Ben's 914 TURBO Official World Premier, 'cuz it didn't blowd up. Options

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Ok, so it isn't as cool as Chapman's 914-6 Turbo 3.0, but it's a turbo 914 all the same. Ladys and Gentlemen, at about 10:00 PST I got boost and there was much rejoicing. I took the car out, filled it with premium, tuned it with the laptop a little to make sure it got plenty of fuel under boost, and the mission was a sucess. Boost starts to come on at ~2,700rpm and is going full-steam by 3,500rpm.

I stand (ok, sit) here before you my brothers to declare that yes indeed, you can turbo a 914. (IMG:style_emoticons/default/clap56.gif)

Details:

Engine: '73 1.7, stock internals
EFI ECU: Perfect Power MIC3 (Cost ~$500 to get on the car and running 3 years ago)
Misc EFI stuff: Subaru 1.8T injectors, Holly throttle body off a 3.0 Chrysler, BMW 5xx fuel pump, foam motorcycle aircleaner (temporary)
Turbo: IHI off 1.8L Subaru (including wastegate)
Misc Turbo stuff: Bosch blow-off valve (for a Saab I think). Cheap. Plastic. Works great.
Total cost to add turbo: $175 (EFI was already on the car. Use Megasquirt+turbo and you can do this for <$400 easy)

I tried to modify my fuel pressure regulator with a boost-reference port like the in the dune-buggy.com article but I broke off a wire guage drill bit about 1.5" deep into the bolt. Dang. Only had about a quarter-inch to go too. So I just bolted it back on the car and set the fuel pressure at the 30psi I have the ECU turned for. I tried to crank up the injector pulse width under boost to compensate, but they hit 100% duty cycle at 5,000rpm because at that point they only have 20psi effective pressure (because there's 10lb of boost by that point). So I'm keeping it under 5k rpm until I get a rising-rate pressure regulator. The wideband O2 says mixtures are just fine below that point. I estimate I'm getting 110hp (That's not a WAG. I really did the math) which doesn't sound like much but is sure better than the 80hp I had before. I would still like to add an intercooler which could put it in the neighborhood of 130hp without getting too boost-happy. Even as it is now I would say it's 100% more fun to drive. I'm really happy about it. I'll get the pressure regulator issue squared away so I can run it up to 6k and I think it'll keep me happy for quite a while.

Rick said "This thread is worthless without pictures" so here's the best I could do. If you missed the earlier thread I'll throw in one of the earlier pics too. I tried to make a video but all you hear is wind noice and the blow-off valve between shifts.

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MORE UPDATES:

Wow, thanks for all the great tips guys. Yes, Mark, I'm using a 2-bar MAP sensor. Ed, thanks for the info on ignition angles. Wow! Sammy, you are right (more on that in a second).

So yesterday and early tonight I worked on modding my fuel-pressure regulator for a boost-reference port. I got it finished around 9:00pm. It works perfectly. Fuel pressure rises pound-for-pound in synch with the pressure on the reference port. So now I've got 30psi fuel pressure off-boost and up to 40psi when on-boost.

So I set my pressure to 30psi and went for a drive. I had to back-out a whole lot of boost-enrichment I had programmed in before fixing the pressure regulator. I did some low and mid-range off-boost tuning to smooth things out because there was some part-throttle bucking in one spot where it was going rich. Got that resolved and it drives pretty nice now. Ok, time to really get on it. I went to some isolated road (Ha! I remember Sammy talking about his special tuning road. (IMG:style_emoticons/default/smile.gif) ) and started pulling some full-throttle runs, watching the WB-O2 and laptop to tweak the boost-enrichement where needed trying to at least get somewhat of a constant mixture. At this point I was just trying to get the mixture at WOT roughed in to between 11.0:1 to 12.0:1 across the whole rpm range because when I started it was all over the place (mostly rich). This process was easy at first, but as I got the mixture closer and more constant the power just started to POUR ON. It was getting harder and harder to tune further because there is enough power now that things are happening too fast to drive, watch the WB-O2, and laptop at the same time. Cool. I've now got the mixture hovering around 11.5:1 under all boost conditions (and around 12.7:1 off-boost). Any thoughts on optimum boost mixtures? I don't figure 11.5:1 is optimal, it's just a target I used tonight to rough things in.

It looks like I might need to go to larger injectors. The Subaru injectors I'm using are now hitting 100% duty cycle at around 5,900 rpm. I might try a few more pounds fuel pressure but that's not going to be a permanent solution. I think that will be easier to deal with than a 5th injector. At least now I can run the engine up to almost 6k rpm under full boost. WOW! I honestly NEVER thought I'd like this 1.7, but I can't deny that I'm having a ball with it now. Sammy, you are so right about the torque curve. I'm used to the power dropping off rapidly above 4,500 rpm, but now it just keeps getting stronger. The higher it gets the harder it pulls! Its really a new experience. (I can only imagine what Chapman's car is like!)

One other thing that was a pleasant surprise - after working the mixtures into the ballpark I started getting boost much earlier. I'm now seeing possitive manifold pressure as low as 2,200 rpm!!!!!!

Ok, it can't all be good, right? The bad new so far is:
1) two small oil leaks (will fix Saturday)
2) choking on the price of synthetic oil
3) burning through a tank of gas this week faster than I can say "YEEEEEeeeee HaaaaAAA!!!!"