Thirim

Anyone have any success stories with Megasquirt and the LT1?
I am close to buying a DIY Megasquirt I V3.0 kit. Thinking I will manage the spark with a Ford EDIS and a 36-1 crank trigger. Doing this I think I can bypass the Opti altogether. the motor is a 96 so there is a crank trigger but from what I have read, it is nearly useless with the megasquirt as it doesn't have the resolution needed. Truthfully I would much rather see a set of LS1 coils and gear rather than the Ford stuff, but Ford seems to have a nifty package there.. hard to resist.
I have a couple of questions..

Where am I to secure a 36-1 crank trigger/sensor to fit a GM crank?
Any better idea than the Ford EDIS? I already have the EDIS(freebie)
Is the LT1 bank fire or sequential? currently im running on a 94OBDI ECM
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to eliminate the stock ECM .. I will need the SGI-5 Dakota Digital box.. which I own.. that will provide my correct speedo signal from the T56 .. but would wokr for T5 etc.. Not sure what people would do for the Autos... buy a clutch pedal i guess.. haha

Deaclen

iTrader: (1)

Thirim, I have thought about doing the exact same thing. I have thought about several different options and still working on the logistics. I have not done enough research to know yet and I won't know without that research but here is my idea:

Megasquirt system using the MSD crank trigger with the DIS4 and have that power the coils. I would still only get four coils unless you split it off and did like a bank fire instead. My engine is a 94 and does sequential. Now you can probably tell me if this will work or anyone else. I never said it out loud and didn't want anyone saying you retard you can't do that. But anyway... I do recall that 92-93 they used bank and 94 is the switch over year to the sequential fire. You can also find the 36-1 crank trigger/sensor on ebay and then either weld it on your harmonic balancer or make a mounting plate like a buddy of mine did for his V6.

Firebat

iTrader: (7)

This guy has done the megasquirt in an LT1 and completely eliminated the opti. http://brian-esser.com/?page_id=24 Someday I plan on just eliminating the high spark through the opti and use coil packs. However, i'll still keep the pcm and use the opti for fuel injector signals, unless i learn megasquirt.

Thirim

ok. I ordered up a MS1 V3 kit..
Still not sure how to mount up the trigger.. I guess im going EDIS ... will be looking for a non opti timing cover.
thanks for the info!

anyone with crank trigger input?

Brian Esser

Thats my old site. I have since moved it to http://www.projectlt10.com

I haven't had a chance to update it for awhile as I am still waiting for my shop to be built. But, i will be glad to answer any questions as well as lend assistance or suggestions.

Megasquirt with the additional I/O board can do sequential. However for the added benefit I don't think it's worth the hassle. True sequential does improve idle quality and throttle tip in. But, batch fire works more than fine for 99% of the engines out there. As for the igniton side of it. I have seen possible workarounds for using two EDIS4 systems together on a V8, but i don't recall seeing any actually running.

The MSD crank trigger will not work with the EDIS system. it relias as already stated on the 36-1 toothed wheel for it's reference. The MSD trigger will work with the Megasquirt though if you had a different ignition setup. I used a crank trigger from http://www.diyautotune.com after trying several triggers (I'm picky lol).

Here is some background information about Fords EDIS system as well as how I used it on my 94' LT1. http://projectlt10.com/edis.php

I modified my setup though and decided against using the Ford 4 tower style coils as the wirse required for such towers are expensive and not readily available as standard end plug wires are.

Here's some photos of my engine, though these were taken last summer.

Deaclen

iTrader: (1)

Brian, thanks for the info on the MSD crank trigger. I knew it wouldn't work with the EDIS system. I just don't like the idea of putting Ford parts on a Chevy vehicle. Seems very evil to me and gives a cold shiver. LOL! You have a nice setup and actually gave me an idea of where to put my Coil packs when I get the setup built. I believe now since you managed to answer my question I think I can use the MSD DIS4 for my ignition with that crank trigger. According to MSD tech they should work nicely together.

Question? In your last picture there you have your MAP but no wiring. I think I see some wiring or are you still putting this Bad Larry together?

Brian Esser

Actually. That MAP sensor will be removed and a cover plate made. The Megasquirt has it's MAP mounted directly into the ECM itself. So I won't need the stock one in the stock location. I have a vacuum line ran into the cab where the ECM is.

The DIS4 system is very nice! I used it on a Cavalier with a warmed over 3.1 in place of the 2.8 and it would easily walk a 305 F body. However it also had a Holley C950 ECM and some other mods done to it.

