How to Megasquirt your 3G Hemi

-
Update:

1-
Had my battery fall over and short to the body. Couldn't get th car started. Sent to DIYautotune, who said it was fine. Got it back, re-wrapped the crank sensor wiring, and things were good again. The 5v VREF feed was grounding to my crank sensor ground- fixed.

2-
Had DIYautotune install the knock module while they had the box. Haven't wired it yet. Will update when I do.

3-
Couldn't get the car to rev over 5,000-5,300 rpm. I tried everything I could, and it turns out all I had to do was de-activate the crank sensor filtering in tunerstudio. I didn't even know there was crank sensor filtering. I adjusted the crank and cam pots in the board prior to that- lowered the voltage required as much as possible.

4-
Had a lean condition above 5,000 rpm. Calculated the percentage I needed to change the AFR to get where I wanted to be, and added that percentage to the appropriate cells in the VE table. Still needs more fine tuning, but I'm in a safe AFR range up to 6,000.

5-
I'm considering running two separate VE tables, with the switching threshold set to a certain TPS trigger. I say that because I get similar MAP readings at similar RPM's when cruising vs heavy throttle. I was super lean down low at heavy throttle when I started tuning yesterday, added fuel to get it acceptable, but then I ended up at like 10:1 AFR when cruising. I'll update the thread when I settle on a plan.

I still haven't been over 6,000 rpm. I was at 77% duty cycle at 5800 rpm and 13:1 AFR on 44 lb/hr injectors. The math puts that over 500 hp crank at .50 BSFC. I know that's a crude calculation, but it tells me I'm headed in the right direction.
 
Really glad you didn't brick your Megasquirt ECM. A $600.00 doorstop is not fun. Was your 5v to the crank sensor finding its way to ground, I'm a bit confused?

Good to know about the crank sensor filtering. Whether I have issues or not, it is good to know, every issue someone else figures out is a benefit for the rest of us. :)

Based upon you're build I think 500 HP at the crank is realistic. This is truly amazing, twenty years ago a built small block with ported heads was lucky to make 400-450 HP. I remember Hot-Rod engine builds where they broke 400 HP with a 383 Chevy Small block and I was astounded. Now we have 345 Cubic inches making 500 HP and don't bat an eye. We truly live in a great time for hot rodding.

Keep the posts coming I enjoy every one.

Regards,

Joe Dokes
 
I've been researching for over a year trying to learn what I can. Your post with real problems helps a lot in trying to get my mind around the more unique functions. My project is to do a parallel install maintaining the OEM pcm to run the accessories and feed the TCM on a 03 Ram. I just found this forum which has more information then I have found else where. Good job and excellent read.
Thank you,
Greg (Redtruck-VA)
 
Joe Dokes said:
Really glad you didn't brick your Megasquirt ECM. A $600.00 doorstop is not fun. Was your 5v to the crank sensor finding its way to ground, I'm a bit confused?

Good to know about the crank sensor filtering. Whether I have issues or not, it is good to know, every issue someone else figures out is a benefit for the rest of us. :)
Click to expand...

Yes, the 5v was finding its way to ground, but only when the box was hooked up (made it particularly hard to find for me). The way I 'found' it was I made a test harness (plug with 3 wires) that went from the harness on the car to the box. I ran a ground, a 12v, and a 5v. I put my multimeter on the 5v, then started walking a 4th wire from pin to pin (making sure I didn't cross connect), and saw where my multimeter dropped from 5v to 1.2v when I tested pin 7. It is a dedicated ground for my crank sensor. Not sure how 5v was finding its way to that wire, but I'm thinking the header heat affected the shrink tubing to the point that a connection was made.

Here's more numbers and math for y'all. Copied from my notes, so it may be a bit difficult to follow:

My VE table is 142.2 VE at 4400 rpm. 13.4:1 AFR at that. MAP of 98.7.*

Also, my MAP reading is 109.7 at 3879 rpm. Over 100 from 3600-4000 rpm. Elsewhere it is ~95-99

The tuner studio VE table uses something called 'required fuel' as a reference. I used 10.4, which was calculated using 44 lb/hr, 348 ci, and 14.7 AFR. If you swap in 13.5 AFR, then it goes to 11.3. So a 8.6% difference. If you take 8.6% off my 142.2, then we're looking at 129.9 % VE.*
More info- my gauge reads lower than my computer. So if it was actually 13:1, then I'm looking at 124.4% VE.

