new exhaust setup... pls help...confused

[rocky_b]

hey guys!

i finally got my DC Sports 4-1 Headers 2.5" outlet.
and HERE are the questions.

im wantin a High Flow Cat > best size? (2.25 or 2.5)
best catback size piping to my E's Muffler? (2.25 or 2.5?)
I got a quote today from Precision Mufflers at Croydon for $700
to..

install headers w/gaskets
high flow cat (redback) 2.5"
2.5" mild steel Mandrel Bend piping to..
front resonator (hotdog)
2.5" mild steel Mandrel Bend piping to my E's Muffler
is this the rite size piping or do i lose backpressure coz its 2.5"?
please let me know.... simply put 2.25 or 2.5?
really confused...i dont want to lose power...:o
thanks guys

[VT3C]

well IMO 2.5 for a modidified (or to-be-modded) B-series is PERFECT for top end and mid-range power.. you might sacrifice a little low down, but who cares cause we dont drive V8's that live under 2000RPM.. plus if you go over-axle, it wil add a couple more violent bends thus creating backpressure. is that header of Knightrider ? if so it's very nice I checked it out.

[rocky_b]

yeah its knightrider's one :D
dc sports hard to get here so i made every effort to get it. LoL

so VT3C.. 2.5" size piping all the way thru-out system is all gud?

[VT3C]

dang I was goin to buy that header untill someone beat me to it ;)

well IMO it is better for top-end.. you have B16A which is all about top-end.. since you bought the 4-1 (not the 4>2-1) it's designed for mid and top-end performance.

ONLY problem with 2.5" I find is that it is louder/deeper tone than the raspy/farty 2" but the noise is mainly determined by what muffler you use and if you use a mid-resonator. I hoonestly think the Jap-guage steel which is in between 2.25" and 2.5" is prob the best size but not sure if it's available in AUS.

if you plan to do power adders like full ECU/Cams/Boost/etc, then i'd recomend 2.5" if you just want stock B16A with stock header and intake, then go 2.25".

[civicdacbiet]

Personally i'd go 2.25 because it would go with the rest of my setup. Both sizes have been highly recommended however, but i feel safer with the 2.25.

[notorious_ahmie]

im my b16b i got 2.25 with 4-1 jdm headers and super highflow cat..im lovin it..

i thought ITR would be 2.5 oh wells..shows how much i know haha

btw ive seen a thread that gives the best suited size for each car!!

[egSi]

vtec knows his shit, 2.5 :thumbsup:

[rocky_b]

so what if i...
Headers 2.5" -> HighFlowCat 2.5 -> Resonator 2.25 -> E's Muffler
or would this cause a bottleneck in my system?
well wat would ya'll do eh?

[VT3C]

what do you do with your car ?
daily driver ?
show car ?
sat-night-street-racer?
track car ?
drag-car ?

[hondar]

so what if i...
Headers 2.5" -> HighFlowCat 2.5 -> Resonator 2.25 -> E's Muffler
or would this cause a bottleneck in my system?
well wat would ya'll do eh?

yes,

why would you want back pressure? back pressure as far as i understand is that the exhaust fume cant get out as quick as it can and therefore causing pressure to build up and slow down the exhaust velocity.

if you want big back presurre use your old stock muffler. as far as if you want performance, you want to minimise back pressure.

looking at the pics on the left hand side is the inner diagram of what your stock muffler looks like. it is not straight thru and therefore it causes "destructive interference" which cause to cancel sound wave of same frequency and opposite phase. thats why your stock muffler is quite and most racing muffler is loud.

having said that, if you intend to go for 2.25 inch piping it is better to have 2.25 header.

hope that helps :D

http://img.photobucket.com/albums/v326/hondar/muffler.jpg

[rocky_b]

what do you do with your car ?
daily driver ?
show car ?
sat-night-street-racer?
track car ?
drag-car ?


well my car used to be a daily driver, now i jus go drive it on the weekends.
I blitz it here and there jus to hear the vtec roar, mainly weekends, jus to put a smile on my face. So thats the main reason why im gettin this exhaust system done. hopefully by the weekend:D

My B16A2 engine is currently stock apart from...

J's Replica Intake with a new SIMOTA open air pod
E's Muffler (straight thru muffler design) axle back
Car has...

Cusco Coilovers Ek9 'rally spec'
rolling on stock EM1 rims w/ Toyo Trampio TPGs
Spoon Duracon gear knob:D
in a 3-12 months i'll be looking to get...
(no particular order)

Skunk2 adjustable Cam Gears
Skunk2 Short Shift
Skunk2 intake manifold
Skunk2 Throttlebody
ACT Clutch Kit and Flywheel
Rota SlipStreams or Rota Circuit 8s 16"
and possibly even a Buddyclub Bodykit :rolleyes:
Yes, so these are my plans for my EM1...
so back to the question..
if i do end up gettin 2.5" size piping all the way, would this give me more response, power etc... or just create a loud ass sound and lose power with my E's Muffler?

[revNhevN]

u should aim to keep all the piping the same size.

[rocky_b]

ok. so it looks like 2.5" size piping all the way!
:thumbsup: