Mild Cams and emissions - Real World Experience

Scubynubie · 01-30-2013, 03:51 PM

I have been looking at putting in some cams with the engine build that I am starting, but I have to pass emissions where I live, and I really don't want to go to all of the trouble of putting them in to find out that I will have to pull the engine and yank them out when I have to pass emissions.

So I was wondering if there were people in California, Colorado, etc. that have passed emissions with a mild cam. Something like 272 or less duration.

I have called a couple manufacturers and they don't seem to test for this sort of thing, and that is why I am posting.

Engine would be a 2.5 liter longblock, and down-pipe would be stock for testing purposes.

Any experience or advice would be greatly appreciated.

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FlatironsTuning.com · 01-31-2013, 12:14 PM

Wrong Post...

kakarot09 · 01-31-2013, 12:33 PM

Single avcs, dual avcs, no avcs? I don't have any personal experience but it may be helpful to note for anyone who might. Have you tried contacting cosworth and fishing around? Maybe motoiq? They've done a ton of testing on engine designs and might be able to help. If you happen to do that it would be nice to post what they say.

sense of nature · 01-31-2013, 12:47 PM

Most emission testing is done by OBD2 port scanning or Visual Inspection.
I would think it'd be near impossible to tell by inspection as most 272's really don't have lopey idles.
& as far as OBD2 goes, no Cel is almost always a PASS unless ur readiness monitors aren't set.

kakarot09 · 01-31-2013, 01:07 PM

In California and probably some other places they run the car on rollers too. Usually not a big deal for us since we have awd they make an exception for that. But maybe that's why he is asking. Where I live I just have the plug plugged in the OBD port.

Scubynubie · 01-31-2013, 01:24 PM

Thanks for the help. I live in Colorado, and they test our cars on rollers with a sensor in the tail pipe, so it is the actual effect on emissions that I am concerned about. The visual would not be the issue.

And this would be non-AVCS cams going in a non-AVCS WRX. But I would be putting them in D25 heads.

I am leaning towards something that is even less aggressive like the GSC stage 1 cams, but they aren't sure how much they would effect emissions either.

I may call Cosworth as well just to see. I suppose that if someone has passed California emissions with 272 cams, then I should be okay with 266's, but you never know I suppose.

I will post back if I find anything, but hopefully someone will chime in with actual experience.

sense of nature · 01-31-2013, 07:10 PM

I would "think" that that would be more tune specific in that case, if you can find out what rpm they test @ it might get u a better idea , obviously it's gonna be year & car specific , Just make sure your not running pig rich & you "should" be ok .... as long as it's not an 07 Sti.. lol

01-30-2013, 03:51 PM	#1
Scubynubie Scooby Newbie Member#: 103757 Join Date: Dec 2005	Mild Cams and emissions - Real World Experience I have been looking at putting in some cams with the engine build that I am starting, but I have to pass emissions where I live, and I really don't want to go to all of the trouble of putting them in to find out that I will have to pull the engine and yank them out when I have to pass emissions. So I was wondering if there were people in California, Colorado, etc. that have passed emissions with a mild cam. Something like 272 or less duration. I have called a couple manufacturers and they don't seem to test for this sort of thing, and that is why I am posting. Engine would be a 2.5 liter longblock, and down-pipe would be stock for testing purposes. Any experience or advice would be greatly appreciated. * Registered users of the site do not see these ads.

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01-31-2013, 12:14 PM	#2
FlatironsTuning.com NASIOC Vendor Member#: 171650 Join Date: Feb 2008 Location: Boulder, Colorado	Wrong Post...

01-31-2013, 12:33 PM	#3
kakarot09 Scooby Specialist Member#: 182375 Join Date: Jun 2008 Chapter/Region: SWIC Location: Northern Nevada Vehicle: 08 Sti Wrbm	Single avcs, dual avcs, no avcs? I don't have any personal experience but it may be helpful to note for anyone who might. Have you tried contacting cosworth and fishing around? Maybe motoiq? They've done a ton of testing on engine designs and might be able to help. If you happen to do that it would be nice to post what they say.

01-31-2013, 12:47 PM	#4
sense of nature Scooby Guru Member#: 112759 Join Date: Apr 2006 Chapter/Region: MWSOC Location: In the V hole! Vehicle: 02 Srp STi... R ur Boltz to long????	Most emission testing is done by OBD2 port scanning or Visual Inspection. I would think it'd be near impossible to tell by inspection as most 272's really don't have lopey idles. & as far as OBD2 goes, no Cel is almost always a PASS unless ur readiness monitors aren't set.

01-31-2013, 01:07 PM	#5
kakarot09 Scooby Specialist Member#: 182375 Join Date: Jun 2008 Chapter/Region: SWIC Location: Northern Nevada Vehicle: 08 Sti Wrbm	In California and probably some other places they run the car on rollers too. Usually not a big deal for us since we have awd they make an exception for that. But maybe that's why he is asking. Where I live I just have the plug plugged in the OBD port.

01-31-2013, 01:24 PM	#6
Scubynubie Scooby Newbie Member#: 103757 Join Date: Dec 2005	Thanks for the help. I live in Colorado, and they test our cars on rollers with a sensor in the tail pipe, so it is the actual effect on emissions that I am concerned about. The visual would not be the issue. And this would be non-AVCS cams going in a non-AVCS WRX. But I would be putting them in D25 heads. I am leaning towards something that is even less aggressive like the GSC stage 1 cams, but they aren't sure how much they would effect emissions either. I may call Cosworth as well just to see. I suppose that if someone has passed California emissions with 272 cams, then I should be okay with 266's, but you never know I suppose. I will post back if I find anything, but hopefully someone will chime in with actual experience.

01-31-2013, 07:10 PM	#7
sense of nature Scooby Guru Member#: 112759 Join Date: Apr 2006 Chapter/Region: MWSOC Location: In the V hole! Vehicle: 02 Srp STi... R ur Boltz to long????	I would "think" that that would be more tune specific in that case, if you can find out what rpm they test @ it might get u a better idea , obviously it's gonna be year & car specific , Just make sure your not running pig rich & you "should" be ok .... as long as it's not an 07 Sti.. lol