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      03-05-2009, 03:52 PM   #45
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The questions about "spiking" were answered
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      03-05-2009, 04:11 PM   #46
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Quote:
Originally Posted by dadasracecar View Post
So I question your boost control - for lack of a better term - logic and now I have "absolutely no understanding about the basic fundamentals of engine theory." That's a little out of left field wouldn't you say? Especially considering you haven't really answered any questions with anything but complete BS, e.g. "natural pumping efficiency of the engine."
Actually it sounded more like a "challenge" than a question.

Perhaps that explains the reaction?
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      03-05-2009, 04:27 PM   #47
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instead of maintaining a flat boost curve (or as flat as the efficiency of the turbos will allow for) which might mean more torque in various areas - i think shiv was trying to achieve a very smooth and flat torque curve - like stock but more potent.

this does lead to a pleasurable driving experience.

most flash tunes for the 2.0tfsi vw engine ring the turbos neck down low where it is capable of almost 2.5x the stock boost - and the end result is a mountainous toruqe curve that quickly tapers off. sure it makes the car more powerful in some areas but when driving you get a huge rush of acceleration followed by a feeling of "what now?" as opposed to that of an engine with a very flat torque curve whos response and character are similar at almost any rpm/load range.
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      03-05-2009, 04:38 PM   #48
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Originally Posted by mwahlert View Post

most flash tunes for the 2.0tfsi vw engine ring the turbos neck down low where it is capable of almost 2.5x the stock boost - and the end result is a mountainous toruqe curve that quickly tapers off. sure it makes the car more powerful in some areas but when driving you get a huge rush of acceleration followed by a feeling of "what now?" as opposed to that of an engine with a very flat torque curve whos response and character are similar at almost any rpm/load range.

What you describe is Exactly what I experienced with my GTI


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      03-05-2009, 04:49 PM   #49
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Quote:
Originally Posted by dadasracecar View Post
So I question your boost control - for lack of a better term - logic and now I have "absolutely no understanding about the basic fundamentals of engine theory." That's a little out of left field wouldn't you say? Especially considering you haven't really answered any questions with anything but complete BS, e.g. "natural pumping efficiency of the engine."
An engine's pumping/VE efficiency curve is BS?

I'll try this again. This engine is designed (head design, cam profile, bore/stroke, etc,.) to be biased towards max low end torque. In fact, assuming a flat boost curve, peak torque occurs at the point at which peak boost is reached. Which, depending on boost pressure is at 1900-3000rpm. At 15psi of boost, at 3000rpm, the engine will make upwards of 400lbft of torque at that engine speed. No sense in that. Just unnecessary strain on the engine and trans. And tough to support on pump gas. So we only run 10-11psi in the low end, gently tapering upwards to 12-13psi in the midrange and then up again to 14-15 up top. And then down again sharply above 6600rpm. The end result is a nice flat torque curve with great top end power. This is the benefit of mapping a boost curve that complements the VE curve of the engine. I've tried to break this down as simple as possible. If you still think I'm full of BS, then you are just a troll

Shiv
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      03-05-2009, 05:03 PM   #50
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I don't think he meant : "Why are you not boosting X psi all the time".

We pretty much all know the boost targets differ at various rpm (barring new forum members)...

I think he meant : "Why does the boost curve look like high frequency noise"

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      03-05-2009, 05:13 PM   #51
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If we go back to the data logs, what would the difference be in horsepower ut 80 vs 90?
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      03-05-2009, 05:18 PM   #52
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Nope, he was claiming that boost should be held constant at every rpm. If you watch the cp-e video, they show themselves doing just this... holding exactly the same psi throughout the whole rpm range.


Quote:
Originally Posted by scheherazade View Post
I don't think he meant : "Why are you not boosting X psi all the time".

We pretty much all know the boost targets differ at various rpm (barring new forum members)...

I think he meant : "Why does the boost curve look like high frequency noise"

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      03-05-2009, 05:34 PM   #53
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Originally Posted by jpsimon View Post
Nope, he was claiming that boost should be held constant at every rpm. If you watch the cp-e video, they show themselves doing just this... holding exactly the same psi throughout the whole rpm range.
Hmm, that [cp-e] actually sounds pretty cool.

I bet you feel more lag/rush, with a way bigger punch.

I wouldn't mind seeing a tune that tries to peg the boost at the beginning, just for the "BAM" factor.

