How to Megasquirt your 3G Hemi

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I have 6.1 timing tables somewhere. I'll have to look. They're the factory computer tables- MBT table and WOT table. It's not as straight forward as you're hoping for. The factory computer is constantly pulling timing, etc, so I'm not sure just plugging in the WOT or MBT table and going with it is going to be your best option.

I'll see what tables I can find for you.
 
oldschoolmuscle said:
Awesome thread and great work. Can the latest mega squirt handle Vvt functions yet ?
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I don't know. I'm not sure what it takes to activate VVT in the hemi.

I'm sure you could make it work, but it definitely would be far from plug and play. I believe there are a few guys working on it on msextra.com
 
Yeah, I think the computer can do just about anything you want to it, but you have to figure it out, lol. The circuitry to run it is probably moderately simple (guessing it's something like a variable valve), but the programming and logic behind when to deploy it is the big question.

Guessing it's similar to MDS. Technically speaking, you could probably just have an on/off switch on the dash that powers the MDS solenoids, but the transition would probably be pretty noticeable and if the operating conditions aren't right you might be hurting the engine. The factory computer monitors so many sensors to determine when to activate MDS that's really the main question. Turning it on and off is easy, figuring out when is more difficult. I think VVT is a little more complex in that I'm guessing it has a "range" of activation (advance/retard cam 1-5 degrees or something like that) as opposed to "full on" and "full of". I could be wrong though. I think VTEC is an on/off style VVT.
 
I think they said they cam control VVT on the Chevys. Be nice to take advantage of the variable runner 6.4 intake too. Waiting on a guy on LX forums to dyno his stroker with that intake and a standalone controller.
 
So for right now could I lock out the Vvt and then run a non Vvt cam? I'm leaning heavy towards ms.
 
I think someone makes a VVT lockout plate, don't remember the vendor off the top of my head. Don't necessarily have to run a "non-VVT" cam as I believe the system is independent of the cam itself and more or less just works on the timing chain. However, the stock cam is probably designed with it in mind, so it might not perform the best at the locked setting.
 
The VVT is oil controlled. Hangs off the front of the cam. The lock out kit is ~$100 from comp cams.

The cam in the VVT motors has different dimensions than the non-VVT 5.7 & 6.1. You have to get a cam specific for that motor. I would recommend the comp cams offering or get a custom grind by a vendor.

Also, if you've got a 5.7, see if you can find a used 6.4 cam. Much cheaper (~$100 vs $1000), and is fairly aggressive. Lock it out and go.

I agree with Map- not sure how a locked out factory 5.7 VVT cam will perform. Though, A cammed 5.7 VVT motor locked out should perform no different than a cammed non-VVT 5.7.
 
Ya I was looking at pictures of vvt cams vs non vvt cams. they are different. I've also looked at the 68 dollar 6.4 cam :burnout: I'm getting pretty excited I'm not going to lie:glasses7:. Just need to do a little more reading before I start pulling the trigger.
 
oldschoolmuscle said:
Ya I was looking at pictures of vvt cams vs non vvt cams. they are different. I've also looked at the 68 dollar 6.4 cam :burnout: I'm getting pretty excited I'm not going to lie:glasses7:. Just need to do a little more reading before I start pulling the trigger.
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Pull the trigger!! $64 is cheap! That's an AWESOME cam for a 5.7 eagle motor.

5.7 Eagle stock cam: 188/205, .530/.517, 115 LSA
6.4 Apache stock cam:215/221, .600/.566, 121 LSA

Other option:
Comp 274: 226/234 .619/.612, 116 LSA
 
Uhcoog1 said:
I'm going to outline my megasquirt install for everyone, make it easy for the DIY crowd.

I chose the Megasquirt 3x, as it provides sequential fuel and spark, the fact that I can tune it myself, and the fact that tunerstudio has a 'self-tune' setting that will adjust the fuel tables to match your specified air/fuel ratios. There are a ton of other features that make it comparable or better than the commercial grade offerings. This isn't quite a plug and play, though; you'll be wiring the thing yourself. Go here for a feature comparison between the megasquirt and the FAST - both offer things the other doesn't, but are very similar in most features.

