skafia

Alright, my friend just swapped a B16A SiRII into his 97 Hatch. Right now it is running with the stock B16 Exhaust manifold and stock DX exhaust system.

He purchased a JDM 4-1 header and an APEX muffler but he's heard different things about this setup on a B16A motor.

I've heard two setups with the JDM 4-1.

1) JDM 4-1 + straight pipe + 2.25" b pipe + APEX N1 Muffler
2) Stock B16A Manifold + straight pipe + 2.25" B pipe + APEX N1 Muffler

What's the best setup, what setup do you guys run as far as headers/exhaust goes? Let me know ASAP because we're going to a muffler shop tomorrow?

skafia

Anyone?

2000_Civic_Si

JdM header > 2.5" Testpipe > Aftermarket exhaust!

That will do you good.

ciRcuitJerk

id say best bang for your buck....jdm 4-1 or 4-2-1 and apexi n1 with custom piping

eg_nezay

The JDM 4-1headers are designed to give you top end.You actualy lose a lil. power at low rpms but gain it at high rpms.I would recommend you to wait and at least get some cams and a chipped ECU so you can rev higher and feel the difference, otherwise you wont really feel a difference reving at 8k and losing power at lower rpms.
BTW, I recommend 2 1/4 pipping and any aftermarket exhaust(ES muffler)


[Modified by eg_nezay, 9:06 AM 8/9/2002]

EG6-SiR

For street applications i recommend a 4-2-1 aftermarket header...
B16a's are a bit down in the guts department at low revs, so if you're streeting it you probably want as much low-end power as u can get... go with the 4-2-1

Track use? Open header anything or for the weak-hearted, 4-1 with 2.25" exhaust or if you're going for something japanese i believe they prefer 60mm (2.36~") for b16a...

I wouldn't waste time with the jdm4-1... it ain't pretty and there are so many better headers around than that...

Personally i run a Fujitsubo 4-2-1 header on my eg6, with rsr 60mm exhaust piping, cat free, one rsr resonator, with a J's Racing muffler...

Personally wouldn't recommend that system unless your area doesn't have a decibel limit for exhaust... :D

But yeah... street, go 4-2-1 if you like your bottom end with ~60mm exhaust piping and your choice of muffler.

skafia

Even with a B18C5 do you guys recommend 2.5" or 2.25" piping?

KoRn_vIRuZ

I want to know that too. Is there a way to optimize the piping diameter from horsepower/torque figures?

Doctor CorteZ

a good exhaust needs to maintain constant velocity

jdm 4-1 , hi-flow cat (94006) and 2.5 catback or custom

just make sure its mandrel bent , crush bends suck

nwdave

Huh? There was a noticeable difference in power when I replaced my exhaust system. I used a DC JDM ITR header and 2.5" piping all the way back (2.5" cat too) and there was nice gain in top end power.

I think the answer for this question would depend on what the plans for the B16 are. I'm going with cams in the future so I wanted a large enough exhaust to support them...I might lose some power now but I didn't want to redo my system twice. If I/H/E is all that is planned, then I think a USDM 4-1 (DC 4-1 for instance) and 2.25" exhaust would be fine. I don't think a 4-2-1 header would be necessary. If you want to go fast in a B16, you don't floor it at 3000 rpm. The whole point is to make power up top, and that's what a 4-1 header is good for. Trying to get torque out of a B16 is kinda pointless IMHO.

skafia

delsolguy, thanks for the response... I totally agree with you. You gotta REV hard to make power anyway!

nwdave

No problem. I hope you get your exhaust issues straightened out...

Solo2Vtec

JG Edelbrock with a 2 1/2 collector will be your best bet. You also need 2 1/2 exhaust. The b16a needs to breath to make power.

nwdave

I wasn't aware that there was a JG Edelbrock header with a 2.5" collector. Is it made for the ITR or something?

skafia

I know it needs to breath to make power but wouldn't you want a little bit of back pressure (2.25") because of the small displacement?

Doctor CorteZ

I know import builders mods the JG header , but I didnt think it was a 2.5" collector

hybrider

best bang for buck on the header test were the dc and itr 4-1's, keep in mind though, as you become more modified, the bigger daddy peices such as toda,mugen,etc really show their cost becoming effective.......

i say go for the itr 4-1 with a nice 2.5 carsound cat, and from their 2.25 or 2.5 pipin will do just fine....

skafia

No cat is going to be used. No way of being legal anyway.