Firebat

iTrader: (7)

Brian - What would be the estimated cost to run coil packs in a LT1? Estimated cost to run coil packs and megasquirt computer? I would try to get used parts off of ebay.

Brian Esser

The Megasquirt will run you anywhere from $240 to $430 depending on which variant you choose. I would go with the latest pcb version and the MS2 processor. The MS harness will run you around $60 for a 12' harness. You will need all the sensor plugs depending on which sensors you use. Megasquirt is cool cause it uses GM stuff, and readily available stuff at that.

Here's the sensors the Megasquirt uses.
Coolant Temp Sensor (tuneable to nearly any sensor out there)
Throttle Position Sensor (tuneable to nearly any sensor out there)
Intake Air Temp Sensor (tuneable to nearly any sensor out there)
Manifold Absolute Pressure Sensor (mounted on PCB in MS unit)
Oxygen Sensor (can use either narrow or wide band)

The coil packs brand new are around $20 a piece, however most junkyards sell them for a few bucks a pop. I have a ton of them laying around from vehicles I've stripped over the years, so they cost me nothing.

The EDIS8 parts can be found at most yards. I spent about $50 for the EDIS8 module, and the VR sensor and pigtails. I didn't bother grabbing the coils as I knew I wasn't going to use them. Expect to pay upwards of $100 for the coils, module, vr sensor and pigtails. That will vary depending on the yard, and your location too. You can get all the parts used online as well from various sources. http://www.diyautotune.com is selling very nice trigger wheels now as well. The VR sensor bracket and mounting the trigger wheel, will of course depend on your engine and setup and space constraints.

So if you are starting out with no MS unit and no EDIS parts, expect to pay anywhere from $400 to $600 for the setup. Of course that can be almost cut in half if you find donor vehicles or score the EDIS parts for free etc. Be carefull buying MS units from Ebay and private sellers. I've seen several people burned by buying MS units that weren't assembled correctly or were fried. I highly recommend DIY Autotune (http://www.diyautotune.com). I've literlly spent thousands with them and they have always been on time and gave me great service. There are several dealers who sell fully assembled MS units.

This is taken from my site regarding finding EDIS parts for others who are looking...

For the rest of it, check out http://projectlt10.com/edis.php

I've pretty much scoured for all the EDIS info I could find and tried to gather it in one place and have it make sense. If anyone finds any errors please let me know, or if anyone has any additions I should make.

Toehead

+1 for DIYautotune. They were a great help for me. I am not running anything as exotic, but the MS does run the stock 8 pin module very well.

KBcobra

i have a few questions? let say you convert you system how do tune for a normal LT1 tune without going to a tuner and dyno it? How do you get the gauge cluster to work with the megasquirt? A/C?

Brian Esser

thats what makes megasquirt a slight challenge for the novice not familar with EFI and tuning. You must tune it yourself and as for finding the optimal setup, most take it to the track and let the ET's tell them if they are making more power. Others get it close and call it quits. But, again it depends on your knowledge of EFI and basic engine and tuning principles.

As for the gauge cluster, most guys piggyback the MS on top of the stock ECM letting the stock ecm control the trans and gauges while the MS controls fuel and spark.

Toehead

If you replace your current ECM, you dont need to change the gauges.

I removed my factory ECM and replaced it with the megasquirt. All of my gauges work fine.

You may have issues with the speedometer depending on if the ECM buffers the signal, but I think you will be fine. Unplug the ecm and roll down a hill to test


As for the tune...

The Megasquirt is speed density, and relies on a volumetric efficiency table. If you can get a table from a stock bin, it will give you a baseline.

KBcobra

What about a/c?

Deaclen

iTrader: (1)

A/C on the LT1 is not controlled by the computer to my knowledge. I just wired it into my Thirdgen wiring when setting up my LT1 to run in my Thirdgen and I don't recall it having to do anything with the PCM. Plus on the Thirdgen it isn't computer controlled anyway aside from when it kicks on it raises the idle a bit if I remember correctly. But, I have been known to be wrong.

Brian Esser

You are correct

kowboy59

iTrader: (8)

I just need to know what powers the megasquirt. Oh can anyone tell me the fuel pump relay thing. How did you wire urs? Im almost done with it. lol and im so anxious

Toehead

The power wire powers the megasquirt?


Just use the stock power for the ECM.

It needs to be hot in crank and run and not hot with ignition off.