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Showing posts from March, 2020

On "Microsquirting" the Porsche 914 - Part 9, Tuning

Tuning Back to Part 8  Wow. You've made it this far...? Good for you, you're no "TL;DR"! Or did you cheat and skip ahead...? Tuning. Another "oof, I have no idea what I'm doing." Gotta figure it out though. I began with a baseline tune from Mario at The Dub Shop (if you're gonna do this, buy from Mario)  and that's what I used to fire up the car. But Mario has not done a setup like mine; Mario has his individual throttle body setup for Type 4 engines . That's overkill for a dead stock engine like mine (and outside of my target budget). So I needed to improvise. But he knows these engines so I requested a base tune. I adjusted Mario's tune for a few things like injectors and fuel pressure. The stock FPR would only do 36psi; the injectors I used were rated at 3 bar (43.5psi). So I used the TunerStudio program and an online calculator to adjust the injector size and edited that into the tune. I reviewed all the other setting

On "a Movie"...

Ever watch Steven Spielberg's movie, "1941"? It's hilarious! Quick summary, it's 1941 and America is on edge because of the recent bombing of Pearl Harbor. The entire West Coast, and especially LA, is convinced that Japan is going to invade. Slapstick hilarity ensues as people panic, thinking there was a "Jap" soldier under every rock (which of course there wasn't). But wait! There actually was a Japanese submarine lurking offshore, with inept officers and an inept German officer on board, observing the coastline. They were there to "destroy something honorable" in Hollywood. The Japanese submarine did manage to torpedo...a Ferris Wheel.* But in the end, it was the societal panic that caused the real damage: LA downtown destroyed, Hollywood damaged, anti-aircraft fire lofted all over the city at a civilian airplane (and a pursuing P-40 Warhawk, both shot down, one crashing into La Brea tarpits; a home shot up by the homeowner

On "Microsquirting" the Porsche 914 - Part 8, So, Will It Run?

So, Will It Run? Back to Part 7 Spoiler: It runs! But first... The drivetrain install went fairly smoothly. If you've removed/installed one of these, you realize it's really not so bad of a job. I hate, hate, hate the concept of removing a drivetrain to repair something (Lotus manual for changing the oil: Step One, Remove the Engine) but the 914 is really not that hateful. A couple wires, a couple cables, the eight (yes only 8) drive axle bolts, and the whole thing is held in by four more bolts. I used to laugh at Edd China casually removing a drivetrain on a car to do some work on it but after watching him remove the 914 drivetrain in an episode (Season 9, Episode 5, worth the watch) I'm kinda with him there (and I use his "drop on my toolbox and raise the car off with the lift" trick). Yeah, it's a pain in the butt to a certain degree, but the amount of time you save having things right there in front of you and accessible makes it so much morez bett

On "Microsquirting" the Porsche 914 - Part 7, "Ignition, Wiring, and Terminals, Oh My...Part Dos!"

"Ignition, Wiring, and Terminals, Oh My...Part Dos!" Back to Part 6 Ok, so we know where we're mounting the Microsquirt ECU. And we know how much MS harness we have to work with. And we know the general wiring concepts and what pin housings and terminals we're going to use. But there's still some outstanding questions. One issue is grounds. The MS needs two different grounds: a chassis one for the MS unit itself (it has two black chassis ground wires) and one back to the MS for the sensors. The chassis ground is pretty easy: there's a multi-pin ring terminal at a case half bolt in the back-middle of the engine. The engine grounds to the transaxle and there's a big ground strap on the back end of the transaxle to a stud on the chassis, and the battery negative wire goes to that same chassis stud. Soup. I can run MS, wideband controller, and ignition coil to that. The sensor grounds require a bit more thought. Each sensor -- CPS, TPS, IAT, MPS, C

On "Microsquirting" the Porsche 914 - Part 6, Ignition, Wiring, and Terminals, Oh My!