I figure ~125% VE is peak at torque peak (4400 rpm- which is the Tq peak of dudeiwin's 5.7 with this cam on Lxforums)
5800 rpm
77.1% duty cycle
99.6 MAP
80.8% Throttle
13.0:1 AFR (~12.6:1 on gauge?)
Plus-
134.8% VE in table using 10.4 req fuel
=
12.2 req fuel if using 12.6:1 AFR.*
=
17.3% off (mult by table VE)
=
111.5% VE actual at 5800 rpm


So my best estimate for my motor's efficiency:
125% VE at 4400, and 111.5% VE at 5800.
those two points should be real close to tq and hp peaks.
 
I am so glad to read your write up. I have been torn between ms3x and xfi. After your price break down you did. It opened my eyes to the truth about it all. Xfi is about the same price as ms3x when said and done. Besides sensors. There is a lot of hasle taken out of everything with xfis plug n play. I know ms3x is an awesome peice I know. Its the on your own aspect and trouble wiring ect... that leaves one hesitant. For me anyways as I'm a high powered turbo build and I need some peice of mind. I truely appreciate your write up in so many ways. I can not thank you enough.

You have a link to the guages? I was considering vdo as I didn't want autofeeders like all he rest.
 
turbofreek said:
I am so glad to read your write up. I have been torn between ms3x and xfi. After your price break down you did. It opened my eyes to the truth about it all. Xfi is about the same price as ms3x when said and done. Besides sensors. There is a lot of hasle taken out of everything with xfis plug n play. I know ms3x is an awesome peice I know. Its the on your own aspect and trouble wiring ect... that leaves one hesitant. For me anyways as I'm a high powered turbo build and I need some peice of mind. I truely appreciate your write up in so many ways. I can not thank you enough.

You have a link to the guages? I was considering vdo as I didn't want autofeeders like all he rest.
Click to expand...

I'm glad you enjoyed the write up. Though the last time I checked, the comparable Hemi XFI kit was about $3000. This can be done for $1600-$1800. Were you looking at a different XFI product?


Copy and paste of XFI vs MS3x written by Matt cramer of DIYautotune:

Here's an XFI vs MS3 comparison I put together on another site.

The FAST XFI and MS3 are pretty similar on paper. I'm looking through
the FAST manual to see if there's any major differences, and here's what
I have noticed. Look like some points land in favor of FAST and some for
MS3. Overall, the MS3 has a bit more precise fuel control.

1. The fuel and ignition tuning process is almost EXACTLY the same for
the main fuel and spark maps. Unlike some of the other John Meany ECUs,
the FAST system uses a VE type fuel table, which MS also does.

2. The only acceleration enrichment option in FAST is a "accelerator
pump" type enrichment; MS3 (and MS2) also has a model based acceleration
enrichment that is a bit more sophisticated. This generally has very
little effect on a drag car; it's more useful on a road racer.

3. FAST has more nitrous channels (4 instead of 2), while MS3 can run
its nitrous control progressively.

4. FAST boost control is closed loop only. MS3 (and MS2) has closed and
open loop boost control. MS3 can also adjust boost as a function of
vehicle speed - although this is not allowed in the NHRA.

5. FAST has a dedicated EGR function (this could be done with a generic
output on MS3).

6. FAST has a time based traction control option to meet NHRA rules
against monitoring wheel speed.

7. FAST individual cylinder corrections are a fixed percent or degree.
MS3 has 6 x 6 tables for each cylinder.

8. FAST has 8 extra analog inputs; MS3 has 3 to 5 depending on setup.

9. FAST can switch between 4 internally stored maps; MS3 has 2.

10. FAST does not support MAF input or blending alpha N with speed
density. MS3 (and MS2) supports both.

11. FAST does not seem to have the same sort of gradual staged injection
capabilities as MS3 and MS2, although I could be wrong.
 
If for just fuel control I'd jump on ms hands down and I still may. Xfi is plug and play which is hours of no screwing with wires and tuning every single aspect of the system. As in punch in a few things your engine has and it will run. Ms you have to do all the programing from cold start, to each percetage of fuel per adjustment box across all tps and load and speed windows of the system. Xfi will give you a close proximity and you adjust accordingly. No math to mess with for everything. Megasquirt has great tuning ability but it isn't as user friendly for the masses. If it was it would tech support similar to xfi and base tunes available to upload besides another forum member on diyautotune.com. matt cramer is a hell of a guy and I am in no way of dismissing ms as a viable efi as it is a great product. It is just not for those who can't do it themselves with zero efi knowledge and no time to learn its hours on end tuning perameters in order to make it function well.

It is still on my possibility list but with time not on my side for it. I am uncertain I can go with ms as easily as I could xfi or bs3.

