Megasquirt Mappings, for 1.7L engine Options

[bd1308]

Converting it all in a weekend and getting it base tuned is a stretch. That's a great goal, if you can do it props to you.

I have all my MS build pics in my signature. I put the brain under the dash and ran the DB37 cable to a 2nd relay box behind the drivers side firewall. I have heard of people having problems with soldering and crimping pins. However I believe that if you use the proper tooling and crimp properly you won't have problems. I borrowed a real crimper and got the job done. You should also strain relief the cable at both ends and not rely on the mechanical retention mechanism on the box/board.

You can easily setup MS to trigger an alarm if your "coolant temp" goes over a certain value. However keep in mind to date I don't know of a way to setup warm up enrichment without scaling your temp sensor output. Warm up enrichment is set to shut off at max 180F, so far.... unelss they've changed the firmware. For me it doesn't really matter.

IMO cooling the heads with a water mist when head temps are over 400F is after the fact. I would try to devise a method to either retard timing or richen the mixture if thats the culprit. Head temps are an indication that your combustion is running too hot. I believe you shuold be cooling from within (combustion related, not heatsink related). My thoughts are that your engine will fail from high temp due to a mechanical failure of valves, seats, warped surfaces, etc... the head temp sensor doesnt respond quick enough to a sudden change in temp.

Just a though... interesting idea though. Let me know what you decide to do.

Good luck!

btw- the cabling is DB-37, not db-25.

You're correct sir, it is DB-37. I remember thinking it was bigger than 25, but forgot that fact. I like your solution with the overtemp deal. I was discussing this with a friend of mine, and he thought the water cooling was too much junk..he liked the idea of richening the mix or retarding timing. Both sound good to me (IMG:style_emoticons/default/smile.gif) But you're correct again, that I should probably fix the underlying problem instead of patching things. I just wanted something to kick in as temp approached 400, the timing would go down to aleviate this, a la emergency limp mode or something. Warm-up enrichment cut off at 180F is alright, I dont see why I'd need much higher than that anyway. I also plan on using a IAC system if its not too hard, but may chicken out at the last moment and just leave it as-is.

[mightyohm]

180 is for water cooled cars.

It turns out (on my car) that the engine isn't warmed up until the CHT reads around 300. Depending on how you set up your thermistor settings in MS you can represent that number in different ways. I scaled mine by 1/2, so a CHT temp of 300 reads as 150 in megasquirt. Thus my warmup needs to terminate around 145-150F as opposed to the 180 default. There are other ways to do it but this was one of the easier ones.

[yarin]

Head temps really should never get to 400F. If so there is a problem with your system. Any severe increase in head temps is typically caused by improper tuning, excessive environmental conditions or component failure.

BTW - i'm a big fan of running dual head temp sensors. One factory and one under the #1 spark plug. Just in case somethign isn't balanced (ie: air leak, clogged injector, etc)

jkeyzer - thanks for the info, i'll add it to my list of STD this winter. (IMG:style_emoticons/default/smile.gif)

[bd1308]

why not #3?

[toon1]

MS has program out now called easy therm. You can download the program a seperate from MT. It had a Bosch table in there for air cooled motors using CHTS.

Once the settings are made you can then load that info into the processor via the bootloader.

Just my .02

[bd1308]

cool. you mean the thermocouple CHT like the vdo setup, or the stock kind?

[toon1]

the stock CHTS. You can go on MS forum web site and download the file and take a look. You do not have to have MT downloaded