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Megasquirt Prep- 740 Turbo

2

240Toast

New member
Joined
Jan 30, 2016
Location
Boise,ID
Hello everyone! I have decided that my lh2.2 740 Turbo needs a good megasquirting, and I wanted some opinions of those who have done it and wanted to run a checklist of things that I will need. I am new to standalone managment, but I have a friend who is not who is helping me along the way, however, he has never done an lh2.2 motor before.

So the simplest way to start this thread will be to ask what I'm missing, thus far, in my cart I've got:

-MS1V3.0 With Mapdaddy4 Upgrade (in case I ever decide to get reckless with boost levels :oogle:)
-Megasquirt Pull Up Resistors Mod kit
-Megasquirt IAC TIP120 Mod Kit
-10 foot Megasquirt wiring harness
-Wideband o2 sensor

Is there anything else I'm going to need as far as luxury or ease of use type items?


I'm still researching how exactly I need to assemble it in the car itself, trigger offset and setting up the ignition in general. I have found many old posts about the lh2.2 IAC not being compatible with MS, but never one that really identifies why, and according to the DIYautotune instructions, the TIP120 mod seems to be the resolution to that situation. Can anyone shed some light on the situation for me?

I look forward to seeing your responses!
 
Might want to start with ms2, you'll probably want to upgrade at some time anyway.

Are you wanting spark control also?
Planning any boost control?

The map daddy upgrade.... Are you going to run more than 20 psi?

Add a good set of crimpers to your list. Get a stim if you are soldering your kit, get some practice. If you buy a prebuilt pm me and I could set up a loan/rent stim for you.
 
cwdodson88 said:
Might want to start with ms2, you'll probably want to upgrade at some time anyway.

Are you wanting spark control also?
Planning any boost control?

The map daddy upgrade.... Are you going to run more than 20 psi?

Add a good set of crimpers to your list. Get a stim if you are soldering your kit, get some practice. If you buy a prebuilt pm me and I could set up a loan/rent stim for you.
Click to expand...
I was lead to believe that ignition could be directly controlled with MS via the hall sensor, is that incorrect?

Boost control will be external and mechanical. I don't intend to run more than 20 PSI off the bat, but I do have another redblock bottom end that I'd like to run forged internals in down the road. So to have the option from the get go is nice. A local MS enthusiast is going to assemble my board.
 
Yes you have a single coil spark control on the msXv3.0 board, so you can control spark with ms1. But the resolution isn't much. I would personally substitute the map daddy upgrade for an ms2 chip just for the resolution. Cheaper to upgrade the map sensor down the road than the chip.
Everything else on your list looks good. Although if your funds allow, a yoshifab DSM CAS adapter would be a good addition as well for future sequential injection/ignition mods.

In order to get any further we're going to want more of your future plans in order to compile a more specific parts list.

You may also want to pick a hp goal to sort out how big of injector you run (it's just cheaper/simpler to buy them once) get hi impedance injectors, otherwise you have to run resistors or fiddle with pwm... It's not difficult but it ain't fun either.
 
I see you have WBO2 listed, but bear in mind that MS doesn't have WB controller inbuilt, which is needed for the ECU to make sense of a WB sensor output, so you'll need to look into that. 14point7.com carries them for less than 100$ complete with Bosch sensor. Just a heads up.
 
nordmaschine said:
I see you have WBO2 listed, but bear in mind that MS doesn't have WB controller inbuilt, which is needed for the ECU to make sense of a WB sensor output, so you'll need to look into that. 14point7.com carries them for less than 100$ complete with Bosch sensor. Just a heads up.
Click to expand...

I had intended to simply use a wideband o2 sensor with a gauge inside as a reference point to avoid having to set up a controller with the MS.

Given that this car has a borg warner GM5 turbo on it my safe horsepower goal is around 225 at the wheels. I was told it already runs fine as it sits, but I would like to install the megasquirt system to take further and more advanced control of the fuel to insure to myself that it will not only run fine as it is set up at the wastegate pressure of the turbo (16 PSI), but further down the road will be able to tune it for more boost, bigger injectors, etc. etc.
 
To utilize the tuning capabilities and be able to accurately log/tune your megasquirt, you will need a WB02+controller. I had overlooked that in your OP. Really the "setting up" of the controller to the MS is 1 wire, and 2 drop down boxes. Too easy to not do it.
 
cwdodson88 said:
To utilize the tuning capabilities and be able to accurately log/tune your megasquirt, you will need a WB02+controller. I had overlooked that in your OP. Really the "setting up" of the controller to the MS is 1 wire, and 2 drop down boxes. Too easy to not do it.
Click to expand...

Likely going to pick up a wideband sensor/controller from innovate.

