JDM 7m, passes smog, nothing but cat...

[suprabones]

Hey there everyone, thought I would let everyone know I passed Ohio's emissions testing purrrrfectly with the JDM NA 7mge. It took me 3 trys with the help of my SAFC to tune. I thought I would be running rich, considering I am running the NA with all turbo electronics, and 440's, HKS SMF Intake, Honda Intake pipe mod, JDM 5 knob SAFC, OBX header, downpipe, 2.5" exhaust, High flow cat, and a Apex-I N1 muffler. I tuned out 10% fuel at 800, 2400, and 4000 RPM. and retarded the timing as far as I felt comfortable with my EGT's. first try was basically a base run to see where I was at. Well, I am sure everyone would know this but, I was running REALLY lean... so I failed.. I was like 3000 in NO, with an allowable 984.. LOL. So I reset timing to as close to 10 as I could by ear, and went with no fuel reduction or addition on the SAFC, ran it again, this time I was lean at 1024 with an allowable 984.. so my last run I added 10% fuel to 800, 2400, and 4000. rolled her again, this time I passed at 890, pretty much a cake walk, took me all of 30mins.. I thought I would be rich, but when I did finally pass, I was at 12.4 with an allowable of 140... So it seems I am pretty lean.. does anyone have a idea of what could cause this? bad 02 sensor? my car does "bog" down at 2400 RPM, the only way to get around it, is add 30% fuel at 2400, and use ECT on the auto.. maybe my fuel pump is craping out? anyone have any ideas? Thanks
-Matt.

 

[Adrian98]

what were your numbers?

 

[A-to-the-J]

in CA, you'd fail. by default. lol. CA = car nazi land

 

[suprabones]

I will post my Emission #'s sometime today for all who are interested.

 

[jetjock]

As long as the engine is mechanically healthy, in fuel control, and with a good cat it would pass no matter where it came from or what aftermarket gadgets are on it. The visual inspection aside that includes California. After all this smog stuff isn't rocket science.

That said it sounds like you simply suppressed NOx by upping CO but not enough to bust the limit. Until we see the numbers it's just a guess though. If true the engine may have passed smog but still isn't running right. Many people seem to forget there is no better way of knowing an engine is operating correctly than when it has good emissions numbers.

 

[suprabones]

Ok here is my #'s for everyone that is help me.. Thank you all.

Emissions ASM:

TEST READING UNITS LIMIT RESULT

Hc 12.4 PPM 140.0 PASS
Co 0.02 % 0.89 PASS
No 980.5 PPM 984.0 PASS
Co2 15.02 % N/A

Well everyone that is my emissions test.. Hope this helps with the diagnosis.. Thanks for the help Jetjock.. you are truly a supra tech..

 

[ATL88Supra]

ehhh i do not like high flow cats, never had much luck with them



i would get a Good cat not a high flow infact cats work by heat if its high flow how will it get hot enf to work like it needs too so spend a extra 30 bucks to get
a full blown cat. as for the tune while on dyno i would never do that.. do things the right way man. my numbers on my smog test was that of a brand new car

 

[jetjock]

Got certified on emissions just to learn but have never done it for a living. I also buy, repair, and re-sell older emission analyzers as a hobby. Twisted huh?

Pretty decent numbers. CO2 is an indicator of combustion efficiency and 15% is nothing to sneeze at. NOx is still high (lucky you squeaked by) but since you said "nothing but cat" I'm assuming you don't have EGR on the engine. If you do it may be partially blocked or otherwise not operating quite right and your catalyst (which looks to be very healthy) is picking up the slack.

The other gases are excellent. You could be just a tiny bit lean (it'd be nice to know O2 but I guess Ohio doesn't provide it) but otherwise your engine and EFI system seem in fine shape.

Thank you for the kind words via PM...

 

[suprabones]

Thanks for the quick responses everyone.

Jetjock, you are correct in thinking I am not using a EGR.

So the #'s arent too bad? I wonder what is causing the engine to "bog" down at around 2400-3000 RPM. actually when I hit 2400, it likes to drop down to about 2200 then start to climb, this happens at partial throttle and even at WOT.. I checked diagnostics on the the tranny (a340) none to be found, no codes on the motor, and my egts are staying at right around 650-700c at highway cruising speeds (65-75) timing is dead on at 10 deg. BTDC I am thinking of installing a FPR to dial in my fuel at the rail.. as for actual fuel pressure, I am not even sure what it is.. I am lacking in the tuning department, I really could use a wideband.. arghh :3d_frown: