Sounds good! Thanks for doing the testing!

The walbro fuel pump won't like you increasing the static pressure, especially if you intend on running 24 psi boost.

Basically as you increase the static pressure your max flow coming out the pump will drop. So as load increases you might be at 70% injector duty but you will start to lean out as the pump can't flow enough fuel. If you reduce your static pressure to stock you will be able to get more flow out the pump and get the injectors up to a higher duty cycle.

It is a compromise between the pressure you run. High pressure means a better spray pattern/atomisation at the expense of flow and a lower pressure means more flow at the expense of the spray pattern.

Just stick to stock pressure I would suggest.

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GOLD PIG STI

Hi all,

Hope all is well with you guys.

Every engine is different to some extent. Setting fuel pressures on adjustable regs does not involve guess work unfortunately.

Regards,
Mao

Hey guys, need some help.

So for those who have been following, the SARD's have been put in, car has been back on the dyno and it seems there is a misfire @ around 6200 rpm?

Power seems to drop right off. There was a similar sensation when we had the 550 pinks in there, but that wat the IDC maxing out @ over 100%, but it seems different this time.

To recap, the pinks got me to 305hp at 6100 ish rpm, then it almost seems like a misfire, but was the injectors running out of room to put more fuel in.

The 800cc SARD's are in now and there is a similar sensation although different at 100 ish, rpm higher.

Plugs have been pulled, the plug in the cylinder closest to the radiator (cylinder 1?) on the drivers side, is slightly lighter (white) compared to the other 3. To us this would indicate it leaning out. But why on this cylinder? Is it due to not having parallel fuel rails? My understanding is that the last cylinder to get fuel is #3 on the standard 03 STI fuel system?

I cant see how it is an ignition issue, as the plug is showing that that cylinder is slightly leaning out, but could it be lack of spark? It has 4 new "whiz bang" as Rossco put it, spark plugs in, which did not seem to be a issue on the first dyno run, before the pink injectors maxed out.

I am thinking the fuel pressure is not high enough? Maybe the standard reg is tired and needs to be put to rest (in the bin)?

What else could cause this. I have a Vipec ECU, so it cant be the AFM, as I don't run one.

Any info would be much appreciated and if I have not made sense in this post, I am happy to clarify anything I have said, or explain in detail further.

Cheers in advance guys!!

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Cheers,

Simon.

Does Mao not know what it is?

I doubt it's the reg. Could be your pump though.

Hey Russ,

Mao has called me (I'm away at work atm) telling me what has happened. He believes it to be spark (ignition) related, due to it feeling like a misfire. He is a little hesitant to say it definitely is, due to one cylinders plug showing it running lean (slightly lighter colour plug). He also thinks it may be fuel, buts it hard to tell at his stage as it was late in the day when the car got on the dyno.

I am wondering now if the Vipec has a boost cut setting in it? I know I had an issue after the first Verso tune, where I was getting a boost cut issue, that felt very similar to a fuel starvation issue I also get on right hand corners.

The guy at ASG, upped the boost cut setting to 1.7 bar and bingo, issue gone....

Its a bit of a mystery, hence I am asking here.

Hope you are good matey

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Cheers,

Simon.

I forgot to mention the ASG guys put a Walbro in a year ago (6000ks)

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Cheers,

Simon.

Good evening. As I said many times, we run an open policy where I do take into account customers' opinions. My job is to keep the customer informed at all times throughout the whole job.

Only 8hrs in a day, so we havnt gone back to trigger calibrations on the Vi-pec as yet. Subarus run very high crankscase pressures, so I have to look at the trigger calibrations again. At the same time, I will have to go thru every aspect of the vehicle again, chking exisiting coils, fuel lines and pressures(we are still using the 150,000km stock reg).

Also Russ, you have a point. There is supposedly to have a Walbro fuel pump in it already, so we have to check that tmr. We have gone from high 246hp to 309hp now very safely with no timing advancement yet, as it is a 150,000km motor.

As a matter of fact that it had a cam sensor error to begin with, left us with an additional task on hand to try to solve it. We have been provided with a sensor to chg and we did it but the error still came up. However, after a few good runs on the dyno, the error has not surfaced and it must be engine oil related--- from bad oil before (note: This problem is still to be updated if the error does decide to show up in the coming days, otherwise I will say it is solved by the Cusco Oil).

It might be right to say that I am expected to do my job above and beyond, but time is always a factor here, as I always want to produce a 100% job at the end of the day. To know an engine that has gone through a multitude of workshops with 150,000kms on it and an exisiting code is quite a task, but we will be up to it at the end of the day, but good results do take a lot of effort.

A lot of workshops would palm it off at 310hp or more and I could easily decrease boost to reduce crankscase pressure and increase the timing and let it go at 320hp ---- but to do something like that is not my cup of tea.

Regards,
Mao

Your FPR will be fine, do not go aftermarket.

Does the Vipec do any kind of logging?

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]

Does anyone have a spare coil pack I could borrow? Want to go through each possibility, coil pack being one of those possible issues.

Its for a 03 GDB STI. Let me know if you have a known good one I could borrow for the day.

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Cheers,

Simon.