End user mappable Motronic?

[john_banks]

Thanks Chris. It does sound like it is just the part throttle boost that is the problem then. The throttle position sensor aware electronic boost controllers would fare better here I think.

Dippy, I sounds like they are also upgrading the injectors +- fuel pump, and also probably checking and retarding the ignition as necessary on a map already designed for K03s at higher boost.

[Verruckt]

Well I'm pleased that I've managed to understand this discussion so far. Although it's only academic (I have no intention of 'home brewing' my car), I am still concerned about your previous statement.

Are you saying that there are guys who are making 400 HP at the wheels with just bigger turbos, a zener to limit MAP voltage and an MBC to control boost spikes? What about extra fuelling?

Nope, you missed a few things. You actually CAN use this setup on stock fueling, but you are limited to about 315 g/s of massflow and will make roughly 400 hp at the flywheel, not the wheels. We call that a Stage III- setup in the USA. People sometimes do this if they cannot afford to upgrade the turbos and the fueling at the same time.

I also have fueling mods. Here is what is necessary. (I also have intercoolers, catback, downpipes, etc...)

-K03 chiptuning (this setup cannot be done on stock software)
-Larger MAF housing (stock MAF sensor)
-Larger Injectors
-MAP clamp (also known as Throttle Cut Defender)
-MBC in parallel with N75
-4.85 bar FPR (although you can size your injectors according to the stock 4 bar as some have done).

[Dippy]

Interesting. How much is hp related to airflow? In my naivity I'm assuming that at the top end there must be some sort of proportional relationship for any given engine. The reason I ask is that I've measured a peak of 280 g/s on my car (with VAG-COM) which by using a ratio from your figures gives me 356 hp. Now that's above the corrected figure produced by RR tests, but then that allows for the probable conservative mapping by my tuner.

[Diesel]

>>OFF ECU TOPIC<<

Hi John

Nice to hear you say the unit’s a good ‘un – that means a lot! I drove an RS4 fitted with Konis on Sunday which was quite together on a very bumpy B road, and today’s standard 04 RS4 was very taught too. But I do know exactly what you mean – I drove (& filmed) an S2 doing just that ‘porpoising’. I don’t think a larger heavier estate will ever rival an Sti due to that car’s lower CoG and lower weight, and frankly better steering; however that doesn’t really matter – the Audi remains a fab Qüalitaswein stormer - even the salesman was grinning during a composed confidence inspiring 4 wheel drift today! When you getting yours? I think I will be making someone an offer this week... Cant wait!

>>BACK TO ZENER DIODE DUTY CYCLE DOO-DAAHHS;)<<

[Verruckt]

Interesting. How much is hp related to airflow? In my naivity I'm assuming that at the top end there must be some sort of proportional relationship for any given engine. The reason I ask is that I've measured a peak of 280 g/s on my car (with VAG-COM) which by using a ratio from your figures gives me 356 hp. Now that's above the corrected figure produced by RR tests, but then that allows for the probable conservative mapping by my tuner.

It's generally accepted that (airflow)/(0.8) when airlow is in g/s will give you an approximate hp figure. This figure can be brought up or down with the use of advanced/retarded ignition timing.

When I had a GIAC X chip, cat back, downpipes, and race fuel...I could pull about 290 g/s.

[john_banks]

Diesel, my wife has a new job, and is going to opt out of the company scheme I think, depending on what the fuel rate is per mile we'll then decide. She may also keep on another car which could be an S4 if she gets a boring diesel.

I'm sure I'll get an Audi with a turbo at some point. I like them a lot. I've learned a heck of a lot in this thread about the Motronic anyway, I hope it has been useful for others to draw together some info as well. Most appreciated all. Don't let this stop further contributions by the way