# High flow cat vs. Test pipe **URL:** \ **Category:** SON240sx Automotive\ **Created:** [June 11, 2010, 4:14pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373 "2010-06-11T16:14:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![BoOsT-HuNgRy](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/boost-hungry/32/5721_2.png) [@BoOsT-HuNgRy](https://forums.speedlife.net/u/BoOsT-HuNgRy)\ **Post date:** [June 11, 2010, 4:14pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/1 "2010-06-11T16:14:00Z")
Ok so heres the skinny. Bing made a parts run on his way back from border i got an exhaust isis dd to be exsact. Its basicly a straight pipe exhaust. but i have a felling with my KA-T its going to sound stupid loud and i will be daily driving the car. So who here is running similair and can give me an out side perspective . ---
**Author:** ![a\_ahmed](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/a_ahmed/32/5411_2.png) [@a\_ahmed](https://forums.speedlife.net/u/a_ahmed)\ **Post date:** [June 11, 2010, 4:37pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/2 "2010-06-11T16:37:06Z")
lol its a tie 1:1:1 ---
**Author:** ![jzavalinsk](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jzavalinsk/32/5713_2.png) [@jzavalinsk](https://forums.speedlife.net/u/jzavalinsk)\ **Post date:** [June 11, 2010, 5:02pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/3 "2010-06-11T17:02:59Z")
when i got stopped by cops for my exhaust, i had to point out where the cat was. Ended up walking away with no ticket becuase i had a cat and just passed a etest, or getta cat and hollow it out ahaha, best of both worlds. ---
**Author:** ![XSNRGE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/xsnrge/32/5565_2.png) [@XSNRGE](https://forums.speedlife.net/u/XSNRGE)\ **Post date:** [June 11, 2010, 6:46pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/4 "2010-06-11T18:46:13Z")
Actually, a hollowed cat is just as bad, if not worse than a regular cat. Hollowed out cats act like a turbulence chamber, exhaust gases enter it in lets say 3" of piping, then expand to whatever the volume is of the hollowed cat, create turbulence and cause backpressure, then exit at 3" piping. ---
**Author:** ![BRA\_GANZAAAAAA](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/bra_ganzaaaaaa/32/5673_2.png) [@BRA\_GANZAAAAAA](https://forums.speedlife.net/u/BRA_GANZAAAAAA)\ **Post date:** [June 11, 2010, 6:55pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/5 "2010-06-11T18:55:21Z")
> [@XSNRGE](#): > > Actually, a hollowed cat is just as bad, if not worse than a regular cat. > > Hollowed out cats act like a turbulence chamber, exhaust gases enter it in lets say 3" of piping, then expand to whatever the volume is of the hollowed cat, create turbulence and cause backpressure, then exit at 3" piping. drill a hole through the catalytic shit and slide a tube through and weld it ---
**Author:** ![jeeta\_s](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jeeta_s/32/5758_2.png) [@jeeta\_s](https://forums.speedlife.net/u/jeeta_s)\ **Post date:** [June 11, 2010, 7:32pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/6 "2010-06-11T19:32:00Z")
i got a magnaflow 3" hi-flow cat with the 3" bing exhaust, i should be getting my ecu back soon. ill post a vid of how it sounds, its a ka-t as well ---
**Author:** ![kapetajr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/kapetajr/32/5445_2.png) [@kapetajr](https://forums.speedlife.net/u/kapetajr)\ **Post date:** [June 11, 2010, 9:34pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/7 "2010-06-11T21:34:20Z")
Test pipe. Blame bing done!!!.. in all seriousness I read some where that the difference between high flow and a test pipe is negligible, but i read it on the internet so take it with a grain of salt… then again i got a 3 inch high flow cat so what do I know ---
**Author:** ![RUSSKII](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/russkii/32/5696_2.png) [@RUSSKII](https://forums.speedlife.net/u/RUSSKII)\ **Post date:** [June 11, 2010, 9:42pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/8 "2010-06-11T21:42:38Z")
i have a test pipe on my sr and it’s pretty quiet especially with the silencer on. ---
**Author:** ![XSNRGE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/xsnrge/32/5565_2.png) [@XSNRGE](https://forums.speedlife.net/u/XSNRGE)\ **Post date:** [June 11, 2010, 10:41pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/9 "2010-06-11T22:41:29Z")
> [@BRA GANZAAAAAA](#): > > drill a hole through the catalytic shit and slide a tube through and weld it There ya go. ---
**Author:** ![Feint](https://avatars.discourse-cdn.com/v4/letter/f/71e660/32.png) [@Feint](https://forums.speedlife.net/u/Feint)\ **Post date:** [June 11, 2010, 11:51pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/10 "2010-06-11T23:51:02Z")
> [@RUSSKII](#): > > i have a test pipe on my sr and it’s pretty quiet especially with the silencer on. Your exhaust is quieter than mine, and mine is quiet. I had no idea lol. ---
