Megasquirt owners thread

Mr nanotech · Postby **Mr nanotech** » Thu Dec 12, 2013 8:40 pm

Best I can do is get it going for 2 seconds at best. Each time it just dies. Even stranger, when I hit the throttle, nothing. the gauge doesn't change, no feedback. It's like the cable has been cut.

gslender · Postby **gslender** » Thu Dec 12, 2013 10:31 pm

Yep, you'd need to double the reqfuel value (roughly)

G

goonie · Postby **goonie** » Fri Dec 13, 2013 10:22 am

Just wondering if anyone could help me out with this question.

If I disconnect the battery for about a week, will Megasquirt load up with the tune I was last using?

Thanks in advance.

Dweezle · Postby **Dweezle** » Fri Dec 13, 2013 12:24 pm

Yes. Sure will.

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gslender · Postby **gslender** » Fri Dec 13, 2013 9:22 pm

goonie wrote:Just wondering if anyone could help me out with this question.

If I disconnect the battery for about a week, will Megasquirt load up with the tune I was last using?

Thanks in advance.

The MegaSquirt hardware uses the same kind of storage that USB keys use, so yes, even after years of no power it will start just like it last did.

G

Mr nanotech · Postby **Mr nanotech** » Fri Dec 13, 2013 9:36 pm

gslender wrote:Yep, you'd need to double the reqfuel value (roughly)

G

Turned out to be faulty injectors. Thanks for the advice anyhow. I tried it and got nowhere but after pulling the injectors I saw why lol.

david_syd_au · Postby **david_syd_au** » Sun Dec 15, 2013 6:23 pm

My gear from DIY Autotune arrived last week:
- MegaSquirtPNP G2 MM9900
- LC-2 wideband
- Serial/USB adapter

The ECU in my NB8A race car is located in place of the passenger air bag, and it took only about 15 minutes to remove the original ECU, connect & mount the MS2 and run the inlet vacuum tube. I installed Tuner Studio on my linux laptop, connected to the MS2, and it started the car first turn of the key. Almost an anti-climax.
Once the timing was set as per the instructions, it seemed to run much the same as with the original ECU, although I can't take it beyond my driveway to do a proper test.
I have removed the MAF, and next step will be to install the wideband sensor once a race exhaust is done in a few weeks.

So far, so good.
David

gslender · Postby **gslender** » Mon Dec 16, 2013 11:47 am

That's been pretty much my experience with ms2 and ms3 too. Easy as.
G

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chrons_rotary · Postby **chrons_rotary** » Wed Dec 25, 2013 4:05 pm

Hi guys, Merry Christmas.
I decided to install my Xmas presents (MSPNP2 Miata 94-95 1.8L, MTX-L WB kit) in my 93 Clubman NA8, have followed the instructions on installing, but it seems like the idle is way too high (2500rpm), and the AFR seems quite high aswell (~16.5-17.0 AFR).
The throttle position is very low around the 1% mark.
I've made sure i set the project properties to Wideband (default) for the oxygen sensor project setting, and Single Wideband for the EGO control setting.
I also checked the static timing and made sure it was set to the 10* mark, when i set the fixed advance timing to 10*.
I haven't done the Remove Air Mass Flow meter part, as the NA8 meter isnt as much of a restriction as the NA6 one and i thought it wouldnt be necessary to remove it.
My only thought is the air bypass valve under the throttle body could be open, increasing the air going in to the engine. If so, is there a way to get the MS to control this valve?
Any help is very appreciated.

Cheers,
Ken.

chrons_rotary · Postby **chrons_rotary** » Thu Dec 26, 2013 11:36 am

Problem fixed.
Turns out the base map had no idle control set, assuming the air bypass valve is normally open, this would explain the very high idle.
Changed it to PWM closed loop and now it is perfect.

Cheers,
Ken.

david_syd_au · Postby **david_syd_au** » Mon Dec 30, 2013 10:15 am

With my MS2PNP installation complete, I want to check my understanding of a few issues, and ask for advice on tuning from here.

The car is a 1998 JDM Roadster RS with just over 100k kms, imported in 2011 and converted to a race car by me.
It is a track only car, it is not, and can not be registered.
The engine related mods are:
- Air intake system replaced with race CAI
- MAF removed
- Catalytic converter removed
- Mazspeed muffler
- MS2PNP & LC-2 wideband installed

I have a licensed copy of Tuner Studio 2.5.05.
The car starts ok with the tune config that came with the MS2PNP.
For tuning, my plan is to run the car for a day at Wakefield Park race track during a practice day using Tuner Studio autotune to obtain a better base tune, then take the car to a dyno tuner to tune the ignition advance and fine-tune the VE table.

So, to my questions. I have done plenty of reading on the web, but have a few questions that are not resolved:

1. Is the AFR target table that comes with the MS2PNP suitable for a track car?

2. I believe the AFR target table will not have to change for basic engine mods (eg exhaust, cams) as the tuning process is intended to achieve that AFR target for whatever mods. Is that correct?

3. What preparation is advisable for a day of autotuning on the race track, other than normal car preparation ?
eg Is the default tune a good starting point?

4. Is there a recommended process for race track autotuning to minimise risk, and obtain best results?
ie EGO on/off? Accel enrich on/off? as suggested by the Megasquirt PNP Gen2 manual for dyno tuning.
What sequence of revs and throttle load combinations?
Articles I have read on autotuning suggest doing normal driving, however, that seems to be for road cars.

If there are some articles available which cover these topics, I am happy to read them and learn.
If not, then please help with answers to my questions.

Thanks in advance
David

gslender · Postby **gslender** » Mon Dec 30, 2013 8:35 pm

1. Base tune AFR is ok.

2. When VE is tuned to match AFR you can change AFR table and the fuel will be changed as it is calculated as a multiplier of the VE. Which means when you decide to lean an area you only fiddle with the AFR table.

3. Tune by being gentle for a few laps, try and hit all load points (light throttle through WOT) and all RPM points. After about 3 laps you should be fine.

G

david_syd_au · Postby **david_syd_au** » Wed Jan 01, 2014 11:16 pm

gslender wrote:1. Base tune AFR is ok.

2. When VE is tuned to match AFR you can change AFR table and the fuel will be changed as it is calculated as a multiplier of the VE. Which means when you decide to lean an area you only fiddle with the AFR table.

3. Tune by being gentle for a few laps, try and hit all load points (light throttle through WOT) and all RPM points. After about 3 laps you should be fine.

G

Thanks for that.

I am going to search around for other examples of AFR Target tables for non-FI 1.8s, as it does seem strange that the default AFR Target table that came with the MS goes up to 200 kPa, presumably based on the assumption that many owners will have turbo cars, but the max RPM is only 6000, when an Aus NB redlines at 7000, and my JDM NB has a stock redline of 7500.

david_syd_au · Postby **david_syd_au** » Thu Jan 02, 2014 11:29 am

In answer to my own question about the maximum RPM in the AFR target table, for RPMs above that maximum the same value is used.
So, as long as the target AFR should not need to change above 6,000 RPM at any load, the default AFR target table is fine.

gslender · Postby **gslender** » Thu Jan 02, 2014 3:54 pm

sorry. the base table is "ok" meaning acceptable for general/avg use... sure, for specific applications you may need to add another column above 6,000 (I did) and you might want to chop out the rows above 120kpa if you're absolutely sure that you want need above that in the future (I did) so whilst it is "ok" you can do better by looking at some of the available AFR tables on the internet...

G