Megasquirt owners thread

[david_syd_au]

After some internet searching tonight, looking for AFR target tables, I found this interesting piece:
http://www.dsmtuners.com/forums/newbie-forum/434754-afr-table.html
which argues that the 14.7 stoichiometric AFR commonly used is actually for 88 RON petrol,
and calculates that 95 RON has a stoichiometric AFR of 15.87
and for 98 RON it is 16.37.

Does this mean that an "ideal" AFR Target table, based on a 14.7 stoichiometric AFR, could be scaled up by 16.37/14.7 = 1.1136 to produce a table suited to 98 RON fuel?

[ausbuoy]

HELP WTD.[color=#0000BF]
Is there anyone out there (Brisbane or Newcastle) able & willing to assist me (not gratis) to get this M'squirt 2 finished/altered to fit to my NA Turbo. The car is currently being controlled by a Link piggyback that has reached its 'use by' date. Comments about this unit and it's capabilities made by G Slender are added below.
It's a MS2 kit and pretty much all assembled but hasn't been setup for any particular engine yet. Has never been used.

It also comes with the MapDaddy upgrade, JimStim Simulator, Megasquirt Relay Board, and the Megasquirt Relay Cable.

http://www.diyautotune.com/catalog/ms23 ... p-513.html
http://www.diyautotune.com/catalog/jims ... p-178.html
http://www.diyautotune.com/catalog/mega ... -p-31.html
http://www.diyautotune.com/catalog/mega ... -p-47.html





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[/color]"The kit is actually complete and will suit any NA/NB system with the exception that it won't drive a later model NB with sequential injection, but that can be dríven as batch. The spark is batch and will work fine off the kit as is >> http://www.msextra.com/doc/ms2extra/MS2 ... htm#2coils
The software and cpu on this MS2 would support a VVT or any similar output that is triggered by things like when rpm > 4000 set output to active/on. In fact this kit can do a ridiculous number of things - from launch control to load/rpm based boost control.

The only thing this original MS2 kit needs is a circuit added to drive a relay, switch load, or pwm valve as the board doesn't have anything other than a logic output from the CPU. This is why the MS2 original kits all look like an electronics experiment with wires and components soldered in odd places all over the place - the later DIYPNP kit (still an MS2) has a more advanced multi-layer board with all the typical output and input circuits already included (thus why it is more a of a PNP kit compared to this one).

For example, it looks as though the crank and cam circuits need to be completed on this kit - there are several ways to do this and many places on the Internet have options and advice on how to do it - the board itself just needs the extra electronic components (resistors, capacitors, transistors etc) soldered in and wired up the way you need them to build the right cam/crank input circuit to suit your car... hall sensor, opto, VR etc...

The base functionality is the same, just that with this MS2 kit you need to do more electronics work and be familiar with what is needed. The DIYPNP is more complete and proven (but costs more) and there are tested and confirmed circuits and all components to build for a MX5 NA/NB in the kit".

The kit is in Brisbane, and the car is in Newcastle waiting for a possible union.
Greg S. 0439939930

[PhilM]

Anyone got any ideas why a MSPNP (12months old) seems to loose its tune- i.e. the A/F ratio is set at mid 13:1s but after 200kms when at WOT it gets down to low 12s even 11:1.

[david_syd_au]

Anyone got any ideas why a MSPNP (12months old) seems to loose its tune- i.e. the A/F ratio is set at mid 13:1s but after 200kms when at WOT it gets down to low 12s even 11:1.

Assuming you are using a wide-band sensor, maybe it needs recalibration.

[gslender]

Anyone got any ideas why a MSPNP (12months old) seems to loose its tune- i.e. the A/F ratio is set at mid 13:1s but after 200kms when at WOT it gets down to low 12s even 11:1.

How are you sure that the mspnp tune/configuration is changing? Technically, there is no concept of a configuration being lost... It is only changed, so why would it change? And why always to a lower AFR, when logically any value would be equally valid from a computer's perspective.

So, more likely is the O2 wideband sensor drifting or needing recalibration. What brand is the wideband and where are you getting the AFR metered (gauge separate from the MSPNP or are you logging the data on 1 month and seeing the log data months later be completely different (which would easily tell you if indeed the tune/configuration is changing or is it just the reported AFR)

G


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[PhilM]

Thanks for the replies
The WB is a Bosch LSU4.2 Sensor through an AEM controller to the MS.
The controller reading has been checked against 2 end of exhaust probes and found to be accurate, 1st time using Dann's portable set up and then on a dyno that my new engine was tuned in February with cams that were supplied with incorrect grinds so they have been taken out and the std cams put in 2 weeks ago, so I got Dann to so some on road tuning and the car went well with observed O2 reading that appeared to be correct, Last Sunday I went on a 300 kms Club run and the car was noticeably down on power and I noticed that the O2 gauge readings were about 1 - 1.5 units lower than they should be. A following car also told me "your car smells very rich" and there is black soot on a rear bumper that was washed in the morning.

