Best Efi Route

a91what said:

I agree it does not. however the boards do not have to be in your case they can be mounted externally..

FYI i actually design quite a bit of my own stuff... so if you need something designed or made for your specific application I can help with that.. I am releasing my own expansion module soon but it only has 2 VR conditioners.

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To be honest, I am not sure I even need all 4. I think the factory only uses 4 sensors to be able to throw a code if the intake cam sensors or the exhaust cam sensors aren't reading the same(or if one cam phaser isn't functioning correctly). Its not like Ti-VCT intake cams on one bank are going to be different than the other bank. I think they double up the sensors for diagnostic purposes, but that is an assumption on my part...and having better diagnostic capability is always a good thing.

I suppose I could run 2 sensors and diagnose by unplugging the cam phasers if needed.

If you want control of that cam then yes you need its input... the ECU needs the value so it can run the VVT to achieve the desired cam angle

All the power is made in the intake cam... you could just not use the exhaust cams and lock them out

a91what said:

If you want control of that cam then yes you need its input... the ECU needs the value so it can run the VVT to achieve the desired cam angle

All the power is made in the intake cam... you could just not use the exhaust cams and lock them out

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What I meant is that couldnt you just take the angle from one intake cam sensor and assume the other intake cam matches it(with the same being true for exhaust)? Thus using only 2 of the 4 sensors.

I would have to see if the software would let me do that, however even if it is doable... I would want to be able to check the cam position vs the commanded position.. whats to say that the required PWM between the two cam phasors is equal? if they are not then you will never know the actual angle of the cam just what the ECU assumes it is based on the measured cam angle.
IMO this is not a good way of going about it, If it were me I would simply lock the exhaust cams and apply VVT to the intake cams if I had to choose out of the two methods.

a91what said:

I would have to see if the software would let me do that, however even if it is doable... I would want to be able to check the cam position vs the commanded position.. whats to say that the required PWM between the two cam phasors is equal? if they are not then you will never know the actual angle of the cam just what the ECU assumes it is based on the measured cam angle.
IMO this is not a good way of going about it, If it were me I would simply lock the exhaust cams and apply VVT to the intake cams if I had to choose out of the two methods.

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Naw, far easier and better to just use the 4 sensors and run 2 2-circuit external JBPerf boards in some plastic enclosure. I saw that someone had mounted one of them in a gutted relay so it should be fairly easy.

wicked93gs said:

Naw, far easier and better to just use the 4 sensors and run 2 2-circuit external JBPerf boards in some plastic enclosure. I saw that someone had mounted one of them in a gutted relay so it should be fairly easy.

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now we have moved from make it work back around to do it right... you will be happier this way

wicked93gs said:

I can say for a FACT your assertion about an amateur tuner not being able to get a better tune that a factory 80s car is just dead wrong.

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It's not wrong because that's not what I said.

I had mine dialed down to almost perfect and I didn't even spend all that much time tweaking it...most of it was done with autotune in conjunction with a wideband o2 sensor, with just a few manual tweaks by me here and there. You can literally setup Megasquirt and be driving within 15 minutes of idling for the first time, and have a good solid tune down with VEanalyze with a few days of driving...everything past that point is just refinement. Will you be able to match a MODERN OEM for tuning? If you put in enough work....sure, but most amateur tuners never will.

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Your seat-of-the-pants self-evaluation of how good your tune is, again to my original point, doesn't compare to what OEMs were doing 38 years ago. That loosens the requirements on what an aftermarket standalone ECU really needs to do for the end user. Even crank triggers and sequential injection isn't a must-have here.

That's great that you like your MegaSquirt. Lots of people do. That doesn't change that it's still an amateur product and definitely not the best option, nor the only one in its price range.

65ShelbyClone said:

It's not wrong because that's not what I said.



Your seat-of-the-pants self-evaluation of how good your tune is, again to my original point, doesn't compare to what OEMs were doing 38 years ago. That loosens the requirements on what an aftermarket standalone ECU really needs to do for the end user. Even crank triggers and sequential injection isn't a must-have here.

That's great that you like your MegaSquirt. Lots of people do. That doesn't change that it's still an amateur product and definitely not the best option, nor the only one in its price range.

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You are correct...you actually said:

"An amateur tuner is going to be hard-pressed to match the level of tuning that OEMs were doing even in the early '80s regardless of the intake design or EFI style. "

I have owned enough 80s cars that even my "seat-of-the pants evaluation"(backed up by the way with dyno numbers, AFRs and datalogs) to know that as an amateur tuner I did indeed match and exceed the tuning of the cars of that era and I wasn't hard pressed to do it. I wont claim that I matched or exceeded tunes from cars built in the 90s or later...but certainly the 80s.

