How to Megasquirt your 3G Hemi

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Nice write up.
When I get my 5.7 back together I will be doing pretty much the same of you're doing.
Although my engine's fuel will be LPG, which uses 2 more driverboxes for the low-impedance injectors.
 
Not trying to be critical at all, but I notice that in your settings you are using a MAP sensor, is there enough of a manifold signal to your map sensor to get a decent reading? I ask because some people who run ITBs have to run Alpha-N because there simply isn't enough manifold volume to get a stable reading.

By the way I re-read your description, man you took some serious time in your write up. It's write ups like these that keep me coming back to FABO.

Thanks again, let us hear some more when you get the tune dialed in.

Regards,

Joe Dokes
 
Thanks for the kind words, joe!

My kPa at idle is around 70 and fairly stable. Drops down around 50 at 2000 rpm. MS3x has an ITB setting that uses an alpha-N table for idle and low rpm, and a speed density table for everything else. I'll probably give that a try at some point. Honestly the car idles great right now (when warm), so I may not need it at all. I've still got a fairly small cam in the motor (218/224). I would imagine the ITB setting would be needed with more overlap.

I've been finishing up some other items on the list, but it's almost ready to truly drive (I've only run it around the neighborhood so far). I'll run ~500 miles of street driving (break in clutch), and use that time to let tunerstudio self tune the low kPa part of the speed density table (or as much as I can get it to). I've talked with a shop with a mustang chassis dyno that will allow me to steady state tune the car, so that's the next step.

Also, I have not activated acceleration enrichment or warm up enrichment yet. I understand you need to get the speed density table spot on before bringing those into the mix.
 
Thank you so much!!!
I been gone for a while, came back and saw this. This is exactly what i was looking for, for all those months after i got my hemi. Now I have some direction to proceed with.

Now if only I didn't have to rebuild the entire engine first (i took the heads off, forgot to cover it, when the roof on the garage was redone, the roofers got wood chips/saw dust all up in it...guess that slight "tick" wont' be an issue anymore"
 
+1 also have to rebuild my engine first. But knowing what I'm getting myself into is excellent :)

I notice you bought both
MS3 wiring harness (8 ft): $67
MS3x wiring harness (8 ft): $72

Was there a reason for this? How much of the original engine loom was used?

Thanks
 
Modz said:
+1 also have to rebuild my engine first. But knowing what I'm getting myself into is excellent :)

I notice you bought both
MS3 wiring harness (8 ft): $67
MS3x wiring harness (8 ft): $72

Was there a reason for this? How much of the original engine loom was used?

Thanks
Click to expand...

I only used the plugs from the factory harness. I took a couple feet of factory wire with the plug when I was able, which proved useful for the injector wiring and coil pack wiring.

I could have wired every pin individually, but I wanted all the wires labeled so when they made it to the engine bay it was easy to know what was what.

Theoretically you could get the factory wiring harness manual and do it the exact opposite of what I did (i.e. You could plug everything in, route the factory plug to the megasquirt, then cut all wires and make that connector).

The factory wiring would have needed some lengthening for the injectors with the hilborn, and would not have been as clean of an install. But, of you're running 6.1 covers or similar, the factory harness routing would be ideal. That would be a good way to save money (if you mounted the ms3x box where the factory harness would reach, anyway). Lots of research figuring out the factory wiring colors though I imagine.
 
As a side note, one of the benefits of the tuning software for Megasquirt is that it is Mac OS compatible. Or more specifically they have a Mac version. FAST, AEM et. al. don't have Mac versions, of course you can run Windows natively on a mac, but why buy a license for windows if you don't have to? You do however need to download a USB driver.

This page at DIYAutotune.com may help you find the drivers and tuning software.

http://www.diyautotune.com/softwarelinks.htm

Best of Luck,

Thanks again Uhcoog1

Regards,

Joe Dokes
 
I just called Matt at DIY auto tune.

He said:
The knock module board is an $85 part
Labor is $75/hour, minimum of 1/2 an hour (said it would take no more than 1 hour to do at the MOST)
*I'm guessing it wouldn't be as much to have it added at the time of building the box

He's not sure if the hemi sensor is an untuned or tuned knock sensor.

I would have to set the knock module for the frequency. Apparently there are a number of calculators you can use to estimate the frequency, but the 'right' way would be to record the readings and play them back through a spectrum analyzer.

He also mentioned to first try the fundamental frequency, and if that didn't work, to try the 2nd. If you aren't getting feedback, you aren't on the correct frequency.

I told him my initial plan was to use a homemade set of knock headphones. Apparently they use a set of electronic knock headphones themselves when they tune, as it is easier to decipher what is and is not knock.

