Go Back   Honda-Tech > Honda and Acura Technical Forums > All Motor/ Naturally Aspirated
Sign in using an external account
Register Forgot Password?
Search


Welcome to Honda-Tech!
Welcome to Honda-Tech.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Honda-Tech community today!


Reply
 
 
 
submit to reddit
 
Thread Tools Search this Thread
Old 11-09-2010, 12:35 PM   #1
todahead
Honda-Tech Member
Garage is empty, add now
 
todahead's Avatar
 
Join Date: Oct 2010
Location: Hellas
Posts: 188
iTrader Rating: (0)
Icon2 3'' exhaust vs 2.5'' on b18c any dyno's??

i'm searching for an exhaust upgrade i own a dc2 swap on ek chassis .
current mods are 3.5'' intake with flow stack,rmf narrow header,decat and a 2.25'' hks silent cat back exhaust.engine internals are stock.
soon i'll tune using a chipped p28 and i need a new exhaust since hks has some bends etc.

i found here some people suggest 3'' exhausts even for stock b16's
but i haven't seen any dyno runs or any comparison between a smaller diameter exhaust.
with my set up i will have some power gains or just only a louder ex system?
cheers !
todahead is offline   Reply With Quote
Old 11-09-2010, 12:39 PM   #2
DDTECH
Honda-Tech Member
1992 Honda Civic
 
DDTECH's Avatar
 
Join Date: Aug 2009
Location: Baton Rouge,Louisiana
Posts: 7,180
iTrader Rating: (0)
customcams
Send a message via AIM to DDTECH
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

3'' inch ..period.

If you'd search correctly you'd find a ton..

http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust


there's a ton more, you dont need a dyno to see, 3'' exhaust should be a minimal for any all motor setup, if its a d series or b series or f or k it shouldn't matter, its been proven time and time again that a 3'' is better.
__________________
DDTECH(DDTECHCAMS.com) - Round2Motorsports - Myers Manifolds - YCU - AFITurbo - Sheepey INC - Phearable.net - SpeedTrapp Consulting
Custom Camshafts, VTEC Killers, and Rollers for your Honda
DDTECH is online now   Reply With Quote
Old 11-09-2010, 01:30 PM   #3
dntnedvtec
Honda-Tech Member
Garage is empty, add now
 
dntnedvtec's Avatar
 
Join Date: May 2009
Location: Saint Paul, Minnesota
Posts: 1,087
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

I haz a 3" exhauze.

Its loud, but when blazing down the strip, who cares? But for DD, not a good thing.
__________________
Quote:
Originally Posted by diablo2184 View Post
is it better to reply or bump an old thread or create a new one? cuz some people go crazy when someone makes a new one and they say to search
dntnedvtec is offline   Reply With Quote
Old 11-10-2010, 07:33 AM   #4
todahead
Honda-Tech Member
Garage is empty, add now
 
todahead's Avatar
 
Join Date: Oct 2010
Location: Hellas
Posts: 188
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by dntnedvtec View Post
I haz a 3" exhauze.

Its loud, but when blazing down the strip, who cares? But for DD, not a good thing.
why is a bad thought if you use big resonators it can be good even for cops ears ...
todahead is offline   Reply With Quote
Old 11-10-2010, 07:41 AM   #5
todahead
Honda-Tech Member
Garage is empty, add now
 
todahead's Avatar
 
Join Date: Oct 2010
Location: Hellas
Posts: 188
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by ALL M0T0R View Post
3'' inch ..period.

If you'd search correctly you'd find a ton..

http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust
http://honda-tech.com/showthread.php...%27%27+exhaust


there's a ton more, you dont need a dyno to see, 3'' exhaust should be a minimal for any all motor setup, if its a d series or b series or f or k it shouldn't matter, its been proven time and time again that a 3'' is better.
hmmm i think i can trust you on that most ppl here use 2.5'' witch actually is a true 60mm (ID) on b18 i'll go for a full custom 3'' exhaust thanks for the search btw !
todahead is offline   Reply With Quote
Old 11-10-2010, 03:49 PM   #6
88Hatchy
Honda-Tech Member
Garage is empty, add now
 
88Hatchy's Avatar
 
Join Date: Oct 2007
Location: Tampa, FL
Posts: 1,248
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

No need for a custom exhaust. Thermal R&D makes a 3" exhaust for all our cars.
__________________
NSRacing tuned.
88Hatchy is offline   Reply With Quote
Old 11-11-2010, 04:39 PM   #7
89LSED
Honda-Tech Member
Garage is empty, add now
 
89LSED's Avatar
 
Join Date: Sep 2009
Location: Lotus (BFE) CA
Posts: 775
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

3" exhaust on a stock internal NA motor?

