[Gearhed90]

So I am all about DIY stuff and not paying the big bucks for convenience. I want to use Speeduino on a 1974 VW bug to convert it to FI with turbo, I just don't know what all I need to buy for the Speeduino. Is it just the Speeduino board and an Arduino? I'm in the USA so I'll be ordering stuff from WTMtronics and just want to make sure I get the correct stuff before completing the order. Do I get the Speeduino v0.4.3? What is the UA4C? I already have an Arduino Mega. As far as the other components such as injectors and sensors I will get that later, I am a career auto tech so I know about those, I just need help with the Speeduino hardware.

[LPG2CV]

Hi
I am sure there are some air cooled vw engines on here already. Have a search to see what they have done. Learn by their mistakes

[PSIG]

+1. Lots of knowledge to help with your plans. Always start with your plans and goals for the project. The more you know about what you want to do and why, the simpler it is to make choices to answer those plans and goals.

Then a list of hardware requirements, so you can choose an ECM that will properly control that stuff, i.e.: IAC, and what type? Boost control valve? What trigger system will you use, and do you need a signal conditioner for that type sensor? Where are you placing the TPS? And so on. BTW - almost any Speeduino ever designed will control a turbo 4-banger. Examine each for their differences in controls, connection and packaging, for what works for you. Have fun!

[Gearhed90]

+1. Lots of knowledge to help with your plans. Always start with your plans and goals for the project. The more you know about what you want to do and why, the simpler it is to make choices to answer those plans and goals.

Then a list of hardware requirements, so you can choose an ECM that will properly control that stuff, i.e.: IAC, and what type? Boost control valve? What trigger system will you use, and do you need a signal conditioner for that type sensor? Where are you placing the TPS? And so on. BTW - almost any Speeduino ever designed will control a turbo 4-banger. Examine each for their differences in controls, connection and packaging, for what works for you. Have fun!

Would it be safe to plan the engine and build it then make the ECM the last purchase? That way all those questions are answered and I'll be able to buy the latest hardware right?

[PSIG]

As much as possible, do the planning concurrently — plan everything you can together. For example, the fuel you choose for the build is one of the first decisions, and is partly to meet goals and partly what is available and within budget. Balancing the required and desired factors gets you the answers you need for the build and parts required for it. Decisions such as what connecting rods or injectors to use become much clearer and easier for specific reasons, rather than "the best or biggest I can afford" because you don't really know what it will need. That's solved by planning.

Or, it can be a lot better, quicker and cheaper to plan your trigger, ignition or injector placement before the build, to avoid having to modify the build for it. This is akin to deciding you want to go turbo after a build. Not a good position to get caught in.

You see where this is going. You can get there 101 different ways, but I would suggest paths that take-in all considerations (as much as possible) as you proceed, not as an afterthought. It sucks for many reasons to go back and change things, and planning doesn't take long. Start with the high-level fuzzy purpose, use, goals, fuel, etc, and work your way down to the important stuff. The details will almost fall into place from there with a solid foundation. Have fun!