i've always wanted to be able to go catless with a flip of a switch.

i've asked a tuner about straight pipe compared to test pipe with muffler on an all motor honda.
he said u would be losing power with a straight pipe because there isn't enough back pressure.
he said having a muffler and a test pipe is better.

so that's where i came out with this idea.

my idea of bypassing the cat with an electric cut out.
most ppl just have it open but i want to run with the muffler to have some back pressure.

has anyone tried this already?
i'm wondering about clearance issues under the chassis. if it would fit?
i have a 95 integra RS with B20vtec

 

exhaust gas would take the path of least resistance, but you would still have some residual flow through the cat... I just don't get the point. electric cut outs are expensive, test pipes are cheap, bolt up and can be installed and removed in less than 10 minutes by anyone competent with hand tools...

why re-invent the wheel

 

i like it cus i can go catless on the fly and go back to cat with a flick of the switch. this helps with cops or if i just want to quiet down the exhaust sometimes when i'm not doing some spirited driving.

my real question is has anyone tried this and if it will fit under my dc2

 

seems pretty inefficient. either just test pipe it, or keep a cat/upgrade to a high flow unit. as previously stated, that design still has the flow going through the cat, all your bypass would do is trap some of those gasses when its closed, and cause a longer route to get out when opened. so if anything, you would probably be robbing yourself of a bit of power, as well as decreasing backpressure. if you want a cutout, it will have to be post-cat. so again, your most efficient options are either test pipe, or keep/upgrade your cat

 

I have a cutout and love it. I dump mine though to atmosphere though. I have a turbo car too though. But just push the button cutout opens and race ready. Push the button close the cutout and the car is nice and quiet. Just to bypass the cat might not be worth it though.

 

Don't think you'll have enough room in the integra tunnel for that. If you went with a 200 cell cat you probably won't notice the difference in power.

 

It's a good waste of stainless. You've done nothing really to impact performance other than maybe, MAYBE a few whp.

 

Here is how I have done for an BMW M3 e46 Turbo.




The idea is to dump the exhaust gasses right before all the mufflers/catalysts.

 

it's pointless.... you're adding weight and complications to the car, plus the cat presents a restriction since the exhaust flow will back up before the cat (what doesn't pass through first) and then it has to take 3 turns to get back into the normal exhaust flow, this in itself prevents backpressure since air doesn't like to turn.

not to mention the cost. the cutout, plus the material.... a test pipe is so much cheaper, proven, and more effective. If you're too lazy to get back under your car and replace 5 bolts to put the cat back on for testing and such then you shouldn't work on a car.

Not to mention you won't have enough room under the car without removing heat shielding and sectioning the tunnel... which won't work because the shift linkage is in the way

 

 

[/QUOTE]

i've asked a tuner about straight pipe compared to test pipe with muffler on an all motor honda.
he said u would be losing power with a straight pipe because there isn't enough back pressure.
he said having a muffler and a test pipe is better.

so that's where i came out with this idea.

my idea of bypassing the cat with an electric cut out.
most ppl just have it open but i want to run with the muffler to have some back pressure.

has anyone tried this already?
i'm wondering about clearance issues under the chassis. if it would fit?
i have a 95 integra RS with B20vtec[/QUOTE]
__________________________________________________ _______


here is my electric exhaust cutout on my integra dc2 turbo. This is the best spot i could find. no clearance issues.

vid:
http://www.youtube.com/watch?v=wlmYUY7iyRo

 

Where I live, that's just as illegal as a 4" dump to atmosphere. There's no point.

I love my 2.5" exhaust I had built a few years ago, it's nice a quiet; cat, resonator, s-bend muffler... and I don't look like a street racer pulling into work. I was in the same boat, I've spent hours looking at dumps and dreaming up clever ways to mount them. In the end I went with getting under the car and turning wrenches.

When I get to the track or dyno I would drop the exhaust entirely. I used a band clamp as a quick release and unbolted the control arm - down she goes! It's the best way to go on a weekend-racer street car IMO. Cheapest, lightest, and quietest method. My only con is that it changes the fuel requirements as it runs quite rich once I put the exhaust back on after dyno/track tuning. I end up having to create street tune and a race tune. no biggie if you do the tuning yourself.

This time around I'm switching to a vband. I'll also be looking at exhaust hangers that I can bolt on/off quickly, I don't want to break a nail.