E85 - going too lean @ WOT

[chaser27]

I realize my compressor map isn't perfect but the shaft speed will have to increase from 5500-6k in order to maintain boost at 17.5 psi. How much? I don't know. We could be arguing over 5-10 hp, maybe less, I don't know that either. But if I was him, I would try to keep the rate of change of my shaft speed steady for as long as possible and then drop off as it chokes up. Not dropping only to increase again at Redline.

[Enki]

Actually that may not necessarily be true.

Back when I was stock turbo, with stock EBCS in stock configuration, I could hit 17 PSI on an ots map, but as I added timing boost dropped off while airflow remained the same. I was hitting 100% WGDC from about 4500 to 6k rpm.

[chaser27]

hmmm. that's interesting.... I'm thinking one of two things. Maybe you can give some insight..
1) As you increased timing, you were getting better evacuation of the cylinder increasing Volumetric Efficiency, but having less energy left to spool the turbo. Boost drops, airflow remains the same.
2) I changed my mind... was originally thinking something about stock EBCS needing a restrictor pill with higher boost K04's, but I'm back to thinking number 1.

[OCspeed]

Originally Posted by Enki What is your timing at 3k? hard to say from the log. I agree, I had mine set to 18 @ 3k then went full beans from there..

Timing taken from the high throttle/OL (No Knock) is as follows starting at 2500:

-1.00 2.50 4.50 7.50 12.00 14.00 16.00 17.00 18.50 19.50

^ That timing curve is with the recent edit of taking away .5 of a degree at 3000rpm and 1.5 degrees from 3500-4000rpm ^

So what you guys are saying is to just target 18psi as a peak and taper it off to 17?
current boost targets from 2500 RPM and on is as follows:

21.00 21.00 21.00 21.00 21.00 19.00 18.00 18.00 18.00 18.00

[chaser27]

Originally Posted by OCspeed Timing taken from the high throttle/OL (No Knock) is as follows starting at 2500: -1.00 2.50 4.50 7.50 12.00 14.00 16.00 17.00 18.50 19.50 ^ That timing curve is with the recent edit of taking away .5 of a degree at 3000rpm and 1.5 degrees from 3500-4000rpm ^ So what you guys are saying is to just target 18psi as a peak and taper it off to 17? current boost targets from 2500 RPM and on is as follows: 21.00 21.00 21.00 21.00 21.00 19.00 18.00 18.00 18.00 18.00

I think @Enki; is saying you are pretty much tapped out as far as boost goes. He can correct me if I'm wrong. I was saying you need to smooth the taper down to redline more if you wanted to squeeze a bit more out of it, instead of adding more timing. (I wouldn't really add any more timing than you have without verifying on a dyno) How much power is left (if any) is debatable, which is what we were going back and forth on.

I'll update this when I get home with a better "recommendation" of numbers, but not quite like that. You have more of a "Step" function there ^ with the 2500 number beyond the surge line.

Again, I'll update this in a bit when I'm not at work and have access to my tools, but something more like
15, 18, 21, 21, 20.5, 20, 19, 17.5, 16, 14

If you look at the compressor chart I posted above. I put in the boost pressures you were running at each 500 interval from your logs. The y-axis is the pressure you are running, the x-axis is the amount of airflow and the part I was really looking at is the curved lines. The line is supposed to signify a shaft speed of the turbo. How many rpm's your turbo needs to spin at to achieve said boost at said airflows. Take it all with a grain of salt because assumptions are made in plotting where you fall, but it looks to me as if your current boost targets fall off slightly before they have to (in that "V" section at the right of the plot)

If you can hit 17.5 at 6k, you can hit higher than 17.5 at 5500 is what I'm getting at. With the added shaft speed at 5500 that comes with higher boost, you shouldn't have to work as hard to hold 17.5 at 6k.

[OCspeed]

