[maddmatth]

Didn't get much response in the MHD thread and I don't want to be annoying by bringing it up again there...

I'm just trying to get a better understanding of this, how much of an issue it is and what I should do about it.

My car: N55 DCT, no upgraded DP or FMIC.
Running 95 RON fuel with the MHD 95 RON stage 1 map v0.90 (currently sthe latest)

From doing some logging there is one issue - at high RPM I get timing corrections on all cylinders of around -3/-4.
Seems to correspond with IATs hitting 100 degrees.

This pull has timing corrections up to -3
http://www.datazap.me/u/matth5/log-1...zoom=1262-1335

The next pull, timing corrections as bad as -3.8
http://www.datazap.me/u/matth5/log-1...zoom=1406-1481

There's more if you zoom out and there's a 2nd log if you click the 'Change log' button.



My spark plugs are about 3000km old at this point, I didn't give the shop any special instruction so I believe they just gave me stock BMW plugs and didn't reduce the gap. Perhaps I should have requested this but I wasn't sure at the time.


What I've done as a precaution for now is drop down to the 94RON map, I presume that will have less aggressive timing so will be safer under aggressive driving.

Car was driven (not very hard but the odd WOT pull) for about a week before I logged it, and there is a bit of aggressive driving before the logs start, so it should have been well adapted.

Also I've just filled up with 98 RON, there was about 10% of 95RON left in the tank. Puts me at around 97.5RON I guess, still ok to flash the 98 map or shall I stick with 95 map?

[bahn]

Originally Posted by maddmatth

Didn't get much response in the MHD thread and I don't want to be annoying by bringing it up again there...

I'm just trying to get a better understanding of this, how much of an issue it is and what I should do about it.

My car: N55 DCT, no upgraded DP or FMIC.
Running 95 RON fuel with the MHD 95 RON stage 1 map v0.90 (currently sthe latest)

From doing some logging there is one issue - at high RPM I get timing corrections on all cylinders of around -3/-4.
Seems to correspond with IATs hitting 100 degrees.

This pull has timing corrections up to -3
http://www.datazap.me/u/matth5/log-1...zoom=1262-1335

The next pull, timing corrections as bad as -3.8
http://www.datazap.me/u/matth5/log-1...zoom=1406-1481

There's more if you zoom out and there's a 2nd log if you click the 'Change log' button.



My spark plugs are about 3000km old at this point, I didn't give the shop any special instruction so I believe they just gave me stock BMW plugs and didn't reduce the gap. Perhaps I should have requested this but I wasn't sure at the time.


What I've done as a precaution for now is drop down to the 94RON map, I presume that will have less aggressive timing so will be safer under aggressive driving.

Car was driven (not very hard but the odd WOT pull) for about a week before I logged it, and there is a bit of aggressive driving before the logs start, so it should have been well adapted.

Also I've just filled up with 98 RON, there was about 10% of 95RON left in the tank. Puts me at around 97.5RON I guess, still ok to flash the 98 map or shall I stick with 95 map?

Pretty normal with higher IATs and low octane fuel. Post a log of the 95 RON map on using your 98 RON you just filled up with.

Ideally you need an intercooler or methanol injection and I would recommend tightening the spark plug gap to 0.018"

[GripAndRip]

Originally Posted by bahn

Pretty normal with higher IATs and low octane fuel. Post a log of the 95 RON map on using your 98 RON you just filled up with.

Ideally you need an intercooler or methanol injection and I would recommend tightening the spark plug gap to 0.018"

I haven't put my ngk's (1 step colder) in yet but BMS suggests .022" why go as low as .018 with stock or just one step colder? Or better yet why do they recommend .022 for 1 step colder?

I agree with Bahn. 100+ IAT with low octane will induce timing corrections. You are also using a OTS map which was designed to perform relatively okay on a large spectrum of individual vehicles. If you go custom, you can kiss your issue goodbye, as your tuner will very finely tune your specific vehicle to work at its best on your chosen fuel. I'm interested to see your log using higher octane on same map.

I have a WOT log 2-3 gear with IAT 115+ and zero timing corrections. I'm on e30. This was only my second revision.

http://www.datazap.me/u/gripandrip/c...26&solo=4-7-26

You can tell I'm getting heat soak though. My 2 logs prior to this one (all back to back) performed better.

http://www.datazap.me/u/gripandrip/c...og=0&data=4-12

http://www.datazap.me/u/gripandrip/c...solo=4&mark=54

[bahn]

Originally Posted by GripAndRip

I haven't put my ngk's (1 step colder) in yet but BMS suggests .022" why go as low as .018 with stock or just one step colder? Or better yet why do they recommend .022 for 1 step colder?

I agree with Bahn. 100+ IAT with low octane will induce timing corrections. You are also using a OTS map which was designed to perform relatively okay on a large spectrum of individual vehicles. If you go custom, you can kiss your issue goodbye, as your tuner will very finely tune your specific vehicle to work at its best on your chosen fuel. I'm interested to see your log using higher octane on same map.