Seem a little to big for me. Dont you need soooome back pressure?
__________________
1990 Wagon DX B20B-/B17
89LSED is offline   Reply With Quote
Old 11-11-2010, 05:00 PM   #8
DDTECH
Honda-Tech Member
1992 Honda Civic
 
DDTECH's Avatar
 
Join Date: Aug 2009
Location: Baton Rouge,Louisiana
Posts: 7,180
iTrader Rating: (0)
customcams
Send a message via AIM to DDTECH
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by 89LSED View Post
3" exhaust on a stock internal NA motor?

Seem a little to big for me. Dont you need soooome back pressure?
Nope
__________________
DDTECH(DDTECHCAMS.com) - Round2Motorsports - Myers Manifolds - YCU - AFITurbo - Sheepey INC - Phearable.net - SpeedTrapp Consulting
Custom Camshafts, VTEC Killers, and Rollers for your Honda
DDTECH is online now   Reply With Quote
Old 11-11-2010, 10:17 PM   #9
FlewByU352
Honda-Tech Member
Garage is empty, add now
 
FlewByU352's Avatar
 
Join Date: Apr 2009
Location: Florida
Posts: 2,508
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

It is impossible to get through to 98% of people that you do not need back pressure. Ive tried to explain my 100+ pages of reading and research and they say no you definately need back pressure. Yeah ok (rolls eyes). I went with 2.5" which is actually 2.36" because its not a Vibrant (which makes the most beautiful exhaust lol and is true size ID). I used this over 3" simply due to it is a DD more so than a track car. It does see the track but 2.5" was more appealing. I think the only way I would go 3" is boost but I like NA so it would be a full time track car.
FlewByU352 is offline   Reply With Quote
Old 11-11-2010, 11:26 PM   #10
C_Rock77
Honda-Tech Member
Garage is empty, add now
 
C_Rock77's Avatar
 
Join Date: Sep 2002
Location: Little Rock, AR
Posts: 1,850
iTrader Rating: (0)
Send a message via AIM to C_Rock77
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by 89LSED View Post
3" exhaust on a stock internal NA motor?

Seem a little to big for me. Dont you need soooome back pressure?
Only if you believe the backpressure fairy will put some WHP under your pillow at night.

3" exhaust has been shown to produce power in a VARIETY of builds...in B16s where people THOUGHT they wouldn't, it picked up power.

Like many have said, they go with 2.5" as a compromise.
__________________
Vouch Thread: http://honda-tech.com/zerothread?id=751961
C_Rock77 is offline   Reply With Quote
Old 11-12-2010, 03:57 AM   #11
flipmoderacing1
Guest
Garage is empty, add now
 
Posts: n/a
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

I put a 3'' on my dsm and yeah its loud at lower rpms n when ur runnin wop, but there's no harm in it. I mean as long as u use a hi flow cat n dont mind loosin some mpgs..... It wont b as bad on ur car as it was on mine. I went from 29 mpg to like 13, but i've also got 532 cc injectors usin a fuel management system. it wont hurt the engine at all n might give u a max hp gain of 15 hp or so. But it will def sound nice! Just beware of really strict residential areas! he he
  Reply With Quote
Old 11-12-2010, 09:56 AM   #12
bonesx0x2x4x
Honda-Tech Member
1998 Acura Integra
 
bonesx0x2x4x's Avatar
 
Join Date: Oct 2009
Location: UPSTATE NEWYORK
Posts: 128
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

i had a 2.5" on my b18 teggy for a while...moved to a 3" recently...alot louder better performance by a hair and deff good if your thinkin bout a turbo in the future