Originally Posted by chaser27 I think @Enki; is saying you are pretty much tapped out as far as boost goes. He can correct me if I'm wrong. I was saying you need to smooth the taper down to redline more if you wanted to squeeze a bit more out of it, instead of adding more timing. (I wouldn't really add any more timing than you have without verifying on a dyno) How much power is left (if any) is debatable, which is what we were going back and forth on. I'll update this when I get home with a better "recommendation" of numbers, but not quite like that. You have more of a "Step" function there ^ with the 2500 number beyond the surge line. Again, I'll update this in a bit when I'm not at work and have access to my tools, but something more like 15, 18, 21, 21, 20.5, 20, 19, 17.5, 16, 14 If you look at the compressor chart I posted above. I put in the boost pressures you were running at each 500 interval from your logs. The y-axis is the pressure you are running, the x-axis is the amount of airflow and the part I was really looking at is the curved lines. The line is supposed to signify a shaft speed of the turbo. How many rpm's your turbo needs to spin at to achieve said boost at said airflows. Take it all with a grain of salt because assumptions are made in plotting where you fall, but it looks to me as if your current boost targets fall off slightly before they have to (in that "V" section at the right of the plot) If you can hit 17.5 at 6k, you can hit higher than 17.5 at 5500 is what I'm getting at. With the added shaft speed at 5500 that comes with higher boost, you shouldn't have to work as hard to hold 17.5 at 6k.

Oh okay, now I understand what you're saying. It does make sense that I could push more

boost in the 5500 region when looking at the 6000 region and the given boost its making.

I'll check back later when you are not at work

[Enki]

No I was saying you should reduce target boost (and wgdc) at 3k down to 18. Rest can stay as it is since you're on corn and not pushing timing to the limit.

[chaser27]

Hey man, I looked at some numbers and my estimate from before was pretty much what they should have been. It may get you a little more area under the curve. You're already pretty quick with a 60-100 time of 5.67 seconds.

I can't find the thread right now, but IIRC you're doing good for a K04.

[OCspeed]

Originally Posted by chaser27 Hey man, I looked at some numbers and my estimate from before was pretty much what they should have been. It may get you a little more area under the curve. You're already pretty quick with a 60-100 time of 5.67 seconds. I can't find the thread right now, but IIRC you're doing good for a K04.

You think its worth a shot to input those values? Regardless i'm changing the 2500 rpm and

3000 rpm boost target

[Enki]

It won't hurt to flatten out the boost curve, just don't push it too much past where it is at 6k+.

[chaser27]

I pretty much think anything is worth a shot haha. Maybe you'll get 5.63 seconds

But as he said ^, we aren't saying up the boost everywhere, just in that small section

[OCspeed]

Originally Posted by Enki It won't hurt to flatten out the boost curve, just don't push it too much past where it is at 6k+.

Originally Posted by chaser27 I pretty much think anything is worth a shot haha. Maybe you'll get 5.63 seconds But as he said ^, we aren't saying up the boost everywhere, just in that small section

Alright i'll give it a shot haha

New boost targets are as follows starting from 2500 RPM:

15.00 18.00 21.00 21.00 20.50 20.00 18.25 17.50 16.00 14.00

Instead of pushing (or trying to push) 19psi at 5500, like suggested above, I input 18.25psi and to first see if it makes a noticeable difference carrying the boost in the other areas of the curve

[OCspeed]

Alright, update time after a long and busy week!

Went out tonight to get 2 clean logs. While the car on vdyno doesn't show to be making more power, for some reason it felt like it pulled harder.

Data-log 1 and 2 are from tonight with the new map featuring the change in timing (less timing in the lower part of the RPM band, and 1 degree of more timing added to the upper RPM band) along with the boost target changes as suggested by ;chaser27@

For a better idea of what HP the car is making, I factored in my weight to the vdyno graphs as shown. This also lets me think the car is making more powah!

Data-log 3 and 4 on the vdyno are the two logs from the previous map

[chaser27]

It looks like the boost curve is basically identical to the old one, minus the lower rpms.
You have a bit of boost spike down low, you could back down WGDC there a bit. Double check all your load tables and makes sure you aren't hitting any limits around 5500. Looking at WGDC there, you can see it levels off and then kicks up again.

[OCspeed]

Originally Posted by chaser27 It looks like the boost curve is basically identical to the old one, minus the lower rpms. You have a bit of boost spike down low, you could back down WGDC there a bit. Double check all your load tables and makes sure you aren't hitting any limits around 5500. Looking at WGDC there, you can see it levels off and then kicks up again.

At 5500 RPM's on both logs i'm only hitting a calculated load of 2.03 in one log and 2.04 in the other. From what I can see on my map, i'm not hitting any load limits

I too saw that the boost curve, besides the spool up, looks exactly the same. It actually seems to be slightly under boosting.

I also think i'm getting to the point where timing is gonna have to stay where it is, unless you or enki think I can run another half degree to a full degree up top. It feels like i'm missing something to make more power, but maybe that's just me wanting more and more haha

[Enki]

You're about tapped out it seems. On 50/50 E85 mix, I never could make more than 250 @ 6k rpm with the stock boost control setup due to elevation. That was with MBT timing, and 100% WGDC.

