IM240 test

[letsboogie351]

Well today was the day I had been dreading....IM240 test!
I had heard of other cars in Vic failing this test so I was not very optomistic when I left home (or for the past few weeks if i'm truthful). So, after a liesurely cruise down the eastern and into town, the time came to tie my little girl to the dyno. The first run was to ensure the car was at optimal operating temperature, and the tester deliberately didn't look at the result. And I did not know what the figures were meant to be so it was no good me looking at the result.
It was quite interesting to see how the bloke in the driving seat used throttle and brake to keep the icon within the speed trace shown on the computer screen.
Anyhow I'm not sure if my results will please some or infuriate or frustrate them. The first test run was an overwhelming success! Well under the prescribed limits. Subsequent runs showed the same story.
Looks like that good 'ole "Henry" bent eight under the bonnet delivered the goods and made me the happiest bloke in Melbourne today. Now we wait to hear from Vic Roads I suppose.

Doug

[Merv and Sharon]

Well done Doug! The old Ford still cuts the mustard. Which motor did you use?

[letsboogie351]

Hi Merv
I have the Boss 260 quaddie in mine. Kept everythingas stock as possible

[boxhead]

That is great news Doug.
Well done on the pass and hope the rest falls into place for you.

[sambo]

Well done Doug! Stock cats too?

[stephen low]

Good work Doug!

Might have been explained in previous posts but where in the emissions ADR scheme of things does the IM240 test fit?

Is it equivalent to the previous 37/1 ADR limits or something tougher or softer?

I remember my test at Enklemans and I think I barely registered on their equipment against part of the testing. I susre their gear would not be to the same sort of detection standards though.

However as I have since learned my 5L motor at that time was actually pretty clapped out by the drag racing dingbat that had owned the wrecked AU I sourced the motor, gearbox and the cats from.

I'm surprised it wasn't old smoky given I got to see the crank scoring and colouring it had suffered once Don rebuilt it as part of the accident.

So there must be some level of latittude in the measuring tolerances.

Anyway again good work Doug but don't hold your breath waiting for VicRoads to issue the VIN quickly. Though for your sake I hope they do!

Ciao

Slo

[Mando]

Doug, well done, you must be relieved. One step closer!

Regards.

[benny s]

Well done Doug,first Cobra to pass i hear.Hopefully you are on the road by Christmas

[Mando]

Went for my IMO240 test today, these are the results that sunk me.......

NOx should be 1.93 I've got .466 pass
CO should be 9.30 I've got 22.20 fail
THC should be 0.93 I've got 3.378 fail

Back to the tuner

Regards.

[stephen low]

Running rich if my chemistry is right there Mando.

THC -Total Hydrocarbons would be a measure of the unburnt fuel being belched out of the system I'm guessing.

Not sure how it then relates to carbon monoxide though and even what the cats are meant to help reduce.

I'd presume a decent tuner should have some similiar analytical gear so get a reading before any retuning of the engine. This will benchmark your output based on their gear and will simplify comparing any further tuning and results.

Bad luck though on the results.

[letsboogie351]

Mass Emissions
THC (g/km) 0.06356
NOx (g/km) 0.08610
CO (g/km) 0.28836
CO2 (g/km) 267.41998
Fuel Consumption (L / 100km) 11.18607
NOX correction factor (KH) 0.83224

Here are the results of my test. As you can see I was really surprised. I was going to get a mate at the local ford dealer to tune before the test but he said not to worry about it. Then i thought I would take the car for a long run at highway speed but.....you guessed it, it was pissing down. So I did absolutely nothing

cheers
Doug

[NASSTY]

As I broadly understand it, NOx is mainly affected by timing.

CO and CO2 is more a fueling issue.

Mando, is your set up running closed loop? If not, unabling closed loop should fix alot of your tuning issues as the ECU will trim up your A/F ratios to 14.7:1 which is what your cats need to work properly. I assume you're using aftermarket EFI.

