[Vwgrk1]

There is good information in many threads, but it is hard to pick out tips specific to a Cobb-only setup (no other mods). Can anybody share their experiences and thoughts with the forum?

Consensus seems to indicate that about 4 gallons of E85 is safe. In time, I bet 50/50 will be the standard (or more; I come from the WRX world). It looks like folks suggest increased timing in small increments while watching fuel trims, but it is hard to understand where timing should be increased. Also, why does it seem that nobody increases boost with this more stable mixture? Should we also be leaning out the mixture a bit?

Lastly, are there other inputs that should be changed? ATR gives us control over a lot of variables and I have to admit that I don't understand them that well.

[VNeBLOB42]

check this thread out, if you haven't already,

http://www.e90post.com/forums/showthread.php?t=714433

[rader1]

Originally Posted by Vwgrk1

There is good information in many threads, but it is hard to pick out tips specific to a Cobb-only setup (no other mods). Can anybody share their experiences and thoughts with the forum?

Consensus seems to indicate that about 4 gallons of E85 is safe. In time, I bet 50/50 will be the standard (or more; I come from the WRX world). It looks like folks suggest increased timing in small increments while watching fuel trims, but it is hard to understand where timing should be increased. Also, why does it seem that nobody increases boost with this more stable mixture? Should we also be leaning out the mixture a bit?

Lastly, are there other inputs that should be changed? ATR gives us control over a lot of variables and I have to admit that I don't understand them that well.

People using ATR and actively discussing are usually running the stage 2+ maps and doesn't leave much room to increase boost because of the tiny TD03 turbos. The maps designed for stock cars they run less boost due to very restrictive DPs/intercooler.

How I would do what you're talking about is to take the stage 1 aggressive map and log it running various e85 mixes and learn what the most you can get away with before trims Max out. Once you figure that out then start adding adding 1 degree of timing in the load cells over 100.

Now here's the tricky part.

With that much e85 it's possible you pass the point of MBT before you start getting corrections. Unless you're on a dyno it'll be hard to tell for sure. Virtual dyno can help with this but it's not exact/repeatable enough to rely on IMO.

I would probably think 10 degrees in the mids and maybe 12 degrees up top running the stage 1 boost levels would work.

[Carl Morris]

I've been doing it on a stock+DCI car running 20-25% E85 and I think it's going well. The problem is that I'm also at high elevation and even though I can request a load of 186 I only get max loads in the 150s. So I'm paranoid that if I give somebody else my map they'll use it at sea level and my timing map may be set too aggressively at loads above 160. If you log religiously under worst case conditions and reduce the map a bit where necessary it's no problem, but I'd hate to be involved in helping somebody blow up a motor if they weren't being careful enough.

Like rader1 said, I've got my timing going from 9-12 degrees at full boost and that's been great so far. I had also reduced the timing pull from the Timing Cor. Factor (Charge Air Temp) map significantly because with the stock IC the temps were getting high and it was pulling more timing than I wanted. I did some testing in 100 degree heat yesterday and put some of it back, though. I was getting some knock events on the 9-12 curve at high CAT temps. Now in very high temps it automatically dials it back to 7-10. No more knock events in the limited testing so far.

[Vwgrk1]

Originally Posted by VNeBLOB42

check this thread out, if you haven't already,

http://www.e90post.com/forums/showthread.php?t=714433

Yeah, I saw it and got a bit excited over what Shiv started alluding to. The original poster was on a Stg2+ setup, so I sort of tuned out, figured that something that modded was not comparable to my car. The overall theory is good, though.

[Vwgrk1]

Originally Posted by rader1

People using ATR and actively discussing are usually running the stage 2+ maps and doesn't leave much room to increase boost because of the tiny TD03 turbos. The maps designed for stock cars they run less boost due to very restrictive DPs/intercooler.