F THE POLICE!
bonesx0x2x4x is offline   Reply With Quote
Old 11-12-2010, 10:13 AM   #13
neverstop
Honda-Tech Member
Garage is empty, add now
 
Join Date: Jan 2010
Location: norcal
Posts: 539
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

this whole argument is dumb..... do race cars run tiny exhaust for "back pressure" or does nearly every fast drag car run open header?

done.
neverstop is offline   Reply With Quote
Old 11-12-2010, 10:21 AM   #14
00Red_SiR
All Motor Mentor
2000 Honda Civic
 
00Red_SiR's Avatar
 
Join Date: Aug 2004
Location: 902, Nova Scotia, Canada
Posts: 6,987
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by flipmoderacing1 View Post
I put a 3'' on my dsm and yeah its loud at lower rpms n when ur runnin wop, but there's no harm in it. I mean as long as u use a hi flow cat n dont mind loosin some mpgs..... It wont b as bad on ur car as it was on mine. I went from 29 mpg to like 13, but i've also got 532 cc injectors usin a fuel management system. it wont hurt the engine at all n might give u a max hp gain of 15 hp or so. But it will def sound nice! Just beware of really strict residential areas! he he
lol...
__________________
"And what have you ever done besides troll on H-T and act like you have a clue? A cam swap? A shiny car with expensive wheels? Hard parking nut swinging troll...." -Natural Aspirations describing the All Motor forum and saying what needs to be said.
00Red_SiR is offline   Reply With Quote
Old 11-13-2010, 09:26 AM   #15
todahead
Honda-Tech Member
Garage is empty, add now
 
todahead's Avatar
 
Join Date: Oct 2010
Location: Hellas
Posts: 188
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

learned :velocity is good
back pressure is bad
so the bigger is better on top of all is open headers thanks!!
todahead is offline   Reply With Quote
Old 11-14-2010, 06:04 PM   #16
fv8s
B*a*n*n*e*d
Garage is empty, add now
 
fv8s's Avatar
 
Join Date: Sep 2009
Posts: 3,876
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by todahead View Post
learned :velocity is good
back pressure is bad
so the bigger is better on top of all is open headers thanks!!
haha. lesson learned
fv8s is offline   Reply With Quote
Old 11-15-2010, 07:27 PM   #17
89LSED
Honda-Tech Member
Garage is empty, add now
 
89LSED's Avatar
 
Join Date: Sep 2009
Location: Lotus (BFE) CA
Posts: 775
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Well i think then im gonna suck up and do it!

I just made my own 2.5 system on my wagon.

Im gonna get a baseline done at Midnight, then build myself an exact same system out of 3. Run it again
__________________
1990 Wagon DX B20B-/B17
89LSED is offline   Reply With Quote
Old 11-16-2010, 06:36 AM   #18
DVDr
Honda-Tech Member
Garage is empty, add now
 
DVDr's Avatar
 
Join Date: May 2008
Location: Coldnorth, on, canada
Posts: 956
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by 89LSED View Post
Well i think then im gonna suck up and do it!

I just made my own 2.5 system on my wagon.

Im gonna get a baseline done at Midnight, then build myself an exact same system out of 3. Run it again
Thats great for comparison .

going to dyno ?
DVDr is offline   Reply With Quote
Old 11-16-2010, 11:34 AM   #19
89LSED
Honda-Tech Member
Garage is empty, add now
 
89LSED's Avatar
 
Join Date: Sep 2009
Location: Lotus (BFE) CA
Posts: 775
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

yup.
cant do it right yet, because my motor is blown... but as soon as midnight builds me a new one then ill get some numbers
__________________
1990 Wagon DX B20B-/B17
89LSED is offline   Reply With Quote
Old 11-16-2010, 11:58 AM   #20
VtecCarHauler
Honda-Tech Member
Garage is empty, add now
 
VtecCarHauler's Avatar
 
Join Date: Sep 2004
Location: Pembroke Pines, FL, USA
Posts: 616
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

