[leftcoastman]

Shiv (and others) - Does the PROcede interfere with the ECU's ability to compensate for altitude?

Here's why I ask:

At sea level, the stock ECU will call for 8.8PSI of boost max. To compensate for altitude, it will increase boost up to 11.8 PSI. There is 3PSI of possible altitude compensation. This is according to the BMW engineer responsible for this engine.

At sea level, the PROCEDE will call for about 14PSI of boost max, which is roughly 5PSI over stock.

Now, it would stand to reason that at altitude, a PROCEDE'd 335i would call for 14PSI boost and the ECU would compensate and add an additional 3PSI, totalling up to 17 PSI of boost.

Unfortunately, that is not happening. The PROCEDE is simply calling for 14PSI boost and the car completely ignores the built-in altitude compensation.

I'm not sure how the interceptor works and the mechanics behind the boost targets. Is there some sort of ambient pressure sensor that the PROcede is interfering with?

[Terry335]

Originally Posted by leftcoastman

Shiv (and others) - Does the PROcede interfere with the ECU's ability to compensate for altitude?

Here's why I ask:

At sea level, the stock ECU will call for 8.8PSI of boost max. To compensate for altitude, it will increase boost up to 11.8 PSI. There is 3PSI of possible altitude compensation. This is according to the BMW engineer responsible for this engine.

At sea level, the PROCEDE will call for about 14PSI of boost max, which is roughly 5PSI over stock.

Now, it would stand to reason that at altitude, a PROCEDE'd 335i would call for 14PSI boost and the ECU would compensate and add an additional 3PSI, totalling up to 17 PSI of boost.

Unfortunately, that is not happening. The PROCEDE is simply calling for 14PSI boost and the car completely ignores the built-in altitude compensation.

I'm not sure how the interceptor works and the mechanics behind the boost targets. Is there some sort of ambient pressure sensor that the PROcede is interfering with?

I know the Terry Tuner passes through ECU boost increases.

For the procede I guess it depends how they programmed it, but don't forget air temperature is also a variable that can add or take away a pound of boost.

[OpenFlash]

Originally Posted by leftcoastman

Shiv (and others) - Does the PROcede interfere with the ECU's ability to compensate for altitude?

Here's why I ask:

At sea level, the stock ECU will call for 8.8PSI of boost max. To compensate for altitude, it will increase boost up to 11.8 PSI. There is 3PSI of possible altitude compensation. This is according to the BMW engineer responsible for this engine.

At sea level, the PROCEDE will call for about 14PSI of boost max, which is roughly 5PSI over stock.

Now, it would stand to reason that at altitude, a PROCEDE'd 335i would call for 14PSI boost and the ECU would compensate and add an additional 3PSI, totalling up to 17 PSI of boost.

Unfortunately, that is not happening. The PROCEDE is simply calling for 14PSI boost and the car completely ignores the built-in altitude compensation.

I'm not sure how the interceptor works and the mechanics behind the boost targets. Is there some sort of ambient pressure sensor that the PROcede is interfering with?

Altitude compensations are still function with the PROcede. But the turbo hardware does have its limitations. We routinely see more boost at higher altitudes with the PROcede. But this needs to be measured with a boost gauge that is referenced to ambient pressure. Not by a MAP sensor or an electronic boost gauge which is referenced to 100kpa or thereabouts.

Shiv

[leftcoastman]

Originally Posted by shiv@vishnu

Altitude compensations are still function with the PROcede. But the turbo hardware does have its limitations. We routinely see more boost at higher altitudes with the PROcede. But this needs to be measured with a boost gauge that is referenced to ambient pressure. Not by a MAP sensor or an electronic boost gauge which is referenced to 100kpa or thereabouts.

Shiv

Shiv, the data was recorded using the software included with the PROcede. It showed -2.xx PSI on the MAP channel at idle, which coincides exactly with the ambient air pressure reduction at this altitude.

Under full boost, the max achievable is 12 PSI on the MAP data channel, which is a total of about 14PSI of boost.

That indicates to me that the PROcede is interfering with the ECU's ability to compensate for altitude. If you look at ADHD's data that he recorded at LACR, he showed -1PSI at idle (which correlates perfectly to his altitude there) and about 13'ish PSI at boost, which again shows a total of about 14PSI of boost.

If I send you the data (rpm, map, fuel correction, ignition correction), can you decode what's going on?

[trickydick]

oh sh!t is my car going to blow up?

[OpenFlash]

Originally Posted by leftcoastman

Shiv, the data was recorded using the software included with the PROcede. It showed -2.xx PSI on the MAP channel at idle, which coincides exactly with the ambient air pressure reduction at this altitude.

Under full boost, the max achievable is 12 PSI on the MAP data channel, which is a total of about 14PSI of boost.

That indicates to me that the PROcede is interfering with the ECU's ability to compensate for altitude. If you look at ADHD's data that he recorded at LACR, he showed -1PSI at idle (which correlates perfectly to his altitude there) and about 13'ish PSI at boost, which again shows a total of about 14PSI of boost.

