[beepbeep]

Originally Posted by StartupJunkie

With all the time being invested on this debate (by both sides), it would do the community a great justice if this "joint" testing can be done and the results disclosed publically. The problem with just asking Shiv to post his testing results is that it will invariably lead to an arguments questioning its "truthiness" (to borrow from S. Colbert). And then more debate.

I understand that you are busy. But sometimes one just needs to see how much time he invests in arguing in a thread (or multiple threads on the same subject) and realize that just one evening of doing actual joint testing, with proper equipment, suddenly sounds like a good investment in time.

Junk

Again, you guys are trying to ruin this thread with facts. Cut it out!

[Mike@N54Tuning.com]

Originally Posted by Prowess Symphony

With no long term n54s around and the fact that most people arent gonna be keeping their cars into the 100k+ mileage, this debate is useless. Now for those that are keeping their cars a long time, and not on a lease, then you need to do your homework on the technical aspects of each tune, or better yet, not tune at all.

Neither tune has made a n54 fail. Your much more likely to get a hpfp failure from bmw before an aftermarket tunes knock sensor screws things up.

I think there is more than enough data to draw initial long term conclusions. Many JB3 tuned cars have 40-50k miles with the tune, some as many as 80k. The reliability issues for this platform have not proven to be knock related (headgasket, piston rings, etc). It's just a red herring brought up for scare tactics.

The real long term risk with this platform is turbo failure. And in that arena the JB3 offers a more comprehensive two-layer hardware and software based safety system. As time goes on you will be hearing a lot more about engine failure as the result of compressor failure than blown head gaskets or ring lands.

On CPS datalogging, I have plenty of V3 and JB3 logs showing interesting and surprising things. I can bump the thread or repost them here if anyone is interested in discussing them. At the time all the technical gurus seemed to take the week off.

Mike

[mmmotornutz]

Originally Posted by StartupJunkie

With all the time being invested on this debate (by both sides), it would do the community a great justice if this "joint" testing can be done and the results disclosed publically. The problem with just asking Shiv to post his testing results is that it will invariably lead to an arguments questioning its "truthiness" (to borrow from S. Colbert). And then more debate.

I understand that you are busy. But sometimes one just needs to see how much time he invests in arguing in a thread (or multiple threads on the same subject) and realize that just one evening of doing actual joint testing, with proper equipment, suddenly sounds like a good investment in time.

Junk

I'll put it this way, I'de rather spend whatever time I have left after work with my family.

Even if I conducted the test w/ Shiv, people will still have doubt behind the testing methods - debate will still follow. The debate will only end when someone with a JB3 pops a headgasket or puts a hole through a block. That is why I asked Shiv to send the logs to me, for my own education.

You are fairly local, why don't you run the test with him? It looks like he has a JB3 on hand.

[mmmotornutz]

Originally Posted by Mike@N54Tuning.com

On CPS datalogging, I have plenty of V3 and JB3 logs showing interesting and surprising things. I can bump the thread or repost them here if anyone is interested in discussing them. At the time all the technical gurus seemed to take the week off.

Mike

Mike,

Can you bump those threads?

Thanks!

[StartupJunkie]

Originally Posted by mmmotornutz

I'll put it this way, I'de rather spend whatever time I have left after work with my family.

Even if I conducted the test w/ Shiv, people will still have doubt behind the testing methods - debate will still follow. The debate will only end when someone with a JB3 pops a headgasket or puts a hole through a block. That is why I asked Shiv to send the logs to me, for my own education.

You are fairly local, why don't you run the test with him? It looks like he has a JB3 on hand.

Yes but due to the partisan nature of this forum, any resultant findings would likely be dismissed given the tune that is currently in my car. Right or wrong, I will be labelled as a "Procede guy" (or more likely as a more colorful conjuction involving gonads ). Testing with someone on the other side of the argument makes far more sense.

Besides, Ive already run a JB3 in my car. I already know what it does and how it does it. I don't need any more convincing.

Junk

[Mike@N54Tuning.com]

Originally Posted by mmmotornutz

Mike,

Can you bump those threads?

Thanks!

I'll just post the original logs here for reference. The debate focused on whether or not timing drop outs were reduced/prevented with CPS as implemented, and whether timing drops always indicate knock retard. As often happens people were more focused on the colors in the chart than the actual data. Which to me was very interesting. The test car was BMS' 135i with 91 octane fuel, ~100 degree ambient, default Stage 3 maps for the V3 and map 7 for the JB3. Basically aggressive setups on 91 octane fuel in hot weather. Worst possible conditions. The V3 logs do not reflect the timing the V3 is taking out via CPS as the timing advance is read right from the DME. So actual V3 timing is 3-4 degrees lower. In the end, both systems were running almost identical actual timing and exhibited similar drop outs.

