End user mappable Motronic?

[john_banks]

Thanks.

Controller for throttle stepper motor or whatever it uses, linked to throttle pot Yes, it would be a bit of hassle to restore a real throttle.

Does sound like the doors are a little bit closed, quite literally

[S2tuner]

Hi again,

Pansies

Doesn't sound much different to the late Subaru ECUs in terms of the number of compensation maps, including intake, EGT, altitude etc.
I did simplify my descriptions to the basics of what is commonly adjusted - a lot of compensations simply don't need to be touched.

This is where you and many so-called VAG tuners are wrong. A 2.7 running different turbos, injectors and so on has about 45 parameters that need to be changed, otherwise the engine will not run properly.

On a totally stock engine, there's about 30 of them that need to be readjusted. Just asking for more boost, dumping more fuel and timing in isn't going to get you anywhere near optimal power and the ECU might not be totally happy with this....

Knock control is not per cylinder on the Subaru yet, but most of the rest of it sounds similar. I've mapped about 80 engines, including one to over 200 BHP per litre which survived and is still running a year later in lesser tune , so I would happily take on another engine, especially something relatively unstressed.

I have tuned about 150 VAG engines (80 S2-RS2-S4, some up to 550 crank HP, 30 1.8Ts including hybrid turbos and big injectors, 15 2.7Ts including RS4s and about 25 TDI engines up to 230 HP), so it's experience talking here... not trying to put you off though, all the tools that you need are out there and you just need money and time to get there...

I have no interest (nor the skill or time) to decode the ECU though, shame there aren't the tools for the end user to do it IMHO with all the map descriptions sorted. Stops it really being an enthusiast's project in the same way to me.

Well, assuming you can find map descriptions, you'll have to learn german, and then you'll have to basically do this: decode the ECU. There's also program code disassembling involved if you want to be able to understand all the basics of the ECU and how it works, plus read and study dozens of formulae that describe each function thoroughly. Again, experience talking.

I'd be very tempted to just hook up a wideband, charge and EGT probes, det cans, frig the fuel cut and dig my AVC-R out and play with some K04s. We'll see.

There's WB and EGT on the engine already, get a full licensed version of VAG-Com and you can get to all of it with no additional hardware if you don't mind being slightly restricted by sample rate when monitoring all this...

It is a bit tricker than getting a new STi, reprogramming the ECU, fitting a bigger turbo, exhaust, fuel pump and injectors and getting 400 BHP relatively easily though. Or is it?

Getting 400 HP out of a 2.7 is a matter of bolting the proper turbos on, new fuel pump, injectors, exhaust (pre-cats and cats suck) and then spending a day on the dyno with a real-time emulator. BTDT several times, it's not very hard once you know how the ECU's logic functions work.

It would be in the interests of established tuners to make it mysterious when it may not be so?

Well, from "our" (VAG tuners) standpoint, it has to remain mysterious so we don't lose our share. I think it's normal.

However, where many tuners can sell or even do themselves chips for an old S2 that's bone stock or close to it, finding someone who can map the engine for you real-time up to whatever HP the turbo/injectors/bottom end can take is no easy task. I think there must be 10-15 such people in the world (meaning who can do it properly and where the engine won't blow in the next 3 months) and I think I'm lucky enough to be one of them.

Now even if the S2 maps information was less mysterious, there's still thee knowledge of the embedded fuctions and the way the maps interact between themselves that will make the difference between a tweaker and a tuner. Being able to map an engine for loads of HP is not that hard, being able to map it to loads of HP minus 10/15 HP but with absolutely no retarding from the ECU all the way through the rev range at WOT (just because it would have no reason to <beep> timing) isn't that easy.

Now, if you take a 2.7, there's gonna be even less people who will be able to do a proper job, and where most people out there claim they can do lots of things, most of them only resell stuff from the few that know their stuff, or they simply override basic security functions so they can get the HP they want without the ECU noticing or keeping failsafe features...


Here's my thoughts on this.

As I said before, if you want to tune your engine, not tweak it, there's no way without real-time emulation, everything else is pure BS and commercial crap. I am not allowed (AFAIK) to advertise for my job here so I won't say much more about all this.


