# Will going down .1" exhaust piping diameter....cause bottlenecking? **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [July 12, 2006, 9:20pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495 "2006-07-12T21:20:16Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 12, 2006, 9:20pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/1 "2006-07-12T21:20:16Z")
Ok. I LOVE Apex-i World Sport II, exhausts. They look awesome, and sound even better. On the hatch I currently have a 2.5" Downpipe, cat, and catback exhaust…to some huge ricer ebay cannon. Well, the wonderful exhaust, is now rusting. So, after doing some swindling with my buddy, and I am essentially getting a brand new WSII full catback exhaust. Here lies the problem. The current exhaust has a piping diameter of 2.5". The WSII exhaust has a piping diameter of 60mm. Or 2.36" for all you yankees. If i bolt this .1" smaller catback exhaust on tomorrow, am I going to see a loss in power? Am I going to see a change in powerband? Is the exhaust going to be “bottle necking”? I already talked to a few people, and they said .1" is not going to make me gain, nor lose power…especially with only my 14b/16g hotside combo. Howster, said I might see a slight change in powerband…w/e thats fine. Aslong as I don’t have to listen to that blaster cannon anymore. I just don’t want to get a large loss in power, and have the exhaust “bottleneck”…but with it only being a catback, and not the downpipe…i don’t see such a big deal. And this kid on [D-Series.org](http://D-Series.org), said his WSII has a lot of deadening material in it, and all the carbon build-up has cause a lot of back pressure. :wtf: Let me know boys. ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 12, 2006, 9:29pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/2 "2006-07-12T21:29:58Z")
bump fuckers. ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 12, 2006, 9:46pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/3 "2006-07-12T21:46:15Z")
holy shit. quit reading about detailing and muscle cars. BUMP. ---
**Author:** ![Jagermeister](https://avatars.discourse-cdn.com/v4/letter/j/f19dbf/32.png) [@Jagermeister](https://forums.speedlife.net/u/Jagermeister)\ **Post date:** [July 12, 2006, 9:51pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/4 "2006-07-12T21:51:58Z")
You may barely see a loss in hp, but minimal if any. .5" is a big difference, .1" is not. ---
**Author:** ![ILCisDEAD](https://avatars.discourse-cdn.com/v4/letter/i/a87d85/32.png) [@ILCisDEAD](https://forums.speedlife.net/u/ILCisDEAD)\ **Post date:** [July 12, 2006, 9:52pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/5 "2006-07-12T21:52:43Z")
well… (2.5/2 ) \* (2.5/2) \* 3.14 = 4.9ish… (2.36/2) \* (2.36/2) \*3.14 = 4.3ish… (4.3/ 4.9) \* 100 = 87% so thats 13% less area (providing if you are thinking of air as slices), for exhaust to go through… I am gonna stop there cause I hated Thermo and I Don’t remember all of it 3.14 / 4.9 \* 100 = 64% difference making the .1 a 1/3 of a big difference ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 12, 2006, 9:54pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/6 "2006-07-12T21:54:47Z")
> [@Jagermeister](#): > > You may barely see a loss in hp, but minimal if any. > > .5" is a big difference, .1" is not. ok awesome. cause i’ll sacrifice a good sound, and better looks for a couple HP. :tup: thanks buddy ---
**Author:** ![mindless](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mindless/32/7286_2.png) [@mindless](https://forums.speedlife.net/u/mindless)\ **Post date:** [July 12, 2006, 10:09pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/7 "2006-07-12T22:09:56Z")
with the amount of power u make with the .1 less it will flow the same i would think. ull never notice a difference ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 12, 2006, 10:12pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/8 "2006-07-12T22:12:42Z")
> [@mindless](#): > > with the amount of power u make with the .1 less it will flow the same i would think. ull never notice a difference u fuggin bitch. why i oughta… come in and buy another bike, or atleast visit you 🙂 ---
**Author:** ![93dx\_hatch](https://avatars.discourse-cdn.com/v4/letter/9/90ced4/32.png) [@93dx\_hatch](https://forums.speedlife.net/u/93dx_hatch)\ **Post date:** [July 12, 2006, 10:18pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/9 "2006-07-12T22:18:16Z")
its a D series ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 12, 2006, 10:22pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/10 "2006-07-12T22:22:10Z")
> [@93dx--hatch](#): > > its a D series Q: Whats worse than owning a d-series? A: Being in Uncle Ben’s ---
**Author:** ![Shrives](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/shrives/32/7250_2.png) [@Shrives](https://forums.speedlife.net/u/Shrives)\ **Post date:** [July 12, 2006, 10:30pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/11 "2006-07-12T22:30:41Z")
Bill’s car lost 20whp when he put the sticker on his car, no joke… ---
