TRAXION

The time has finally come. I will probably be going for my IM240 treadmill test next week. !EGR, !AIR, !Cats, 230/245 cam. Holy crap is this going to be interesting

I've decided to see what I minimally need in order to pass. In other words - I will roll into emissions and try to pass with only PROM changes and some CRC G2P in 1/8 tank of gas. If that doesn't work then I will do the same thing but put my real cats back on the car. If that doesn't work then I will have to put the stock cam back in. Anyhow, I am looking for suggestions on PROM changes. I have already made the following changes to my 'IM240.BIN' - lol - ...

1) Fan temps set high in order to keep the car hot.
2) Bumped Injector constant up *slightly* in order to lean it out a bit across the board to help HC counts at the expense of other counts.
3) Bumped maximum added advance DOWN to 16 in order to keep maximum advance at 26 and under (my base timing is at 10). This should work hand in hand with #2 in order to have the engine utilize less fuel.
4) Disabled PE via %TPS to enable PE.
5) Disabled highway mode.
6) Bumped idle up to 1000rpms (to help disguise my rediculous lope).
7) Bumped my pumpshot down to control off-idle richness that could occur during throttle opening.

Any thoughts?

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

gravitar

For the emissions reason alone, I think I will never move out of Michigan!

Kevin91Z

iTrader: (1)

Tim, if your IM240 test is like ours in California, they check your timing as well. It has to be at stock setting of 6º. I think they give you 2 or 3 leeway, so you'll need to set your timing lower than 10º.

Other than that, I think you'll need to put the cats back on to pass with your setup.



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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

BOWTYE8

I agree with last post. I feel you will not pass without cats.
With cats you shouold pass. Here in IL. we have the treadmill test as well. 2 years ago I went thru with my miniram383,219,headers,trueduals(no cats),ported heads. I siad let me try. Well I was off the charts I failed so BAD. I mean off the chart. I did back into the chart evey now and then but it was embarressing.
Next step. I installed ,y sotck exhaust manifold and factory exhaust with a new cat. 85 corvette has one center cat.
Must have been running still rich. That 85 exhaust is pretty restrictive. After the cat it was glowing red.
Well I drove it to the test sat more for 8:00.
I PASSED with flying colors. I mean I was clean like a 2000 new car. The new cat definately helped over a old one.
Came home swapped back to headers and true duals and was back on the road for 2 years until now. I have my test again. This time I have diferent ins. So trying for show car exemption.
Good luck Tim

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85 vette,383,miniram,ZF6,4.10's..best ET 11.56@119.00 60' 1.59
w/100HP nirous 11.05@127
http://geocities.com/bowtie8
http://bowtye8.tzo.com

TRAXION

I totally agree with you guys on the cats thing. In fact - been there done that. I tried to pass with the STOCK heads/cam with no cats and failed. Put the cats back on and passed with flying colors. However, I just want to see how badly I fail. You never know - I might get lucky. I talked to an 'expert' in our area and he is the one who gave me the tidbit on the CRC stuff. He told me NOT to use it as directed. He said to dump a whole bottle of CRC G2P in 1/8 tank of gas. Drive around for 5 minutes to get the car hot and to get the CRC up to the injectors and then go to the gas station. I am not looking to pass this test on the merit of NOT having emissions. Heck - if you stand behind my car your eyes will water I just want to see if I can get through emission without having to 'jack the car up' and work on it - lol.

They don't check timing here. All they do is put a mirror under the car and inspect the exhaust system to make sure that cats are there. It looks like I have cats


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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Grumpy

Fresh oil change
Good long drive immediately before the test.
Lots of in tank help.

If that doesn't work, huge FRESH cats.

Double check the tune, look at the plugs and note what needs done, fresh cap rotor.

PLUG WIRES, spray em with water using a plant mister, to make sure they are 100% good.

Grim Reaper

I am GLAD I no longer have to do that test. I was subject to testing from 1991 to 1999 before I moved out of the Lower Mainland of BC.

Though I wasn't into PROM Burning the last time I tested my car in early 1999, I had done a couple of Diacom readings that gave me some interesting information.

I found that taking my car on a nice "highway drive" and then driving straight in gave the lowest readings. I got my highest readings when I was stuck in line. This is because my car went into Open Loop due to prolonged idling.