Inputs needed for the megasquirt box:
Crank trigger input (5v power, common ground to box, and signal out)
Cam sensor input (5v power, common ground to box, and signal out)
Throttle position sensor (5v power, common ground to box, and signal out)
Coolant temp input (common ground to box and signal out)
Intake air temp input (common ground to box and signal out)
Wideband O2 sensor (O2 sensor to it's own box, then common ground to box and signal out)

Outputs for my install:
Logic level spark (12v fused feed and box controlled ground, through coil drivers, to fire coils) (more on this later)
Injectors (12v fused feed and box controlled ground to fire injectors)
Idle air control (not installed by me- there is no idle air control on a hilborn) (should be 12v fused feed and box controlled ground to operate)
Fuel pump relay control (via ground- turns pumps off if car not running after 3 seconds in key on position)
Tach signal (single signal wire to run to tach input)

Additional Hemi specific notes:
-For the box to be able to read the Hemi crank sensor, a special pull up needs to be installed in the box. DIY auto tune did that for me for $12 before sending me the box.
-The Cam and Crank sensors are 3 wire - ground, signal, and 5v power. There is only one 5v source on the megasquirt box, and that is the Throttle Position Sensor VREF wire (pin 26 on main MS3 connector). That feed is shared between the TPS, the crank sensor, and the cam sensor.
-The spark output for the megasquirt is logic level - that doesn't work with the hemi coils. So, you need to use coil drivers; you can use either the diyautotune BIP373 version, make your own Bosch BIP373 box, or get the bosch 211 factory part. I am using the bosch 211 version - the most difficult part of using these is finding the connectors, which I outline in the parts list below (and give a source - $27 shipped for everything). Here is a link to info on the Bosch 211 including all applications they were used on.
-buy the IAT and Coolant temp sensors from DIY Autotune; the megasquirt is already calibrated for (you can re-calibrate the settings for other sensors if you want).

Parts list:
Megasquirt 3x box assembled with $12 pull-up: $657
MS3 wiring harness (8 ft): $67
MS3x wiring harness (8 ft): $72
Innovate O2 sensor (MTX-L): $199
Bosch 211 (I bought Meyle): $140 ($70x2)
Bosch 211 connectors: $27 (outlined below)
Factory connectors for injectors, coil packs, cam sensor and crank sensor (and alternator):$100-$200 for factory harness from junkyard
TPS Sensor & plug: $40-$150 (specific to your throttle body)
Idle Air Control Valve & plug: ??
GM Intake Air Temp - open Sensor & Plug: $20
GM Coolant temp sensor and plug: $16.25
Cable driven throttle body: $100-$400
Throttle body adapter (if running GM cable driven throttle body): $60
3 relays: $24 ($8x3, including wiring)
A bunch of extra wire: $60
Buy Tunerstudio & MegaLogViewer software: $60
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Thank you for this post. I got the same setup for my 352 Desoto hemi. I have the engine built and got the same Megaquirt setup as yours. I know almost nothing about the computer setup. I made a 32-1 trigger wheel and am using a hollow magneto to distribute the spark to the cylinders. The mechanical advance has been locked by welding the counterweights. I did download a Megasquirt program into a computer for use later. Hopefully you can help walk me through this when it is all wired up. Thank you, Bill
 
Bill-

We will all help you as best we can- though we'll all be learning along with you when it comes to your spark!
 
Is there any reason you could'nt use the factory map sensor? Still kicking around WTH im gonna use but I have an 04 Truck harness and has the wrong coil plugs and cam sensor plug for my 6.1. Im also curious if the MS3 Pro needs coil drivers? I still cant swallow going the OEM route then needing an email tune.
 
