Recirculation Valve on an SR

JDMSpeedS14 · #1 03-23-2006, 12:42 PM

I have a Blacktop SR20DET(zenki) and was wondering if i need to take the stock recirculation valve(located under the fuse box) off becasue i installed a HKS BOV. I've heard to take it off, but i'm not sure. Thanks guys

D-Bo · #2 03-23-2006, 12:54 PM

you can take it off and vent to atmosphere with the bov or put a hose on the bov leading back to the intake and recirculate the air.. its up to you.. basically yes you can take it off and it won't hurt.

sidewayzS13 · #3 03-23-2006, 01:28 PM

im confused you have on the hks and the stock bov?

JDMSpeedS14 · #4 03-23-2006, 03:53 PM

Quote:

Originally Posted by D-Bo

you can take it off and vent to atmosphere with the bov or put a hose on the bov leading back to the intake and recirculate the air.. its up to you.. basically yes you can take it off and it won't hurt.

Cool thanks. I'll take it off then

JDMSpeedS14 · #5 03-23-2006, 03:55 PM

Quote:

Originally Posted by sidewayzS13

im confused you have on the hks and the stock bov?

Yeah, I put the hks BOV on, but there is still a stock recirculation valve that is hooked up. I heard that you can take it off or leave it, but i wanted to make sure that you can and won't affect anything. The stock recirculation valve is louder than the HKS one and also heard that it is better to take the stock one off when you get an aftermarket one. Just needed to clear things up before I did it.

Skylindrftr · #6 03-23-2006, 05:35 PM

The one downside is your car might backfire a bit more with an open air bov (didnt happen to me but did with my friend) b/c the air expected by the cpu is a bit off, but it doesnt matter that much...

slideways... · #7 03-23-2006, 11:42 PM

ummm where did you hear that it wont hurt?
i guess not really but theres a reason for this backfire...unplugging your recirc on your BOV will make you run rich as hell. it will foul your plugs way faster and generally you wont run as quickly or cleanly at all. i wouldnt do it if i were you.

JDMSpeedS14 · #8 03-24-2006, 12:22 AM

Quote:

Originally Posted by slideways...

ummm where did you hear that it wont hurt?
i guess not really but theres a reason for this backfire...unplugging your recirc on your BOV will make you run rich as hell. it will foul your plugs way faster and generally you wont run as quickly or cleanly at all. i wouldnt do it if i were you.

Yeah, one of my friends said that taking off the recirculation valve might make the car run richer, but he wasnt sure. My car is already backfiring like crazy though, and i'm running the the recirculation valve and HKS BOV. It's wierd cuz i've seen pictures with the recirculation valve off, while running a BOV. But if taking it off will make my car run worse than, i'd rather leave it on.

Skylindrftr · #9 03-24-2006, 12:33 AM

I don't have one, my idle is fine with 264 cams, it doesnt run too rich and it almost never backfires...

Skylindrftr · #10 03-24-2006, 12:34 AM

I don't have one, my idle is fine with 264 cams, it doesnt run too rich and it almost never backfires...

slideways... · #11 03-24-2006, 07:44 AM

actually it only goes rich when you let off the gas, since thats the only time that the BOV actually does anything.

the reason is that a mass airflow metered car registers air coming into the intake as a mass and any that escapes the intake tract before entering the engine will already have been measured and sent as a signal to the ecu telling how much gas to use, so the ECU will think that there is all this air that just got blown off still in the intake and supply enough fuel for it. you are running rich when this happens whether you know it or not. its not possible to compensate for this using any piggyback, although i suppose it would be possible to program an ECU to go temporarily lean when you let off the throttle, but that would be dangerous because if you get it wrong, you could blow something.
running over rich actually doesnt really hurt anything, it just leads to faster carbon buildup, possibly eventually causing valve blowby, and spark plug fouling.

stang805 · #12 03-24-2006, 08:33 AM

Quote:

Originally Posted by slideways...

the reason is that a mass airflow metered car registers air coming into the intake as a mass and any that escapes the intake tract before entering the engine will already have been measured and sent as a signal to the ecu telling how much gas to use, so the ECU will think that there is all this air that just got blown off still in the intake and supply enough fuel for it.

on that subject, I was thinking about relocating the mafs to right in front of the intake to avoid false readings, and hopefully provide for better running, what do you guys think about that idea, and or, has anyone tried it?

D-Bo · #13 03-24-2006, 12:01 PM

as far as i know, you should have the mafs as close to the filter as possible.. as long as you have consistent intake pipes then thats where it should be

JDMSpeedS14 · #14 03-24-2006, 12:05 PM

You are guys are really helpful. Thanks for all the info.

TRUBO_89 · #15 03-27-2006, 04:49 PM

Quote:

Originally Posted by stang805

on that subject, I was thinking about relocating the mafs to right in front of the intake to avoid false readings, and hopefully provide for better running, what do you guys think about that idea, and or, has anyone tried it?

yeah ive asked this one before in the technical
heres the thread

http://www.automotiveforums.com/vbul...+throttle+body

POST REPLY TO THIS THREAD