RomRaider

Yeah the 20G's are a great turbo for the STI. It is the turbo they shoudl have come with. Stock-like spool and gobs of TQ all the way to redline. Last road dyno (yesterday) netted the same peak numbers, but HP held until redline. It was 55 outside. Sweet!

I am gonna wire up the Meth tonight. I have to take the IC off again to fix a clamp that is starting to come loose on a tapped boost source off the IC pipe. I think I'll run the Meth boost based at first so it comes on full at 15 PSI and starts at 9 PSI. That way I don't have to run MAF and it won't stop spraying at full at redline because I'll be at 17 PSI still. I want gobs of low end TQ and running boost based will allow me to be on full spray at peak TQ, when running MAF I would not be able to because of the failsafe portion of my mapping (WG boost).

That should work great on your car. I like boost-referenced kits for the most part, but the Aquamist trigger from the injector signal is very nice as well. The last car I tuned on meth netted almost 7 degrees more timing advance from 3000-6500, and fueling from high 10s to high 11s. Beastly....

Nice. I still need to install it, I am quite lazy after work lol.

Right now, I decided to start playing with latency again. So my MAF is scaled nicely, but now I am going to have to scale the lower end lol. I have exhaust leaks in my CB, and the car would afterfire almost always. Bumping up latency to 0.97 MS @ 14v and increasing the scaler a bit to compensate took care of the afterfire. Go figure. There is still a huge leak, but it doesn't make noise. Now I need to scale the lower portion of the MAF. What prompted me to do this is because I am running almost 0.5 AFR points leaner when it is warmer outside (on the drive home) where loads are lower. We will see if it hits fueling targets on the way home. I am hoping so. The static (latency) offset plays a larger role at lower loads, so this should richen it up just right when it is warm out.

So if this works, I take it all back. The Subaru roms must need a code change in order to run real world latency.

Here's a road dyno plot. Similar conditions as last one. Got 3 less peak HP, but more TQ, so more area under the curve and it pulled harder to redline.

Running 02-05 WRX latency:



Running new latency and bumped scaler:

And.... We have a winner. Latency of .98MS @ 14v with a scaler of 748.85. I have one small lean bump around 4200 RPM and have to rescale the lower portion of the MAF, but that is it. I hit fueling targets now in hot weather and cold weather pulls.

So what does this tell me about how to tune an unkown setup (new piping, new fuel injectors, etc)?

Figure out latency by doing pulls back to back while changing the boost (EL) profile until both the high load pulls and lower load pulls match fuleing targets (or are at least off by the same amount).

Then scale the MAF (upper and lower). My car stopped aferfiring as well. That can be an indicator that you have latency off. The injectors must have still been open when the engine cut timing.

I also changed the per injector fueling compensation to match 02-05 WRX values.

And to show how much power you lose when you drive in 90+ degree weather:



That is the same tune as this one (60 degrees out):



And here is my best dyno run on the stocker before it popped (tuned to the edge, 29 degrees outside):



Yeah the 20G at 29 degrees outside will blow that away. Need to hookup my Meth injection now.

The 20G isn't even pushing hard right now, lol.

Yes the latency I am using now (.97 MS) seems to work great. Now I need to add timing into the upper rpms so power does not drop off. Or... Install meth! yay!