We think this might be a normally aspirated, stock ECU record for the 1.8 liter Miata. This run was on California 91 octane pump gas. Built for a local time trial series, Roadster Cup, we navigated the rules carefully to come up with what we think will be a competitive engine package for Street class. It was strange sitting on the dyno with no laptop in the passenger seat. Just watching the MTX and listening for knock. Stayed conservative on the FM adjustable timing wheel. Maybe 26° on top, dunno exactly. Ended up with 58psi on the AFPR. With race gas I could lean it out and maybe add a few degrees of timing to reach 168whp or so. Easy 175whp on E85.

NB1 block & head
Supermiata CNC +2 head
Supermiata race cams
11.0:1 CR Supertech pistons
1952cc
FM adjustable timing wheel
TSE COPs
NGK wires
NGK BKR7EIX-11 plugs
AFPR, Fuelabs
ND440cc injectors
JDM ECU (7500rpm)
4.43mhz crystal to add another 750rpm
Square top intake manifold
Skunk2 throttle body
SPM DIY cold air intake
Racing Beat header
Racing Beat resonated midpipe
Racing Beat muffler

Supermiata twin organic clutch
Supermiata OS Giken 4.875 diff

 

It would be interesting to see it dynoed with a full ECU to see how much difference there is. Probably not much, maybe just a bit with more aggressive timing.

My only concern with running with a stock ecu is engine safety in the long term... It would be better on E85. Can't you run it in that class?

 

Why's that? If there's no knock and the AFR's are good, then what's the issue? (Srs question).

 

No programmable ECU or reflash allowed. Programmable ECU with net a few more horsepower on top but a whole bunch more torque by being able to fine tube the tables. As it is we're just making crude global trims to spark and fuel to keep the pistons from melting 7000 to 8000 and leaving the mid-range wherever it ends up. Also it takes forever to warm up, has no throttle response below 3000 and idles like ****. All of which would be perfect if we could throw an ms3 Pro in it.

 

If fuel changes at all... so fuel pressure or mixture could cause a lean out and detonation. Could be voltage related or filter clogging etc.

No oil pressure engine cuttof or other safety features.

No logging. I'm always checking my logs. Often I tweak the fuel tables to fix a slightly lean area of the fuel map.

But you have to run with what the rules are and work with what you have. Pretty cool that this is acheiveable with a stock ecu.