i had always been a honda fan... and then the mini came around. as a honda owner i used to love the dump valves... it was a easy way to gain a mess of HP for a race.

sooo i got under my car yesterday morning and i removed the second o2 sensor.... so it can kind of work as a dump vlave.

it took a few seconds to see the first difference... jeje the car a lot louder!

and a few hours later as i was drving the car began to get faster and faster... i guess the ECU was getting used to it.

this morning when i turned on my car LOUD as yesterday but man when i pulled out my house... that thing is on crack! its so fast, its insane!
i dont think in going to dyno because well i dont wanna spend the money on it. plus i got to put it back the SES light is on.
but i feel a gain greater than when i put the 19% pulley.

anyone ever tried this?

 

I dont know a ton about the underside of the MCS yet, from your Honda days (where I spent 14 years), Im assuming youre talking about running a test pipe of sorts? From full exhause to a "dump" exhaust by opening up a section of the exhaust? If thats what youre talking about...how big is the hold the 2nd O2 sensor creates? Pics?


Edit: Found a diagram:



Is the 2nd o2 sensor on #17?

-Jake

 

I took this picture from the how-to header by randy and i made some points in it.

my header is not this one but it looks alike.

i removed the 2nd o2 sensor on my after market header. the openning is about 1/2 inch maybe im not sure.

but the low to mid range it feels like i have 20 more lb/tq...

i would like someone to run some test... witha dyno... with the added torque its a very good set up for a weekend auto crossing if one can handle the extra noise

 

wont you kill the cat if you do that?

 

Hard to base gains like this on anecdotal data, but I don't think there is much to be had by opening the 1/2 inch bung. It might be due to the lack of the O2 sensor causing a reading that is affecting the ECM.
A 1/2 inch opening is not that much by itself, so I think the gain if any is elsewhere. You are also affecting the exhasut flow scavaging with unknown effects... possibly making it worse in the various rpms...

 

I'm not sure if I'd want an open exhaust under the car, not a big fan of carbonmonoxide.

 

You've got to be kidding me... the gains are all in your head. Open header maybe a slight gain... but all you did was remove an oxygen sensor?

 

mikem53, i totaly agree with youit might mess up other things... i just did it to see what would happen i will put my o2 sensor back on tomorrow... how ever i will talk to a local shop maybe then can make me a short 2.25 tube pointing down. i will test that later on this month.

i do think there is a great power gain from doing something like that.

on my last integra the ls/vtech i did a test with exhaust and with just header and the power gain was or 16hp and 9.5 lb/tq to the ground... i mean my motor wasnt stock at all. but for one race that kind of gain can make a difference.... llike a weekend autocross

 

might be all in my head but if you get next to a someone who you usualy pull about a car on and then you pull almost 3... you tell me.

 

Maybe they don't want to race against such a loud car because the loud car draws too much attention:smile:

Without the sensor the ECU cannot ever go into closed-loop mode and falls back to a default map. Even if this map were more responsive than closed loop, the gains would all be at part throttle because WOT is always open loop.