HTH,

Mihnea

[john_banks]

I'll be in touch then if I get one so I can get it done properly

[Verruckt]

Thanks

Any links to the software you mentioned?

Why the K03 rather than K04 chip? When you mention the K03 chip this has the new MAF and injector calibration in it?

What size are the stock S4 injectors? The RS4? Fuel pressure on both?

Can you get full boost in every gear using the ECU's boost control?

Because K03 software is readily available, cheaper, and well developed. Many tuners won't sell their K04 stuff without their fueling kit. If you proportionally scale the MAF housing to the injector flow rate, you can get away with using K03 software designed for stock injectors. Without any fuel tweeks, my fuel trims were within 5%.

Stock fuel pressure is 4 bar. Stock S4 injectors flow 350 cc and RS4's flow 481 cc/min @ 60psi.

You should actually be fine with the normal S4 fuel pump.

Nope, it does even worse, it shuts the throttle off. This is why I don't think you can tweak it with a fuel cut defender and a boost controller, you'd need a throttle cut defender and many more things, which might end up being more expensive than what you'd initially think.

It can be done very easily. A Zener Diode on the MAP sensor and an MBC in parallel with the N75 valve will let you play with the boost all you want. Combined cost is about $50. However, I would NOT attempt that without at least a chip.

[S2tuner]

Thanks

Any links to the software you mentioned?

Why the K03 rather than K04 chip? When you mention the K03 chip this has the new MAF and injector calibration in it?

What size are the stock S4 injectors? The RS4? Fuel pressure on both?

Can you get full boost in every gear using the ECU's boost control?

Because K03 software is readily available, cheaper, and well developed. Many tuners won't sell their K04 stuff without their fueling kit. If you proportionally scale the MAF housing to the injector flow rate, you can get away with using K03 software designed for stock injectors. Without any fuel tweeks, my fuel trims were within 5%.

That's not a very bad idea but the issue is that the ECU won't have a clue as to what the real air flow is.... but as long as the fuel trims are ok and you're not overfuelling at idle/part throttle, I guess it's not too bad for a "hack" solution...

Stock fuel pressure is 4 bar. Stock S4 injectors flow 350 cc and RS4's flow 481 cc/min @ 60psi.

You should actually be fine with the normal S4 fuel pump.

As far as I've heard, the stock fuel pump is somewhat of a limiting factor, especially if it's slightly worn out....

Nope, it does even worse, it shuts the throttle off. This is why I don't think you can tweak it with a fuel cut defender and a boost controller, you'd need a throttle cut defender and many more things, which might end up being more expensive than what you'd initially think.

It can be done very easily. A Zener Diode on the MAP sensor and an MBC in parallel with the N75 valve will let you play with the boost all you want. Combined cost is about $50. However, I would NOT attempt that without at least a chip.

Hmmm, yeah, hack mods, zener mods on the MAP sensors were very current on 5 cylinder 10 valve turbo engines, now are we talking 2.7 with ME7 for such hack mods? I'm LMAO, I know of no one who's successfully attempted zener mods on S2s/RS2s, nevermind newer cars like 2.7Ts with ME7 ECUs....

You would have to have a chip, because MAP sensor limits are usually increased in all modified chips, on a stock chip you'd get nothing because the ECU is really far from being stupid. I find all these hack mods very risky and I wouldn't ever do something that could potentially lead to disabling failsafe functions of the ECU, although I do have some respect for the people who are pulling their hairs trying to find a way to hack these ECUs without actually getting to the chip....


Mihnea

[Verruckt]

Thanks

Any links to the software you mentioned?

Why the K03 rather than K04 chip? When you mention the K03 chip this has the new MAF and injector calibration in it?

What size are the stock S4 injectors? The RS4? Fuel pressure on both?

Can you get full boost in every gear using the ECU's boost control?

Because K03 software is readily available, cheaper, and well developed. Many tuners won't sell their K04 stuff without their fueling kit. If you proportionally scale the MAF housing to the injector flow rate, you can get away with using K03 software designed for stock injectors. Without any fuel tweeks, my fuel trims were within 5%.