Ignition, Wiring, and Terminals, Oh My! Return to Part 5 The electrical design and the wiring... oof . Had I known in advance how much brainpower and effort this was going to take...let's just say it was a lot of work. D-Jet ECU Diagram 1 of 3... I began by learning all I could on how the D-Jet's electrical system was designed. "Why?" you may ask. "After all, you're getting rid of the D-Jet!" Fair point, but recall one of my design parameters what that I wanted it to be as bolt-in (or plug-in) as possible, with minimal modifications to the stock parts of the car so D-Jet can be reinstalled if desired. So I wanted to understand how D-Jet interfaced with the car and engine and possibly leverage that. I pored over wiring diagrams and schematics writing notes and reminders, and meticulously documented in a spreadsheet what each wire and circuit does. There's no write-up I'm aware of that just offers design concepts straight-up (though Paul

On "Microsquirting" the Porsche 914 - Part 5, Ignition Coil, Bracket, and Injectors

Ignition Coil, Bracket, and Injectors Back to Part 4 Remember the IGN4-VW coil? Install was going to be a breeze...or so I thought. I tossed around several location ideas and wasn't happy with them. Then EricP showed me a bracket he made to install his in the area where the original distributor was... of course! Duh. Eric fabbed a bracket that also mounted his MPS, but since I didn't need that I "went simple" and made a plate out of sheet metal I had laying around. It fit right over the distributor hole plug and used the distributor clamp stud and two sheet metal screw holes. Drill, tap, three rivnuts later and the coil was mounted. 3/28/22 Update:  Please read Part 11 Addemdums. I no longer recommend mounting the coil here, as it was overheating and causing misfires. Description and photos left for reference -- of what NOT to do... ;) By the way, this wasn't the first time Eric saved my bacon...the TPS choice and TPS mounting bracket was his idea too...

On "Microsquirting" the Porsche 914 - Part 4, The Sensors

The Sensors - cont'd Return to Part 3 The box of sensors finally arrived from The Dub Shop. It wasn't too long before I was trying different locations on the engine, deciding where to mount them. I started with the CPS. The crank position sensor is mounted behind the cooling fan shroud and needed to be in place before anything else went on. The location bothered me a bit, as failure of the CPS would likely require removing the engine to get the fan shroud off to get to the sensor; of course, there's no way it would be field-serviceable. But it's one of those "necessary evils" let's hope this is a hardy sensor. The Dub Shop Crank Position Sensor The aluminum block to the left is Tangerine Racing's oil cooler block/thermostat for an external cooler Installing the sensor itself wasn't that difficult; it literally just bolted in. However, it's in a tight space and took some fiddling to get it positioned correctly; you had to e

On "Microsquirting" the Porsche 914 - Part 3, The Design

The Design Return to Part 2 Recall my design parameters so far: Use the stock intake manifold(s) and throttle body; Use stock injectors; Use stock fuel pump and pressure regulator; Replace D-Jet components only when it makes sense; Upgrade fuel injection only, ignition to follow later; Bolt-on wherever possible so others can install it; Should not require permanent mods to stock components (so it can be reverted); Price-sensitive -- keep as inexpensive as possible. I quickly learned early on I had one conflict: the D-Jet system uses "low impedance injectors" and the Microsquirt system needs "high impendance injectors". I'll lead you to this link if you want to learn the difference but it basically comes down to electrical resistance. I could use the D-Jet injectors if I added a resistor pack -- which is exactly what VW/Porsche did when they used similar injectors on the L-Jet system for the 1.8L 914 engine.  FiveO High Impedance Injectors

On "Microsquirting" the Porsche 914 - Part 2, Which Aftermarket Fuel Injection System?

Which Aftermarket Fuel Injection System? Return to Part 1 Scenario: two Porsche 914s, one 2L 4-banger street car with stock engine, one 2L 4-banger race car with modded engine. Greg's street 914 The street car engine has a fully-functioning Bosch D-Jetronic system, but as noted in Part 1 I don't trust it. It seems to work great at times but every now and then, usually when I'm an hour away from home, it'll have this massive burp and run bad for a bit. Makes me nervous. And it seems to be extremely sensitive to fuel selection; a couple times it just did not like the fuel I got from some stations. The race car's engine is modified and uses dual Dellorto carburetors. I have given thought to preparing prepping it to SCCA's Limited Prep Production regs, which requires fuel injection using the stock throttle body and intake manifold. Combine the two needs and maybe I can mod the street car and learn something about EFI in the process that could apply to