[OCspeed]

Originally Posted by Enki You're about tapped out it seems. On 50/50 E85 mix, I never could make more than 250 @ 6k rpm with the stock boost control setup due to elevation. That was with MBT timing, and 100% WGDC.

Does my timing look close to MBT?

And what do you think about upping WGDC in some areas to help up and hold boost a little better, or should I just leave as is and stop whining? haha

[Enki]

It's hard to say. Every car is different as to what timing numbers it likes, but it is possible. The question is, how far do you want to push this?

Too far and it won't last nearly as long; stock block power is a tradeoff of zoom vs longevity, which not only applies to your engine, but turbo as well.

If you don't care about longevity of the engine, then by all means, find out what she can do.

[OCspeed]

Originally Posted by Enki It's hard to say. Every car is different as to what timing numbers it likes, but it is possible. The question is, how far do you want to push this? Too far and it won't last nearly as long; stock block power is a tradeoff of zoom vs longevity, which not only applies to your engine, but turbo as well. If you don't care about longevity of the engine, then by all means, find out what she can do.

This has to be the most tempting post ever. I want the zoom, but not the boom

It looks like i'm gonna keep the tune where it's at. I'm all about making power, but this is my DD, and i'm not down to push it so far where i'm on the ragged edge

[Enki]

Do you know where the ragged edge is yet?

[OCspeed]

Originally Posted by Enki Do you know where the ragged edge is yet?

Maybe I have an idea in some aspects considering the turbo and stock block along with aggressive timing. But really, no

[Enki]

You should be fine to find out, but don't run that tune full time.

[OCspeed]

Originally Posted by Enki You should be fine to find out, but don't run that tune full time.

I'm gonna take my chances and not try to find out. In all honesty, i'm happy with where the car is right now. I don't feel like going into the unknown and taking a risk. Am I leaving a couple HP or TQ on the table? Maybe, but who cares, the car feels great

Also, I couldn't have gotten to where I am at the moment without all the info on MSF, mister Enki for his fuel mix cheat sheet and all his help, Chaser27 with all his help, and everyone else that contributed to the the thread, so really, THANK YOU

[OCspeed]

Just for a little update, the car is still running great and feels strong. I don't get the chance to get on it a lot, but when I do it feels great

Just a quick question and concern: I remember reading something along the lines that if you tune for E85 during the winter, you will go lean during the summer months. Being in California and how random the weather here is in socal, should I be worried for the upcoming warmer days/months since I tuned during cold temps?

Maybe i'm over-thinking this, but any input would be appreciated

[Enki]

You're on 50/50; I wouldn't be too worried if I were you, just take a look at your fuel trims every now and then.

[OCspeed]

After getting pulled over, stocking out, and facing the state ref, I finally have my car back

to the way it was. I changed my catted DP to a catless setup and went back to the 50/50

mix and flashed my tune. I did one log getting on the freeway and it seems like everything

is running fine (log attached). Going catless I expected to have boost issues here and

there but it seems to run fine and seems to be slightly under boosting by a little (.5-1psi).

The new E85 station that opened up down the street from me last week has got me

thinking to switch over to 100% E85 since I have a oil change coming up in a hundred

miles and go with the Royal Purple and the S-1 combo. Should I expect gains from

switching over? I think I read Enki (or maybe it was someone else?) mentioned that you can keep the

same inputs on the tune and just calibrate the intake and you should see some gains? I may be wrong

though

[Enki]

Stock turbo you can gain a touch of airflow up top by going full corn; the biggest benefit, however, is the smoothness and only one pump per trip to the gas station.

[OCspeed]

Originally Posted by Enki Stock turbo you can gain a touch of airflow up top by going full corn; the biggest benefit, however, is the smoothness and only one pump per trip to the gas station.

So I guess the only loss i'll have/might have is my fuel level sensor going out with the E85 eating away at the connectors

[Enki]

Originally Posted by OCspeed So I guess the only loss i'll have/might have is my fuel level sensor going out with the E85 eating away at the connectors

There's a thread on this issue and how to resolve it.

[g00s3y]

Originally Posted by OCspeed So I guess the only loss i'll have/might have is my fuel level sensor going out with the E85 eating away at the connectors

And about 100 miles less per tank.

[Enki]

Depending on tune/driving style.

[OCspeed]

Originally Posted by g00s3y And about 100 miles less per tank.

Eh, evens out with the cheaper cost of E85/gallon