Big Slice of Reality Pie., 2056 D-jet Dyno run |
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Big Slice of Reality Pie., 2056 D-jet Dyno run |
Olympic 914 |
May 6 2021, 08:25 AM
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#1
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Group: Members Posts: 1,680 Joined: 7-July 11 From: Pittsburgh PA Member No.: 13,287 Region Association: North East States |
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 |
May 13 2021, 05:54 AM
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#2
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Advanced Member Group: Members Posts: 2,311 Joined: 22-February 13 From: Middletown CT Member No.: 15,565 Region Association: North East States |
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 |
JamesM |
May 13 2021, 12:17 PM
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#3
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Senior Member Group: Members Posts: 1,922 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
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. I dont think they left much on the table, at least for the motor they built to work with it (some maybe due to mass production and the limits of technology) but d-jet is an analog system and therefore will not match exact engine fueling needs across the entire operating range and more importantly, d-jet is 50+ years old and at this point so any of them being "properly-functioning" is questionable, not to mention there is nothing to account for slight differences in engine build/wear etc. and to be fair, did anyone actually claim going with modern injection will get you 20% more power? AFAIK all that has been reported on is what has been observed (dyno results) As long as an engine is getting the ideal amount of fuel and producing the spark at the perfect time then there are no performance gains to be had by changing the setup. That being said, throw a timing light on a car with a stock distributor and one running a 36-1 crank wheel+coil pack and you can visually see the difference in timing accuracy. More accurate timing, more accurate fuel mixture, better fuel atomization from modern injectors, etc... these things add up. |
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