Xfi ecm is 1800 add the harness from them at 400ish and you have efi. Then another 650 for the ignition side of it o go msd for ignition controls. All depends on who is using these things and their ability to over come nobody to help when a true issue arrives.

Or buy a test system to test it yourself when failure happens? That sounds fun no?
 
With as many people as there are screwing with EFI, I'm surprised someone has not developed software that will interpolate brand X maps into brand Y, 'er whatever.

Biggest gripe with my old (but cheap) Holley Commander 950 is it's all manual all the time programming. I did however pickup up some alternative software by "Tazman" which is sort of self learning whenrun

This is a very informative thread.
 
The choice is fairly simple- if you're a DIY guy who wants to tune your own motor, MS3x is a great way to save $1000-$1400. If you don't want to tune your motor, then buy the computer your tuner tells you to.

I've never tuned or played with EFI before this. It isn't difficult. I find it much easier than old school tuning, actually.
 
Turbofreak,

Totally off topic but I really like the stance of your post car. Did you mini-tub the rear?

Regards,

Joe Dokes
 
Uhcoog1 said:
The choice is fairly simple- if you're a DIY guy who wants to tune your own motor, MS3x is a great way to save $1000-$1400. If you don't want to tune your motor, then buy the computer your tuner tells you to.

I've never tuned or played with EFI before this. It isn't difficult. I find it much easier than old school tuning, actually.
Click to expand...

I agree completely with you. I am just argumenitive some times. My appoligize.

Will the ms2 run the fuel side alone?
 
Joe Dokes said:
Turbofreak,

Totally off topic but I really like the stance of your post car. Did you mini-tub the rear?

Regards,

Joe Dokes
Click to expand...

Yes stock leaf location with the bolt in offset hangers. Look up my recent posts to see my build thread. It is not a widened stock wheel well.
 
turbofreek said:
I agree completely with you. I am just argumenitive some times. My appoligize.

Will the ms2 run the fuel side alone?
Click to expand...

Yes, it will run the fuel side alone. I cant recommend running fuel and spark on different computers- increases the cost and requires extra work to tune. Now if you started with a carb and swapped to EFI and wanted to keep the spark you already have, that's different.

I'm sure you already know this, but ms3x has a self tune feature in tuner studio. Very easy to work, and Is a very useful tool to dial in the lower cells in your VE table. Also, there is a VE table generator that you input approximate hp and tq numbers and the rpm that happens at, and it generates a VE table for you. It provided me with a fantastic starting point that was very close across the board.

For WOT tuning, it's really quite simple to tune fuel. Log your WOT pull, then view the log and see what percentage your AFT's are away from where you want them to be. Go into your VE table and change the corresponding cell(s) by that percentage, and you should hit your target AFR spot on.

The only part of tuning that your 'on your own' is the timing table. With all the different timing tables that have been posted, it's quite easy to find a good starting spot.
 
I ask cuz I can get the msd box and harness at about 50% off list. It is easily tunable with available maps to use and adjust as needed. This is my initial idea of way I want to go. I'm completely torn on it. As I have seen lots of issues with megasquirt start up stuff. Maybe buying allready assembled is the way to go? I already have sensors just no harness.
 
I'm about to MegaSquirt my 5.7 and I must say you have done a fantastic job, Uhcoog1!

I'm gonna use as much as I can of the original wireing, but I'm not sure about some sensors... And which ones are the cam and crank-sensors?



1. Don't know

2. Knocksensor?

3 and 4. Oilpressure and temp, but which one is what? Guess no. 4 is presssure...



5. Camsensor?



6. Not sure...



7. Not sure...

Please help... :)
 
1- crank
2- knock (there's also one on the other side, same spot)
3&4- oil
5- cam sensor
6- looks like water temp area
7- looks like map sensor area

For a megasquirt install, you'll need the factory crank and cam sensors, that's it. The megasquirt also needs these GM sensors:water temp, intake air temp (DIYautotune sells the plugs with the sensors)
And you'll need these: throttle position sensor (on whatever cable TB you use), port for MAP hose (my map sensor is inside the MS3x box), and idle air control (also on the TB of your choosing).

For gauges- use the sensors that match your gauges. Use adapters to make them fit the motor.

What's the motor going in? You should start a thread in the Hemi swap section that shares about your build, we'd all love to see it.
 