I have a WOT log 2-3 gear with IAT 115+ and zero timing corrections. I'm on e30. This was only my second revision.

http://www.datazap.me/u/gripandrip/c...26&solo=4-7-26

You can tell I'm getting heat soak though. My 2 logs prior to this one (all back to back) performed better.

http://www.datazap.me/u/gripandrip/c...og=0&data=4-12

http://www.datazap.me/u/gripandrip/c...solo=4&mark=54

The tighter gap helps with spark blowout at higher boost levels. You could do 0.022 but for my tune 0.018 was better correction wise. Keep in mind that E30 cools the combustion chamber more than regular gasoline which helps deter knock and therefor corrections.

[maddmatth]

Ok so it is definitely the car sensing knock rather than just some algorithm that induces timing corrections based on temp, that clears up some uncertainty for me, thanks guys

But is is bad for the engine? Or is that something we don't really know?

Weather is colder here now so I suspect if I try a comparison now I probably will just have lower IATs. I flashed the 98RON map last night but perhaps I'll switch to the 95RON map instead if data from that is more useful (and for safety). If I get out to the backroads I'll log it.

Ideally you need an intercooler or methanol injection and I would recommend tightening the spark plug gap to 0.018"

I agree with Bahn. 100+ IAT with low octane will induce timing corrections. You are also using a OTS map which was designed to perform relatively okay on a large spectrum of individual vehicles. If you go custom, you can kiss your issue goodbye, as your tuner will very finely tune your specific vehicle to work at its best on your chosen fuel. I'm interested to see your log using higher octane on same map.

As this map is labelled for a stock car, and there is the stage 1 + map that people with upgraded intercoolers, I think we should rather aim to get the map tweaked to suit a stock car - even if that means toning it down a little.
Like you say it's meant to run on a large spectrum of cars, it needs to be safe for the cars it is labelled for - stock and 95RON.

This is assuming other cars will have the same result as mine, I have yet to see another log of a car running the same map and fuel as me. But if others have the same results, then I think the timing at high RPM is just too aggressive for this fuel.

Where I live isn't a particularly hot place, so other people will hit these temps more easily...

I am considering ordering myself an upgraded intercooler, but for the purpose of this thread I'd rather focus on what should be done to my car and/or this map to get it running well and safely

As for spark plug gap, I'll see if I can find out what my workshop used when they replaced them. At the time there wasn't a clear answer in the MHD thread on what was good to use, so I decided to play it safe and let my workshop handle it.

[bahn]

Originally Posted by maddmatth

Ok so it is definitely the car sensing knock rather than just some algorithm that induces timing corrections based on temp, that clears up some uncertainty for me, thanks guys

But is is bad for the engine? Or is that something we don't really know?

Weather is colder here now so I suspect if I try a comparison now I probably will just have lower IATs. I flashed the 98RON map last night but perhaps I'll switch to the 95RON map instead if data from that is more useful (and for safety). If I get out to the backroads I'll log it.





As this map is labelled for a stock car, and there is the stage 1 + map that people with upgraded intercoolers, I think we should rather aim to get the map tweaked to suit a stock car - even if that means toning it down a little.
Like you say it's meant to run on a large spectrum of cars, it needs to be safe for the cars it is labelled for - stock and 95RON.

This is assuming other cars will have the same result as mine, I have yet to see another log of a car running the same map and fuel as me. But if others have the same results, then I think the timing at high RPM is just too aggressive for this fuel.

Where I live isn't a particularly hot place, so other people will hit these temps more easily...

I am considering ordering myself an upgraded intercooler, but for the purpose of this thread I'd rather focus on what should be done to my car and/or this map to get it running well and safely

As for spark plug gap, I'll see if I can find out what my workshop used when they replaced them. At the time there wasn't a clear answer in the MHD thread on what was good to use, so I decided to play it safe and let my workshop handle it.

I was running the e30 ots tune and stage 2+ when my car was stock. You just need to realize IATS will climb quickly and the stock intercooler easily becomes heatsoaked. The DME will reduce the load request as IATS rise but timing corrections are driven from the knock sensors.

[maddmatth]

Oh I do, but a tune can still be adjusted to account for that surely? My knowledge on this is still pretty basic, but I'd imagine it would be done by reducing timing on the higher RPM ranges - sacrificing a little performance for safety and consistency.

Or maybe the tune isn't intended for people to thrash their car like a madman, and I should tone down my driving or use the less aggressive maps due to that

I don't usually thrash my car as hard as when I'm recording those logs though, I'm just trying to push limits there and have some fun.

Edit: Just flashed the 95RON map now, we'll see how it does with the 98 fuel.

[Cory S]

Spark timing doesn't get pulled until IAT's approach around 125*F