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View Full Version : Yarg. Tuned my own car



Sarra
11-29-2009, 06:25 PM
Since I don't have a Legacy, I figured I'd put this here as it's off topic. :p Anyhow, I'm impatient, and somewhat broke, so I decided I would use the one advantage the 2002 WRX has over most other cars, a small turbo.

I borrowed a Tactrix 1.3 cable, downloaded ECUFlash, RomRaider, ECUExplorer, and Learning View.

Car is pretty simple, TurboXS shorty intake, Godspeed turbo inlet, TGV deletes, wrapped crossover pipe, wrapped Megan racing up pipe (which sucks, never buy that brand unless you hate yourself), stock downpipe and second cat, and finally, a hackjob catback (straightpipe to a Flowmaster Series 40 muffler). I installed the intake, inlet, UP, and wrapped the exhaust myself. I did the TGV deletes as well on my own, minus taking out most of the material, a machine shop did that.

Anyway. I started logging and saw an IAM of 13, and it was pulling timing in weird places. I also saw it was only pushing 12.3 PSI of boost, should be making 13.6 PSI. I pulled the stock ROM, and found a horrible 9.55:1 AFR in the upper RPM's, and my injector duty cycle was up in the 107% range. Yikes.

I fiddled with the WGDC, target boost, etc. I eventually had it so the car should have run unregulated boost. It never got past 12.3 PSI until about 3,500 RPM, then it would creep up to 13 PSI. I shut down around 4,000 RPM because there was no taper on that map.

I turned the wastegate arm in a full turn, reset the tune, aimed for 14 PSI, and voila, 14 PSI!

Then, on to the bottom end. I started by reverting to the stock map, and gradually tuned it via open loop, timing, target boost, and WGDC, so that right now, if I floor it in my car with a warmed up engine but a 'cool' exhaust, it makes 13.9 PSI by 2,700 RPM. It holds 13.9 PSI until 5800 RPM, and then starts tapering to wastegate pressure by redline.

Lowered the AFR's from 9.5:1 to 11:1, and verified them with a wideband.

I also added in more timing in the high load area of the low RPM bands, and added fuel. It goes to 12:1, instead of the 13:1 it was stock, due to way more boost (was originally making 7-8 PSI of boost up to 3,000 RPM, then would jump to 12.3 PSI by 3,250 RPM, now it hits 6 PSI at 2,000 RPM, is at 10 PSI by 2,500 RPM, and 13.9 by 2,700 RPM, so more fuel to keep temps down and motors happy). I tuned several boost dips out in the lower load areas, and removed most of the 'timers' for CL to OL transition. It was causing driveability problems for me. Now, 67% throttle = open loop no matter what. I also rescaled my MAF, and my injectors, which stock (stock airbox and everything else), were running 105-107% duty, are now in the 95-97% range, much more comfortable.

Doing this took a week, 1,000 miles of logging, driving, and 4 tanks of gasoline. I had to give the cable back, I'm very tired, and now I want to get a permanent wideband (borrowed that as well).

Future mods are going to be a fuel pump, better brakes for my winter setup (destroyed them today), and a turboback exhaust. First few times driving, it was kinda lumpy from 2-3k, but now it's a smooth rush of power from 2-6k, no bumps or dips like on the stock map. It also doesn't blow a forest fire out the tailpipe if I'm flooring it for extended periods of time. It will use more gasoline though, if I do drive in the hills, because of the lack of a timer for the CL to OL transition.

Sorry, no dynosheet, or even a guess of power output, because the nearest dyno is a 5 hour drive away. I'm also looking for a used 2.2 turbo bottom end, block, crank, rods, pistons that's usable, I want more low end boost. ;D

Robbks
12-02-2009, 01:00 AM
Nice work mate. There's a sense of satisfaction when you get these things runing nicer by yourself.
that's basically the way i'm tuning my Twin Turbo Legacy fitted with a Haltech interceptor
just keep on logging data and making fuelling changes until it's smooth and AFR's are good.

i have no knock detection hooked up at the moment so i'm not touching the timing, but the original ECU is from a high comp EJ20H and the new engine is a lower comp EJ20R so there should be no real issues with causing knock from too much timing.

however my problem was it was running extremely lean due to the higher flowing engine, and i'm talking WOT AFR's of 13.5:1 on only 9 PSI

I'll get the fuelling sorted slowly then be able to hand it over to my tuner for a final squirt on the dyno to optimise the timing for MBT and also modify the fuelling as needed to keep EGT's under control

While i have a good respect for good tuners to do what they do, and do it quickly. It's not that difficult to get your own fuelling/ boost levels sorted for better drivablility/ economy and response and even a touch more grunt (especially mid-range torque)

Also 2002 WRX fitted with a stock TD04 I assume, you're probably looking at ~140ish KW ATW on about 15-16PSI

Sarra
12-02-2009, 01:33 AM
Yeah, the wastegate arm is out of adjustment, and I ran out of C clips, so the max boost it makes right now is 13.9 PSI. The nearest dyno is a 4 hour drive away from me, and right now I'm coming up on finals, so no dyno sheet yet. ;)

Once I get a few things straightened out, and some new C clips, as well as a new fuel pump and modify my fuel pressure regulator, I will be increasing my boost to 16 PSI. Then I'll put it on the dyno and see what I can do to smooth things out even more on power delivery.

It's more fun to drive now than it was before, that's for sure! Final phase of tuning will be to tweak the altitude modifiers for flawless boost control while doing hill climbs. A local Sports Car Club gets the county Sheriff to close down a road for 3 days, once a year, and hosts a hill climb event. Happens in July (summer), though, at high altitude, so I have to make sure the car is perfect with transitions from low to high altitude as far as boost control goes.

