Ok im going to the track, i have a 3inch helix exhaust and testpipe. On my silvia i would remove the exhaust after the test pipe (it was also 3 inch) and there was a good gain in spool time, and maybe a tad of power. Has anyone had good results with the on the evo? Its only 2 bolts and the hangers but i had to ask before i try

 

Yeah, if you run only the downpipe, you should run well. Remove your exhaust after the DP and before the TP, then add some leaded race gas, too.

 

running leaded gas will mess up your front o2 sensor

 

Shrug. It doesn't mess it up immediately. It's fine as long as you don't do it on a regular basis.

 

this might be stupid, but running exhaustless from the downpipe could be a little dangerous couldn't it? Are you going to risk getting CO poisoning for a 100th of a second?

 

hmmm, you sure?

 

no more dangerous that running catless.....unless you are parked in a closed garage, you'll be fine

I ahve doine this on an Evo once....spool time with a stock turbo went totally down the drain FWIW

 

Are you serious... All the big Boys run with no exhaust. I would not do it myself but the professionals do it.

 

Haha, what? CO poisoning? Not out in the open air. I used to run with no exhaust at all on my FWD eclipse, just because I still had the stock exhaust. I would disconnect the DP from the O2 housing and just haul ***. 12.58@110 on the stock 14b was badass.

I had no issue with spoolup, and I don't see how anyone would have issue with spoolup at the drag strip, since you're never below 5500 rpm...

 

Hey man, I don't know... I worry about stupid stuff like that...

 

I would think spool up would be better as there is less back presure. I think im gonna go for it. Anyone else done it on evo's?

 

I have a cutout that is right after the DP, my spool time is noticeably better, and i feel like it has a bit more power too(i gained 1mph with it open)

 

Not when the exhaust is disconnected



BTW be careful of fuel cut.. I did this once on stock ECU and car wanted to boost 21psi and would hit fuel cut.

 

you don't disconnect your FRONT o2 sensor.....that wouldn't work too well if you took off the o2 housing

 

Doh.. your right. hahaha


Most cars i have worked on have both O2s by the cat.. forgot the DSMs have them in the o2 housing.



Anyway.. runing it a few times wont hurt, but it would probably be best to pull the O2 sensor and get a plug for the bung.