3 inch all the way. I remember ppl saying 2.5 was to big back in the days.
__________________
AR Performance 9.987@147.79mph stock sleeves/stock trans 24.5 tire
(DD) 93 Eg N/A B-series
AUTO TRANSPORT http://www.floridadirectautotransport.com
VtecCarHauler is offline   Reply With Quote
Old 11-16-2010, 12:25 PM   #21
DDTECH
Honda-Tech Member
1992 Honda Civic
 
DDTECH's Avatar
 
Join Date: Aug 2009
Location: Baton Rouge,Louisiana
Posts: 7,180
iTrader Rating: (0)
customcams
Send a message via AIM to DDTECH
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

Quote:
Originally Posted by VtecCarHauler View Post
3 inch all the way. I remember ppl saying 2.5 was to big back in the days.
Thats because people were uneducated.
__________________
DDTECH(DDTECHCAMS.com) - Round2Motorsports - Myers Manifolds - YCU - AFITurbo - Sheepey INC - Phearable.net - SpeedTrapp Consulting
Custom Camshafts, VTEC Killers, and Rollers for your Honda
DDTECH is online now   Reply With Quote
Old 11-16-2010, 06:36 PM   #22
2k.civic.si
Honda-Tech Member
Garage is empty, add now
 
2k.civic.si's Avatar
 
Join Date: Jun 2004
Location: los banos, ca
Posts: 3,914
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

i switched to 3"....and im never looking back...it made more power everywhere
__________________
EFI University Certified Advanced Tuner http://www.artietuned.com
Ecu chipping,Street/Dyno tuning,Crome Pro/Gold,AEM,FAST,Motec, and more.
www.westcoastnationals.org
2k.civic.si is offline   Reply With Quote
Old 11-16-2010, 06:45 PM   #23
mrbsponge
Honda-Tech Member
Garage is empty, add now
 
mrbsponge's Avatar
 
Join Date: Aug 2003
Location: TDCperformance.net
Posts: 4,098
iTrader Rating: (0)
Send a message via AIM to mrbsponge
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

we have countless dynos of cars going from small exhausts to 3in, i wouldnt put anything else on a gsr or larger nowadays as everyone will eventually want to step up thier motors, i dont see many people adding a couple parts and quiting these days.

a solid muffler, and or resonator will do its job to keep the otne down and sound nice
__________________
Lexus SC300 B/W S366 9.51@146 Drag Radial Street Car
Top Dead Center Performance(www.tdcperformance.net)
Mobile Alabama, 251-661-6067, Neptune Dealer/Tuner
mrbsponge is offline   Reply With Quote
Old 11-17-2010, 12:31 AM   #24
rhymeshark916
Honda-Tech Member
Garage is empty, add now
 
rhymeshark916's Avatar
 
Join Date: Mar 2008
Location: Sacramento, CA, USA
Posts: 1,442
iTrader Rating: (0)
ibr Sasquatch
Send a message via AIM to rhymeshark916
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

"89lsed", make me a 2.5" piping with one big resonator for my 92 h/b.
__________________
92 EH2 BARD B18C1 GC KONI 5x114.3 15" GM ITR
rhymeshark916 is offline   Reply With Quote
Old 11-17-2010, 05:23 AM   #25
Ohio
Honda-Tech Member
Garage is empty, add now
 
Join Date: Jul 2010
Posts: 32
iTrader Rating: (0)
Default Re: 3'' exhaust vs 2.5'' on b18c any dyno's??

im having a custom 3 inch done too, Just got my KiddRacing Header.. Now its time to start looking at 22 inch long magnaflow mufflers for my Custom 3 inch side exit exhaust on my DB8
__________________
1998 Acura Integra GSR/Sedan

168Hp-124Trq
Ohio is offline   Reply With Quote
 
 
 
submit to reddit
Reply

Tags
25, 3, 3in, b18, b18c, california, cams, dyno, exhaust, good, honda, inch, mild, na, shop

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -8. The time now is 04:13 AM.



2008 Copyright, InternetBrands Inc.
Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Honda-Tech.com content, comments, or advertising. Honda-Tech.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Honda-Tech.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.
Emails & Contact Details