I also may be putting in an EJ20G closed deck shortblock soon. I believe it is 9:1 compression. I will be using USDM WRX 2 liter heads. Again, I'll tune it myself, and retain the TD04. Hoping for improved low end spool and better top end due to better fueling and more compression.

anothernord
12-08-2009, 03:15 PM
High altitude is where F/I shines. Here in CO, most places are above 5000 feet, so having boost helps a ton. Especially I-70, the interstate that goes over Colorado. It goes up to 9000 feet with a speed limit of 75 the whole way. Back when I was N/A, this was not fun to drive up.

Are you planning on modding the stock FPR, or using an aftermarket one? Also I recommend a Walbro for your new fuel pump.

Sarra
12-08-2009, 06:48 PM
Going Walbro possibly. Also trying to find a fuel pump that would be happy running static 100-140PSI static fuel pressure, but that probably would cost a fortune. This would be a conversion to a returnless system though... I've been researching it a little and not really finding much on it.

Walbro's are cheap and well known as good, so that will most probably be the route I go. I will probably use the extension and light tapping method on my FPR to get higher fuel pressure in boost, or a JDM STi FPR. Same difference. ;)

Also on this subject, my injector O rings are leaking when cold again, so I'm about to ditch top feeds, get some STi TGV housings, and go side feed. STi injectors, TGV housings, and probably Perrin fuel rails. So tired of the stupid, JUNK fuel rails Subaru put on this car.

As for altitude, I'm around 1,000 feet here, but I do get up to around 4,000 feet, the highest I can get is 8,000 feet, which is just a parking lot. :p There's a hill climb here that goes from 800 feet to 5,800 feet though, in the summer, in July. Last year, the start line was 107 degrees F, and the finish line was 58 degrees F. Such a massive change in temp, and altitude is hard to tune for, but I'm gonna try! Gotta wait for summer to come back.

rougeben83
12-09-2009, 01:35 PM
You really should get the fueling system parts, injectors and pump especially. I think ideally you should be running the duty cycle on injectors below 90%...

Sarra
12-09-2009, 03:23 PM
Yep, that's the plan. :) As it is, I never run it past 6,000 RPM anyway, no power up there. Also never gets over 70% IDC until you get past 6,000 RPM.

greenspeed
12-09-2009, 03:42 PM
If you go GM Boost control Solinoid I may be able to give you my state 2 td 0 slow tune. I was tuned at 19lbs and running about 11.8:1 AFR's.

One thing I've figured out is setting fail safes. My buddy tunes my car and always sets them in for people cause they never do it. If something happens the car needs something to fall back on. More important if you're running water.

Make sure your MAF graph is linear. Moving at a constant straight line up with no jumps, or dips. You'll be suprise how much this factors out.

Also don't mess with the wastegate arm. I think if i read it right you said you went ahead and adjusted it. That usually leads to Waste gate creep and other bad stuff.

can you send me copy of your tune? I'm curious what you came up with.

Sarra
12-09-2009, 05:30 PM
If you go GM Boost control Solinoid I may be able to give you my state 2 td 0 slow tune. I was tuned at 19lbs and running about 11.8:1 AFR's.

One thing I've figured out is setting fail safes. My buddy tunes my car and always sets them in for people cause they never do it. If something happens the car needs something to fall back on. More important if you're running water.

Make sure your MAF graph is linear. Moving at a constant straight line up with no jumps, or dips. You'll be suprise how much this factors out.

Also don't mess with the wastegate arm. I think if i read it right you said you went ahead and adjusted it. That usually leads to Waste gate creep and other bad stuff.

can you send me copy of your tune? I'm curious what you came up with.

Not gonna do GM BCS, I might go hybrid EBCS/MBC.

Failsafes I left alone, they were actually pretty 'safe'. :p Would use a ton of gasoline, but would keep things cool and lubricated in the heads in the event of a failure or excessive knock.

When I rescaled my MAF sensor, I actually drove for most of a day, and there were no 'outliers' or dead spots at all. The idle was crazy all over the place, but I had a vacuum leak at that point, and now with it fixed, it's more consistent.

As for the wastegate arm, I was running a map with 30 PSI in all of the high load tables, and WGDC at 96% in ALL of the tables, and the maximum boost I could get was 12.3 PSI. It spooled instantly to 12.3 PSI at 3,500 RPM, so it wasn't an exhaust leak. I turned the wastegate arm in 1.5 full turns, and now I can hit target boost without any spikes or any other ill effects, however I suspect the spring is getting worn. I have a wastegate actuator with lower miles on it from a different bugeye, I may swap that on the car in the near future if I have a failure of my actuator.

As for the map, sure. PM me your email, and I'll send it to you.

greenspeed
12-09-2009, 05:35 PM
I pmed you earlier.

I forgot that TD 0 slows were dumb. some where crazy boosters and others wouldn't move out of their own way.

Are you an automatic? or manual?

Sarra
12-09-2009, 07:39 PM
lol I only got one PM. :lol: Got your address now.

I've got a 5 speed, using stock BCS for now.

greenspeed
12-09-2009, 08:16 PM
okay i didn't know if subie did what they did on the dsm's back in the day adn give teh auto's a smaller turbo so thought I'd ask. Never seen a auto wrx in person

Sarra
12-10-2009, 12:40 AM
okay i didn't know if subie did what they did on the dsm's back in the day adn give teh auto's a smaller turbo so thought I'd ask. Never seen a auto wrx in person

The 1990-1994 Legacy MT had a 'different' turbo than the 1990-1994 Legacy AT. The only difference was in the designation of the turbo, they were basically identical (VF11 and VF10).

All WRX's from 2002 until 2008 had the TD04, IIRC.