T3 megasquirt II conversion

[akokarski]

very nice Max! I am glad you were able to get these issues ironed out.

I am waiting on my parts to come back from machining for 1776

[Max Welton]

It was a nice day today, so I brought the laptop along and took this screen-shot on the way home. Thought you-all might find it interesting.

I have my table set up to give a lean-cruise below 65 Kpa. The road in this sample was undulating a little so to maintain a constant speed required a little throttle (and thus MAP) movement. Shows the transition rather nicely.



Max

[andy198712]

nice!
what speed is that rougly?

[Max Welton]

That rpm is around 66 mph with the 195x65s.

Max

[andy198712]

That rpm is around 66 mph with the 195x65s.

Max

nice cruise! temps all happy to hold that right? nice low TP also

might have to take the same shot with my 1200 if it didnt sound like it would blow up at 66mph

[Steve Arndt]

That rpm is around 66 mph with the 195x65s.

Max

nice cruise! temps all happy to hold that right? nice low TP also

might have to take the same shot with my 1200 if it didnt sound like it would blow up at 66mph

I cruise at 5 to 6 percent throttle at 65mph. Oversized throttle bodies in my case.

[Max Welton]

OK, I've decided it's time to get rid of the stock ignition. So I've ordered up a trigger wheel from supersuk.

The squareback is my DD so I'm going for minimum risk and downtime. So I'm hoping to do this in stages.

When I have the sensor and the wheel in hand I'll drop the engine and install them and reinstall the engine. I'm hoping there is a way to configure the hall sensor as my trigger (instead of the points), but temporarily keep the coil and distributor. While I'm learning how to setup the ignition timing control, the stock distributor (and compufire) will still be there in case I screw it up.

Stage two will be to replace the distributor and coil with EDIS or something in a wasted-spark configuration.

Anybody BTDT?

Max

[Corysvdub]

I'm sure Mario has a solution for you Max. I just went straight to edis on mine, stock coil would get heat soaked after I shut it off and wouldn't start until after it cooled for 30 minutes. What an improvement the new ignition made.

[Devastator]

I don't know what version of MS you are using, but I used a Hall sensor, 36N1 wheel, and dual coils from DIY. I also switched out my old coil driver and added a new one for the second coil. If you stick with MS2, (assuming that is what you are running), you will need an EDIS module. If, however, you upload MS2Extra code, you only need the sensor and the additional coil driver, or the Quadspark coil driver, also available from DIY.
Just looked at the gauge in TS from your earlier posts. It shows you running MS2Extra already, so you are 1/2 way there. I don't think you'll want to retain the original stuff. It only takes a few hours to get underway wasting sparks. My challenge came from having the sensor too far away from the toothed wheel. Directions read "1mm away from the wheel". Should have read "1mm away from the wheel max." I'm at .016 now and it runs great!
There is some information in my build thread if you want to read it.

[TouringBubble]

What temp are you reading at the 280º mark? Oil or cylinder head? Just curious for my own setup as I run it all off of the oil temp. I haven't decided on values for killing WUE, triggering the fan, etc.

[Max Welton]

That is from a ordinary GM CLT sensor I put in the valve-train galley of the 3/4 head. It's probably a lot closer to CHT than anything, but it is probably well outside the accuracy range of the sensor. That sensor shows change much quicker than OT and is therefore a lot more useful for WUE control.

Back on page 12 of this thread there are pictures.

Max

[TouringBubble]

Got ya ... so it's really measuring ambient air and oil under the valve cover? That makes sense I guess. I know that with my oil temp use I have to go with uncommonly low numbers for WUE due to the sump and the oil's resistance to temperature change. Operating temps should be pretty easy to work with though.
Thanks for the pics and the explanation. I need to catch up on the thread. The pics on 12 looks great. Nice work on the fuel line! Super clean.

[Max Welton]

OK, back to the ignition. If I understand correctly, this coil comes with it's own ignitor. I should be able to run it directly from D14 on my MS-2, without a BIP373 right?

http://www.diyautotune.com/catalog/ign1 ... p-394.html

Max

[Piledriver]

You need a 1K 5v pullup on the LED circuits.

The best diagram of that is in http://www.msextra.com/doc/general/sparkout-v22.html under logic level spark out. For V3 board http://www.msextra.com/doc/general/sparkout-v30.html

Basically all it requires is a 1K resistor diagonally from the 5v side of the LED limiting resistor to the switched leg of the LED (which you can leave in place) it actually is even easier/faster to do than it looks.(if you don't have a v3.57 board)

On a single coil setup you are going to have to watch your dwell and for arcing in the cap, as that is a very serious ignition coil.

Or have you decided to go with the full meal deal?
Those will work fine in wasted spark controlled in pairs

[Max Welton]

Here's the thing Pile. I don't know what a "1k 5v pullup" is.

I never developed any facility with electronics (or anything else with color-coded bits). I did manage to do the second map sensor modification, but only with some pretty detailed guidance. Me holding a soldering iron is an inherently dangerous thing.

The possibility of frying the ECU in my daily-driver is a very real possibility for me. If I hurt it there's very little chance I'll be able to fix it myself or explain to someone else how I hurt it so they can fix it.

So I'm being very conservative here. A solution that requires no mods to the ECU has a certain appeal to me. That said, I might go for a very simple mod (2nd baro level mod) with probably a lot of detailed guidance. Perhaps the BIP373 mod or this "1k 5v pullup" of which you speak.

At this point I'm just trying to change the ignition triggering device, not get a hotter spark. That can come later.

PS, the ECU I am using: http://www.diyautotune.com/catalog/mega ... p-171.html

Max