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Ryan C

Couple issues with Subaru and G4 Xtreme

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Hey guys! OK, I've managed to work through a couple issues myself... quick background: Old engine: STi Ver 6 EJ207, larger turbo, stock injectors + supporting mods New engine: Built EJ257, 1000cc EV14 inj, GT-35R (even larger turbo) + AVCS JDM EJ207 heads (ported/polished, O/S valves, Kelford Cams, ETC) New setup uses the late model 36 tooth crank trigger. Old setup used the OEM 6 tooth crank trigger. Current trigger choice reflects 'Subaru Ver7-10 JDM' Car ran great on the Link with the old setup. Swapped the new engine in, started up, ran decent with a little tuning. After break-in, ran the engine up to 5000 RPM and hit the 'rev-limit'. Did a log check, 5100 RPM @ 19.35 sec into the log 25,000 RPM @ 19.36 sec ' ' Trigger err count increasing when this occurred. Tried altering the arming thresholds. No joy. Tried going down (and up) in voltage. Sometimes it would break up @ 5K, sometimes @ 6K. Double checked my wiring and polarity. Cam and crank sensors were using the OEM engine harnesses. Grounds checked good. Turns out it was my 8 month old cam/crank sensors that I purchased new from Subaru. I swapped my original sensors (tan top, probably from 2000) and it doesn't hiccup anymore (no more trig err). However, I'm still seeing a slight drift because my log will play out like this... 50hz rate, 100% TPS : Time / RPM / Speed 795.02 7440 164 795.04 7600 164 795.06 7452 164 795.08 7649 164 795.1 7494 164 795.12 7494 165 795.14 7687 165 795.16 7521 165 795.18 7656 165 795.2 7512 166 795.22 7712 166 795.24 7566 166 795.26 7716 166 795.28 7572 166 So I end up with a wavy RPM log up top. Any suggestions? Is it the arming thresholds? I *believe* I'm currently still at .5v for 0 RPM and 2.0V for 1000 RPM on up. Next question: Had 505cc stock injectors.. Fuel master was 9ms Now have 1000cc EV14's Fuel master is 11ms My idle numbers are around 29 and I ramp up to around ~60 @ WOT, if I recall correctly. Does this seem 'right'? I know you are shooting for around 50 or so, mid-map. How does Injector duty cycle play into the master (if at all)? Because I'm showing around 88% duty cycle at 7500 RPM. AFR's are around 11:1. And this *only* at .9 bar (13 psi). I figured 1000cc injectors would carry me out a little further than that! I've got methanol to supplement, but I figured I would have more overhead on the injectors. Last question on a Bosch knock sensor. It's the Bosch Motorsports KS-P, P/N 0261231120 (OEM in the Porsche Boxster as well). 2 wires, (Sig +) and (Sig -) . On my G4 Xtreme, obviously, I have one knock input. Do I connect (Sig +) to the knock input and (Sig -) to sensor ground? My old Subie knock sensor only had one wire. I'm guessing it was grounded through the sensor... That's all I've got for now. On the positive side, my 60mph - 95mph (97km/h - 153km/h) acceleration time has dropped from 4.7 secs down to 3.6 with the new engine :D. Not to mention that 4.7 secs was recorded @ 1.6 bar with the old turbo versus only .9 bar on the new engine/turbo! Thanks, Ryan

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Oh yeah, one more minor issue. On a warm start, the engine will read about a point to a point and a half leaner for about 30 secs to a minute on idle. It then settles out back to 14:1. It's kind of annoying more than anything. Does anyone know of any settings that could cure/contribute this? Never had this issue before but I was running a different throttle body, inj, etc Ryan

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Hi Ryan,

Try setting your Trig 2 lockout to 7000rpm and see if that fixes the drift issue.

Yes you're correct on the knock sensor.

For the warm start you may need to increase your post start enrichment, after doing this you may need to reduce your warmup enrichment in the colder areas to compensate.

-Cameron

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So when you ran the 505cc injectors, your master fueling was at 11 and what did your fuel map look like (similar to what it is now?) I would think that since you are doubling your injector size you would be cutting your master fuel value in half to keep similar values in your fuel map. Did you change the injection settings? IE. Were you running sequential before and now or were you running single/multiport group injection?

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Found something else kind of odd. We've been trying to track down a momentary lean tip in condition on a shift. I turned off overrun fuel cut in the software but whenever I lift off completely, my wideband goes lean (IE: fuel is cut). The cells that the engine enters during overrun have near matching fuel numbers as the cruise area. Is the overrun fuel cut always enabled in this particular FW release? I'm on 4.7.1 Thanks, Ryan

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Hi Ryan,

I have tried this on the bench and Overrun Fuel Cut does seems to turn off okay.

Just because the numbers in the fuel table match does not mean you should get the same fuel delivery, one of the biggest differences is that if you are in vacuum, your fuel pressure regulator will drop the fuel pressure meaning the same pulse width on your injector will deliver less fuel. If you make a log of it using PCLink I'd be happy to have a look and see where the issue is coming from.

When you say 'lean' do you mean full scale lean, or just leaner than it should be?

-Cameron

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