2.5i Tuning

Last year I was going to try tuning my 2.5i 6MT. I bought a used tractrix cable cable, downloaded my stock program and asked for it to be defined on Romraider. I worked on tuning other cars, so I am not completely new to this but I started researching and realized to fully understand the logic of Subaru ECM it was going to take a bunch of time. I decided to put it off off a while. While I was researching NA tunes, I found some who did NA tunes for 4th gen Lgacy's.

http://forums.nasioc.com/forums/show....php?t=2017329

Someone else also tried to do a GP on this forum this as well

http://legacygt.com/forums/showthrea...od-206082.html

After reading the 3.6R tuning thread it got me motivated to look into tuning again. So I decided to take a leap of faith and try it out, it is $150 and you need a tactrix cable. We did 4 revision and 4 datalog sessions.

I am very happy with the results. My car is 100% stock and I just use high octane gas. Most of the tuning was done on hot days this month and my car felt like it was winter. It been 60-70's the last couple days and I can really feel the difference (my car has never felt like this even on he coldest days) The power is especially noticable 3000 + rpm. I would recommend this tune to anyone look for more power.

I brought my car to the track last fall. At some point and time I will bring it back the track to measure the difference.

As a side note, using seat of the pants and looking at my logs its pretty obvious the power starts to drop off after 6000 rpm despite the 6400rpm tach. Initially, I was going to raise the rev limiter to 6500, but its pointless.

Good work!! Do you have anything that quantifies power output before and after like dyno runs or 0-60 times?

I will never bother doing a dyno on this car. I could easily do a G-Tech 0-60 time & swap back my oem tune to see the difference.

I am curious to see what difference my track times end up being.

It seems like mpg has improved as well. My last 3 tank full since the tune has been complete have been all around 33mpg and my driving style hasn't been the best for mog either. I tend spin the rpm up more often plus I keep find my self driving 70-72 mph where it used to drive 65-67 mph with the same gas pedal input.

Previously, I usually was averaging 31-32mpg on my commute during the warm months.

i'm all for tuning my 2.5i for better mpg

Will this tune work for a CVT equipped car?

Where do you get this tune? I take it you need to buy software and a cable? Will it work for a CVT equipped car?

Nice. I wonder if this would work with my CVT outback.

I guess you could change the torque curve and hp minutely to get better mileage or torque. It's just hard to see much benefit though. It would be interesting to see hp/torque numbers and some 0-60, 5-60, 30-60 and other numbers. I suppose you might cut off a couple tenths of a second. I've tuned a couple turbos and seen substantial gains, but never thought of doing it to the 2.5 n/a.

Originally Posted by TXLegacy

Where do you get this tune? I take it you need to buy software and a cable? Will it work for a CVT equipped car?

Check the links in the first post. The tractrix cable cost me $125 used. The software is, free romraider forum has a instructions on getting started and where to download romraider & ecuflash. Ecuflash is used to read and upload the bins. Romraider is used for datalogging and editing the tables.

Basically I bought a tractrix 2.0 cable, uploaded the programs to my laptop, post my stock program (bin) to romraider forum to be defined. I Wait for it to be define and sent definition and bin to mike botti (tuner). I used romraider to log the info.

It should work for a cvt. I don't think many of the 5th gen 2.5i cvt were defined, only the 6mt 2.5i

Originally Posted by hmmrdwn

I guess you could change the torque curve and hp minutely to get better mileage or torque. It's just hard to see much benefit though. It would be interesting to see hp/torque numbers and some 0-60, 5-60, 30-60 and other numbers. I suppose you might cut off a couple tenths of a second. I've tuned a couple turbos and seen substantial gains, but never thought of doing it to the 2.5 n/a.

Last night, I looked through some difference of the stock vs final tune.

It's pretty obvious to me who has done some tuning I must have gained some hp. My afr at wot went from 11.3 to 12.7:1 (leaner). 11.3 is really rich for NA motor (its even a little rich for a turbo.) most of my timing was also increased throughout the wot loads, except right at the top of the rpm band. It's almost like Subau increase the timing at top of the rpm band just to get a peak hp number.

At some point I would like to get back to the track for comparison, I don't know if that will happen this year. I will do some 0-60 time with a gtech this fall with the stock and modified tunes after I change my fluids.