JB4 Logging, stacking and Map 6 Discussion

[Diggs24]

Knock retard is actually bad terminology for the timing adaption. In most cases its not knock related.
The car will also adapt timing on heavy boost onset to assist with torque targeting.
In essence what you are seeing is a live adaption channel hence many times when its present overall timing does not take a dip. The norm though is when it does go higher than 3 is for it to be knock related.

Thanks George. That helps my fear. It has never gone above 3.

Further question, do you know why the car would spike very lean (and why I think trims took off) in this instance?

http://www.datazap.me/u/diggs24/log-1489092652?log=0&data=1-2-3-4-6-11-14-18

This is the only time I've seen this and actually the only log in which I didn't get KR readings in cylinder 2. Anomaly?

 

[0bLiViOuS]

More oxygen content makes it more prone to pre ignite. Also cars at higher altitude can handle more timing/boost based on the same principle.

Thanks George. I never really thought of this as a factor but very true and good to get a simple answer

 

[Thegoat]

I an trying to figure out if running an E85 mix is worth doing in these sub 32 winter temps. Since E85 when mixed has better cooling capabilities and raises the octane of standard gas, does the cooling out weigh the increase in octane especially in colder temps? Thinking about what george said in reguards to colder air can cause some preignition.

 

[0bLiViOuS]

You'll get the increase octane rating so better than nothing. I get your thinking tho. You could try without it and see how it does.. only way to know for sure is to experiment

 

[TwinDad]

I an trying to figure out if running an E85 mix is worth doing in these sub 32 winter temps. Since E85 when mixed has better cooling capabilities and raises the octane of standard gas, does the cooling out weigh the increase in octane especially in colder temps? Thinking about what george said in reguards to colder air can cause some preignition.

I notice it. I can run more boost with better timing. It's about the temperature in the combustion chamber, not the IAT

 

[Cruiser]

Looks clean. May want to add pedal, throttle and trims to the graph so you can make sure your trims are looking good but other than that I think it's a solid run!

Alright! Good news. Yeah, I will add those, Thanks!

 

[Thegoat]

I notice it. I can run more boost with better timing. It's about the temperature in the combustion chamber, not the IAT

So even in sub freezing temps when the temp outside os below 32F and iat is below 32F or close to it, running E85 still works well in correcting timing even if it lowers the temps more? Knowing that too cold of air entering the engine causes some timing issues.

Id like to run E85 mix and meth at some point and want to know if anyone has timing issues using both or either in the below freezing temps we get in the north east usa

 

[wy2sl0]

So even in sub freezing temps when the temp outside os below 32F and iat is below 32F or close to it, running E85 still works well in correcting timing even if it lowers the temps more? Knowing that too cold of air entering the engine causes some timing issues.

Id like to run E85 mix and meth at some point and want to know if anyone has timing issues using both or either in the below freezing temps we get in the north east usa

It doesn't work in that way. E85 burns cooler, it isn't itself colder. Because its potential energy is also lower than gasoline you use a larger amount which also helps reduce combustion temps. When you are compressing air and fuel to hundreds of PSI liquid has a much higher specific heat capacity than air so it helps drive down temps. This is why even water injection works (without meth).

 

[Thegoat]

It doesn't work in that way. E85 burns cooler, it isn't itself colder. Because its potential energy is also lower than gasoline you use a larger amount which also helps reduce combustion temps. When you are compressing air and fuel to hundreds of PSI liquid has a much higher specific heat capacity than air so it helps drive down temps. This is why even water injection works (without meth).

I understand it isnt colder and that it actually lowers cylinder temps to help prevent pre ignition and timing pull like water/meth do. Maybe im not asking the question correctly.

So we know that air that is too cold entering the engine can pre ignite in the combustion process. E85 and water/meth have a cooling effect in the cylinder to combat detonation, which is great in warmer weather.

But what about sub freezing weather where iat's are freezing and now your lowering cylinder temps with fuel that burns cooler? I could be wrong on this so correct me if i am but if you lower the cylinder temps and have air cold enough to cause some pre ignition, wouldnt having fuel that burns cooler not help with the pre ignition?

I am maybe way over thinking this.

I am having timing pull in really cold weather and i am curious to know if some E85 and/or water/meth will help since it helps prevent timing pull. or will the cooling effect it provides not help since the air entering the engine is so cold it doesnt warm up much during the compression stroke in a cooler cylinder.

 

[mirtskhu007]

Hello, can i use these map6 settings on my mk7 gti is20, the car is manual, with castless downpipe and air intake?
1500 16
2000 18
2500 20
3000 22
3500 23
4000 23
4500 22
5000 20
5500 19
6000 19
6500 18
7000 17

 

[Diggs24]

Hello, can i use these map6 settings on my mk7 gti is20, the car is manual, with castless downpipe and air intake?
1500 16
2000 18
2500 20
3000 22
3500 23
4000 23
4500 22
5000 20
5500 19
6000 19
6500 18
7000 17

You'll ever know until you run a log to see how the car reacts.

 

[MauricioGTI]

I tested a similar configuration in my car, but I'm downpipe stock.

I would very much like the boost to follow the target line, but he is always below.

example:

 

[TwinDad]

I understand it isnt colder and that it actually lowers cylinder temps to help prevent pre ignition and timing pull like water/meth do. Maybe im not asking the question correctly.

So we know that air that is too cold entering the engine can pre ignite in the combustion process. E85 and water/meth have a cooling effect in the cylinder to combat detonation, which is great in warmer weather.

But what about sub freezing weather where iat's are freezing and now your lowering cylinder temps with fuel that burns cooler? I could be wrong on this so correct me if i am but if you lower the cylinder temps and have air cold enough to cause some pre ignition, wouldnt having fuel that burns cooler not help with the pre ignition?

I am maybe way over thinking this.

I am having timing pull in really cold weather and i am curious to know if some E85 and/or water/meth will help since it helps prevent timing pull. or will the cooling effect it provides not help since the air entering the engine is so cold it doesnt warm up much during the compression stroke in a cooler cylinder.

The freezing temperatures and cold IAT is not causing knock. It's causing the computer to think more about the possibility of knock and it then makes timing corrections. The computer is always using a torque targeting and will try to decide what it thinks is best for the air quality its reading. It will compare that to what it is reading post combustion and try to be a nanny for you. The e85 blended in will help the post combustion readings, so it will then allow you to run more boost without it trying to correct things.

 

[Diggs24]

I tested a similar configuration in my car, but I'm downpipe stock.

I would very much like the boost to follow the target line, but he is always below.

example:

Probably because your IATs are very high. An IC would be very beneficial for your climate.

 

[MauricioGTI]

Probably because your IATs are very high. An IC would be very beneficial for your climate.

I think that's not it, the IAT in the log is not too high. That day the temperature was 20 degrees celsius and the IAT is 36.

Is it the lack of a downpipe?