Also, I tried virtually every T-stat there was (160*, 180* and 195*) and found little difference in my readings between the various T-stats....in fact, getting it HOT with prolonged idling (causing Open Loop) gave the worst readings. Pulling straight up with a 160* and 195* and not sitting in line gave basically the same results. That is when I noticed that I remained in Closed Loop during the test.

Now that I can burn an eprom, if I had to do testing again, I would play with the "commanded" Air Flow Ratio if I was "off side" on a reading. E.G. If my HCs were high, I would increase the AF Ratio to lower it a tad. Conversely, if my NOx was high, I may try lowering my AF Ratio to reduce it.

But, again, try and keep the car in Closed Loop. My worst readings always occured when I fell into Open Loop due to prolonged idling.

Kevin91Z

iTrader: (1)

Be careful if you fail by too much. Get a "pre-test" if you can so you arent put into the computer as a "gross polluter". Thats a very bad thing.

AlexJH

Is there a minimum idle for the test? Where I live if you are above 900rpm (I think that's the right number) at idle, it's an automatic fail.

gravitar

Aren't there any cars that have a stock curb idle above 900? I wanna say my old Cosworth Vega idled at 1100..

FastBroker

Pull the PCV valve out of the grommet, too, if they don't check for it. The gasses it sucks up don't help you out. If they check for it, you cold block the hose so it is not working. the ECU will adjust the fuel anyway. If you have a lot of blowby, this will help a lot. 2 cents. every little bit can help.

drive it

iTrader: (1)

Big ditto on that!!!! Here, if you get the dreaded gross polluter designation, then for the next few years you MUST go to a state smog station for testing-and those guys are hard headed!(I'm being very tactful with that one)-ANY non stock parts (including the prom!!!!) without an oe #- forget about it!

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86 406

SATURN5

I am so glad my Malibu will be exempt in 4 years...hehe, time for that 396 and homebuilt intake, that is if the turbo tpi doesnt survive.. ;-)

JakeJr

The water spray test is interesting. Got some more details on it?

Thanks,

Jake



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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

SATURN5

misting the wires should show if there is any breaks in the insulation, the water will make it easier for the wires to ground to the block, head etc, causing it to spark..could make for a neat light show at night if your wires are shot..lol, Bob

Hunter Motorsports

Here, Kitty Kitty Kitty...

Cats (converters, not the furry, cute little ones) are most certainly the way to go. A good quality fresh cat makes the difference between failing miserably and passing with flying colours. Get a BIG single 3-way converter and slap that puppy on there! It will make all the difference in the world.

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Karl Hunter
Hunter Motorsports
Vancouver, B.C. CANADA

BTS88IROC

Any updates? I'm curious to know if you passed or not?!?!

TRAXION

It was so hot out that they were NOT putting cars on the treadmill. They were doing idle sniffs only. They told me that it was a good thing that they were ONLY doing idle sniffs because there is no way that they would let me on the treadmill with my bald back tires. That means that I have to put a set of good tires on the back of my car. Oh well. Mo money. Anyhow - I failed miserably.

HC limit = 220ppm
My car = 871ppm
CO limit = 1.20%
My car = 2.85%

WOW. As you can see, I failed pretty badly. I didn't think I was going to fail that badly – especially since I was running 1 gallon of alcohol in 1/4 tank of gas along with 2 bottles of CRC guaranteed to pass. The alcohol that I used was Denatured Alcohol (ethanol) as available at your local Home Depot / Lowes. I really think I would have done better on the treadmill test but oh well ... it just wasn’t in the cards. The guys at the testing station were very cool. They tried to help me pass but no luck

In retrospect I think that the chip changes were too aggressive based on the fact that I had ZERO evidence to tell me what changes to make. I just slapped a crapload of changes in there. Learn from me. I always preach not to make changes unless you have evidence to tell you what changes to make (or unless you are experimenting). With that said – I am going to slap my real cats onto the car, put in my real street tune, and just go. I’ll make changes as they are necessary / warranted. I’ll update further when I have more news.

Tim


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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Z_Ghost

I have seen cars that were almost that bad, pass when a new cat put on it.

