Finally got a chance to do some street tuning of the Miata with my dad behind the wheel and me in the passenger seat focused on the laptop computer. We started off slow just in the neighborhood and as we gained more confidence we ventured further away. Filled up with fresh 93 octane fuel. Did some auto tuning and tried to hit as many throttle position / rpm bins as we could, riding the brake to simulate loads when necessary.     Coolant temps were stable around 200F the whole time, with brief spikes to 215F immediately after a […]

I spent all day Saturday stripping a wiring harness from a junkyard Honda Pilot to get some quality OEM wire and then running a new TPS ground wire from my sensor to my ECU analog sensor ground. I didn’t want to drill any new holes in my firewall and there wasn’t enough room to run it through the same hole as my vacuum reference hose. So I did what many others have done and just poked a tiny hole in the large rubber boot that seals the hole where the vast majority of OEM wires pass through the firewall to […]

Unboxing my new Rogue Engineering steering wheel quick release adapter Here it is in all it’s glory. Should make it easier to sit in the driver’s seat with the laptop computer open when tuning the car in my driveway or on the dyno. Will also make it easier to get in/out when I temporarily fit race seats for track days. You can rotate the release paddle to any position you want. The little dimple serves as an index mark, which I located at the 12 o’clock position. This puts the release button, which serves as a safety mechanism to prevent […]

Here is a screenshot of a video I took with the timing light to verify my ignition timing. Initially I set the base timing using the Trigger Wizard per the MS Labs instructions. This was just a sanity check to make sure that when the ECU is commanding 14* BTDC at idle the crank pulley timing marks agree that it is in fact at 14* advance. The red marks on the timing belt cover are T and 10 (ProTip: paint the lines white or red so they’re easier to see). You can use either the T mark on the timing […]

So I’ve been talking with some other Megasquirt users to request help getting into the ball park with my tune, share ideas and help validate my work so far. omgpham and Valvecovergasket were nice enough to share their tunes with me. And Reverant at MS Labs finally responded to my email with some AFR1, VE1 and Spark1 tables that were scaled for TPS. The maps in his original base tune were scaled for kpa, which is completely meaningless for Alpha-N. But he also admitted he’s never tuned an ITB car before and the tables were just best guesses. I can’t […]

Check original base tune setting for CLT thermistor setting. So which is it, Mazda or RX-7 S4&S5? So I read some old posts on Miataturbo.net and Braineack says several times to use RX-7 S4&S5. Every time I go to Tools –> Calibrate Thermistor Tables and set CLT to RX-7 S4&S5 and write it to the controller, when I open it back up again it shows that CLT is set to RX-7_AFM(S5 in AFM). Both Common Sensor Values share the same data tables so I’m thinking this is just a bug in Tuner Studio.   Figure out why MS3 is not […]

Figure out why MS3 is not reading NB cam sensor. Could be bad sensor or bad wiring between sensor and CAS harness. So I think I fixed the cam position sensor (CMP) issue: power and ground were apparently swapped by mistake due to misread wiring diagram (sensor pigtail has three black wires so no help there). I Googled pictures of exemplar 1999-2000 Miata engines and zoomed in on the CMP sensor to verify the OEM wire colors.   Apparently when reading wiring diagrams, the view is as though you’re looking at the back of the connector where the wires go […]