@DannyP posted:So, a couple questions for you, Mike.
What coil pack is that from/fitment? Is it a smart or dumb coil? Speeduino interfaces easier with smart coils, that way you don't need to buy and wire a coil driver.
You have 17 lb./hr injectors. I tried two different online calculators, and then did the math myself. I have a 172hp 2165, and come up with 28 lb./hr injectors on all 3 tries. I don't remember the rate of the ones that came with the CB throttle bodies, but I measured and they are 2 ohm injectors, so I'll swap them out for high Z or high impedance(12-17 ohm) injectors at the proper rate. Speeduino likes the high Z injectors. Looks like $50-65 each without resorting to Chinese crappy ones(8 for $50 and a seriously high failure rate)!
Can you tell I'm really spending some time pondering this? Love your success BTW, Mike.
Thanks, Danny. Coming from a guy with your knowledge and experience, that's high praise. I'm using a Bosch ignition coil 032 905 106 cross ref 0986221048 - fits 2000 Golf GTI 2.0L engine - uses LS/LT1 terminals. I've got 2 of them, one very cheap eBay special spare and one genuine Bosch ($68 from Amazon). They are slightly different when I measured input impedance, but they seem to fire very much the same. The Bosch one is the one on the car. It is a smart coil and triggers directly off of the Speeduino board outputs without anything special. It is a wasted spark coil so it has two channels, and fires two spark plugs every time it fires. I wouldn't say it's the Porsche of ignition coils, but it's well known in the aftermarket ECU builder community and has been bench tested up to 24,000 rpm by James Cortina, one of the Megasquirt luminaries.
I think your injector size estimates are very reasonable for your horsepower. If I were doing it again, I'd still get the VW Speed Shop ITBs, but I'd spring for the mini-injectors rather than sourcing the full size Accels I picked up off of eBay because of the tight space in the engine bay. I also totally agree with you on getting quality injectors.
Come on in, the water's fine!