That's not a very bad idea but the issue is that the ECU won't have a clue as to what the real air flow is.... but as long as the fuel trims are ok and you're not overfuelling at idle/part throttle, I guess it's not too bad for a "hack" solution...

Stock fuel pressure is 4 bar. Stock S4 injectors flow 350 cc and RS4's flow 481 cc/min @ 60psi.

You should actually be fine with the normal S4 fuel pump.

As far as I've heard, the stock fuel pump is somewhat of a limiting factor, especially if it's slightly worn out....

Nope, it does even worse, it shuts the throttle off. This is why I don't think you can tweak it with a fuel cut defender and a boost controller, you'd need a throttle cut defender and many more things, which might end up being more expensive than what you'd initially think.

It can be done very easily. A Zener Diode on the MAP sensor and an MBC in parallel with the N75 valve will let you play with the boost all you want. Combined cost is about $50. However, I would NOT attempt that without at least a chip.

Hmmm, yeah, hack mods, zener mods on the MAP sensors were very current on 5 cylinder 10 valve turbo engines, now are we talking 2.7 with ME7 for such hack mods? I'm LMAO, I know of no one who's successfully attempted zener mods on S2s/RS2s, nevermind newer cars like 2.7Ts with ME7 ECUs....

You would have to have a chip, because MAP sensor limits are usually increased in all modified chips, on a stock chip you'd get nothing because the ECU is really far from being stupid. I find all these hack mods very risky and I wouldn't ever do something that could potentially lead to disabling failsafe functions of the ECU, although I do have some respect for the people who are pulling their hairs trying to find a way to hack these ECUs without actually getting to the chip....


Mihnea

We have cars in the US putting down more than 400 whp with these "hack" mods and offering better driveability than off the shelf big turbo kits.

You know the airflow calculations are based primarily off of the MAF readings. Nothing is changed there. The ECU knows exactly what it's getting. You really aren't removing any safeguards at all. The N75 is fully functional. The ECU can read boost vaules under 12 psi so it is fully capable of putting the car into limp mode and metering boost there. I've tested it. With an MBC wired up in parallel with the N75, you can safely cap the maximum boost level. There is no chance of overboosting. This strategy is not risky at all. For some reason, the zener even improves ignition timing across the board.

There is quite a "homebrew" tuning revolution occuring in the US right now. There are 25+ cars running around with similar setups to mine with no problems. A friend of mine who had a $7000 AWE tuning Stage III kit took my car for one spin around the block and promptly ditched his setup for a homebrew setup.

[S2tuner]

Hmmm, I can't say this isn't interesting, but one problem that you guys do have in the US, it's the lack of custom tuning, or real-time tuning. This to me is the answer to all these problems. You want more at a certain RPM level? You can have it if it's safe to have it.

Re: MAF: I think you are wrong. The ECU reads a 512*1 line with MAF sensor output voltage as x-axis and corresponding actual air flow in kilograms/hour. If you change the diameter of the MAF tube, you offset this reading so the ECU doesn't know the real air flow anymore.

Now, if the cars run fine, if there's no retarding nor any pinging and if the mixture at WOT is rich enough, I guess you guys can be pretty happy and I'd say it's cool for you. But for me, there's still nothing like custom, hands-on tuning where each parameter is adjusted as much as it is possible.


Cheers,

mihnea

[Verruckt]

Hmmm, I can't say this isn't interesting, but one problem that you guys do have in the US, it's the lack of custom tuning, or real-time tuning. This to me is the answer to all these problems. You want more at a certain RPM level? You can have it if it's safe to have it.

Re: MAF: I think you are wrong. The ECU reads a 512*1 line with MAF sensor output voltage as x-axis and corresponding actual air flow in kilograms/hour. If you change the diameter of the MAF tube, you offset this reading so the ECU doesn't know the real air flow anymore.

Now, if the cars run fine, if there's no retarding nor any pinging and if the mixture at WOT is rich enough, I guess you guys can be pretty happy and I'd say it's cool for you. But for me, there's still nothing like custom, hands-on tuning where each parameter is adjusted as much as it is possible.


