Uncontrollable Boost - M20 w/ 6262

[LowR3V'in]

dang dude so u where running like 7* timing on boost?

[varg]

No. The timing table is inaccurate because the trigger settings are wrong.

From a tuner's perspective, the tuner is incompetent. OP said the tuner verified timing, it's obvious the tuner was not sure what he was looking at by the result. It's better to pull out your phone and search than to pretend you know it all and charge a client for substandard work because you didn't know what you were looking at due to lack of experience with their setup. Usually within minutes you can find the wealth of information available online from the many people successfully running Megasquirt on similar setups.

[Evan_VRM]

Well as it turns out my M20 has the same crank wheel as all of your M20s. Timing was dead on at 0* fixed and the crank wheel settings at 84*. Tuner was embarrassed and is going to take another crack at it next Wednesday. He definitely pooched it "verifying" the timing. I didn't want to drive it too hard/far until I get the tune properly dialed in (and it was raining here last night when I test drove it) but you can definitely tell it is making more power.

[mikey.antonakakis]

Glad you got that sorted.
For the moment, I've only been able to street tune my VGT setup, but I built some electronic det cans that work pretty well. We only get 91 octane at the pump here, and I am almost certainly losing some power with my current timing (I tuned out all perceptible knock, and run pretty strong MAT retard).

My car isn't sluggish, but after a few pulls on a warm-ish day, I was seeing just 11-12deg advance at 180kPa MAP with the combo of my ignition map and MAT retard - from the maps I've seen, that's pretty conservative at that boost level. After those pulls, I drove for about 20 minutes at 60-80mph, which pulled the heat out of my water-air intercooler, and as I merged on the highway I spun the tires a bit in second gear (2.93 LSD with Direzza Star Specs), which it wasn't doing on the previous pulls. I didn't datalog that moment, but some moderately careful calculations of the earlier pulls showed about 280-300whp. Same calculations showed around 260-270whp at 155kPa, so not a ton of extra power for the extra boost, but I retard pretty strongly with boost at the moment.

Hopefully for both of our sakes, there is a good amount of power left in the ignition maps :) I'm going to try a tank of 100 octane soon to see how much I can bump up the advance and to see how the power responds. Interested to see where you end up.

[Evan_VRM]

Well we had another problem at the dyno today. This time it was that my 7 year old 205-width tires were slipping on the rollers. Despite that, the car made 347 whp at 16psi. I am finally comfortable driving it now and the difference is awesome!

[mikey.antonakakis]

Woohoo!!

[varg]

Much better. Burn those tires up and replace them asap so you can start enjoying the acceleration.