B16A Exhaust: 2.38" vs 2.5"

[sifoo]

Hi All,

This is prob THE most confusing/misled/opinionated topic regarding n/a tuning.
Now before you tell me to search, I have, and all topics I have read have been highly opinionated with no actual data.

Tossing up between a 2.38" (60mm) Spoon B-pipe vs a custom 2.5" B-pipe

Plans for my B16a:

CAI
TODA Cam gears
TODA header
2.5" High Flow Cat.
Spoon N1 axle back
Hondata s300

I know this is a fairly light tune but I mainly want to increase mid - top end power

People have told me to match the header collector size (2.5") to the B-pipe, and others say 2.5" will totally **** my torque curve. I was hoping the s300 tuning would solve this???

Does anyone have any before and after dyno graphs regarding 2.5" exhausts for the b16a?

Maybe the real tuners here like Adrian from TODA or Dyno Dave can chime in.

PLEASE if you dont know what your talking about - then do not contribute. Ive heard enough BS as it is :rolleyes:

Your help is appreciated. :)

[DynoDave]

I have only found a loss in power when using a 2.5" if the car was using the STD ECU and no CAI.The power difference in a STD engine between 2.25" and 2.5" will be next to nothing once tuned but if you do further engine mods down the track the 2.5" will give you better results.
Regards Dyno Dave

[Civic Type R]

Whats best for a JDM B18cR?
Currently im using the existing 2.25 cat back that i had mated to the old B16A2. Would i be better upgrading to the 2.5" Dave ?

[VT3C]

well I'm not dyno dave or anything but if it makes you think my opinion is more valid if I have a trendy tech-related name, you can call me "B16 Bede"... ;)

For your mods listed i'd go with the 2.38" as IMO it's perfect diameter for bolt-on mods to a B16A. I've found 2.25 to be too restrictive even on a stock B16A, where in comparo my current 2.5" system is GREAT for mid and top-end but prob looses a little torque down low.. but man who cares about sub-3000RPM zone ? I sure dont.

For adam's and other wild and type R set-ups i'd definately say go for 2.5".
Adam especially, you have prob 10 ponies hiding in your exhaust system.. no shit !!was fime for your B16A but for the monster in there now - give her a chance to blast out the exhaust a bit better.. basically headwork, cams etc will free up the intake side of breathing, but if u can get more air out, you can get more in.. also u might want to consider a straight-thru muffler for more top-end power.

[DynoDave]

Whats best for a JDM B18cR?
Currently im using the existing 2.25 cat back that i had mated to the old B16A2. Would i be better upgrading to the 2.5" Dave ?
From now on I will refer everyone to B16 Bede he writes with such passion and is very accurate in his answer's :p
Regards Dyno Dave

[sifoo]

thanks dyno dave!

[Dxs]

Just wondering if a jap exhaust with 60mm piping would be suitable for a stock b16a1 that only has headers and intake panel filter?

or would i lose torque?

[panda[cRx]]

60mm will be perfect mate, good size for the b16a.

[Dxs]

can anyone else confirm?

[kyle]

Ill let you know how I go with my 60mm BuddyClub catback coming this week.