my car moving with 3"

http://videos.streetfire.net/video/1999 ... _29697.htm

like the idea of having 3" exhaust. bur will it be too much with a long tube header, larger tb, afx race cpu, crane 14, and locked open short runner intake on a 01 rt sohc. im about to install the cam and the long tube header, and i was going to do 2.5" but will 3" be better in higher rpms around 5k to 7800.

lol at the comments...nice run dave, what all mods you have in that run.

2.4 with crane 22's, gobs of bolt-ons, 200+ whp.
that was the first day the track was open for the year, traction was quite limited.

baby launches, baby 1-2 shift, and still trapped high 101's.

was that a 14.17 run? couldnt quite see it in the video , cam moved to fast.
yea traction owned you, still nice run nonetheless.