Thank you very much!!
I'm looking for a suitable TB, not going the Hillborn way...
Maybe another intake, I don't like the truck manifold...
First I'm gonna start it in my garage, just to see if I can get it work, then maybe stuff it in a Barracuda 65... I would like a HemiCuda! :D
 
Gunnar said:
Thank you very much!!
I'm looking for a suitable TB, not going the Hillborn way...
Maybe another intake, I don't like the truck manifold...
First I'm gonna start it in my garage, just to see if I can get it work, then maybe stuff it in a Barracuda 65... I would like a HemiCuda! :D
Click to expand...

If you are keeping the stock computer, you'll need to stick with the drive by wire. There's a bunch of good videos over at hotrodlane.cc about how to use a stock pedal out of truck or Charger. The stock pedal acts as both the throttle and throttle position sensor. Basically when you step on the pedal the computer says, "hmmm guess this guy wants some power better open the throttle."

If you decide to go with any after-market computer you need to use a cable operated throttle body. FAST has an adapter that allows you to use one of the 92mm throttle bodies. Here is a link: http://www.fuelairspark.com/fas/chrysler-5-7-6-1-hemi-adapter-92mm-only.html

Or you can make your own. I did:


The one I made allowed me to use an 85mm Power throttle body, which I bought for $100.00 off of ebay.

Best of luck.

Regards,

Joe Dokes
 

Attachments

  • Throttle body 1.jpg
    53.6 KB · Views: 977
No, I'm going the MegaSquirt way...

A few more questions about the Engine:

What is this hole in the head for and can I just plug it of?



I still don't know what this cables goes to, but it's not the MAP-sensor...
Five cables in under the intake...



I tried to make the original TB mecanical, but I don't know how to take out the trottlebladeaxel...

 
Uhcoog1 said:
Yes, it will run the fuel side alone. I cant recommend running fuel and spark on different computers- increases the cost and requires extra work to tune. Now if you started with a carb and swapped to EFI and wanted to keep the spark you already have, that's different.
Click to expand...

This is exactly what I did. Started with a carb swap because I didn't want to upgrade the whole fuel system to high pressure (because if I did I wanted to go in-tank pump and didn't have the money at the time). I also had an awesome deal on an Megasquirt setup fall into my lap and couldn't pass it up. This all happened around the time I got my job out of college as well, so I suddenly had some money to play with and could afford the new fuel tank complete with pump.

Just running the fuel with the MS is actually super easy with an MSD running the ignition. Granted you're kind of limited to batch injection as opposed to sequential with this setup (unless it's possible to splice into the cam and crank sensors). The MSD uses the cam and crank and you just feed the tach output line of it into the Megasquirt for an rpm signal. You still need the coolant temp, air temp, vacuum, and throttle position, but those are easy enough to do. Had mine running this way for a few years now and have been really happy. The fuel control isn't quite as precise since you're not running sequential, but it seems to run consistent enough.

I'm still curious if anyone has tried this http://www.fuelairspark.com/fas/multiport-retro-fit-ez-efir-kit.html. It's a self tuning setup that uses a stock fuel injection configuraiton instead of the typical "throttle body with injectors built into it" retro-fit that are aimed at older carbed engines. Granted you'd need ignition control and to convert to a wired throttle body, so you might be looking at a similar price point as an all-in-one ECU, but it's potentially another option. I was really heavily looking into this before the Megasquirt dropped into my lap.
 
Ok you got me totally convinced to go with the megasquirt. So simple a caveman can do it. Also already have all the sensors. Just have to wire it up and that seems to damn simple not to do it myself.

But ta better have me a base to to start it. Lmao 160lb injectors fwiw. :-D
 
Gunnar, the wires going under your intake are for the MDS system. For shutting down four cylinders to save fuel. You wont use them. You can actually swap out those lifters and plug the holds with a kit, not sure where you'd buy it though.
 
Red383 said:
Gunnar, the wires going under your intake are for the MDS system. For shutting down four cylinders to save fuel. You wont use them. You can actually swap out those lifters and plug the holds with a kit, not sure where you'd buy it though.
Click to expand...

Here's the kit to plug up the MDS holes:

http://www.highhorseperformance.com/MOPAR_6_1L_MDS_Block_Plug_p/mds-plug.htm

Here's a guy that will sell you some non-mds lifters.

http://www.ebay.com/itm/Lifter-Set-Hydraulic-Dodge-Hemi-5-7-6-1L-Free-Shipping-/370716465190

I have no relation to the above websites and have not bought ANYTHING from them, so use some discretion.

Regards,

Joe Dokes
 
I'm about to start my hemi using MS3pro can you post your current ignition table?
Much appreciate,
 
You must log in or register to reply here.
-

Back
Top