Cheers,

mihnea

No problem Mihnea. These types of discussions are good.

Your statement would be correct if I simply changed my MAF housing size.

However, I also changed my injector flow rate and FPR pressure (custom 4.85 bar FPR) to proportionally deliver the correct amount of fuel in relation to the difference between the ECU "perceived" MAF reading and "actual" airflow.

This isn't hard to do.

If your enlarged MAF flows 30% more air than the ECU thinks it does...but your injectors are also delivering 30% more fuel...you're A-OK.

I agree, it isn't the most elegant setup...but it's very effective, very cheap (less than $1000 excluding turbos), and fun to tinker with. You'd be very surprised how well it works.

[john_banks]

When you adjust the MAF cross sectional area and the injector flow up by the same proportion on a typical Japanese ECU, all is fine with the fuelling, but you have a problem because you just advanced the ignition timing as the ECU sees lower load for the same boost pressure as before.

I have a workable setup planned with a 2 to 2.5 litre conversion, 25% bigger MAF cross sectional aread and 25% higher flowing injectors, with an S-AFC to trim it, zener diode for fuel cut, and manual boost controller - all to run a Legacy Turbo at 400 BHP on the cheap as a track toy. The ignition should not be too far advanced because the engine size has gone up in proportion to the injectors and MAF readings.

So would the ignition be too advanced on the Motronic by increasing both the injector flow and MAF cross sectional area in proportion?

[john_banks]

Verrückt, any links to the nitty gritty of all this on an S4 would be most interesting and welcomed! I am perusing your website presently Thanks.

[Verruckt]

When you adjust the MAF cross sectional area and the injector flow up by the same proportion on a typical Japanese ECU, all is fine with the fuelling, but you have a problem because you just advanced the ignition timing as the ECU sees lower load for the same boost pressure as before.

I have a workable setup planned with a 2 to 2.5 litre conversion, 25% bigger MAF cross sectional aread and 25% higher flowing injectors, with an S-AFC to trim it, zener diode for fuel cut, and manual boost controller - all to run a Legacy Turbo at 400 BHP on the cheap as a track toy. The ignition should not be too far advanced because the engine size has gone up in proportion to the injectors and MAF readings.

So would the ignition be too advanced on the Motronic by increasing both the injector flow and MAF cross sectional area in proportion?

The 2.7T has the best knock management system I've seen on any engine.

In demanding condtions (90+ degrees F) on high boost (25 psi), my knock voltages are in the mid 20's during high load. The saturation point of the sensors is 29.XX and the ECU will pull back timing at this point. I did not have to make any timing adjustments...but doing so would be very easy with Lemmiwinks (and yes, it is very 1 dimensional ) if you had to. Some have had to pull a few degrees and some have been able to add a few degress.

[Verruckt]

Verrückt, any links to the nitty gritty of all this on an S4 would be most interesting and welcomed! I am perusing your website presently Thanks.

No problem. I don't have much of the nitty gritty on there. Those two links are from a friend of mine who has a very similar setup. He ran 12.2@116 mph (3750 + lbs race weight) in the quarter mile.

http://forums.audiworld.com/s4/msgs/1736997.phtml

http://forums.audiworld.com/s4/msgs/1739524.phtml

[john_banks]

Sorry, another thing, those fuel pressures are quite high, are the S4/RS4 regulators running fuel pressure relative to manifold pressure, or are they fixed at the noted pressure all the time? Just that 5 bar plus say 1.6 bar gives 6.6 bar fuel pressure? A bit higher than I'm used to on the Jap crap.

[Verruckt]

Sorry, another thing, those fuel pressures are quite high, are the S4/RS4 regulators running fuel pressure relative to manifold pressure, or are they fixed at the noted pressure all the time? Just that 5 bar plus say 1.6 bar gives 6.6 bar fuel pressure? A bit higher than I'm used to on the Jap crap.

EDIT:

The fuel pressure does vary with boost pressure.

[john_banks]

I like those K16 hybrids BTW