I think for me the right move at this time is to skip the knock module and use the whisper2000 homemade knock headphones to listen for knock. As long as I keep the same grade of fuel (and don't ever get a bad tank of gas), I should be fine. Seems that is the consensus among megasquirt users online as well.
 
Uhcoog1 said:
I told him my initial plan was to use a homemade set of knock headphones. Apparently they use a set of electronic knock headphones themselves when they tune, as it is easier to decipher what is and is not knock.

I think for me the right move at this time is to skip the knock module and use the whisper2000 homemade knock headphones to listen for knock. As long as I keep the same grade of fuel (and don't ever get a bad tank of gas), I should be fine. Seems that is the consensus among megasquirt users online as well.
Click to expand...

THIS sounds like a really interesting idea!!!
 
That is pretty cool. I'd like to use the factory knock sensors, but at this point it seems quite difficult, I don't know of anyone using the factory knock sensors with MS3. This devise would at least help with tuning, which means you could at least keep engine damaging detonation to a minium.

Regards,
Joe Dokes
 
That is the whole thing that scares me about tackling something like this is detonation. I can learn, but most of this is French to me. Thanks for this thread, this is the stuff that will eventually get people, including me, off the fence about slapping a Gen III in my Dart. Their fuel efficiency is unmatched in the Mopar world.
 
Lotta computer work here, need a degree in computer engineering. ha.
carbureted 318 is starting to sound good right about now.
 
Uhcoog1 said:
Yes, you can megasquirt your 410, but it would be an entirely different process and set of directions.
Click to expand...
Sorry, that's what I was asking, if I coulde use all of this for the 410. Write ups like this make everything so much easier.
 
Fst73 360,

On a fundamental level fuel injecting an LA small block is very similar to injecting a late model Hemi, but since your engine was not originally fuel injected you'll have quite a few more decisions to make. I'd spend a fair amount of time reading the Megamanual (this is the manual for Megasquirt), I'd also read through a number of build articles. They have a bunch at DIYAutotune.com

The reality is that the first few build articles you read are going to sound like a foreign language, but after a while you begin to pick up the language and your understanding will increase.

The key issue with MS is that it is NOT (there are some notable exceptions) a plug and play system. Because it is 1/2 to 1/3 the cost of other stand alone systems and because it can be used on almost ANY engine from a single cylinder engine to a V-12, it has is very adaptable, thus it is complicated. Remember universal parts universally don't fit anything without a lot of work. :)

Here is an example to illustrate:

MS needs to know a number of engine parameters in order to inject the correct amount of fuel into the motor. One of these parameters is the engines speed and position. There are a number of different ways to get this piece of information. On the late model hemi you simply correctly wire the stock crank position sensor and cam position sensor and adjust the setting correctly in the tuning software accordingly. But your motor was never fuel injected, as a result you need to decide which method to use.

1. If you are retrofitting MS onto previously carbureted engine and ONLY want MS to control the fuel, you can use the the positive side of the coil as a trigger. 2. If you want MS to control fuel and spark you need to use either a trigger wheel attached to your crank or an electronic distributor with magnetic pick up. 3. If you want to use MS3 with fully sequential fuel injection you'll need both engine speed and postion sensors, thus you need BOTH a trigger wheel with missing teeth and a camshaft position sensor thus, the computer needs to know when the piston is on the compression stroke.

As you can see from the above example that there are a number of decisions to be made, and the only way to make them is to educate yourself on the various options available along with the costs and benefits of each option.

Good Luck. It may seem daunting, but it really isn't rocket science. There is a bunch of youtube videos that can really help.

Regards,

Joe Dokes
 
There are 2 frequencies for the 5.7 and 6.4 Knock Sensors(part# 05033316aa). 1 is 5.9kHZ and the other is 13.72kHz. The frequency used depends on the calibration. Both these are the Center frequency. Hope this helps someone in the future.
 
Okay, since no one else has asked...

Where did you get the gauges in the video? They look great! :)
 
ChargerDude70 said:
There are 2 frequencies for the 5.7 and 6.4 Knock Sensors(part# 05033316aa). 1 is 5.9kHZ and the other is 13.72kHz. The frequency used depends on the calibration. Both these are the Center frequency. Hope this helps someone in the future.
Click to expand...

Thanks for the info! Makes me want to try it. How did you get that info?

vynn3 said:
Okay, since no one else has asked...

Where did you get the gauges in the video? They look great! :)
Click to expand...

Thanks for the compliment! They are Marshall gauges. Marshall makes some really nice stuff, and it seems they put a bunch of different faces in the gauges (and I think other companies use their gauges with other custom faces as well). I know new vintage makes custom faces...
 
Great info, my grand plan is to parallel install a Megasquirt while maintaining the OEM PCM in a 03 Ram.
Thanks for the detail posting.
 
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