Mike

[Mike@N54Tuning.com]

In addition to those logs I just posted, here was some supporting data on the discussion of whether timing drop outs actually represent knock. Or something else. To prove this point I took dynos published by Vishnu themselves and their corresponding logs. It just didn't add up. Serious knock on the logs, yet smooth charts. So there is something else going on here IMHO.

Mike

[bdkevoIX]

oh snap, its a war!

[OpenFlash]

Originally Posted by Mike@N54Tuning.com

In addition to those logs I just posted, here was some supporting data on the discussion of whether timing drop outs actually represent knock. Or something else. To prove this point I took dynos published by Vishnu themselves and their corresponding logs. It just didn't add up. Serious knock on the logs, yet smooth charts. So there is something else going on here IMHO.

Mike

Mike,
Here's the funny thing about tuning: When you know something about it, it all makes sense.

When you are on the top of the MBT curve, torque output is reasonably insensitive within a reasonably wide range of ignition advance.



There are plenty of books on the subject. Not the best substitute for experience but it will do in a pinch.

shiv

[mmmotornutz]

Mike, thank you for the logs! Aside from seeing, at the time, JB3 had better boost targeting control - timing advance from both tunes are fairly similar in profile. That is why I get confused when it is mentioned that the Procede will knock less w/ CPS offset.

What is strange to me is that the timing drops occur roughly at the same spots in the powerband regardless of tune. I saw the same drops in Scalbert's series of logs back when he was testing both the JB3 and V3. The only time I don't see those drops are with the stock timing advance profile.

[Mike@N54Tuning.com]

Originally Posted by mmmotornutz

Mike, thank you for the logs! Aside from seeing, at the time, Procede had better boost targeting control - timing advance from both tunes are fairly similar in profile. That is why I get confused when it is mentioned that the Procede will knock less w/ CPS offset.

What is strange to me is that the timing drops occur roughly at the same spots in the powerband regardless of tune. I saw the same drops in Scalbert's series of logs back when he was testing both the JB3 and V3. The only time I don't see those drops are with the stock timing advance profile.

I thought the JB3 boost control looked better in those logs, as its right under target (but not over) but that stuff is easy to fix/change and wasn't really the focus of the logs. To me the drop outs looked similar and indicate that CPS is not doing what its claimed to do in these conditions. I also found it interesting to see the DME could safely run negative timing advance. It had been suggested that the DME would only pull so much timing and would let knock happen once it got to that floor. These logs showed that was not the case.

Mike

[mmmotornutz]

Originally Posted by Mike@N54Tuning.com

I thought the JB3 boost control looked better in those logs, as its right under target (but not over) but that stuff is easy to fix/change and wasn't really the focus of the logs. To me the drop outs looked similar and indicate that CPS is not doing what its claimed to do in these conditions. I also found it interesting to see the DME could safely run negative timing advance. It had been suggested that the DME would only pull so much timing and would let knock happen once it got to that floor. These logs showed that was not the case.

Mike

Ooops, I meant JB3. I confused the order of the logs.

[usc335]

FWIW from my experience and what others have posted there is always a timing drop at ~4500 rpm on tuned cars. I think we all hypothesize that it occurs there due to the vanos timing shift. But, a stock car doesn't do that. I think most of us that datalog ignore the 4500 rpm timing drop as indication of knock. Now, when it occurs elsewhere, that's a different story.

As far as adaptation and the DME increasing timing making CPS offsets irrelevant, I totally disagree from my personal experience. I did 5 back to back third gear pulls and the timing from 4500 to 7000 rpm were right on top of each other and did not "creep up" to the DME "uncorrected" timing curve. I also believe there is a limit to how much timing the DME can add, so the procede can prevent too much timing advance with the CPS offset (which prevents knock from otherwise occurring).

[mmmotornutz]

Originally Posted by usc335

As far as adaptation and the DME increasing timing making CPS offsets irrelevant, I totally disagree from my personal experience. I did 5 back to back third gear pulls and the timing from 4500 to 7000 rpm were right on top of each other and did not "creep up" to the DME "uncorrected" timing curve. I also believe there is a limit to how much timing the DME can add, so the procede can prevent too much timing advance with the CPS offset (which prevents knock from otherwise occurring).

Interesting observations. Now were these 5, back-to-back, 3rd gear pulls immediately after switching maps or were they fully adapted already? Also could it be that the your timing advance graphs did not creep up because the DME already reached the optimal timing advance?

Your last statement can be true if we assume the DME doesn't advance until it either hits a maximum value or knocks.

[usc335]

Originally Posted by mmmotornutz

Interesting observations. Now were these 5, back-to-back, 3rd gear pulls immediately after switching maps or were they fully adapted already? Also could it be that the your timing advance graphs did not creep up because the DME already reached the optimal timing advance?

Your last statement can be true if we assume the DME doesn't advance until it either hits a maximum value or knocks.

The first 4 were fully adapted and the last one was after I lowered user torque.