How I would do what you're talking about is to take the stage 1 aggressive map and log it running various e85 mixes and learn what the most you can get away with before trims Max out. Once you figure that out then start adding adding 1 degree of timing in the load cells over 100.

Now here's the tricky part.

With that much e85 it's possible you pass the point of MBT before you start getting corrections. Unless you're on a dyno it'll be hard to tell for sure. Virtual dyno can help with this but it's not exact/repeatable enough to rely on IMO.

I would probably think 10 degrees in the mids and maybe 12 degrees up top running the stage 1 boost levels would work.

This is real helpful! I am actually in the mixture testing phase, hoping fuel trims stay in the low 20's now on the 4 gallon mixture. It is painful not add timing yet, lol.

I will take your advice on the timing and MBT...it is near impossible to know where that is on the street. Better to leave room since god knows how the car will behave in the winter with that gas and temperature.

[Vwgrk1]

Originally Posted by Carl Morris

I've been doing it on a stock+DCI car running 20-25% E85 and I think it's going well. The problem is that I'm also at high elevation and even though I can request a load of 186 I only get max loads in the 150s. So I'm paranoid that if I give somebody else my map they'll use it at sea level and my timing map may be set too aggressively at loads above 160. If you log religiously under worst case conditions and reduce the map a bit where necessary it's no problem, but I'd hate to be involved in helping somebody blow up a motor if they weren't being careful enough.

Like rader1 said, I've got my timing going from 9-12 degrees at full boost and that's been great so far. I had also reduced the timing pull from the Timing Cor. Factor (Charge Air Temp) map significantly because with the stock IC the temps were getting high and it was pulling more timing than I wanted. I did some testing in 100 degree heat yesterday and put some of it back, though. I was getting some knock events on the 9-12 curve at high CAT temps. Now in very high temps it automatically dials it back to 7-10. No more knock events in the limited testing so far.

Yeah, I was tempted to play with the temp correction, but it is hard to know if the standard settings are over conservative (like timing is) or if they should be left alone.

[Vwgrk1]

Originally Posted by rader1

Once you figure that out then start adding adding 1 degree of timing in the load cells over 100.


I would probably think 10 degrees in the mids and maybe 12 degrees up top running the stage 1 boost levels would work.

Sorry, need a bit of clarification, if you are willing to help. I am confused about at what RPM you start adding timing. I guess I am confused because my 105 load column already has timing of 14.5 in the 3,000 RPM range. It fluctuates from there as you go up in RPM, but goes no lower than 12.5. I'm likely confused because I am not sure what you mean by mids...is that referring to an RPM range?

So, increase timing in all columns in the 105 and up load zones by one degree at a time? The end result being the 180 load column not to to exceed 9-12 degrees (a roughly 6 degree bump). So, therefore, all load columns 105 and up to be increased by roughly 6 degrees.

Is that at all what you meant? I feel dumb.

[Mangler]

2008 335i MT 63,000 miles new everything, walnut blasted, 25% E85/93oct, wagner, stock everything else, Stg1+ Agg ST 4.02, 90* ambient, FMIC runs about 16-18* over ambient in these temps. This run was after a few good hard WOT runs.

Fuel trims are right up at 34% at max torque then taper to redline. AFR's are okay. I may richen them up a little.

T

[rader1]

Originally Posted by Vwgrk1

Sorry, need a bit of clarification, if you are willing to help. I am confused about at what RPM you start adding timing. I guess I am confused because my 105 load column already has timing of 14.5 in the 3,000 RPM range. It fluctuates from there as you go up in RPM, but goes no lower than 12.5. I'm likely confused because I am not sure what you mean by mids...is that referring to an RPM range?

So, increase timing in all columns in the 105 and up load zones by one degree at a time? The end result being the 180 load column not to to exceed 9-12 degrees (a roughly 6 degree bump). So, therefore, all load columns 105 and up to be increased by roughly 6 degrees.

Is that at all what you meant? I feel dumb.

