Subaru Forester Owners Forum banner

1 - 13 of 13 Posts

·
Registered
2007 Forester XT Sports 5 speed
Joined
·
170 Posts
Discussion Starter · #1 ·
I did a bit of downloading with the cable, nothing specific just played around.

Then I downloaded my stock ROM from the 07 FXT, I was perplexed when I saw the stock timing table. They run 52 deg advance around 2500rpm, yowzers !! I know this is probably to get good gas mileage, I have tuned other ECU from scratch. There is huge drop in timing back down to idle, no wonder it jerks around and is hard to start out in 1st gear. I smoothed this out by upping a couple of numbers between this hump by no more than 1 degree.

I have always hated the way that around 2500rpm, you had to floor the gas to get any acceleration( then it goes crazy). I went into the drive by wire torque requested and upped those cells ever so slightly.

Burned my changes first time ever, scary. The freeking thing didn't want to start. I guess the computer has to relearn for my climate. After it learned everything was alright and started upping the timing, it was completely transformed.

It is so much smoother to drive in light traffic because of the minor timing changes. The power is much easier to in snowy weather, I can feather the throttle so much better ( much more linear).

The car has no more boost, but is way more usable. The tactrix cable payed for itself in 10mins worth of key punching.
 

·
Registered
05 Forester XT
Joined
·
541 Posts
ECU needs about 10 seconds to recalibrate

The freeking thing didn't want to start. I guess the computer has to relearn for my climate.
Same here with a Cobb AP. Freaked me out.
Buried in some posts on the Cobb forums is the fact that the ECU needs about 10 seconds to recalibrate after any kind of reflash. So you should turn the key to on and wait about that long before trying to start it.
 

·
Registered
2004 Subaru FXT MT
Joined
·
1,841 Posts
Yep, there are a number of us on this board that use Romraider. Messing with our cars just wouldn't be as much fun without it:)

Welcome to the forum...
 

·
Registered
2007 Forester XT Sports 5 speed
Joined
·
170 Posts
Discussion Starter · #5 ·
I used Tactrix 2.0 cable, it was very pleasing knowing I did the tuning myself. I am very specific the way I want the car to respond. You may have different tastes, and goals.

I can get you the modifed bin soon. I would caution anyone about just grabbing somones map and loading it on. There were many I looked at and ignored. Learn exactly what is changing, and make very small and deliberate changes. Compare your table to mine, only change the cells you are confident about.

Know what comprimises you are making to the factory tune
Emmisions
Gas Milage
Reliabilty

Mine I made perhaps a small effect on emmisions by increasing timing??Gas milage may be a factor by increasing torque demand, however I won't be going to full boost as often. So there might be a trade of off.
 

·
Registered
05 FXT Broken 5-speed
Joined
·
239 Posts
I am able to run E85 on stock injectors and have some serious fun w/ my car. I love having full control over, what and how, my car drives.
All of this can come at a cost. I bricked my original ecu on my 05 FXT. I am now running an 04 STI ECU. Live and learn I guess.
From what Colby has mentioned, if your laptop freezes up or stops during a reflash, DO NOT turn your ignition off! Reboot your laptop and start the reflash process over. This is very, very good info to know.
I think the RomRaider logger is worth the cost of the Tactrix cable, by itself!
Happy tuning,
Absubtle
CO
 

·
Registered
2004 Subaru FXT MT
Joined
·
1,841 Posts
I am able to run E85 on stock injectors and have some serious fun w/ my car. I love having full control over, what and how, my car drives.
All of this can come at a cost. I bricked my original ecu on my 05 FXT. I am now running an 04 STI ECU. Live and learn I guess.
From what Colby has mentioned, if your laptop freezes up or stops during a reflash, DO NOT turn your ignition off! Reboot your laptop and start the reflash process over. This is very, very good info to know.
I think the RomRaider logger is worth the cost of the Tactrix cable, by itself!
Happy tuning,
Absubtle
CO
I assume that you can only run E85 on your stock injectors due to altitude? I was running E85 on my stockers, stg2, and was hitting 100% IDC by 4k rpm. Just don't want other people to get the idea that they can run 100% E85 on the stock injectors. Flow issue, not a chemical compatibility issue.

Sorry, OT...
 

·
Registered
05 Forester XT
Joined
·
541 Posts
I assume that you can only run E85 on your stock injectors due to altitude?
Related question: I understand (I think) why for a normally aspirated engine you can get away with lower octane at altitude. Less air pressure, so less compression. Which is one of the reason we only get 91 octane in CO.
But what about a turbo engine. Does the same turbo give you more boost in Florida than in CO?
 

·
Registered
2004 Subaru FXT MT
Joined
·
1,841 Posts
Related question: I understand (I think) why for a normally aspirated engine you can get away with lower octane at altitude. Less air pressure, so less compression. Which is one of the reason we only get 91 octane in CO.
But what about a turbo engine. Does the same turbo give you more boost in Florida than in CO?
Given all else is equal, it takes more exhaust energy to achieve the same boost at higher altitude. You get the same pressure ratio, but you are starting with less dense air.

So yes, you can and will make more boost at 1000 ft than you do at 5000 ft.
 

·
Registered
05 FXT Broken 5-speed
Joined
·
239 Posts
I am sitting at 80% IDC. I was close to 95% w/o fuel pump. Once I installed a Walbro 255, I had to retune it, and lean it out. I am running 16-16.5psi of boost.
I was able to make 290 wheel hp on a 09 WRX w/ stock injectors and a fuel pump. He was at 100% duty.
Absubtle
CO
 

·
Registered
Joined
·
121 Posts
Here is small changes in map

Njoy
Do you use a wideband O2 sensor or other instrumentation when tuning?

Thanks - I'm mainly curious to look through it with RomRaider - I plan to have a tuner in Singapore do my car on a 4wd dyno soon.

PS - Thanks for the hex file - it makes fascinating reading going through the tables .... I once was a control systems engineer and it just amazes me that it's all just look up tables! No fancy PID loops or anything .... (the coarseness of the lookup tables has to be seen to be believed - I can't believe the throttle DBW table has only 15 steps from 0 to 100% throttle - I assume the ECU actually interpolates in between but still...).
 

·
Registered
2004 Subaru FXT MT
Joined
·
1,841 Posts
Do you use a wideband O2 sensor or other instrumentation when tuning?

Thanks - I'm mainly curious to look through it with RomRaider - I plan to have a tuner in Singapore do my car on a 4wd dyno soon.

PS - Thanks for the hex file - it makes fascinating reading going through the tables .... I once was a control systems engineer and it just amazes me that it's all just look up tables! No fancy PID loops or anything .... (the coarseness of the lookup tables has to be seen to be believed - I can't believe the throttle DBW table has only 15 steps from 0 to 100% throttle - I assume the ECU actually interpolates in between but still...).
Correct, the ECU doesn't stair step. It interpolates between the cells, and extrapolates off the ends of the tables if you happen to go there (only would happen on load axises unless you changed redline and didn't change the tables).
 
1 - 13 of 13 Posts
Top