**Author:** ![Stiky](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/stiky/32/5692_2.png) [@Stiky](https://forums.speedlife.net/u/Stiky)\ **Post date:** [June 12, 2010, 4:47am UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/11 "2010-06-12T04:47:31Z")
You’ll regret it. No cat + KA = loud ass exhaust. You will have no muffler then. A boosted car can have an open dump and still be quieter than some KAs with a full 3" cat back. The punched cat will also make your car pop and if you’re running rich enough let out the ocasional flame. All in a it’s up to you but it’s a massive fine under hta for no cat. Here’s a run down of a turbo exhaust system. Turbo = somewhat of a muffler Cat = some sound insulation so you don’t get pops and flames Resonator = low end sound… Muffles out the sounds between 1-3000rpm usually Muffler = top end sound insulation ---
**Author:** ![BoOsT-HuNgRy](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/boost-hungry/32/5721_2.png) [@BoOsT-HuNgRy](https://forums.speedlife.net/u/BoOsT-HuNgRy)\ **Post date:** [June 12, 2010, 5:13am UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/12 "2010-06-12T05:13:32Z")
ic sticky see this the run down of my exhaust , t25 bings elbow bings down pipe nothing atm 3inch straight pipe dual tips (isis dd) So from what i gather is run a high flow as my exhaust will be stupid loud. but im still on the fence ---
**Author:** ![Stiky](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/stiky/32/5692_2.png) [@Stiky](https://forums.speedlife.net/u/Stiky)\ **Post date:** [June 12, 2010, 11:59am UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/13 "2010-06-12T11:59:30Z")
I say run a cat. That way if you get pulled over you’ll still be somewhat legal. It’s up to you though, I have never heard bings dd in person but I heard a dart izumi and even with a cat it’s still fairly loud and raspy. ---
**Author:** ![Mr\_Phonso](https://avatars.discourse-cdn.com/v4/letter/m/a87d85/32.png) [@Mr\_Phonso](https://forums.speedlife.net/u/Mr_Phonso)\ **Post date:** [June 12, 2010, 12:04pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/14 "2010-06-12T12:04:36Z")
anyone know the fine for no cat? ---
**Author:** ![Singh](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@Singh](https://forums.speedlife.net/u/Singh)\ **Post date:** [June 12, 2010, 1:19pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/15 "2010-06-12T13:19:36Z")
without a cat, car smells like shit. That and the negligible power loss of a high flow cat, make it worth it. ---
**Author:** ![BoOsT-HuNgRy](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/boost-hungry/32/5721_2.png) [@BoOsT-HuNgRy](https://forums.speedlife.net/u/BoOsT-HuNgRy)\ **Post date:** [June 12, 2010, 3:33pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/16 "2010-06-12T15:33:50Z")
well i may run this with a test pipe. what do you guys think ? [http://www.enjukuracing.com/apexi-70mm-exhaust-control-valve-p-8056.html](http://www.enjukuracing.com/apexi-70mm-exhaust-control-valve-p-8056.html) ---
**Author:** ![Stiky](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/stiky/32/5692_2.png) [@Stiky](https://forums.speedlife.net/u/Stiky)\ **Post date:** [June 12, 2010, 4:42pm UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/17 "2010-06-12T16:42:46Z")
It’s up to you bro… But why not run a servo controlled one? So you flick a switch in the cabin and dump to atmosphere before your cat? Basically cut the dp in half, run a y pipe, put electronic valve on one side of y, put the cat on the other. That way you have full open downpipe or straight through exhaust WITH a cat? ---
**Author:** ![BoOsT-HuNgRy](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/boost-hungry/32/5721_2.png) [@BoOsT-HuNgRy](https://forums.speedlife.net/u/BoOsT-HuNgRy)\ **Post date:** [June 13, 2010, 4:07am UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/18 "2010-06-13T04:07:36Z")
^^^ i never thought of that … ---
**Author:** ![izzo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/izzo/32/5769_2.png) [@izzo](https://forums.speedlife.net/u/izzo)\ **Post date:** [June 13, 2010, 4:41am UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/19 "2010-06-13T04:41:12Z")
to me atleast no cat = dumb move why dont you just have a dump on a side of your fender or some. and run a leget muffler on daily bases. ---
**Author:** ![BoOsT-HuNgRy](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/boost-hungry/32/5721_2.png) [@BoOsT-HuNgRy](https://forums.speedlife.net/u/BoOsT-HuNgRy)\ **Post date:** [June 13, 2010, 5:19am UTC](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373/20 "2010-06-13T05:19:17Z")
well after thinking it over, im going to run a cat. which vendor here sells them. [Next page](https://forums.speedlife.net/t/high-flow-cat-vs-test-pipe/156373.md?page=2)