Tuning the 2.5i by Xtreme Racing Tuning (Tuner: West_Minist)

[west_minist]

Updates made here http://www.xtremeracingtuning.com/forum ... 1225#p1223

[HyRax]

v9 and v9a ROM updates

The v9 ROM contained a new fuel map that Edward originally intended to apply but wasn't able to previously due to lots of pinging when we first started out. The spark plugs were just too worn and the engine really needed a good major service for this new map to be usable. Now that I've had my Interval J service with new everything including spark plugs, we could now revisit the map to see if any further improvements could be made to the v8 ROM.

I flashed up the car and immediately set out. Edward wanted logs sooner than later, so despite it being a very warm night of 29 degrees and humidity so thick that I considered taking a snorkel and fins with me, I set out to get some logs. The roads were very quiet, probably due to the heat, and I got to my back road without encountering many people so I hadn't yet noticed anything new with the car.

I completed six runs and I couldn't really feel anything new other than the speedo reading slightly higher speeds than I remembered the v8 tests did. I'd gotten very used to the v8 ROM over the last five months, so I figured this update would only make subtle improvements.

It wasn't until I drove home that I actually noticed what the real differences were. There was more traffic this time. Overtaking other cars was noticeably easier than before. The pick up down low and in the mid-range had definitely improved and was only noticeable when I had a reference point of driving past something. What was made easy to do in previous ROMs was now made easier again - not a massive improvement, but enough to be very nice. The car ramps up the revs quicker than before (again!), and because of the hot night, I also had my air-con on as well so I was very impressed.

I did a few more overtaking manoeuvres with the air-con off and I was surprised that there was almost no difference in the pull-factor compared to with the air-con on.

So in short, I've now got more power down low and in the mid-range, but the top-end feels about the same as v8.

The v9a ROM contained corrections to the map for which I did some further logs last night. Thanks to the rain, ambient temperatures were down a good 8 degrees and this translated into a massive improvement on torque. THIS I could definitely feel a difference in when putting my foot down and overtaking of course felt even easier still, so like any car, it's still affected by warmer temperatures, but overall the performance even in hot weather is outstanding. Looking at the graphs, the power figure remains virtually unchanged while the torque figure just shoots up when the air is cooler, just like any car of course, but it's good to see the proof on paper.

At this stage in time it's difficult to tell how much of an overall improvement v9a is having over v8, since v8 was tested just as we were coming out of winter last year, so ambient temperatures were even colder. Short of doing new baselines of v8, I'll probably have to wait until winter again. By the seat-of-the-pants-o-meter, there is definitely an improvement however.

This morning I received the v9b ROM which addresses some minor pinging issues in the 4,000rpm region. This time Edward wants me to get some general driving logging done as well as the usual third-gear runs.

[HyRax]

v9b and v9c ROM updates

Nothing new here except for more map corrections down low. Until the bugs in the new map are ironed out, Edward has me doing general driving logs for this rather than third gear pulls for the moment to avoid any unnecessary pinging, so for now, everywhere I go this week, the laptop comes with me, logging everything.

[west_minist]

One log is good enough

[HyRax]

You can never have too much data.

[HyRax]

v9d and v9e ROM updates
As before, more fine-tuning to wring out a ping here and there.

v10 ROM update
Edward feels we're nearly at the end of what we can do without doing mods to the engine. He wants me to let the car do some learning over the next few days to see if it deals with the last handful of pings itself. Before anyone wonders, I have compared these logs to some of my stock logs taken last year and even the stock logs showed a ping here and there by up to one degree, so it appears this is "normal", but Edward is trying his best to keep the extra power gained from the new fuel map whilst eliminating as much of the pinging as possible.

After doing an Old Pacific Highway run yesterday, Edward has given me v10a last night with some more tweaks to provide extra heat compensation since the day was a bit warm compared to other recent days due to the rain.

Considering that all this work is post-service and post-initial tuning, Edward has mailed me eight new ROMs in the space of a week, all without additional charge. This is great work, great dedication to his customers, and I thank Edward for his efforts.

[west_minist]

Thank you.

[HyRax]

v10a update

This is the final ROM for this tune. Once again it was more fine-tuning, but from what I can see in the logs, almost every ping has been eliminated now. In fact one of my logs showed no pinging at all.

Since my driving range, even when going hard, generally goes no higher than about 6,000rpm, I've made a small sacrifice of some management up there in order to ensure low and mid range remains as ping-less as possible without reducing the new power gained under the new fuel map introduced with v9. I can go up past 6,000rpm if I want, but things will get a little hot up there so I shouldn't do it too often.

While I haven't got an actual measurement of it, I'd say we've picked up a couple of extra Newton Metres between the v8 ROM and now, but unless I take a new baseline of stock now, or wait until August/September when I did the original baselines, I won't be able to get a true comparative graph to know for sure. One day I may do a dynomometer run just to get something on paper.

Overall I'm very happy. Obviously better performance could be obtained with engine mods and octane booster, but I really wanted to see how far we could go with no modifications whatsoever, and I think that has definitely been achieved - far beyond what I expected, though with the amount of effort Edward put into the tune, I suspect he was hoping for greater results. Sadly the 2.5i is not quite as tuneable as the 3.0 it seems, but the results are still great overall.

I will post up some general fuel consumption figures later, but so far I've obtained a 9.4 litres per 100kms doing a modestly spirited Old Pacific Highway run. This climbed back up to 10.4 when resuming normal city driving. I haven't done a full highway measurement yet, but I have previously achieved 8.6 on a trip to Newcastle.

[west_minist]

Jeff:

You can take the car over 6000rpm. It was made to do so. Per usual there is always the wear and tear . But in hill driving like you do, sometimes you need too. Gas mileage will go up too. Lol. But constantly with any car in the 6000+ range wll create heat and you will find that you will need to have good oil and perform maintenance pretty often if you intend to ulitilised that area often.

I have version b for you and that will be it until future mods. You are welcome to send logs in the future, but you can see for yourself in the logs.

All the best

[HyRax]

You can take the car over 6000rpm. It was made to do so. Per usual there is always the wear and tear .

Yeah that's a given, I'm just making note that it may result in increased wear and tear if I venture up there TOO often.

[west_minist]

Well my 2.0R been design for that. Lol. Hmmm remember the old days.

[dmh87]

I love these updates!

[HyRax]

Well my 2.0R been design for that. Lol. Hmmm remember the old days.

I've noticed that 2.0 litre cars seem to have higher redline limits for some reason. The 2.0 Gen4 Liberties have a factory redline of something like 7500?

Mine is quite short at 6,400 normally, but you bumped that up to 7200 or so for me in the tune.


Click for full size!

I love these updates!

Glad you're enjoying them! I wanted to detail my experience as much as possible so that it may encourage other owners to try tuning. Seems to have worked - I've had a good number of PM's about it so far!

[west_minist]

Your rev limit is 6900 soft, 7000hard. There was a 2.5 DOHC, AVCS that was around 7200 limit. Engine was similar to the 2.0R. Subaru stop making them and kept the 2.0R. Not sure why, unless there had issues.

[west_minist]

Hey Jeff,

How is the car?

Did you see the Raptor SC on the 2.5i?