Ignition Retardation and inlet temperature

[A80Avant]

Does anyone know to tell me the limits of the ignition retardation that the RS2/S2 motronic can handle in degrees and also how that is done according to inlet air temperature and perhaps fuel quality?

Since VAGCOM can detect the inlet temperature i can say that i can identify higher inlet temperatures in the summer and i would like to know how much the ECU is retarding according to temps,so as to protect the engine.
for example: if temp is more than 80C then the retardation is at which degrees?

also what is the maximum that can retard?

Finally,the quality of fuel can only be detected if i see negative degrees in timing on full throttle?retarding instead of advancing?

[A80Avant]

anyone??

[UrS4boy]

anyone??

I think you are forgetting the role of the two knock sensors. Knocking = ECU retards ignition, either because of inlet temps or poor fuel.

[A80Avant]

that is excactly what im saying.The sensors will detect knock for the ECU to retard ignition.SO how much is it retarded with IATs?? supposing that fuel quality is ok?That is one part of the equation.How much is the top of retardation in degrees so that it cannot compensate anymore and thus knocking will still appear?

[UrS4boy]

that is excactly what im saying.The sensors will detect knock for the ECU to retard ignition.SO how much is it retarded with IATs?? supposing that fuel quality is ok?That is one part of the equation.How much is the top of retardation in degrees so that it cannot compensate anymore and thus knocking will still appear?

Your questions are something that a remapper like Mihnea or Doug at MRC could answer but since you cannot change anything without remapping, having the information would be useless to you. Unless you were going to experiment with your own remapping. Which, in my opinion, is a receipe for disaster.

But hey...

[A80Avant]

nothing like that.No expert,BUT since i do have VAGCOM and can have a look at the ignition retardation degrees i can make a log and probably see what is happening on WOT before something ugly happens with high temperatures or bad fuel,see??

[UrS4boy]

nothing like that.No expert,BUT since i do have VAGCOM and can have a look at the ignition retardation degrees i can make a log and probably see what is happening on WOT before something ugly happens with high temperatures or bad fuel,see??

Just get a good remap done or buy generic remap software from MRC or the like. What you are talking about is constantly agonizing and worrying about how your car runs which will totally make you nuts and take away from the enjoyment of owning and driving the vehicle.

Leave the remapping to experts, run a FMIC (if you aren't already) and buy the highest grade of fuel you can and stop worrying.

[A80Avant]

I have all that,only thing is that the 2 values that are most likely to make you worry,are apparent where i live,and those are heat and fuel.Although the remap has been done by one of the best,a little precaution never hurt anyone!
At least this way,on the most rigid conditions i can give a feedback to my tuner about how the engine and remap works.Its not something i tend to monitor constantly(i understand what you say about going nuts and taking the fun away,but sometimes a bit of safety will save some $$$ in rebuilding!!)

Trouble is that in the UK or Germany,or to say the least Canada where you live,dont get 40C celcius as ambient temperature.SO tuners either become extra safe,or dont tune at all.I have asked my tuner to be get the car as strong as safely possible,but having the car tuned on Germany temps and fueling conditions,there is no actually a definite answer if it will be OK in 40C and possible medium quality fuel.Sometimes even the safer tuned cars do produce knock due to those factors.

Call me a safety nuts,but even with IAT 40C on a 30C summer day im still worried if an expert comes and tells me what is normal and what is not.So i choose knowledge versus ignorance and total devotion on any remap(especially if this one might be edgy on extreme conditions on my request!

[UrS4boy]

Trouble is that in the UK or Germany,or to say the least Canada where you live,dont get 40C celcius as ambient temperature.

Actually we do get 40 deg C weather in Canada. Not in right Vancouver where I am, but just 70 km east in Abbotsford or around Pemberton, near Whistler, and all of the lower Fraser River Valley (Cache Creek to Hope), Kamloops, and the Okanagon Valley, e.g. Kelowna. Same in the Prairies, e.g. Regina, and in the US, as close as Washington State and anything south of there. Nobody worries as much as you seem to want to. Our worst gasoline (petrol) is 91 (RON+MON)/2. I run 94 (RON+MON)/2

You can hear pinging. If you do encounter it, back off the throttle and/or drop a gear.

IMHO, you are worrying too much. (Unless your tuner was too agressive. MRC in my experience is one who is not - tunes to the safe side ).

If you are really concerned, you would be better off investing in an Aquamist-type system or a system that sprays water ONTO the FMIC under WOT.

But these are just my opinions

[A80Avant]

probably i do worry too much,cause i already do have water injection!!! but better safe than sorry!