i don't know what you've been reading...headers have been proven time and time again to put out decent power on the VQ.....maybe not as great as some people would like (like expecting 30rwhp from them, lmao ) but hella lot more than 3-5

 

if you're looking for a more pronounced exhaust note on a budget that will be noticeable on WOT- but not constantly crank in the interior, I would start with the cat. if you're looking for a incremental and complete approach to getting good hp from NA- start at the top- CAI, plenum, header (headers in combo with a cat usually will be pronounced inside & out), resonators and finally a cat. each should get gains by itself or in nearly any combo- but no individual component by itself will get you over 15 rwhp on a g like on some other VQ iterations.

 

ricer math...intake 10hp, plenum 15, headers 17, cats 20, y pipe 8, exhaust 10-15.
10 + 15 + 17 + 20+ 8 + 10
almost 80 WHP!! DAMNNNN mang

 

btw, headers are good for atlesat 40!!!!!

 

haha i wish they were...if only hp #'s really worked like that

 

If I could net 15 hp from test pipes and the skunk 2 plenum spacer, I would be happy. I am looking for a Z tube or Nismo V2 but havent decided which route to go yet. Anyone have one?

Oh yea ignore my previos post where I said the GReddy was true dual, because I just found out that it is not. Anyone know the GReddy pipe diameter where it merges after the y?

BTW I found the skunk 2 spacer for $169 here:

http://shopping.lightningmotorsports...cat=592&page=1

 

keep in mind teh horrible quality of skunk2

 

I have test pipes (non-resonated) on my G with stock exhaust and love them. Much lower growl at low and cruising RPM's. The only rasp is from about 3500-4200 when you're in the gas hard, or in the morning after startup. It is kinda raspy throughout the RPM band after starting it up, but it goes away once it gets warmed up.

My next exhaust mod will probably be a Y-pipe, unless I can go full dual.

The test pipe install was easy. The hardest part is the fact that the bolts are rusted...hitting them with PB Blaster first and letting them sit will loosen up the rust and make it go quick.

 

Yea, thanks I already bought it. I liked the Skunk 2 because it is made of glass filled nylon, which will conduct much less heat into the upper half of the plenum than the aluminum spacers. It is also the tallest spacer at 5/8", and since I already would have to lose the engine cover with an MD 1/2", what could the extra 1/8" hurt? The only bad thing I have heard is about the bolts, but for $169, I can buy all new bolts if I need to and still be cheaper than an MD spacer. Skunk 2 also has a pretty good rep with the Honda community so I wasn't too concerned. I guess I will find out soon enough.

 

skunk2 has had very bad reviews in our community, but hopefully you wont have a bad experience with them. you could get a MD 5/16 for about 230 which isnt bad at all..
as for the Greddy exhaust. it has a y-pipe but right after the pipe it splits into a dual again...

 

The original question was restrictive contraints on hp, so my response is completely ignoring a different desired sound........

I don't think these cars have a big enough motor to benefit a whole lot from some of these aftermarket products. Aftermarket cats, headers, cat-backs, etc. The reason Stillen catbacks are dynoing low hp #'s, and the reason that headers are showing relatively low gains is simple.

My answer is intake. Look at the diameter of our MAF and TB. Sure plenum spacer does a little. But you could put an open 4" exhaust with a before the axle dump, like I had on my Camaro that I raced, and you wouldn't gain a thing. In fact, I proved that with the Camaro. Kept putting on bigger "things" from the exhaust manifold back, and quickly realized there was no gain to be had.

Now, for the nitrous and FI guys, that's a different game. But I really think people spend a lot of money on popular mods without looking at the whole picture. Until these cars get a vendor that can make a better TB, MAF, intake manifold, and tuning to make it work, there's only so much you can do. And the $/hp ratio will be very high until then.

 

214/2= 107 * 6000rpm= 642,000/1728= 371.5 * 0.82[+-] = 305 CFM

As you said not a lot of air/exhaust flow. Modern enginees design individual components to not impede flows by more than 1% [the entire intake tract is less than 28" wc or 1psi or 6.8% [most of which comes from MAF and throttle plate {TB}] really tough to find 1-2% improvements no matter what you spend!

 

Been a while since I've had to crunch the #'s, but thanks for the supporting data!!

 

You don't have to crunch numbers a 1.2-1.25 SCFM per HP.......the key is the S in SCFM...............60-70F and 29.92"Hg barometric pressure. Otherwise you must correct.........exhaust is hot but mass in = mass out.