**Author:** ![95Z28](https://avatars.discourse-cdn.com/v4/letter/9/85e7bf/32.png) [@95Z28](https://forums.speedlife.net/u/95Z28)\ **Post date:** [July 12, 2006, 10:36pm UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/12 "2006-07-12T22:36:36Z")
I’d say go for the WS2. It’s hot as hell and like Bill said, you probably won’t even notice any difference. I was looking into that and the RS\*R ExMag for my Integra both are awesome exhausts. ---
**Author:** ![Minglor](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/minglor/32/7373_2.png) [@Minglor](https://forums.speedlife.net/u/Minglor)\ **Post date:** [July 13, 2006, 12:55am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/13 "2006-07-13T00:55:08Z")
> [@beckington](#): > > Q: Whats worse than owning a d-series? > > A: Being in Uncle Ben’s sig worthy. I would say don’t risk the power loss and sell the exhaust to me. ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 13, 2006, 4:19am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/14 "2006-07-13T04:19:11Z")
> [@Minglor](#): > > sig worthy. > > I would say don’t risk the power loss > > and sell the exhaust to me. buy my old exhaust. cheap 🙂 ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex034/uploads/speedlife/original/2X/b/b7170c8eddc0b95ece6b88172b2f416a08489a45.png) [@system](https://forums.speedlife.net/u/system)\ **Post date:** [July 13, 2006, 4:19am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/15 "2006-07-13T04:19:58Z")
> [@95Z28](#): > > I’d say go for the WS2. It’s hot as hell and like Bill said, you probably won’t even notice any difference. I was looking into that and the RS\*R ExMag for my Integra both are awesome exhausts. Yeah I’m picking up the WS2 fo sho, and my buddy is picking up the RS\*R for his Civic SI. :tup: ---
**Author:** ![MaximaSE98](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/maximase98/32/7600_2.png) [@MaximaSE98](https://forums.speedlife.net/u/MaximaSE98)\ **Post date:** [July 13, 2006, 4:58am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/16 "2006-07-13T04:58:53Z")
just up the boost a PSI or 2…WS2 is pimp…i had and still is on my white maxima… ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [July 13, 2006, 5:03am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/17 "2006-07-13T05:03:04Z")
> [@blacke36](#): > > well… > > (2.5/2 ) \* (2.5/2) \* 3.14 = 4.9ish… > (2.36/2) \* (2.36/2) \*3.14 = 4.3ish… > > (4.3/ 4.9) \* 100 = 87% > > so thats 13% less area (providing if you are thinking of air as slices), for exhaust to go through… I am gonna stop there cause I hated Thermo and I Don’t remember all of it > > 3.14 / 4.9 \* 100 = 64% > > difference making the .1 a 1/3 of a big difference beck, did you not read this post? 13% less area the WS isnt going to be any mroe quiet that the current far cannon. you’re a retard for wanting to go with a smaller exhaust on a turbo car that you want to put a bigger turbo on and turn the boost up more on. go 3" and stop being a fucking retard ---
**Author:** ![LZ1](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@LZ1](https://forums.speedlife.net/u/LZ1)\ **Post date:** [July 13, 2006, 5:08am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/18 "2006-07-13T05:08:01Z")
:word: lol let him do what he wants :tup: ---
**Author:** ![MaximaSE98](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/maximase98/32/7600_2.png) [@MaximaSE98](https://forums.speedlife.net/u/MaximaSE98)\ **Post date:** [July 13, 2006, 5:13am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/19 "2006-07-13T05:13:25Z")
> [@Zer0DazE](#): > > beck, did you not read this post? > > 13% less area > > the WS isnt going to be any mroe quiet that the current far cannon. > you’re a retard for wanting to go with a smaller exhaust on a turbo car that you want to put a bigger turbo on and turn the boost up more on. > go 3" and stop being a fucking retard it wil give him a better exhausr Note though…i think thats what he is trying to get at ---
**Author:** ![LAFENGAS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lafengas/32/7573_2.png) [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)\ **Post date:** [July 13, 2006, 5:15am UTC](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495/20 "2006-07-13T05:15:04Z")
by definition, no you wouldn’t be “bottlenecking”. Obviously, you’re restricting the flow though. FI Cars… one of the important things to do is get the exhaust gasses the hell out of there. With this, i say go bigger. To re-word this in terms you may be able to understand. It’s the difference between a 15yr old vagina and 30yr old vagina. Viewing it this way, i can see why you would choose the smaller exhaust. [Next page](https://forums.speedlife.net/t/will-going-down-1-exhaust-piping-diameter-cause-bottlenecking/14495.md?page=2)