I have a few updates:
Some may have noticed my annoying questions in the tuning forum.
Especially thanks to @
Wayno , who not only suggested me to get a Tactrix OBD2 adapter and flash a tune myself, but also answered a lot of questions.
For those who doesn't know anything about ECU tuning (which I didn't a 2 weeks ago either), it's not hard to flash the ECU yourself at all. It takes some time to get a grasp on the concepts though. What I flashed is Wayno's Stage 1 (stock car) tune v. 108.2. So far I didn't get to drive it a lot, because my brakes were/are shot, but did get to do a few logs.
To illustrate one of the many differences a tune makes, here are two screenshots of a logfile showing timing vs. rpm. The green lines are 5000 and 7000 rpm reference lines, gray is rpm, purple timing:
Stock tune:
Wayno's 108. tune:
Besides from the obvious difference in the curves, notice the difference at max rpm. Stock tune the rpm are jittery, which is hitting the rev limiter. The sharp rise in timing, is me letting off the throttle.
Stock the ECU will cut the fuel at 7450 rpm, when the rpm drop to 7100 the ECU opens for the fuel again. That leeds to the very annoying and abrupt braking feeling when hitting the rev limiter.
On most customised tunes it will look like the curve in Wayno's 108.2 tune. The actual rev limiter has been risen to 7600 rpm, but as you can see in the timing curve, a lot of timing is being removed from 7450 rpm (the big dip). Because of the timing dropping off, it just feels like you can't push through. If you do so anyway by being persistent, the fuel with be cut at 7600 rpm, but not with the on/off feel of the stock tune, because the power has already tapered off. Already at 7550 rpm the ECU opens for the fuel again. But it throws you back down into the "dead" power band between 7450 and 7600.
All together, the rev limiter is very soft and noticeable without being annoying. And the car is actually drivable in that area if needed for a shot while - like between two curves where an upshift doesn't pay off.
Just a feature like this alone makes it all worth it.
Here another two curves for illustration showing variable intake valve timing (the additional first green line is 4000 rpm):
Stock tune:
Wayno's 108. tune:
This, from my understanding, is to help reduce the torque dip. Funny thing is that you hear it very noticeably. At exactly 4000 rpm the intake/valve noise has a very aggressive grrrr to it.
So for those (like me 2 weeks ago) who think of tuning like black magic, the changes are very real and visible if you look at the logs.
Next up for me is to flash a map with more aggressive timing, as I have no knock.
But first...
New brakes:
My XP10 pads arrived from Carbotech Europe. Look at those beauties!
I probably feel the same as when a woman sees this:
To compliment them I got the 2005 Subaru Impressa WRX Brembo discs. They are 2.8 lbs lighter (when both new) than the stock discs. They cost the same.
Scale shows metric kg.
Looking on the back side you'll find the reason:
Stock disc 2.5 inch (6.4 cm):
WRX disc 2.1 inch (5.4 cm):
Insider info say that the WRX discs has better heat treatment. The lack of 0.4 inch (rusty part) seems to enable more air to flow for cooling too.
I didn't want to remove my dust shields, for more reasons. They are just as much there to protect the discs from road dirt. I think they keep the airflow more controlled and lastly I don't want a 900 degree F piece of metal radiating heat directly onto my damper.
Instead I trimmed off the corners blocking the flow from my Porsche brake guides:
I wanted to do the bedding of the brakes tonight, but once I drove off, my rear brakes were making noises as if the wear indicators were touching the discs! I probably could distinguish the noises with the old brakes up front.
I do have new XP10 pads (as you can see in the pic), but I am waiting for the rear discs to arrive. This brake story is never ending.
