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Discussion Starter · #1 ·
I received my Link ECU today. My mom called and told me it arrived. I left work early. :D It took my about an hour and a half to install the new ECU. I'll post a tutorial later once I get the pictures developed. I put the ribbon cable behind the glovebox, so I can tuck it inside when I'm not tuning.

My first impression, AWESOME!! Aside from a typo in my fuel map (131 instead of 113), the default maps make the car feel smoother and lighter. We'll see if it's any faster tomorrow in MD. My only complaint is the lumpy idle. I have no idea how to set up the idle control and the stock ECU did a MUCH better job of making the WRX pur at 800rpm.

The Link software is very powerful, allowing you to control fuel, spark, and boost from 0 to 10,000rpm and 0 to 300kPa. For those of you who are wondering what all this means: 300kPa is about 28psi of boost and don't think I need to explain 10,000rpm.

I should probably take my car to a good engine tuner with an AWD dyno, but I am having too much fun playing with fuel and spark. Unfortunately, with out a dyno or a 1/4 mile, I have NO idea if I am really accomplishing anything.

More news as it breaks...

-Jim
 

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PlatinumWRX, excellent investment on the ECU. Time to get a tuner and turn your rex into a X wing fighter :D
 

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Hey Jimbo,
Best thing to do is go drive the car ;) Serious!

Find a deserted stretch of road and do a bunch of 3rd gear pulls. If you are solo, use the datalogger and log MAP, RPM, Knock, %FF, and o2. Depending on what turbo and boost numbers you are running, you want to aim for no more than 80-100 knock counts at WOT at the top of 3rd. After the run, scan the logs and find any problem areas... too much knock/advance.. too little or too much fuel. Make SMALL adjustments.. like 1 or 2 degrees in timing and the same for fuel. Rinse and repeat.

You can get a decent street tune that way. Just FYI, the Lambda closed loop tuning is garbage. I've not been able to get a decent smooth around town map with it. You'll want somebody to drive or ride shotgun to make the small part throttle adjustments for closed loop driving.

I'm working with another vendor right now to get some better logging software written for our Link. As it is right now, you have to import the tab delimited text file into Excel and let it draw the graphs for you. Kinda time consuming imo. And I could use the couple hundred megs of space that Excel took when I installed on my laptop.

Anyway, it'll be nice to have another person to compare notes with. Good luck.
 

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ooo ooo meee meee!
jim you know i'll be back in yardley around may 12 right?? just lettin ya know that i'll be your lackey whenever you may desire... :) btw, did you also get the intercooler hoses? i think they were in the order also...
o-|-<) bryan
 

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Let's see what that bad boy can do with upgraded turbo!!

I've been thinking about modifying the suspension first before any more engine mods, but I might just do the engine first. I think your approach is very solid. Engine management first, then you can add other stuff later on without worrying about blowing up the engine(given that you tune it properly, which I'm sure you will).

Link ECU seems like a great choice over other piggy back systems with reasonable cost. One other replacement ECU that I really like is TEC 2/3 system from Vishnu, but it costs a lot more. Also, Link is plug and play, and TEC is not. Link seems more and more interesting to me, although TEC has more features that Link doesn't offer. Let us know how it goes. It'll help a lot of people on this board in the long term.
 

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Discussion Starter · #9 ·
Phast,

I can't get my WRX to settle down and idle properly once the engine is warmed up. What are your idle control variables set at? You and I need to get in touch via email and start trading maps back and forth. FYI, I'm still running the stock turbo and I plan to squeeze as much power out of it as possible.

Bryan, I did receive my Samco Hoses, but the engine was too hot to install them. I'm going to take tools with me to MIR tonight and try to install them there. You can be my tuner lackey when you get back in town ;)

Wrinkleboi said:
ooo ooo meee meee!
jim you know i'll be back in yardley around may 12 right?? just lettin ya know that i'll be your lackey whenever you may desire... :) btw, did you also get the intercooler hoses? i think they were in the order also...
o-|-<) bryan
Rich,

I'm not looking to post any phenomenal new speed records tonight. I'm mainly trying to get my bearings in the Link software and keep my motor from grenading. Even so, the absense of a rev limiter should make for some better ETs. I was always shifting into fourth with only 20feet of track left. Now it's WOT until 7,400rpm in each gear !!!!!!! :D :D :D

-Jim
 

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If someone can get me some of the Link logs on a cd, I'd be glad to write up some analysis software. I dig side projects like this, gets my mind off of work. Yes, these are the kinds of things computer geeks do in their free time.

jb
 

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Discussion Starter · #12 ·
I'm getting a lot better at tuning the Link. I found an MRT website that had some useful information on idle control, so that's taken care of. I also nailed down starting the car, cold or hot, although it still cranks longer than the stock ECU.

