RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   3rd Generation Specific (1993-2002) (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/)
-   -   64 rpms and i don't pass smog? (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/64-rpms-i-dont-pass-smog-297153/)

ttb 04-20-04 06:57 PM

64 rpms and i don't pass smog?
 
in california we get on a little roller/dyno thing and i guess they do one 15mph test and one 25mph

the 15mph @ 2870 rpm i was a gross polluter
the 25mph @ 2806 rpm i passed

i dont know much about smog/emission but seems kinda odd that a 64rpm difference can make such a big difference in the emissions.

anybody wanna help me understand?

SpeedKing 04-20-04 07:02 PM

Any mods? I passed recently with downpipe only.

ttb 04-20-04 07:03 PM

intake, IC, DP, CB, PFC
they failed me on the check light thing bc of the PFC.

they also failed me on the check light not working bc of the PFC.

ttb 04-20-04 07:12 PM

oh, from 25ph --> 15mph my HC and CO measures jumped 5 folds, which really seems odd.

SpeedKing 04-20-04 07:24 PM

Tinou, I just dug up my test:

HC @ 15MPH: 10, @ 25MPH: 10
C0 @ 15MPH: .00, @ 25MPH: .02

Did the tech hit the accelerator hard? Maybe you need fresh plugs? Try going to Rick's Rotary. He can smog "pre-test" you to see where you're failing and make adjustments. Also, he has a dash "rig" to make your CEL come on with the PowerFC.

ttb 04-20-04 07:33 PM

well i'm going to put the stock ecu back in and sees what happens. hopefully 2nd times a charm.

ttb 04-20-04 07:34 PM

thanks for #s

books 04-20-04 07:46 PM

Don’t know if this will provide much insight. The ACV along with your catalytic convertor work in unison to improve your emissions. Your airpump is off above 3,250 rpms, thus no air to the ACV which ports air to your catalytic convertor. Normally, during normal driving or cruise conditions the port air bypass solenoid (on your (ACV) channels air or ports air to the cat. This usually occurs above 2,000 rpms. Depending on acceleration you could possibly go above 3,250 rpms cutting off the airpump and subsequently the ACV’s porting to the cat.

I believe the idea behind this is clean emissions is a good idea during normal driving but when extra power is needed for on ramps or passing several 18 wheelers safety takes precedence over emissions.

I have thought about setting the rev limit to around 3,000 rpms so the emission people could not exceed the intended operational rpm range of our emissions equipment.

Sonny 04-20-04 08:00 PM

Ah yes, that wonderful CA dyno smog. I just went through it with my RX-7 and am currently going through it with the state referee for my CRX (engine swap).

Here are the limits:

15MPH
HC (PPM) - 88 (My RX-7 = 14)
CO % - 0.52 (My RX-7 = .21)
NO (PPM) - 704 (My RX-7 = 63)

25MPH
HC (PPM) - 53 (My RX-7 = 13)
CO % - 0.50 (My RX-7 = .14)
NO (PPM) - 738 (My RX-7 = 56)

My setup was bone stock. Both the pre-cat and main cat were in place.

You will need to run the stock ECU unless the PFC can be setup to control the Check Engine light. My CRX is currently stock (put back to stock to pass smog) and it is running cleaner than the RX-7 on both HC and CO. However, the NOx was too high on the first try. I passed by raising the fuel pressure.

Sonny

Sonny 04-20-04 08:07 PM

BTW-If you get tagged as a gross polluter, it is illegal to drive your car until it's fixed (straight from the Ref's mouth and also on the DMV web site). Do not get yourself pulled over between now and when you get it through smog or you could end up with more hassles/fines.

Sonny

ttb 04-20-04 08:09 PM

thanks. didn't know that. seems kinda stupid. do they expect me to tow it everywhere?

aw101584 04-20-04 09:01 PM

Here are mine numbers:

15MPH @ 1844 rpm
HC (PPM) - 88 (My RX-7 = 88)
CO % - 0.52 (My RX-7 = .16)
NO (PPM) - 704 (My RX-7 = 384)

25MPH @ 2976
HC (PPM) - 53 (My RX-7 = 53)
CO % - 0.50 (My RX-7 = .09)
NO (PPM) - 738 (My RX-7 = 392)

I have dp, streetport, intake
Good luck!
~alan

aw101584 04-20-04 09:07 PM

Here are mine numbers:

15MPH @ 1844 rpm
HC (PPM) - 88 (My RX-7 = 88)
CO % - 0.52 (My RX-7 = .16)
NO (PPM) - 704 (My RX-7 = 384)

25MPH @ 2976
HC (PPM) - 53 (My RX-7 = 53)
CO % - 0.50 (My RX-7 = .09)
NO (PPM) - 738 (My RX-7 = 392)

I have dp, streetport, intake
Good luck!
~alan

Sonny 04-20-04 09:45 PM

alan: damn, that's what I call cuttin' it close!

Sonny

aw101584 04-20-04 10:48 PM

haha yeah you can't get any closer than that lol, I was soo happy to see PASS on the screen. sorry about double post.
~alan

Die For MX 04-22-04 01:20 PM

it seems that there would be more load on the engine at 15mph @ 2870rpm rather than 25mph at 2806, so more fuel getting thrown in. but its really hard to say why, there would have to be more detail about the testing conditions. Shouldn't be too hard to fix though.

clayne 04-22-04 01:28 PM

No, there would be more load on the engine at 2800 rpm while at 25 mph as opposed to 2800 rpm at 15 mph.

They're obviously testing it in different gears. I think it's just a tuning issue. Drop the stock ECU back in for the test.

ttb 04-22-04 01:28 PM

oh, fwiw, i passed. put the stock ecu back and passed with flying colors. i guess i though it was rpm dependent, not speed dependent. but then again i know very little about cars :-/

Sonny 04-22-04 01:31 PM

Smog ref told me that the 15 mph test has to be done in 2nd gear. 25 mph test has to be done in 3rd gear. It seems stupid because most of the time, your engine is seeing at least 2500 when cruising around.

ttb: Is that the "Unwanted Son" in your avatar?

Sonny

ttb 04-22-04 01:32 PM

hahaha..no, that's me. i was a cute baby. not so cute anymore, so better to put up the baby pic

Sonny 04-22-04 01:33 PM

lol...not sure if you've heard of the book, but it's basically about a kid that was the son of a GI who left Vietnam after the war. The pic on the cover looks very similar to your baby pic!

Sonny

Die For MX 04-23-04 07:59 PM

.

Die For MX 04-23-04 08:06 PM


Originally posted by clayne
No, there would be more load on the engine at 2800 rpm while at 25 mph as opposed to 2800 rpm at 15 mph.

They're obviously testing it in different gears. I think it's just a tuning issue. Drop the stock ECU back in for the test.


Like I said, I would've needed more details. Your first statement isn't necessarily true. Load is dependant on a lot more things than just motor angular velocity and vehicle speed.


All times are GMT -5. The time now is 10:07 AM.


© 2024 MH Sub I, LLC dba Internet Brands