You need to determine what load you're requesting at WOT. This is found in your main load table. I don't have ATR right in front of me so these numbers are just for example:
If at 4500 rpm you're requesting 170 load then you'll start at 100 load and work you way to 170 and put 10 in any cells below 10 and any cells already above 10 you should leave alone.
Keep in mid that 170 is your load target so from 160-170 is the columns that will establish your timing at WOT. Your main load table tells you where most of your adjustments should be made.
This kind of confusing and I'm not great at explaining things so I hope this helps.

[Carl Morris]

Originally Posted by Vwgrk1

Yeah, I was tempted to play with the temp correction, but it is hard to know if the standard settings are over conservative (like timing is) or if they should be left alone.

I think they are conservative just like the timing map. At first I dialed them way back, but eventually as I started pushing the limit of my 20% mix I added some back in. I think this table is a big reason for why meth is so popular...if you can keep CAT temps below 45C on the stock maps you get a lot more timing and meth would definitely help with that.

[VNeBLOB42]

Originally Posted by Vwgrk1

Yeah, I saw it and got a bit excited over what Shiv started alluding to. The original poster was on a Stg2+ setup, so I sort of tuned out, figured that something that modded was not comparable to my car. The overall theory is good, though.

yeah, just figured it may give you some direction. I am interested in your results and experience. please post when you are done and or progress.

[Vwgrk1]

Originally Posted by Mangler

2008 335i MT 63,000 miles new everything, walnut blasted, 25% E85/93oct, wagner, stock everything else, Stg1+ Agg ST 4.02, 90* ambient, FMIC runs about 16-18* over ambient in these temps. This run was after a few good hard WOT runs.

Fuel trims are right up at 34% at max torque then taper to redline. AFR's are okay. I may richen them up a little.

T

Are the timing corrections OK? I thought that having negatives in those columns is not good? Or, are small corrections fine to have on these cars?

Also, why is your TPS % only about 80%

[Vwgrk1]

Originally Posted by rader1

You need to determine what load you're requesting at WOT. This is found in your main load table. I don't have ATR right in front of me so these numbers are just for example:
If at 4500 rpm you're requesting 170 load then you'll start at 100 load and work you way to 170 and put 10 in any cells below 10 and any cells already above 10 you should leave alone.
Keep in mid that 170 is your load target so from 160-170 is the columns that will establish your timing at WOT. Your main load table tells you where most of your adjustments should be made.
This kind of confusing and I'm not great at explaining things so I hope this helps.

I think I follow you. Let me know if I am on track, please. If it is anything like tuning a Turbo XS piggyback in the Subie world, then you want smooth timing transitions from load to load and RPM to RPM.

I am to be mainly concerned about the 155 and 180 load ranges, since those are the two highest ones that the ECU will average in order to determine what timing to run (my load at WOT tends to be 160 to 170). However, I have to increase timing in the lower loads (105 to 140) if the timing ends up being lower in those columns than in the 155 and 180 columns.

Lastly, I am to be concerned about those load ranges in the RPMs where I actually reach a 155 or above load.

I can't be the only person needing this kind of help, right?

[Vwgrk1]

Originally Posted by VNeBLOB42

yeah, just figured it may give you some direction. I am interested in your results and experience. please post when you are done and or progress.

Will do. Getting shelled this Thursday, so will get more into this after that.

[enrita]

Originally Posted by Vwgrk1

I think I follow you. Let me know if I am on track, please. If it is anything like tuning a Turbo XS piggyback in the Subie world, then you want smooth timing transitions from load to load and RPM to RPM.

I am to be mainly concerned about the 155 and 180 load ranges, since those are the two highest ones that the ECU will average in order to determine what timing to run (my load at WOT tends to be 160 to 170). However, I have to increase timing in the lower loads (105 to 140) if the timing ends up being lower in those columns than in the 155 and 180 columns.