If I send you the data (rpm, map, fuel correction, ignition correction), can you decode what's going on?

On my car, running v1.45, I see max boost of just under 14psi (just a quick spike), with a steady 11.5-12.5psi through the midrange. Tapering off to 10-10.5psi by 6500rpm. I think you're numbers are perfectly normal. Keep in mind that charge temp, vehicle speed and time-under-boost will also have an effect on boost pressure.

shiv

[leftcoastman]

Originally Posted by shiv@vishnu

On my car, running v1.45, I see max boost of just under 14psi (just a quick spike), with a steady 11.5-12.5psi through the midrange. Tapering off to 10-10.5psi by 6500rpm. I think you're numbers are perfectly normal. Keep in mind that charge temp, vehicle speed and time-under-boost will also have an effect on boost pressure.

shiv

Shiv,

That kinda proves my point, man. I'm just trying to help you improve the map for higher altitudes, because I know plenty of guys around here who are watching closely before they buy it - given that your testing is generally not done at high altitudes. My data is clearly not the same as the sea level guys.

I've attached my MAP data below. This is a full throttle acceleration run from a dig. 60 degree ambient temperatures. Engine was allowed to cool. 93 octane. I tried 100 octane with little to no difference. The right side is cut off in my screen capture, but at idle, the MAP drops to -2.7 PSI, which just about exactly equals the loss in ambient pressure due to altitude. At sea level, I believe this idle MAP is around 0PSI. ADHD has some data from LACR that shows an idle MAP of roughly -1PSI, which makes sense given the altitude there. His MAP chart has the same "magnitude" as mine. Basically take your MAP curve, shift it down 1 PSI and you get ADHD's curve. Shift it down 2.7PSI (how much less air there is here) and you get my MAP curve.

This is but one data acquisition session. I have about 6 others with precisely the same results. I have tried 1.45 and 1.45 low boost target. This is a consistent result.

My "spike" is about 12 PSI which, when added to the idle MAP PSI, means that I'm about right at the same 14-15PSI peak as you. (This means that there is No compensation for altitude)

My "midrange" is about 8-9 PSI which, when added to the idle MAP PSI, means that I'm right at the same 11.5-12.5 PSI midrange as you. (This means that there is No compensation for altitude)

My "peak" of 6400-6500 rpm is at about 7PSI which, when added to the idle MAP PSI, means that I'm a bit below your 10-10.5PSI PSI peak as you. (This means there is No compensation for altitude)

I'm not trying to attack you, I'm just trying to figure this out. Maybe it's installed wrong? What really confounds me is that 3X5PSI, at 5200 ft. gets the same performance as guys at sea level, indicating that his PROcede 335i is compensating for altitude. Maybe it's because he's got the South African version?

http://www.e90post.com/forums/showpo...7&postcount=16

I took a look at his data and looked at the 70-90mph duration because that period doesn't involve a shift, so driver error is out of the picture. The time it takes him to cover that period is 0.5 second faster than I do, indicating he is getting altitude compensated PSI. I calculated the amount of time it takes me to go from 70-90 by looking at the PROcede data acquisition and figuring out the rpms that cover that speed range.

So Shiv, I'm trying to figure this out. I haven't touched it since you installed it and don't get codes thrown, so I imagine it must be installed right. Do you think perhaps the stock ambient pressure sensor got disconnected somehow or something?

thanks.

[leftcoastman]

Here is ADHD's data:

http://www.e90post.com/forums/showpo...99&postcount=1

[OpenFlash]

What is your altitude?

shiv

[leftcoastman]

These tests were done at 5800ft.

[3X5PSI]

Originally Posted by leftcoastman

What really confounds me is that 3X5PSI, at 5200 ft. gets the same performance as guys at sea level, indicating that his PROcede 335i is compensating for altitude.

I'm not sure that it is. I also struggle to get 12psi (with a -2 at idle). So I doubt I am compensating for altitude.

What I can say is that I am much faster than a stocker & the Procede rocks.

[leftcoastman]

what map are you running? your boost stays high faaar longer than mine or adhd's

[3X5PSI]

Originally Posted by leftcoastman

what map are you running? your boost stays high faaar longer than mine or adhd's

I think that was 1.45. What gear u guys logging. The boost curve looks different in 4th compared to 3rd. I think that was a 4th gear log I posted but I will have to confirm when I get home. Becomes a bit of a problem to get enough road to log to 7000rpm in 4th

[RiXst3r]

Originally Posted by leftcoastman

At sea level, the stock ECU will call for 8.8PSI of boost max. To compensate for altitude, it will increase boost up to 11.8 PSI. There is 3PSI of possible altitude compensation. This is according to the BMW engineer responsible for this engine.

Can you do a log with the PROcede with a STOCK map loaded so that you can verify the altitude compensation?

[OpenFlash]

As mentioned earlier, there are hardware limitations involved (max turbo flow capacity and pressure ratio limitations. And this all comes into play at the 5000'+ altitude that we are talking about here.