My cousin, Carl, was driving how from Towson, MD and we discovered a NASTY backfire under about 85% boost between 3500-4000rpm. I added some fuel to those regions and the computer pulled back timing on its own for knock control. It was nothing to dangerous, just a little scary. On my drive home from Carl's house the engine backfired once more in this area, but the computer completed compensation and I haven't had any back firing since.

I talked to Phil and Bill form TurboXS when I was at MIR yesterday. Phil said you really need to rent some dyno time to get the Link dialed in. I'd tend to agree with him, but I think a few more hours of messing around with the maps could yield some pretty decent results.

Phast,

We should get our ignition and fuel maps and put them in Excel and exchange them. I am curious to see how different my maps are from yours. They should be quite similar. Also, what are you using for boost control? I'm curious at how well the Link can control the boost with the stock solenoid.

Later,

-Jim
 

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is what you're hearing an afterfire or backfire?
backfire comes back through in the intake of the car and afterfire is just fuel burning in the exhaust if you've gone catless;)
 

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Hey ...

Post your maps so I can see them :D. I'm looking at different EMS and their maps. I've never tuned a car before but I think it would be fun. I would like a default map and then play w/ the setting myself.
 

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Jim,
Will do. I'll bring them up later tonite on the laptop and put them on my site. I've found that if you prime the injectors before starting, it only takes two cranks for the motor to catch. I hold the key to on for about 3-4 secs and you can hear the injectors priming. Then start and voila! I'll look at the MRT site tonite. Sometimes my idle works nicely, then other times it gets rather rough.

Not sure how close our maps will be since I have a PE1820 and I live at 6000ft ASL. But it'll be fun to compare.

jimb,
I can send you a text file with the output of the Link datalogs and maybe you can play with that. They aren't very big. Let me know... I'd love something a bit more intuitive for graphing logs than Excel.

EDIT:
Jim and jimb,
I moved my maps and logs over to my site.
http://phast.org/wrx/mods/link
 

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Discussion Starter · #16 ·
Jay,

Thanks for posting a link to you maps. For those of you without a Link ECU, you can download the software here.

Can you list the mods that go with the latest map? If you have different fuel injectors than your map doesn't really apply to my WRX at all. It will still help me figure some thing out, though.

My ignition map looks VERY similar to yours. My fuel map looks NOTHING like yours.

BTW, I took out my Joe P and gave boost control back to the ECU. I am very impressed with the way the Link ECU handles boost control.

I am probably going to try single point ground to remove some of the hesitation that was bad before the Link and is more noticable now that the ECU is more aggressive.

Thanks,

Jim
 

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Jim,
I still have stock fuel. Mods are listed in the memo section of that map. After looking at some of m logs last nite, I found that I'm running the stock injectors static at 15psi. Time for more fuel.
 

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Discussion Starter · #18 · (Edited)
jay,

You're idle would probably improve if your increase the clamp to 49 or 50kPa. This takes the car off the fuel map and puts it in closed loop idle mode.

Any idea how I can get rid of the annoying way my car almost stalls when I first touch the gas when the engine is cold?

I have the knock target set at 30 and the RPM correction set at 20.

This gives me the following knock targets:
3000:30
3500:40
4000:50
4500:60
5000:70
5500:80
6000:90
6500:100
7000:110
7500:120

Does this sound about right? I didn't realize that knock was supposed to rise as the rpms rise. I was struggling to keep the knock below 60 at 5500rpms! Now my car is running way rich. I gotta tune in some more knock at higher rpms.

-Jim
 

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PlatinumWRX said:
jay,

You're idle would probably improve if your increase the clamp to 49 or 50kPa. This takes the car off the fuel map and puts it in closed loop idle mode.



Any idea how I can get rid of the annoying way my car almost stalls when I first touch the gas when the engine is cold?

I have the knock target set at 30 and the RPM correction set at 20.

This gives me the following knock targets:
3000:30
3500:40
4000:50
4500:60
5000:70
5500:80
6000:90
6500:100
7000:110
7500:120

Does this sound about right? I didn't realize that knock was supposed to rise as the rpms rise. I was struggling to keep the knock below 60 at 5500rpms! Now my car is running way rich. I gotta tune in some more knock at higher rpms.

-Jim
Cool, I'll look into the idle thing. As for the cold start thing.. I don't know how to fix that.

I think that's what my knock correction looks like on my current map. Took me a while to really understand how it worked. That value actually raises and lowers the sensitivity of the knock sensor. Not the snesor itself, but the ECU's ability to filter out "noise" vs true knock. If you look at the KNKCNT column on a datalog, that should give you a better indication of true knock. I still don't know the threshold for which to tune to that value.

Glad things are going well.

-jay
 
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