UCB

iTrader: (12)

its not a spike like you would suspect from sensor noise. The boost profile actually looks amazing..if I was on C16 . Gonna verify with 2 different boost maps and will install a 3rd party boost gauge tonight to further solidfy

mrfred

iTrader: (50)

See if you can get 2-byte load working as well. It will be helpful in verifying. The IX seems to be able to handle quite a bit of boost at peak spool, esp with conservative timing. I regularly hit 25.0 psi in 4th gear with a middle-of-the-road timing map.

Your boost value at 7000 rpm looks to be about 21-22 psi which is very reasonable for a car with a TBE. (I'm guessing that you have a TBE already).

UCB

iTrader: (12)

Yes..TBE..licp..cone filter..injectors/fp

TouringBubble

iTrader: (2)

I'm re-tuning for my exhaust currently and hit just above 27.5 or so psi the other night with no knock. AFR was ~11.7 and timing was ~4º advanced. My gauge seemed to agree as the needle wrapped the equivalent of about 3 ticks past 1.5 (stock MR gauge). I'm not doubting your readings at all UCB.

mrfred

iTrader: (50)

That's sick! Or better yet, That's Hot! ;-)

nj1266

iTrader: (6)

He is in CA and if he is running 91 octane, then there is no way in hell that the car is boosting to 28 psi.

Also I looked @ the boost in one of my logs in the Evoscan chart and it was smooth and then I looked @ it in DLL and it was all jagged.

If you really want to see the boost profile and wether ther are spikes or not, then plot the numbers in excel.

I have compared countless logs with the JDMMAP and the GM 3 BAR map when I had both of them on my car and there is always a slight variance between the 2 unless you smooth the JDMMAP. That variance could be up to 1 psi in some instances.

Here take a look.



The red trace is the JDM and the green trace is the GM. Both the JDMMAP and the GM MAP are logged directly from the sensors via the LM1/LMA2. Both are perfectly calibrated using numbers from mrfred and GM. Yet the JDM reads 1.29 psi higher @ peak than the GM. That is due to NOISE that is picked up by the placement of the JDM on the intake manifold.

Now here is the same chart with the JDM MAP smoothed by 0.25 seconds. The JDM reads 20.85 psi and the GM reads 20.51 psi. The boost curve on the JDM is smoother and the spikes are less obtrusive.



I know most of you want to believe that you are boosting high, but that is not the case.

Put another MAP sensor on the firewall, calibrated correctly and log both like I have done and you will see the difference.

UCB

iTrader: (12)

I just did some logs at lunch, went back to my old boost profile and got 23 +/- 1psi straight across with afrs <11

UCB

iTrader: (12)

How do you get the JDM map to log in logworks BTW?

mrfred

iTrader: (50)

A few comments/questions:

1) What is the scale in your logs?

2) If the JDM sensor is red, then it appears to be running lower than the GM sensor as shown in the graphs. Doesn't make sense that the values listed in the little window show red higher than green.

3) I don't see a big difference in noise between the GM and the JDM sensors. If the JDM is red, then sure, there is a bit more variability.

4) What do you consider to be the cause of the noise?

5) You suggested that the difference between the two sensors is typically within 1 psi. What is your expectation for agreement between two different brand of MAP sensors?

6) Have you done a bench top calibration on your GM sensor to verify its accuracy?

7) Do you really think a 1 psi difference in your experiments means that instead of UCB's reported 27.5 psi, the boost for his car is actually something like 23-24 psi (i.e. off by 3-4.5 psi?)

UCB

iTrader: (12)

With the last boost profile I posted, thats using the same boost map that read 22-23 psi accross on 2 seperate bay area dynos.

My 2byte was messed up for tha tlog, but on the other log I did with the old map at 26-27psi (revised it slightly), I was hitting 280load accross the boost curve essentitally (hit boost cut at 5k )

nj1266

iTrader: (6)

DL logworks. It is for free. I will send you the logs so you can play with them and figure out the scale.

That does not matter. I have traces that are higher than others but read lower. As you said it is a different scale for each trace. I have no idea what the scale is. Again, DL Logworks and install it on your computer and I will send you the logs so you can view them as you wish to view them.

That chart does not tell the whole story. If you DL Logworks and I send you the logs, then you will have the ability to avg out all 4 logs and put the psi numbers in a 3rd chart so you see the difference. One more time, DL Logworks.

The cause of noise was explained by Klaus in a thread where we first started logging with the JDMMAP sensor. I do not remember off the top of my head what he said, but I am sure you can find it. He recommended placing the MAP sensor away from the intake manifold just like I did with the GM 3 Port MAP sensor.

Edit: Here is the post https://www.evolutionm.net/forums/sh...3&postcount=39

"The "noise" when logging MAP sensors is very dependent on pickup location in the manifold as the natural pumping action of the engine creates pressure pulses. Some Speed-Density based ECUs (not MAF based) solve that either by oversampling the MAP sensor many times through an engine cycle and average the readings though the cycle or they sample at a specific crank angle for each cylinder and average also over the number of cylinder samples."


I do not understand what you are saying

I relied on the data provided by Delphi. I am sure they have done bench top calibration. Plus this GM sensor is so widely used that you can find the data everywhere. I also posted on how to calibrate this sensor. It is in my signature. That was before I got the Delphi data from Eric. Eric also uses a GM MAP sensor (not the same as mine) and I followed the same process that he did to calibrate my sensor.

All I know is UCB did not know how to calibrate his sensor properly (no offense to him), but now we have to believe that his data is accurate!!!! There is no way in hell that his car is boosting to 27.5 psi on 91 OCTANE gas and not knocking or blowing itself to bits.

mrfred

iTrader: (50)

So with these boost settings, the JDM MAP sensor is matching the values measured with the boost gauge at the dyno facilities where you used the same boost settings?

UCB

iTrader: (12)

lol dont insult my intelligence man. We are talking about atmospheric offset, so I was off by .3psi simply because I went and logged it before checking what it was reading.

Its not a real "calibration", as it is subtracting atmospheric pressure such that it reads gauge pressure like most are used too.

How do you explain it dropping back down to 23psi once I turned back to my original boost profile? . So does that mean i'm really running 19-20psi and somehow put down 300whp on 2 different dynos with 19-20 psi, despite both map sensors on both dynos reading..22-23psi?

UCB

iTrader: (12)

Pretty much..maybe .5-1 psi high..but loading on the dyno and loading on the road are not one in the same (and I was going up hill, lol, only shot I had while coming back from lunch)

nj1266

iTrader: (6)

Yeah, but you ddid not know how to do it, and all of a sudden your data is the word of God

Do you really believe that your car is boosting to 27.5 psi on 91 octane gas and not knocking? Do you have ECU boost control? Are you also holding the 27.5 psi to redline and NOT knocking on 91 OCTANE gas!!!! Does that make sense.

Until you hook up another map sensor on your car, place it on the firewall, have a hose attached from it to the manifold, and calibrate it based on manufacturers data and then log it ALONG with the JDMMAP sensor, then and ONLY then I will believe you.