Well, after 9 months of procrastinating, I went to the dyno to tune the car. The results were pretty good considering this engine made 160 at the crank stock: 183.5 hp, 138.8 tq (dynojet).



For reference, it made 169 hp, 137 tq on the stock ECU on a dyno dynamics a long time ago with 6* of advance dialed in on the CAS.



Relevant mods include removed air pump, 5/6 ports, sleeves, actuators. Cold intake, header, exhaust, no cat. MS1 v2.2, error*s daughter board.



Blue = VDI in high RPM mode

Red = VDI in low RPM mode



As you can see, VDI in low RPM mode went lean and STILL made more torque <5k rpms than high rpm mode. If I can get the VDI working again (electric air pump), then I can add fuel there to bring the torque up, restoring the midrange. The weirdness at 4300ish is the injector staging - which I moved down to 2500 rpms to be a non-factor (after I got home from the dyno). We developed a good fuel map (thought their A/F meter was wacky - the LC-1 on the car was reading better), then tweaked spark to find what the car liked. We went through 25 runs to do so, including testing the stock air filter, no air filter, and leading/trailing split changes. I'm going to look for a filter with more area and less restriction - there were gains all over with no filter at all. It was really cool, but I went there on a budget so I had to stop at 2 hours.



It liked more advance (28 ish) and less fuel (13.5) below 6k, and less advance (26) and more fuel (12.8) above 6k. The attached MSQ is with staging at 4300, though I later moved it to 2500 to remove that dip.

Nice numbers!

yeah congrats, thats good stuff!



45 runs in 2 hours is nuts, btw.



interesting timing and afr numbers, its a little backwards from what i'm used to seeing, maybe you're exhaust works?

I know that it isn't the best exhaust: RB header to 2.5 in cat replacement pipe to borla catback (have a thing about not going deaf). I know that my exhaust diffusers aren't there and I'm guessing it has a mild street port - though the exhaust port seems stock. I rebuilt the engine 4 years ago, but didn't know enough to tell whether it was ported at the time. I'm a bit more educated now https://www.nopistons.com/forums/pub...DIR#>/wink.gif but I won't open it until it loses power or blows up. Right now it embarasses my friend's supercharged miata, so it'll work for me!



I had previously tuned from forum advice to rich down low (12.8) to leaner up top (13.5), but as they say - give it what it wants, not what you think will work. oh, and it was only 25 runs https://www.nopistons.com/forums/pub...IR#>/smile.gif

yeah if it wants more fuel up top, do it...

I wonder how it's compares to a stock working 5/6th ports in tern of low end torque when you have removed the acuators and sleeves?



by the way,

great numbers! , suprisingly good flat torque curve!!!!

Any porting on the engine?