Pablo

iTrader: (1)

Thats not that bad, I had a 4 cyl once that failed with 1500 hc ppm and well over the co limit if you can believe that. Tweaked it a little bit and it passed the next time with flying colors

TRAXION

Update:
Went to emissions again. This time I did NOTHING special. I ran straight gas and did no PROM changes. I was running my normal street tune. The only change I did was to put real cats on the car. I still failed but I was surprised at how close it was. I passed the CO but failed on the HCs. State limit is 220ppm and I had like 310ppm. Pretty close.

Interesting observations:
I thought to myself - hey, all I gotta do is change the stoich AFR from 14.7 to something higher and then go back and retest (they weren't checking NOx). Well, I set my stoich to 14.9, 15.1, and the 16.0 doing some testing in my driveway. This change did nothing to my car. The Base Pulse Width remained the same and the O2 voltage looked like 14.7 ... swinging back and forth as usual. The only way I could force my car to run lean is to force open loop via the Temp for closed loop enable and then reset the injector constant to something high (changed it from 33lb/hr to 40lb/hr). With open loop I was able to get the O2 voltage to drop down really low 30mV and lower. Also - the BPW with this setting was still the same as before (maybe single fire mode was engaged?).

I'll retest tomorrow running a lean calibration.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Grim Reaper

That is interesting that the AF Ratio doesn't work, will have to test that and see if I can figure out why. I know that when I bumped it up once by accident, I got the higher number. But it was to like 14.8 or 14.9. I'll let you know what happens when I try it.

For the "highway test" you could also try invoking Highway Mode at a lower speed/rpm. I've invoked it as low as 25 mph (just for testing purposes). Up here, they run your car in second gear at 20 mph to simulate Highway.

Kevin 88

iTrader: (1)

The calibration probably won't help if your cam is way big. Overlap lets unburned fuel/air blow through to the exhaust. The O2 sensor sees the O2 and thinks the motor is lean, and the sniffer of course measures the unburned HC. Now if somebody made a 1.3:1 ratio rocker arm...

TRAXION

Kev88 - in OPEN loop the car does not look at the O2 sensor and no adjustments are made to the delivered fuel. Thus, if you force open loop and run lean .... the car will run lean with no adjustments.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

TRAXION

Glenn - I shouldn't have said that it did NOTHING to my car. The Commanded AFR was absolutely in-line with what I set the value to in the BIN. However, the pulse widths and the overall O2 values did not change.

I think that I could also be on the brink of some injector vs. calibration issues too. At 2500rpms the BPW is 1.1ms. Many people say that this is too low but my car has no problem running with this BPW. Runs smooth as silk. The idle BPWs are around 1.5ms. Idle is smooth except for the lumpy cam . Anyhow - there seems to be something in the code regarding single fire mode for the injectors. There is a threshold around 1.1ms. Funny thing is that when I forced open loop and set the injector constant to 40lb/hr .... the BPW was STILL 1.1ms at 2500rpms. However, the O2 volts told the story with 30mV and less . Load does not fit into this equation for my tests because I was doing the tests in Park in the driveway .... just like they do the idle tests for emissions. Anyhow, I am curious if in one case the car was in Single Fire Mode (open loop, 40lb/hr constant) and in the other case the car was in standard batch mode with 2 fires per cycle (my normal cal which also gave 1.1ms BPWs but with a nice fluctuating O2 voltage). Hmmmmm. I need to figure out how to report the single fire mode bit out the ALDL. I could put it in place of the Power Steering switch in Diacom.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Grim Reaper

Tim, I wouldn't expect a minor change (14.7 - 15.2) to affect the BPW as this is less than 10%. But I will do a test on my car as it typically idles with a BPW 1.5 ms and I will change the AF ratio to 16+ as this SHOULD make the BPW to drop to 1.4ms (or less).

TRAXION

Glenn - I'll also try something rediculously lean. I already tried 16.0 and didn't see a difference. I'll try something in the range of 17+ and see if I see a difference in the O2 and BPW.

Tim


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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

TRAXION

I passed the test today. This time the test was really quick! Probably because my car was SOOOO within the limits State HC limit = 220ppm. I had 17ppm. Yea, that's right - 17ppm. State CO limit is 1.2%. I had 0.04%. WOOHOOO!