This phenomenon was noticed last year on the old engine.

One thought is the AIT sensor has a variable output.

Dann is will have 2 new MSPNPs delivered soon so we will swap it over to see if there is a circuitry problem.

I am entered for a track day on Sunday and it would be nice to have some power.
Phil

[gslender]

You should grab a log of it running fine, and then again when not so you can compare and see what is potentially going wrong. With those logs I could possibly tell you very quickly what is going on.

G


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[PhilM]

I made some changes to the basic setup -used the TS Help dropdowns as a reference and it seems to be working close to the AF targets
Basic Settings -General settings-
Barometric Correction changed to Initial MAP reading
Primary Fuel Load - Percentage Baro
Incorporate AFR Target - include AFR Target

Tools - Calibrate AFR Target - set to - AEM Linear .....

The AF ratio went from 11:1 to 12.9 - 13: 1 ( which is what the table is )

[david_syd_au]

My MX-5 race car has a MS2PNP that I installed earlier this year, which I tuned at a dyno session with help from the dyno operator. The car seems to be running fine, and I have no concerns, but am keen to get the observations or opinions of anyone knowledgeable about MS, as I am sure there is much to be learned from the logs that I don't see.

The link below is to a 500k extract from a log captured during a recent MX-5 Club of NSW track day at Wakefield Park, and covers about one lap of the track, starting and finishing just after the fishhook (turn 7). Most of the lap was flatout, except towards the end when I caught a slower car.

https://www.dropbox.com/s/10ftqu62du478we/2014-06-01_11-52-26.extract.msl

The car is a JDM 1998 MX-5 with
- stock 1.8 engine internals
- MAF deleted
- short air intake
- extractors and race exhaust
- LM-2 wideband

If you have the time, please have a look and give any observations.
David

[gslender]

I will take a look and report back


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[gslender]

You are running a beta version of the 3.3 firmware, so whilst I can't say it would be an issue, you would be best to migrate to a released version (currently 3.3.2)

A few things...

1) You never get more than 93kpa when WOT... which might be correct, but normally it would be 100kpa - but that does depend on what the ambient baro is... so hard to say. Just be sure the throttle is 100% open when it is, and that your map nipple and tube/line isn't restrictive. I can see that Baro cor is at 97.7% which is probably the issue... something is adjusting it down. The MS2 will recalibrate the baro when on/off so redo a run with the engine warm, and then switch off, turn on, and then log a small run and give me that with idle and a run included.

2) MX5 engines like a rich WOT, and you're at 13.5 which is a little lean. Target 12.5 which should give you more power!

3) MX5 engines like a lot of advance, and the max spark advance I can see you running is 28 deg when WOT from 4500rpm - I'd suggest you could even consider going 40deg but you really should test with det cans etc and don't just take my view (this is the area where you can cause damage, but again you are running really retarded). I think if you move it up to 35 deg that should be safe enough as many have even gone as high as 45 with no issues - with good fuel etc. If you adjust the AFR to 12 then it will be safer to not pre-det but don't leave it at 13s etc

Good luck!
G

[david_syd_au]

Thank you very much for the feedback Mr G.
I will action the points you raised, and come back later with the additional logging.

[DanZig]

What do you guys recommend re boost solenoid? I was going to go with diy's boost solenoid but thought I'd chime in and see if there's any other recommendations?

[bartmanftw]

Hey guys I'm in need of a bit of assistance. I've got a pretty much standard na6 which I'm trying to get running with a DIYPNP but I'm having some issues. I downloaded a base map from http://www.megasquirtpnp.com/ and it starts the car alright but my wideband reading is way off the scale reading lean. I'm almost 100% sure I've wired the wideband in correctly.
It's a LC-2 and is powered and grounded on the PCB board of the ecu. I tried sticking the standard ecu in and checking the AFR and they seem normal around 12.5-13.5 (I powered megasquirt with an external power supply to get the wideband to turn on) so I'm fairly certain the wideband is reading accurately.
I've attached a log file of it starting and idling for a bit and my tune file. Any help would be appreciated. Thanks.

[chrons_rotary]

What do you guys recommend re boost solenoid? I was going to go with diy's boost solenoid but thought I'd chime in and see if there's any other recommendations?

I bought a MAC valve solenoid for ~$40 posted, same as the $100+ ones grimmspeed sell, but without the sticker and plug.
Search for them on ebay.