The PROcede does not, in any way, deactivate the altitude compensation. Any reduction in boost is explained by th aforementions hardware limitations as well as the factory ECU attempting to keep the turbos from overspinning. It is possible to eliminate this last limitation but the long term implications of running a turbo that hard is expensive.

shiv

[Terry335]

Originally Posted by shiv@vishnu

As mentioned earlier, there are hardware limitations involved (max turbo flow capacity and pressure ratio limitations. And this all comes into play at the 5000'+ altitude that we are talking about here.

The PROcede does not, in any way, deactivate the altitude compensation. Any reduction in boost is explained by th aforementions hardware limitations as well as the factory ECU attempting to keep the turbos from overspinning. It is possible to eliminate this last limitation but the long term implications of running a turbo that hard is expensive.

shiv

I didn't know we had turbine speed sensors, sweet!

[leftcoastman]

3X5, your taper is significantly less than mine. mine drops like a rock after peaking.

Shiv, what you say makes sense -----except for the fact that 3X5PSI is at nearly the exact same elevation as I am and his boost compensation is significantly better than mine. I doubt he was running at less than 60deg F or higher than 93-100octane.

Fact is - his conditions are the same as mine yet mine is not holding boost in the same manner. Any issues with altitude affecting the turbo's capability to supply boost will likely show up at higher RPMs where the CFM flow is higher. At 3000rpm, it doesn't make sense that the turbos can't flow more.

Unless you're telling me that 14psi over ambient is the max this turbo could possibly produce? Even that doesn't make sense. Let's use round numbers and say that the turbo has a max pressure ratio of 2.

If it's a turbo limitation, we should see that ADHD has the same pressure ratio as I do, but that's not the case. He's at a higher ambient but we're still both pumping out around 14PSI. My pressure ratio is higher. If the turbos have that extra capacity as indicated by my higher pressure ratio, why isn't ADHD getting more compensation at his altitude, given that he's got some headroom?

[musc]

Originally Posted by leftcoastman

3X5, your taper is significantly less than mine. mine drops like a rock after peaking.

Shiv, what you say makes sense -----except for the fact that 3X5PSI is at nearly the exact same elevation as I am and his boost compensation is significantly better than mine. I doubt he was running at less than 60deg F or higher than 93-100octane.

Fact is - his conditions are the same as mine yet mine is not holding boost in the same manner. Any issues with altitude affecting the turbo's capability to supply boost will likely show up at higher RPMs where the CFM flow is higher. At 3000rpm, it doesn't make sense that the turbos can't flow more.

Unless you're telling me that 14psi over ambient is the max this turbo could possibly produce? Even that doesn't make sense. Let's use round numbers and say that the turbo has a max pressure ratio of 2.

If it's a turbo limitation, we should see that ADHD has the same pressure ratio as I do, but that's not the case. He's at a higher ambient but we're still both pumping out around 14PSI. My pressure ratio is higher. If the turbos have that extra capacity as indicated by my higher pressure ratio, why isn't ADHD getting more compensation at his altitude, given that he's got some headroom?

Just curious, have you tried running the data logger with the PROcede bypassed to see what the ECU would compensate at 5800ft? Maybe do back to back logs with the PROcede then stock (bypassed).

And from what I have read, the Alpina B3 bi turbo is running 1.1 bar (16.17 psi) on the stock turbos, albeit with lower CR pistons, but still showing the turbos should be capable of higher than 14 psi.

[leftcoastman]

Unfortunately I have V1.01 of the procede software and there isn't a stock map out for it yet.

I have already deleted V1.0 and I can't find it anywhere.

[Terry335]

I'd suggest going to pep boys and picking up a $30 boost gauge to measure boost. Just run the line inside your window and take it off when you're done. Then measure boost stock, and with the procede, to get a real idea of what is going on. If you can borrow scanning software to monitor IAT that will give you a round-about way of knowing how far out of the compressors efficency range you are.

I don't think this is an issue of the DME requesting a specific boost level and the hardware not being able to keep up, that would throw a limp mode code. I'm sure the turbos will make 20psi if we attenuate the map signal enough, we'll just wind up with 300 degree inlet temps and melted ringlands.


*edit maybe Shiv will compensate you for your data, it will save him a lot of time also.

[musc]

Originally Posted by leftcoastman

Unfortunately I have V1.01 of the procede software and there isn't a stock map out for it yet.

I have already deleted V1.0 and I can't find it anywhere.

I was under the impression that you could install the bypass plug thereby bypassing the PROcede and taking it back to stock.

Here is the post Shiv made with the original reader and stock map.

http://www.e90post.com/forums/showth...highlight=v1.0

[RiXst3r]

Originally Posted by leftcoastman

Unfortunately I have V1.01 of the procede software and there isn't a stock map out for it yet.

I have already deleted V1.0 and I can't find it anywhere.

it is still on vishnu's server... they just removed the link...
http://www.vishnutuning.com/Files/BM...er_Install.zip