Lastly, I am to be concerned about those load ranges in the RPMs where I actually reach a 155 or above load.

I can't be the only person needing this kind of help, right?

This might help answer most of your questions http://www.e90post.com/forums/showthread.php?t=708342

[rader1]

Originally Posted by Vwgrk1

I think I follow you. Let me know if I am on track, please. If it is anything like tuning a Turbo XS piggyback in the Subie world, then you want smooth timing transitions from load to load and RPM to RPM.

I am to be mainly concerned about the 155 and 180 load ranges, since those are the two highest ones that the ECU will average in order to determine what timing to run (my load at WOT tends to be 160 to 170). However, I have to increase timing in the lower loads (105 to 140) if the timing ends up being lower in those columns than in the 155 and 180 columns.

Lastly, I am to be concerned about those load ranges in the RPMs where I actually reach a 155 or above load.

I can't be the only person needing this kind of help, right?

Sounds like you're on your way
This is all a long, interesting learning process. Once you know what you're actual loads are/will be then you know where you're changes should be made and then smooth the table out.

[Mangler]

Originally Posted by Vwgrk1

Are the timing corrections OK? I thought that having negatives in those columns is not good? Or, are small corrections fine to have on these cars?

Also, why is your TPS % only about 80%

The timing corrections are okay at the rpm that they occurred and they were sporadic and not coincidental with other cylinders. The tps does not go over 80% actual in the dme. It's normal.

T

[Vwgrk1]

So, I am trying to figure out tuning with E85 / 93 octane. I ran 25% E85 and increased timing 1.5 degrees in the highest load column. Increased the requested load to 190 across the board, save for the two highest load columns, which I left alone. I got random timing corrections in a cylinder on 4 of the 8 runs. Different cylinders each time. Never in multiple cylinders at once. Highest correction was about -3.88.

At what point do you worry about damage? Is there a rule for when you have real knock that is going to need a reduction in timing?

I am going to aim for a 40-50% mixture now that the scalar is out, but want to make sure that I got this figured out before I go further.

Also, with 25% E85 or more, is 17 to 18 psi in the mids a problem?

Thanks in advance. I want to write a DIY for total newbs (like me) once I get this up and running. There is not a real good how to anywhere.

[rader1]

Originally Posted by Vwgrk1

So, I am trying to figure out tuning with E85 / 93 octane. I ran 25% E85 and increased timing 1.5 degrees in the highest load column. Increased the requested load to 190 across the board, save for the two highest load columns, which I left alone. I got random timing corrections in a cylinder on 4 of the 8 runs. Different cylinders each time. Never in multiple cylinders at once. Highest correction was about -3.88.

At what point do you worry about damage? Is there a rule for when you have real knock that is going to need a reduction in timing?

I am going to aim for a 40-50% mixture now that the scalar is out, but want to make sure that I got this figured out before I go further.

Also, with 25% E85 or more, is 17 to 18 psi in the mids a problem?

Thanks in advance. I want to write a DIY for total newbs (like me) once I get this up and running. There is not a real good how to anywhere.

Having one or two corrections is no big deal. As long as they are not multiple corrections across several cylinders then you're doing ok. 3.88 is indicative of a single correction.

17-18psi in the mids is within the compressor effeciency map. But just for durabilty i wouldn't try to run that much boost with the stock DPs. There's a lot of backpressure there with the cats in place.

Can you post up a log?

[Vwgrk1]

Hope this worked. Run 2 was in 3rd and 3 was in 4th gear. Separate runs, not shifting from one gear to the other.

A few channels are missing because I was more focused on fuel trims.

[Mangler]

Originally Posted by Vwgrk1

Hope this worked. Run 2 was in 3rd and 3 was in 4th gear. Separate runs, not shifting from one gear to the other.

A few channels are missing because I was more focused on fuel trims.

You need an FMIC BAD!! with the timing corrections due to charge air temp you have nearly no timing advance.

T