Then us AWD folks could launch crazy hard.

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      03-05-2009, 05:37 PM   #54
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but as explained in this thread, you'd hit peak torque right away and then it would drop off quick. That isn't ideal

Quote:
Originally Posted by scheherazade View Post
Hmm, that [cp-e] actually sounds pretty cool.

I bet you feel more lag/rush, with a way bigger punch.

I wouldn't mind seeing a tune that tries to peg the boost at the beginning, just for the "BAM" factor.

Then us AWD folks could launch crazy hard.

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      03-05-2009, 06:08 PM   #55
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Quote:
Originally Posted by jpsimon View Post
but as explained in this thread, you'd hit peak torque right away and then it would drop off quick. That isn't ideal
Well, it wouldn't be as rewarding feeling (emotionally) to rev higher up...
But in reality it's not like you'd be accelerating less up top, you'd just have more down low.
(I for one love a car that can buck hard from the get-go)

But the fact remains, that : massive initial torque + AWD + sticky tyres + (assuming your drive train will hold up) = absolutely sick 60'

Granted you could just rev the piss out of the car [without that initial torque] and use a lot of clutch modulation... Which is probably better in the long run since a clutch is cheap to replace.

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      03-05-2009, 07:07 PM   #56
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Quote:
Originally Posted by shiv@vishnu View Post
An engine's pumping/VE efficiency curve is BS?

I'll try this again. This engine is designed (head design, cam profile, bore/stroke, etc,.) to be biased towards max low end torque. In fact, assuming a flat boost curve, peak torque occurs at the point at which peak boost is reached. Which, depending on boost pressure is at 1900-3000rpm. At 15psi of boost, at 3000rpm, the engine will make upwards of 400lbft of torque at that engine speed. No sense in that. Just unnecessary strain on the engine and trans. And tough to support on pump gas. So we only run 10-11psi in the low end, gently tapering upwards to 12-13psi in the midrange and then up again to 14-15 up top. And then down again sharply above 6600rpm. The end result is a nice flat torque curve with great top end power. This is the benefit of mapping a boost curve that complements the VE curve of the engine. I've tried to break this down as simple as possible. If you still think I'm full of BS, then you are just a troll

Shiv
And this is why I prefer a user tunable solution. Where you might not see any sense in 400lbft of torque, I might really want that. Additionally I don't think the turbos can support 15 psi for any significant length of time as that is double the factory boost pressure. I certainly think that is too much at high rpm. Again, that is me and that's why I prefer to tune my car to my spec. Should I be proven wrong about the turbos, I'll be able to adapt my tune accordingly.

This isn't really about the VE of the motor. The thread and my comments were directed toward the PROcede's lack of controlled boost. Your tune fluctuates =/-2 psi throughout the rpm range. That's a variance of 4 which is poor, if any, boost control.
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      03-05-2009, 07:19 PM   #57
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Quote:
Originally Posted by dadasracecar View Post
And this is why I prefer a user tunable solution. Where you might not see any sense in 400lbft of torque, I might really want that. Additionally I don't think the turbos can support 15 psi for any significant length of time as that is double the factory boost pressure. I certainly think that is too much at high rpm. Again, that is me and that's why I prefer to tune my car to my spec. Should I be proven wrong about the turbos, I'll be able to adapt my tune accordingly.

This isn't really about the VE of the motor. The thread and my comments were directed toward the PROcede's lack of controlled boost. Your tune fluctuates =/-2 psi throughout the rpm range. That's a variance of 4 which is poor, if any, boost control.
Enjoy tuning your car!
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      03-05-2009, 11:00 PM   #58
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ok so let me get this straight.
1. Out of the blue, boost that jumps up and down is 'the thing to have' in order to keep the tq curve flat. Dialing constant boost means no unexpected changes. It seems odd to have to retune fuel/timing ect for erratic boost, odd unless thats how the stock ecu does it and its too much of a pita to have to make custom maps for every1 who experiences problems.