To your point though, you are correct in the fact that OEM computers and standalone ECUs are doing 2 completely different tasks...but you can't split off and imply Holley or other brand names are functionally superior to Megasquirt because it is simply not true. You are absolutely correct that Megasquirt is an "amateur" product in the fact that it is not produced by a single company, but implying Holley or Motec or AEM or Haltec etc etc is better because it IS produced by a single company is like saying Windows is better than Linux because Windows is made by a single company.

From Holley's website...one of their sniper units, self tuning, features listed:

• Dual Pattern bolt on carburetor replacement, designed to fit 4150 Flange & Spread Bore manifolds - (Spread Bore Sealing Plate Part #9006 is recommended)
• Throttle body mounted ECU – no extra boxes to mount
• Supports up to 650hp with Four 100 Lb/Hr Injectors!
• Only 4 Wiring Connections Required! (Battery +, Battery - , Switched Ignition & RPM)
• Internal fuel pressure regulator eliminates the hassle of plumbing an external fuel pressure regulator (Preset to 58.5 PSI)
• Integrated ignition timing control & coil driver
• High Resolution Full Color Touchscreen for Initial Setup, Tuning, and Gauge Displays.
• Simple Calibration Wizard (Answer a few questions about your engine and it creates the base map, then starts tuning on its own!) - NO laptop required!
• Self-tuning ECU means you don't have to be a computer/tuning wiz to have EFI!
• Available in base & master kits (Master kits include complete fuel system consisting of; 20ft of 3/8" Vapor Guard Fuel Hose, 12-920 Fuel Pump, Filters, necessary hardware and bulkhead fitting to return fuel into the tank!)
• The included Genuine Bosch LSU 4.9 Wideband Oxygen Sensor provides realtime Fuel Map Learn!
• OEM Style TPS/IAC and Fuel Pressure regulator, for years of dependable service.
• Included clamp-on oxygen sensor kit ensures a leak free oxygen sensor installation, with Stainless Steel T-Bolt clamps and a Stainless Steel (Weldable) oxygen sensor flange
• Certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance. Making Sniper EFI the perfect choice for carburetor to marine fuel injection conversions!
• A Flame Arrestor is REQUIRED for marine installations, such as part number, 720-1 or 720-13
• Patent Pending

What you have here is a self tuning all in one type unit that replaces the carb. It can...control ignition timing and coil dwell, control fuel and comes with self tuning capability. It costs $1040 and comes with pretty much everything you need from the touchscreen control to regulator, etc etc etc. All in all, a pretty good deal and I can certainly see why its popular...however, it is NOT comparable to megasquirt. It CANT:

1. Implement traction control with the use of wheel speed sensors
2. Implement nitrous control(if that is your thing)
3. Implement boost control via an electronic boost controller(if you have forced induction)
4. Read a speed sensor...either for traction control, gauge signal translation, or just for datalogging.
5. Control cam phasers for VVT applications.
6. Run any engine from a single cylinder lawnmower to a W16
7. Mount an anything other than a standard 4 barrel manifold
8. Any number of other custom functions.


Yes, the price is comparable, but the functionality isn't even close. In the end it all depends on what you need and want. If you have a pushrod v8 with a 4 barrel manifold and want to convert it to EFI...Holey is tailor made for that....but, its a lot of money to spend for what will likely be a marginal difference over a well tuned carb. I do see the appeal though, never tune and fiddle with your carb again for about $400 more than a new carb...it is certainly money well spent, a nice and simple installation, set it and forget about it. It won't gain you a lot of power over a carb though....since it has a lot of the same limitations a carb is working with. I would buy a Holley EFI if my goal was to marginally increase fuel mileage, maybe gain a few HP with better AFR control and to never mess with a carb again...but I would not buy one if I was planning on adding forced induction, traction control, ITBs or any number of other features. It certainly is far more complete than megasquirt products generally are though(with some exceptions).

I think our disagreement here stems from the fact that we are comparing apples to oranges. They are different products with different purposes. Holley is quite focused on a single thing and does it well...Megasquirt is far more open-ended...but like any customizable product out there, it needs a lot more work to narrow its focus down to your goal. Regardless, there are a lot of options out there that will work for the OP, a lot of them relatively affordable. Its a great day in the world of tuning when we can argue which $1000-ish dollar standalone is better.

I can literally take the same Microsquirt most guys use for running a batchfire engine and load different firmware and instantly have an I/O box or transmission controller or whatever I can think of wanting it to do..