72BBSwinger said:
Is there any reason you could'nt use the factory map sensor? Still kicking around WTH im gonna use but I have an 04 Truck harness and has the wrong coil plugs and cam sensor plug for my 6.1. Im also curious if the MS3 Pro needs coil drivers? I still cant swallow going the OEM route then needing an email tune.
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MS3 comes with a Map sensor already on the board, but there are additional unused inputs that could be configured to use the factory map sensor. It would take a bit of reading and you'd probably have to calibrate the sensor, not hard to do. MS3 and I believe MS2 allows for two MAP sensors. This is useful for someone who runs Pikes Peak. Normally when you start the car the MAP sensor takes a reading before there is any manifold vacuum and uses this initial reading for atmospheric pressure. This works fine as long as you stay relatively close to the same altitude. By having two MAP sensors you can place one so that it simply measures atmospheric pressure, this allows the computer to register changes in atmospheric pressure and thus change fuel enrichment depending upon changes in altitude. Like I said unless you're running Pikes Peak it is probably not needed.

Yes, you need coil drivers. Unlike Chevy LS motors the coils on the Hemi are "dumb" i.e. they don't have built in drivers. You'll need to use something like two of these:

http://www.diyautotune.com/catalog/quadspark-four-channel-ignition-module-p-481.html

Regards,

Joe Dokes
 
By my math I can go MS3 Pro with 92mm cable throttle body for about $1650. Just gotta score some coil connectors in the next couple months.
 
I think the Pro models are the pre-built more OEM style computer (sealed enclosures, large weather tight connectors, etc.). They're essentially the same internals I believe, just a difference construction.
 
MS3 Pro is closer to plug and play. It's says it supports Gen III Hemi ignitions so thats why I asked. Looking at the coil drivers, those add about 40 more solder joints to the party. And they say underhood mountable, that doesn't mean mandatory would it? One thing attractive when doing a Megasquirt is you can make the harness super clean.
 
72BBSwinger said:
MS3 Pro is closer to plug and play. It's says it supports Gen III Hemi ignitions so thats why I asked. Looking at the coil drivers, those add about 40 more solder joints to the party. And they say underhood mountable, that doesn't mean mandatory would it? One thing attractive when doing a Megasquirt is you can make the harness super clean.
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If you read the technical specs the MSPro has 8 logic level outputs for ignition. This means that you'd still need some form of ignitors.

The ignition modules could be mounted anywhere so long as they are mounted on a metal surface so they can dissipate some heat.

Regards,

Joe Dokes
 
I'm attracted to MS but frankly get bogged down in the endless branches of the information maze. I wish to 'ell MS would do a better job of streamlining their "features list" shall we say.

On the other hand I just bought an as new Holley HP ECU off 'th bay for half what it costs new, so now I have a spare!!!
 
67Dart273 said:
I'm attracted to MS but frankly get bogged down in the endless branches of the information maze. I wish to 'ell MS would do a better job of streamlining their "features list" shall we say.

On the other hand I just bought an as new Holley HP ECU off 'th bay for half what it costs new, so now I have a spare!!!
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I think that this is a legitimate criticism of MS. They have three different processors and several different boards, all of which have differing capabilities and prices. In addition MS was originally designed for fuel only, so supporting spark was initially a hack, which in the end results in various branches to the MS tree. Things get confusing really quick and since it is largely a diy focus documentation can be confusing.

Here's some references that should help.

http://www.ms3efi.com/product.html

http://www.ms3efi.com/product2.html

http://www.ms3efi.com/feature-xref.html

A problem with the above discussion is that if you don't know the terminology it is very difficult to get at the meaning. For this reason you have to read, read and read some more. After a while the terminology gains some meaning and it becomes possible to piece together how the system works.

The big upside is that when you are finished you truly understand how EFI works. I think this is a really great part of MS, so often things become black box and we are forced to look to so called experts. If you install MS you will become an expert in EFI.

Regards,

Joe Dokes
 
Thanks Joe. I'd really like to get into it if not more for experience, but as I age, my energy and attentiveness goes down. It's getting more and more difficult to sit down and read a lengthy technical book without falling asleep.

(Some years ago I used to install Motorola Centracom/ Centralink radio / telco systems. Hell you can't CARRY all the manuals for those two systems!!!)
 
Joe Dokes said:
Are you going to simply run a single plug then?

Regards,

Joe Dokes
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Technically yes. However ill have two plugs in the heads. Just swap use of the other if necessary. Cheaper and cleaner looking. Also less hassle to deal with drivers for ignition etc... could wire up two per cylinder but I'm just not a fan of the dual plug layout. If I was trying tonpass emissions sure but I'm not.
 
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