Big Slice of Reality Pie., 2056 D-jet Dyno run Options

[Olympic 914]

Just got back from having the teener run on a Dyno.

Good and not as good as I expected.

Was hoping for at least 100 Hp, didn't make it.

This run was on a Mustang Dyno, allegedly a Dynojet Dyno reads from 12~15% higher.

First the good.

Runs were extremely consistent. the three runs printed pretty much right on top of each other.

Torque was way up there above 95 tq from 3000 to 4500. with no real dips.

HP numbers were very consistent with a nice smooth line from 2000 to over 4500

Now the bad

Max HP was only read at 88 Hp and max torque was 100.

If I add the 12-15% it comes to 100 Hp. But it is what it is.

Build is

2056 D-jet, Heads by HAM RS+, 8.6 comp. Raby 9590 cam, SS HEs with Triad muffler. I Have adjusted the MPS to what seems to run best for this car.

This car runs great and I just wanted to know what it was putting out, Not really planning to try to tune it for more power. Reliability is the key. and I am so far happy with that.

Dyno sheet added (Date/time is wrong, 5/06/21 8:35am)

[GregAmy]

FWIW, my experience supports Mark's position.

I had a well-used stock 2L with perfectly functioning D-Jet. Everything worked as designed, with recently-cleaned injectors, a Tangerine-rebuilt MPS, replaced TPS board, the works. It stumbled electrically on me a few times, implying it needed a new wiring harness, but the system fired up every time, functioned as expected, and returned ~26mpg.

As described in my blog, I made the decision to design a Microsquirt setup primarily for dependability and for access to modern components and tunability. Plus, I've been giving thought to building a 914 for SCCA's HProduction class (if they ever let it in) and that had to use FI with the stock throttle body. I designed my street installation for batch injection (just like D-Jet does) and wasted spark (for ignition component simplicity).

After firing up the system and properly tuning it (both on the street and on a Dynapack) I did not noticed any increase in power or torque. I do notice ease of start-up and warm up, smoothness of operation, and I got a mpg or two more out of it. But in no way could I claim a ~20% increase in power or torque, that just didn't happen.

The last dyno we did, prior to my replacing the short block over the winter, resulted in 74whp and 96wtq (see post #11). That's pretty much original stock numbers.

No, I didn't dyno the engine before replacing the D-Jet with MS. But honestly, do we really think the properly-functioning D-Jet system was so bad that it would have resulted in ~20% less output than the above? Do you really think Bosch/Porsche left that much on the table, given that D-Jet really does not vary that much in overall concept and functionality from modern EFI systems?

I personally don't.

Bottom line, MS is really cool, and I do like it a lot. I recommend it. It will give you better startup and warm up, smoothness, tunability, feedback control of fuel and ignition, and will have components that are modern and more-available to replace from more sources and less expensive.

But it won't do miracles.

Greg