Since my build thread is closed, I figured I'd start another one. Here's a link to the build for those that missed it:
This summer I've been real busy with the Cayman, truck maintenance, and Formula Vee stuff. All that stuff has settled down a bit.
Now I have the time(and nice weather too) to do some Spyder tuning.
Most of you may remember that I had built, wired, plumbed, and gotten the motor to run on EFI. My first attempts at tuning were lame, mis-directed and pretty sad.
I hit the reset button a few times and started over, and got the car to run almost as well as carburetors with my third try at a tune. But it has more torque, especially in the mid-range(2500-4500). I am 100% certain this is due to 48mm air holes versus the 36mm venturi in the carbs. That's a TON more air(56% more surface area) plus the throttle bodies are smooth and flush with the intake manifold openings(they are 48mm at the top). So a nicely tuned intake system coupled with a superior fuel mist is definitely better.
The software is both powerful and relatively inexpensive. It's $100 for Tunerstudio and Megalogviewer HD. Meaning, you own them. And you get free updates. All Speeduino and Megasquirt ECUs use this software.
Tunerstudio allows either USB or Bluetooth connectivity to program, check, monitor, and change all of your tune. You couldn't get one hour of dyno time and a tuner to adjust your settings for that price.
Megalogviewer HD allows you to chart and plot all your data. Then it allows the computer to analyze the data and make suggested changes based on AFR targets that you specify(I run 14.7 at idle and cruise and 12.5 under heavy load).
Thursday night I did a few short logs at different throttle settings through most of the rpm bands. Michelle helped me by calling out the throttle settings on the screen. I sent those to Mike Pickett who has graciously helped me muddle through this. He made some suggestions, I made some changes. The learning curve is starting to flatten.
The next afternoon I continued logging. Mike suggested at least a 45 minute ride to get a decent chunk of data. I made some more changes. Then I added the after-start enrichment, warm-up enrichment, and barometric(altitude) compensation that Mike provided. The tune is starting to really shape up. I leaned the fuel in some areas, richened it in others, and tweaked a few of the outliers(parts of the fuel table that you'll never hit but are there anyway).
It is raining today but that's OK. I have two really good logs to review. Lenny and I went to the Lime Rock Vintage festival yesterday. It's a 1.5 hour drive each way and I logged it all.
There is another program that's free(or $20 for a more featured version). It's called MSDroid(MegaSquirt for Android). This program allows you to see some parameters on your phone, but the sweetest feature is datalogging. Since I have a bluetooth module in my ECU, it's super easy. Connect phone to car and start logging. Put your phone down and drive normally.
After you're done driving, pull up the datalog and email it to yourself. Now you can pull it up on your computer and make changes. Burn them to the ECU. Easy peasy.
I'm at the stage that it runs extremely well, like a modern car. After thirty seconds it will stay idling(zero cold idle air at this time). The AFR stays where it's supposed to most of the time(I have an under-dash display). I've really only got to do minor tweaking at this point. I'm ready for the mountains in two weeks, that's for sure!
@Michael Pickett Thank you very much!