Re: My Other DIY Project.
Posted: Wed Apr 16, 2014 5:06 pm
I felt overwhelmed the first time I fired up romraider. There are just so many things that can go wrong. You probably will need to rescale your MAF and I think there are some spreadsheets out there that should help with that. If you're running the stock map, it's probably running lean and with timing that's fine for N/A, but not forced induction.bassmonster wrote: Wow, that's pretty quick. I enjoyed the sound of the Megan exhaust on some of your other videos.
To be honest, I would love to tune it myself, but where should I begin? I know the basic logic of the ECU as it pertains to knock control and AFR sensing, but I don't know which tables to modify first, and I don't know how I should modify them. Should I start with rescaling the MAF sensor, then pulling ~20 degrees of timing across the board then gradually making changes in fueling? I guess I should just bite the bullet and get a pro-tune, but being able to tune it myself would be really neat.
I had the benefit of having a well supported car that is already turbo, so it was relatively easy for me to get a basic tune on there. Here's the basics:
-Open the Open Loop fuel table and add some more fuel for higher engine load and higher rpm areas. Anywhere that you're not making boost shouldn't need any changes. Don't go crazy, but you'll want to richen it up in the higher boost, higher rpm areas for safety. You should probably aim for around 10.5:1 at the highest load above 4000rpm and maybe go down to 10:1 at redline. The key is to make everything nice and gradual/smooth. If you take it to get a real tune, they'll hook a wideband O2 up and probably lean it out more, but without a wideband, it's safer to run rich for now.
-Open the Ignition base tables and drop around 10 to 15 degrees of timing in the higher engine load (>2g) higher rpm (>5000rpm) areas. Then adjust the surrounding cells to make a nice gradual change anywhere you're making boost. Obviously you won't need to pull as much timing in the low rpm or low engine load areas, so you'll just need to use some common sense and look at the stock value and adjust it proportionally. Kind of the same deal with the fuel tables.
-Open your logger and log RPM, load, knock sum, throttle %. Drive around for a while and don't be overly concerned about the off-idle or throttle tip-in knocks. Do a few pulls and see if the knock sum increases. If you see a knock at say 2.0g/5000rpm, go to that cell and decrease the timing on that cell by 3 to 5 degrees and the surrounding cells.
-If you don't have any knocks on the pulls, increase the timing in the boost areas a small amount at a time. If you start seeing any knocks at all, decrease the timing in that area to be safe. You'll want to go for a "safe" tune by keeping the timing values at least ~5 degrees below the point where it might knock.
Tuning is one of those things that's really difficult to explain over the internet. There are a lot of good resources out there. If you can find a stage 2 base map for a WRX or Forester XT, that might give you a good reference point for your own map. The worst part about open source tuning is the constant reflashing. I'm probably on revision 30 on my map.
I've flashed to my car only once, that was a stock map that deleted the PO502 speed sensor low input CEL. That's a scary experience knowing you will brick it if there is a malfunction. 
and an SUV appeared so I hit the brakes, and the thin front tire slid out from under me. I smacked my hand on the pavement, then I slid off the road and flipped sideways over the bike and smashed backwards through a fence. It must have looked insane as a bystander. I have some pretty good road rash on my right leg too. Oh well, it could have been worse, and now that I've laid it down bad, I'll never crash it again! 