2. Its just irony that the the stock curve is identical?

3. This jumping boost is measured in the manifold but not seen on a boost gauge. So, pardon the dumb question, but where does the boost go? Boost is boost. Either the gauge is not quick enough to pick up the boost accuratly or the source for those graphs is wrong because last time i checked, once boost leaves the turbo and heads towards the ic, it remains constant. It later looses a pound or two through the ic and remains constant untill it is ingested.
This has been explained many times before by others more qualified than me. A boost gauge reads the true intake manifold pressure, while the procede reader is reading the sensor in the intercooler charge pipe BEFORE the throttle body. So, if the throttle body closes some, then there will be a pressure gradient and the two will not be equal. This is why you see a pressure spike when datalogging during shifts because the throttle body closes and causes increased pressure in the intercooler charge pipe.

I'll turn on valet mode and do a datalog of that so we can compare the "stock" boost curve to the PROcede boost curve. But, it'll have to wait until this weekend. I'll drive around a little bit first to let the ECU adapt. It should be interesting...
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      03-05-2009, 11:12 PM   #59
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Quote:
Originally Posted by usc335 View Post
This has been explained many times before by others more qualified than me. A boost gauge reads the true intake manifold pressure, while the procede reader is reading the sensor in the intercooler charge pipe BEFORE the throttle body. So, if the throttle body closes some, then there will be a pressure gradient and the two will not be equal. This is why you see a pressure spike when datalogging during shifts because the throttle body closes and causes increased pressure in the intercooler charge pipe.

I'll turn on valet mode and do a datalog of that so we can compare the "stock" boost curve to the PROcede boost curve. But, it'll have to wait until this weekend. I'll drive around a little bit first to let the ECU adapt. It should be interesting...
The throttle body closing pressure spike happens when the TB closes abruptly - like in a shift when you lift off of the pedal. That's why you see the spike in the cp-e boost log graph.


The PROcede graph shows a boost pressure climb to 16 psi and holding there before dropping off. That is not TB related.



I can't wait to see your datalog.
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      03-06-2009, 02:12 AM   #60
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Quote:
Originally Posted by dadasracecar View Post
And this is why I prefer a user tunable solution. Where you might not see any sense in 400lbft of torque, I might really want that.
Quote:
Originally Posted by shiv@vishnu View Post
Enjoy tuning your car!
This is why a while back when Shiv was first showing the user adjustable settings, I asked for a spline editor for the boost curve.

Basically something like how you set levels on your stereo.
You increase/decrease your low frequency volume, or mid volume, or high volume. Just have the same thing for boost. Frequency = rpm, decibels = boost.

If procede had this, then you'd just adjust your boost targets as you wish.
You want more down low? : Knock yourself out...
You want to taper less? : Have fun...
Just a simple set of sliders that anyone born after 1980 would intuitively know what to do with...

ex.
http://www.gersic.com/plugins/plugim...d!10_thumb.jpg
http://thumbs.dreamstime.com/thumb_2...5288a08a62.jpg
http://media.arstechnica.com/guides/...p4-1curve2.jpg

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      03-06-2009, 04:15 AM   #61
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Just a simple set of sliders that anyone born after 1980 would intuitively know what to do with...
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      03-06-2009, 07:57 AM   #62
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Quote:
Originally Posted by shiv@vishnu View Post
I don't know what modern turbo engines you've seen lately. But they don't have flat boost curves. Neither does the stock n54. Yet somehow the torque curve looks smooth. In fancy talk, that's an example of employing a boost profile that complements the engines VE (fancy talk for pumping efficiency.). Good day.

Shiv
Here are a few modern turbo engines I've seen lately. They do have flat boost curves... This took all of 2 minutes to find. Seems the general rule to try and get a nice flat boost pressure and tune the car around it.






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      03-06-2009, 08:45 AM   #63
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Lol.....those scales are even flatter than the Procede software graphs.

What about the boost curve for the 2.0 FSI? It's anything but flat.

But you conveniently sidestep that one because it doesn't serve your cause, yet the 2.0 FSI platform represents a large portion of the Audi/VW fleet currently out there.

Trying to use statistics to prove a point is akin to a bikini......they reveal a lot, but cover up the essentials.



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      03-06-2009, 09:09 AM   #64
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dadasracecar,

with all due respect, please take the discussion about the superior cp-e tune to another thread. I believe it deserves it's own discussion thread.

Thank you.
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      03-06-2009, 09:24 AM   #65
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dadasracecar,

with all due respect, please take the discussion about the superior cp-e tune to another thread. I believe it deserves it's own discussion thread.

Thank you.
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      03-06-2009, 10:27 AM   #66
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This is an interesting read...
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