[Mando]

Nasty, I don't know if my system is closed loop. I think it's called Hall Effect and it's connected to the crank. Instead of a distributor I have a signal pickup and run 8 coils. There are some pictures in my gallery that might make more sense for someone who knows what their looking at.

Regards.

[Gav]

The ignition sensor is a hall effect sensor. Most late model cars speedo use the same principal too.
The closed loop that Nasty is refering to in broad terms, is the ECU's ability to fine tune itself according to what readings it is getting from the sensor in the exhuast and other sensors on the motor.
Not running a closed loop would see your motor running to fixed fuel and ignition settings according to throttle position, vacuum and temperature ect and not being able to make subtle changes to keep things like fuel mixture running at their optimum.
Sorry to hear about your test on friday Mando, when will you be getting it retested?

[Mando]

Hi Gavin, it'll be 3-4 weeks before I take the test again. The guy at the testing station gave me the name of a tuner that I'll book in to see ASAP. The only good thing to come out of Black Friday is they didn't charge me for the test. You've got to be lucky sometimes!

Regards.

[NASSTY]

Hi Mando, I assume that because you're using AFR heads and 8 T/bs that a Ford EECV computer wouldn't cope and you're using an aftermarket ECU? I'd also assume if you are using an aftermarket computer that's it's probably tuned with throttle position (TPS) as the load input as you've probably got bugga all manifold vacuum with the 8 t/b setup? If yes to these questions then you've gotta get the tuner to enable closed loop. Why? Because TPS cannot adjust for changes in atmospheric pressure and heat soak of the t/b's especially at idle (there's 8 of 'em so even a little growth will play with the a/f ratios) without closed loop enabled. If tuned under MAP (manifold absolute pressure) then it will adjust for atmospheric pressure changes but not for heat soak of the t/bs. Get your tuner to check the end angle of the injectors too as if the angle is too early then unburnt fuel will go straight out through the exhaust valve on the cam overlap. If it still fails after that then I'd look at individual cylinder tuning (assuming your ECU can do this) because it's a fair bet at idle and light throttle your t/bs won't be balanced which would cause a lot of variance of the a/f ratio between cylinders.
Problem is this all takes a lot of time and $$ so some tuners won't do it or they just don't know how. All you need to do it yourself is a wideband a/f meter and some patience.

Good luck with your next test.

[sevenohms]

Originally Posted by NASSTY

As I broadly understand it, NOx is mainly affected by timing.

CO and CO2 is more a fueling issue.

Mando, is your set up running closed loop? If not, unabling closed loop should fix alot of your tuning issues as the ECU will trim up your A/F ratios to 14.7:1 which is what your cats need to work properly. I assume you're using aftermarket EFI.

Further info: I spent some time at uni tuning a race engine for the FSAE competion the unis do, NOx is timing based but also fuel mixture based as fuel mixture controls combustion temp, which is the driver for CO or NOx as the outcome from the combustion process. Looking at the numbers you can see that NOx is low, but CO is high, so it's off tune. Once it is tuned back to stoic conditions (14.7 is stoicometric fuel combustion ratio) then NOx will come down and CO (and CO2) will come up. What the Cat does is help eliminate the NOx (which is why the manufactures put in better cats to reduce CO2, lean it out = better fuel economy and less CO2, but more NOx which is taken care of by the Cat convertor). So your tuner in this case would put less fuel in, to lower the CO/CO2, but increase the NOx which in any case the cat should be taking care of anyways.

THC is the total hydrocarbons, which is either too much fuel, or oil bypassing rings/etc in an older engine. But cause theres too much CO/CO2 its more likely a fuel rich tune (12:1), which is good for power, but bad for the test which is likely to prefer a 15-16:1 (lean tune).

Hope this helps.

Nathan

[Mando]

Thanks Nathan, I don't know anything about engines or how they work but I'll pass on the information to the tuner who's going to have a go next week. I'm hoping he gets it right.

Regards.