mx5cartalk.com

It can be done! My car has just passed IM240 on its first attempt!

For those too lazy to troll through my build thread for details, here is my setup:

1994 MX5 (completely stock 1.8L internals w/123k kms)
BEGi cast manifold and stainless downpipe;
Ported Garrett GT2560;
Small FMIC;
RX8 440cc injectors;
Megasquirt DIYPNP (Braineack built) running old 3.1.2 firmware;
Innovate LC-1 wideband;
2.5" Jackson Racing hi-flow catalytic converter;
2.5" Enthusa cat-back exhaust.

I haven't switched to COPS yet (even though I have a set waiting to be installed), this test was done with stock OEM coil and NGK leads.

We don't have any fuel stations nearby that sell E85, so on the morning of the test I drove the car to Caltex in Casula (the nearest station that sells it). Thankfully by the time I arrived the tank was almost empty. I filled the tank with E70 (Caltex's winter E-Flex blend only has 70% ethanol), and plugged the laptop in. I upped req fuel by 30% which got me running, then set tunerstudio up to auto tune at stoich in cruise, 12.5 at 100kPa, and 11.7 WOT. I then drove to the testing station up the M5 (working on cruise cells) and then round Botany (working on other cells that I could get). Got about 45 mins of driving/autotuning in before the test.

Once there, I had some issues on the dyno because my car was too low, so it took 20 minutes to set it up (during which time the car got some serious heatsoak going).

First test went 1.96ppm on NOx with almost zero CO2. Failed by 0.03PPM! Second run nailed it though, NOx down to 1.86ppm (still almost zero CO2).

FYI and in case you're wondering, my timing map is only slightly advanced over the basemap.

Lesson learned! To anyone else out there, run E85/E70 and err on the side of richness, and you should do just fine!

So, Megasquirt CAN PASS IM240 EMISSIONS with a road tune!

Thanks zossy1. I will also be going for this test soon.

Thanks zossy, I'll also be putting my car through the IM240 on E85 so this helps a lot

zossy1 wrote:then set tunerstudio up to auto tune at stoich in cruise, 12.5 at 100kPa, and 11.7 WOT

My understanding was that since widebands measure in Lambda and then the software converts it to AFR, unless you've told the software that you're running E70 then stoich will still be shown as 14.7 (Lambda 1.0). Did you change any settings in Tunerstudio? Or did you just set it for 12.5? If the latter I think you would have been running a bit rich at cruise.

Beelzeboss wrote:My understanding was that since widebands measure in Lambda and then the software converts it to AFR, unless you've told the software that you're running E70 then stoich will still be shown as 14.7 (Lambda 1.0). Did you change any settings in Tunerstudio? Or did you just set it for 12.5? If the latter I think you would have been running a bit rich at cruise.

Correct. The LC-1 reads lambda and stoich is 14.7 regardless of whether you're running E70/85 or petrol, unless you mess with your LC-1 settings.

The ONLY thing I did was up the req fuel to compensate, and then autotune. My map was set slightly leaner than 14.7 in cruise for petrol so I dropped it down to 14.7 for the E70. In hindsight, I probably should have dropped it down to 14.4 or so as NOx was a far bigger problem than CO2 when running the E70. The Ethanol gives you loads of headroom on CO2.

Accel enrichments are also an area i'd look a little more closely at if I had failed, as the testing officer indicated that he was seeing NOx spikes when blipping the throttle.

zossy1 wrote:
So, Megasquirt CAN PASS IM240 EMISSIONS with a road tune!

On E85...

Sean wrote:

zossy1 wrote:
So, Megasquirt CAN PASS IM240 EMISSIONS with a road tune!

On E85...

Now, now, Sean!

What's your point? Legal IS legal after all, I'm pretty sure the boys in blue don't cart a 4-gas analyser around in their patrol cars!!



In all seriousness, the guy at the testing centre in Botany indicated that at least 80% of the cars he is passing are running E85. He also told me that he is recommending E85 to everyone who fails, and most of the time they are coming back and passing on E85 a few weeks later.

It is THE way to pass IM240, regardless of whether you are paying $$$ for a quality dyno tune or doing it DIY.

My point is loosely that you could probably get a mechanical injection setup passed on E85.

I'm not meaning to run down your achievement, but as the guy told you, pretty much anything can pass with E85, heaps of guys are passing cars on E85 and still running a dual map (for PULP) as E85 is not readily available everywhere.

I remeber back in the early 2000s seeing a 2litre (non MX5) turbo pass with 1000cc injectors and an old OLD Microtech, maybe an MT4 or 8? The trick was it was running a methanol/PULP mix. I couldn't believe it passed, you could smell it was running some type of special jungle juice mix and it made eyes water in the dyno cell when it was being tuned... Amazingly it was passed and no questions were asked!

So I guess my point is to agree with your latest post - If you want a pass, E85 is the trick, not a Megasquirt, Motec, Haltech or any other specific ECU.

Hey zossy1, do you know how many CPI the Jr cat is? Do you guys think a 100cpi cat with a car on e85 would pass?

rxmx wrote:Hey zossy1, do you know how many CPI the Jr cat is? Do you guys think a 100cpi cat with a car on e85 would pass?

I have NO idea - on either question!

Sean wrote:My point is loosely that you could probably get a mechanical injection setup passed on E85.

...
So I guess my point is to agree with your latest post - If you want a pass, E85 is the trick, not a Megasquirt, Motec, Haltech or any other specific ECU.

Can't disagree with you there. My point was always that there is hope for folks tuning DIY on Megasquirt - I've heard too many people claim it was not possible to pass IM240 with the Megasquirt and a road tune.

zossy1 wrote:

Sean wrote:My point is loosely that you could probably get a mechanical injection setup passed on E85.

...
So I guess my point is to agree with your latest post - If you want a pass, E85 is the trick, not a Megasquirt, Motec, Haltech or any other specific ECU.

Can't disagree with you there. My point was always that there is hope for folks tuning DIY on Megasquirt - I've heard too many people claim it was not possible to pass IM240 with the Megasquirt and a road tune.

Yep, but as with a lot of things on here people who haven't done things or even tried love to be seen as fonts of knowledge.

I'd say it'd likely be possible to get almost any ECU passed on PULP with the right set-up. I'm no expert, but I've done put a few cars through IM240 (other people tuning) E85 is deinitely the way to go for a DIY or even a pro if you just want the pass. If it's available locally it's also a nice cheap way to make some more power. There's two stations selling E flex up my way, both seem to run the winter mix at E70 all year round.

Sean wrote:There's two stations selling E flex up my way, both seem to run the winter mix at E70 all year round.

Lucky... my nearest station is over 100km away. I'd love to run corn juice all the time. Not possible though.

That's the tradeoff for the good roads near your place