Quick question, according to the DIYautotune website:

It appears that earlier models may have used a thermal auxiliary air valve for idle control. Later ones used a pulse width modulated idle air control valve. V3.57 boards need no modifications to control the PWM valve, while V2.2 and V3.0 boards will need a TIP120 transistor, like the one included in our MK-PWMIAC mod kit.
Click to expand...

I'm assuming Lh2.2 to Lh2.4 is what makes the difference here, and since my car is LH2.2, I assume that means I am running a thermal auxiliary-type IAC. What does this mean for setting up my megasquirt?
 
A microsquirt is most likely the best route, and inexpensive, and feature rich for the price.

boost control is a 30$ mac solenoid
micro has an external map sensor, so go with a cheaper GM 3 bar
No circuits or mods needed to run the idle/boost solenoids and no need to sacrifice IO for features
has also flex fuel input, among others. An lh 2.4 valve is recommended due to being a 2-wire PWM valve, instead of the 2.2 3 wire double PWM circuit needed.
Not much else to mention. microsquirt is a nice integrated package in a weather-sealed case, and did I mention the price. Lol.
 
I haven't worked with 740 LH2.2 so please ignore any of this if there's a more qualified response.

- Do you have more time than money, or more money than time? Even simpler, what's your time worth $$$ ?

- Forget the mapdaddy, you can add it later if needed.

- If you're broke, go ahead with the MS1 processor. Otherwise, MS2 processor is better and will be much more familiar to the tbricks board members -- more familiar means you'll get better answers to your future questions.

- You really want to spring for a full wideband sensor+controller, and the extra $$$ for the licensed TunerStudio/MegalogViewer so that you can run auto tune (~$90). Just be happy that you're not looking at a $500 HPtuners license for a single LS PCM.

- Absolutely buy or borrow a stim card so that you can play with tuning on your desktop!

- I don't know about the IAC valves and what to recommend.

- I'm an electronics geek so, if it were me, I'd be really tempted to get a junkyard LH2.2&EZK box, remove the connectors, and make my own short harness between MS and the stock connectors. You'd still need a few extra wires for what's different between LH2.2 and MS. If your engine compartment wiring harness is already toast, then yes, get the long diy harness and re-wire everything. If not, put up a post if anyone has a cross wiring diagram for stock EZK/LH2.2 to MS.

- You'll need a different TPS sensor.

- You'll need to add a air temperature sensor.

- The yoshifab CAS adapter is really nice but, check with others, I think you can start off using the LH2.2 distributor.

- Start off with a MBC. It's much simpler and easier to understand.
 
bobxyz said:
I haven't worked with 740 LH2.2 so please ignore any of this if there's a more qualified response.

...
Click to expand...

So I sprung a little deeper and played the "why not have both?" card. Purchased the MS2 V3.0 with the MapDaddy4 upgrade. I am planning on picking up an Innovate LC-1 Wideband O2 controller.

I'm still a bit confused as to the necessity to replace the TPS.

The Yoshifab CAS adapter is indeed nice, but I'm trying to avoid it. Not only due to the cost, but due to the fact that this is a head mounted distributor motor, meaning the intermediate shaft is not geared and couldn't run it. I'd have to pull the intermediate shaft and replace it with one from a block dist motor, which I just did a couple months ago on my 240 and would like to avoid doing again if I can :-P
 
your TPS is not a Pot type TPS, its a WOT/Idle switch.

you can fire a single coil through a locked distributor and a 36-1 wheel on the crank or a 60-2 flywheel, or a 4 slot trigger from the guts of your stock dizzy.
 
cwdodson88 said:
your TPS is not a Pot type TPS, its a WOT/Idle switch.

you can fire a single coil through a locked distributor and a 36-1 wheel on the crank or a 60-2 flywheel, or a 4 slot trigger from the guts of your stock dizzy.
Click to expand...

Alright cool, is the 850 TPS a pretty common option or is there something simpler?
 
There are others, but the 850 tps is very easy to retrofit.... easier now that yoshifab sells an inexpensive adapter plate between the 850/960 tps and the b230 throttle body.

https://yoshifab.com/store/b230-tps-adapter.html

Also, if you plan to run the lh2.4 idle valve, the tip120 mod is required. It's not difficult.
 
I machined my own, but it came out about the same as the Yoshifab. I'm using a junkyard 850 tps, and it works great with my MS2.

S4GvSol.jpg
 
740atl said:
There are others, but the 850 tps is very easy to retrofit.... easier now that yoshifab sells an inexpensive adapter plate between the 850/960 tps and the b230 throttle body.

https://yoshifab.com/store/b230-tps-adapter.html

Also, if you plan to run the lh2.4 idle valve, the tip120 mod is required. It's not difficult.
Click to expand...

Still a little confused here about the IAC situation. I did order the TIP120 mod just as a safety measure, but is it not possible to use the 3 wire LH2.2 IAC?

Thanks for the link! That's pretty cool, I'll have to grab one of those.
 
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