Cheapest Computer for Alpha-N fuel only

Just as the title says, looking for the absolute cheapest options for fuel only alpha - N tuning. Only trigger would be a distributor ground, and a TPS signal. 

It looks like Speeduino  can do Alpha N. No idea how well they work, though. 

Used/forgotten MS1 , Microsquirt for something new that you don't have to learn a bunch of random lingo from a bunch or Arduino fans.

I’ve got a buddy with a MS1 that I know he’d let go for pretty cheap.

Originally got for a Miata but he never used it.

I have a couple of MS1 processors I'd give to someone if they want to go full DIY and make their own boards (or find an existing build with some damage, etc.), especially if you're gonna run it pretty stripped down for Alpha-N.

For example I picked up a cast-of mini-ms unit here for $10 that is an illegal MS1 clone that was sort of the precursor to the microsquirt (better main connector, compact size, sealed box).

We use speeduino in our race car but with full sensor inputs and it drives everything.

It works fine.

In reply to Stefan (Forum Supporter) :

I would be so down to build it myself if there is still documentation to guide me for it! 
 

pm me 

In reply to Honsch :

I need to look at speeduino more. I can't believe it's that small And cheap. Was it a lot of hassle to set up?

In reply to GPz11 (Forum Supporter) :

Pm me please 

For the record those "homebrewed" boards can be used for non commercial use only per the MS license documentation.  Horse trading would seem acceptable.

In reply to Paul_VR6 (Forum Supporter) :

Haha! What about horse race betting

CatDaddy said:

In reply to GPz11 (Forum Supporter) :

Pm me please 

Emails sent with pics

In reply to CatDaddy :

What application? Some are more problematic than others. The Miata is well documented and can even be had plug and play for about 350$. For racing applications it's fine. For a daily driver it will leave a little to be desired. I think you can only do sequential injection on four cylinders or less. 6 or 8 cylinders and up I think need batch fire. 

CatDaddy said:

In reply to Stefan (Forum Supporter) :

I would be so down to build it myself if there is still documentation to guide me for it! 
 

pm me 

Information is available on the megamanual.com and http://www.bgsoflex.com/megasquirt.html along with the parts list from Digi-Key.  The only thing you'd need is the PCB (which is the tricky bit, but DIYAutoTune.com does carry them)

I just installed a Microsquirt in my MR2.   It was reasonably straight forward to setup and tune.   Its more expensive than a home made arduino setup but likely a lot easier to learn how to get moving unless you are already heavily into the whole arduino ecosystem and terminology.   With about $40 worth of GM sensors I converted the MR2 to Speed/Density during the install.    The whole setup is waterproof and meant for very rough conditions, it cost just over $400 shipped and that included a 8' wiring harness which would be prohibitively expensive for me to try to replicate.

In reply to Vajingo :

Hi, it is for my Infiniti Q45 with a VH45DE. The plan was to make a custom 8 carb intake manifold and convert it to a distributor up front. It's for drifting only and the stock computer costs quite a bit to hack into. 

Now, I decided to skip the carb route, way too many jets to buy. So I wanted ITB's, but it seems ridiculous to buy 8 air filters and the bore spacing is 112mm a lot wider than any bike carbs. Plus I'll be sucking hot air off of the engine bay. 
 

so now I realize I just need a custom plenum,
The stock one is tuned pretty well for about 5200rpm... I'd like it to pull nicely more around 7200 with some over rev to get me through transitions   

 I'm trying to keep the stock injectors and Throttle body to keep everything a little more stock and easy to find parts. One air filter I can put in a cool place. 

now, GpZ11 is going to send me an MS1 that was running on a Miata before for a great price! He's also including a 32-1 wheel And sensor. Should be a great start and maybe I will add at least a coolant temp sensor 

i will Keep everyone updated! 

CatDaddy said:

In reply to Honsch :

I need to look at speeduino more. I can't believe it's that small And cheap. Was it a lot of hassle to set up?

For our car I used a UA4C board with a DSC for the factory VR sensors.

The plug on the UA4C was a pain, I had a difficult time with the crimp pins and I've done tens of thousands in the past.  I had the right tool and the correct gauge wire but the pins kept popping out of the plug.  It's sorted now but it took a lot of fiddling.

Because of the particulars of my engine, the DSC needed me to add a loading resistor to the VR sensor.  I was getting sync losses now and then.  Once I added the resistor it worked perfectly.

As for tuning, it's with the same software as MegaSquirt, so most dyno shops have some familiarity with it.  The tables aren't the same as MS, but there's good info on how it all works online.

Once tuned it has been totally reliable, but that's only two race days because of the COVID shortened season.

CatDaddy said:

In reply to Vajingo :

Hi, it is for my Infiniti Q45 with a VH45DE. The plan was to make a custom 8 carb intake manifold and convert it to a distributor up front. It's for drifting only and the stock computer costs quite a bit to hack into. 

For Speeduino, there are eight cylinder motherboards available if you use the Teensy 3.5 CPU.

Why go half assed when you can go fully assed?  With a little bit of effort the Speeduino can use all of the Nissan sensors and drive the Nissan coil packs.

Had a quick look at some Speeduino offerings, they still don't seem to support more than 4 cylinders of sequential fuel / spark? I saw some threads rumoring about the teensy being able to support 6/8 cylinders, but apparently the Arduino Mega is limited and none of those boards can do it with out batch firing. Not an issue for OP, but their solutions to running 5 cylinders come off as kind of janky to me, and that's a turn off.

Personally, I'm working on making some RusEFI Proteus boards for my friend's build -- A Volvo T5 engine in an E30. It's about $40/board for an 80% assembled product from China, and I'll put on the last SMD parts here with paste and a hot air gun, and hand solder the connectors. I can make a thread when they actually show up and there's stuff to be done. The RusEFI hardware is more powerful, so for not much more money I am choosing to invest in that platform since it should be able to be made to run anything I ever want to put it on. For disclosure on my perspective, I do have some background doing PCB design and assembly professionally and like my projects on the ambitious side -- if they weren't, they wouldn't be projects!

Speeduino does fully support sequential eight cylinder cars - with the right motherboard and CPU.  You are totally correct that the Mega based stuff will not work, you need to use a Teensy based one.

As for RusEFI, I was there at the start but didn't like the software based timers for timing critical things so I stopped caring about it.

In reply to MrRobogoat (Forum Supporter) :

Hey do you have links to the rusefi stuff? I'm coming up blank on my searches. Is this arduino c++ program language?

In reply to Vajingo :

The guy who started it had some threads on here, but they are a little stale now I think. They have their own forum, and a wiki on Github. This is the thread developing the board we are planning on using. I am not married to it yet, but I haven't seen anything I like better for the money -- apparently my googling has gotten weak though, since I am not finding examples of 8cyl sequential injection using Speeduino.

They are using stm32 Cortex-M processors, so it's straight C++, not the weird Arduino variant. From their code style page, it's the 2011 C++ standard.

Very interesting

MrRobogoat (Forum Supporter) said:

they are a little stale now I think.

rusEFI is pretty alive https://github.com/rusefi/rusefi/blob/master/firmware/CHANGELOG.md

Honsch said:

As for RusEFI, I was there at the start but didn't like the software based timers for timing critical things so I stopped caring about it.

But why?

Latest fanciest measurements at https://rusefi.com/forum/viewtopic.php?f=5&t=1657 say 99.8% of all measured samples were in a 0.1 degree wide window, with only 0.22% outside, the worst of which was 0.16 degree later than the earliest.