All I did was force open loop and raise my injector constant from 33lb/hr to 40lb/hr. I don't advise ANYONE to do this for ANY extended period of time. I drove the car on my *normal* calibration until it was warmed up. About 50yds from the emissions station I pulled to a side street and swapped in the lean calibration. I babied it the 50yds to the station. As I took the test I don't think a light on my AFR guage ever lit. My O2 voltage was 27mV and lower as long as the car was over a certain %TPS ... which is where I kept it After leaving the emissions station I pulled over on the same side street and put in my normal calibration.

Now I can get back to business! Here come the long tube headers, indestructable Denny's DS, and 58mm TB.

Tim


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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Grim Reaper

It does prove one thing, as long as you have a proper cat, you can "force" the car to pass emissions via the eprom. I wonder if you had tried that (leaning/open loop) without the cats what would have happened? Should have given it a try. You DID drop by a factor of 10 with that change. The cats only improved by a factor of 4.

Grim Reaper

PS: Congrats...until next year.

TRAXION

Glenn - actually, I think the cats did more than what the tests show. My first test had 871ppm of HCs but that was running a gallon of alcohol, 2 bottles of G2P and many PROM changes (no open loop leanness). I am pretty sure that the HCs would have been well over 1000ppms with straight gas and no alcohol or G2P. Adding cats and running my normal, aggressive street tune dropped the HCs to 310 ... about 30% of the original value IMHO. Running really lean dropped the HCs to about 5% of the preceeding value. If you look at the original value assuming > 1000ppm to 17ppm ... WOW ... that would mean the addition of Cats and PROM changes brought the values down to probably close to 1% of the original. Amazing.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

GregWestphal

iTrader: (1)

Congrats again Tim! Glenn, luckily in Maryland, we only have to get emissions tested once every 2 years. I just passed with my ol' 305 back in February, so I won't even have to think about this for a long time.

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Greg Westphal
'87 IROC 355TPI/A4

MikeH

iTrader: (10)

Way to go Tim....The cam in my 406 has alot more overlap than I thought it would have. I was Kinda wondering, what It would take to pass here if they decided to bring back testing next year.

With the low numbers you got. I wonder if it would have passed without the cats even.

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90 IROC
SuperRamed 406
Trickflow 23* heads

ptc92rs

TOP

I need this!

padgett

Came across this site which has an interesting comparison based on a Firebird and a description of how to tell if the CAT is good or bad (check the CO).
http://www.colostate.edu/depts/NCVEC...erters/az.html

anesthes

iTrader: (12)

Back from the dead....

Tim,

You made a lot of changes but in the end you seeemed to settle on just pw, and open loop forcing a lean condition.

What was your base timing and idle set at? And max timing?

My "running good" bin seems to average out at around .540 02 for most driving. Under boost its another story all together. I'm trying to whip out a quick emissions bin.. Allready put the new cat in this week.

Did you put an AIR pump on your cats???

funstick

dont worry about the air pump unless they are doing a cold start test. best thing to do in the staging lanes is to keep the engine idleing at like 2000rpm. keep the brick nice and hot. what test standard are they using and any 5 ga data to share ?

anesthes

iTrader: (12)

mass is same test as california. basicly we pass california emissions.

-- Joe

TRAXION

First - What I did was incredibly dangerous. I absolutely do NOT recommend this for anyone. I got lucky. Yes, I did settle on forcing open loop and running a larger injector constant to force shorter pulse widths. That's the only way that I could pass the HC's. The cam is just too big. I had virtually new GM cats installed (dual cat setup). This helped A LOT but not enough to make it pass. I need both cats and the forced open loop in order to pass.

I run 10d initial. Max depends on kPa and RPM.

Next time I am probably going to try a full tank of racing alcohol since I know some others who have passed this way.

Tim

anesthes

iTrader: (12)

Tim,

I did my prom similar. Yeah, its dangerous but it runs lean.

Did you use air pumps on your cat?? I'm running a new cat without air and I'm wondering if its gonna melt down.

-- Joe

kevm14

One thing readers should note is, this open loop lean-out trick would NOT work if they also test for NOx in your area. Tim, you were probably WAY off the charts for the CA NOx limit (with correspondingly high EGTs).

anesthes

iTrader: (12)

Well I hooked up the 4th gen air pump to my 3-way cat.. I ran a relay off the power to my fuel pumps, so the pump only runs when the car runs (makes sense, eh?)

The 3-way cat, and slightly colder spark plugs should make it happen..

-- Joe