So all the evidence says that you were hitting 27 psi with your new boost profile on 91 octane?

 

Hell would freeze over before an Evo will hit 27.5 psi on 91 pisstane and not knock. You will have to run negative timing numbers and be pig rich to do that. And even then it will knock.

 

First off, calibrating it wasnt rocket science, and I knew how to do it, I just didnt know it was a "calibration" which is why bryans wording threw me off. Subtracting atmospheric pressure from absolute to get a gauge pressure is far from complicated, you learn that in 9th grade chemistry . And last time I checked, I didnt need to ask for instructions on how to do it, the equation is pretty elementary. I learned subtraction when I was 4

Anywho did you both to look at the log or what else I posted? Im hittin 27-28psi earlier in the rev range, tapering to 22psi-22.5 or so at redline. I'm also running ecu-boost control, but for the 28psi run tbecs were turned off and I'm also using a 3-port solenoid that you don't know anything about

There was some minor knock, but without you knowing my afr or timing how can you assume that I would be knocking at all?

Thanks but no thanks for trying to belittle me, I came in here to see if anyone else had issues with high reading JDM map sensors, not to start a fight with you on what boost levels are possible on 91 octane fuel. The fuel itself does not limit boost, its afr and timing that determine ultimate knock threshold, without those 2 tidbits of data how can you be 100% sure that you are correct in your assumptions that i MUST have somehow calibrated this "plug and play" sensor incorrectly, even though it reads dead on while the car is a idle and turned off.

 

It was rich (not pig rich), timing was not negative, and it only knocked from 5k on

Is hell freezing yet?

Im still a bit skeptical myself, so I will use a semi-conductor grade digital pressure gauge to cross reference this

 

Yes..funny things happen when you turn of tbecs

I will still double check again

 

mrfred,

attached are the 4 logs with JDMMAP and GMMAP. It is in dif format. You can view them in excel. Consistently the JDMMAP reads higher than the GMMAP.

 

3-4psi higher?

 

Personally, I'm finding the data coming from the JDM boost sensor to be causing a bit of a relevation in terms of what boost levels an Evo IX can take. I can think of 5 people now who are boosting past 26 psi on a regular basis with no issues. Granted, most of them are not using 91 octane, but as you said timing and afr contribute here too. (And several of these people have confirmed their readings with other boost gauges.)

Looking forward to the double check with the other gauge, but with the data you've presented thus far, I'm confident that your other gauge will confirm the JDM MAP sensor readings.

 

Why are you playing hide the ball? Post the log so we can see what the AFR and timing are.

Well if you believe that you can boost to 27.5 psi, then by all means keep doing it. More than likely that 27.5 psi is around 26 psi and you got lucky by not knocking.

Go out keep the same alleged 27.5 psi setting and do back-to-back-to-back logs and then post them so we can see them. Hoepfully, your car would still be running.

Once again, POST THE LOG and stop hiding the full picture from us.

 

I looked at the logs. What I am finding most interesting is that when you let off the gas at the end of a run, the GM MAP sensor is reading about 0.75 psi less than the JDM MAP sensor. Do both sensors read 0 psi with your direct LM-1 measurement with key on / engine off?

 

I do not have the GM MAP on my car right now. I am using it to tune two other Evos. I really do not remember off the top of my head. I will put the GM MAP back in the car and check for you.

 

Here is more from Klaus on the proper monuting of a MAP sensor:

"But it does explain it if the GM sensor is logged via the same logging device and its input filter. So the same filtering applies no matter what sensor you hook up.
If the JDM sensor is mounted directly in the manifold, and the GM or whatever sensor is hooked via a hose, the same applies as well. The connection hose damps down peak spikes. If a MAP sensor is mounted in the manifold, you will often see pressure peaks from the pressure waves in the intake manifold. The peaks will be RPM dependant as the pressure wave peak location in the manifold changes with RPM. As the Evo ECU makes its decisions MAF based, I am pretty sure it does not do fancy engine cycle dependent oversampling or crank angle based sampling of the sensor. It just gets the momentary value when it samples, no matter what it is. Most of the MAP sensor ICs I have seen (which are used by the various MAP sensor manuf.), can resolve pressure frequencies up to about 1 kHz. That's faster than needed for most engines. Also, when their linear range is exceeded, they tend to show LESS pressure than actual, not more. A pressure spike in the manifold, as explained, depending on the dynamics of the gas flow, can actually be a few more PSI at the sensor location than the engine sees as end pressure when the intake valve closes. Which is what really matters.

- Klaus"

https://www.evolutionm.net/forums/sh...3&postcount=48

Hi,

The FPR pickup location is actually a very good spot as it is carefully selected by the OEM to reflect the true manifold pressure during the injection process. Otherwise the fuel pressure would fluctuate a lot as well. Just make sure that the T-off connection to the sensor is as short as possible. You don't want resonances in there that would affect the actual fuel pressure. Best would be to T off as close to the manifold connection as possible.

- Klaus

https://www.evolutionm.net/forums/sh...3&postcount=51

 

No. Simply NO

I have nothing to prove to you or anyone else, and I'm not HIDING anything, I came here looking for help WITH THE BOOST SENSOR, not to be attacked by naysayers. I'd prefer not to post the timing maps because they are not 100% my own. AF was not rpm referenced so its not as meaningful as I want it to be. I can post knock count if you want (i never said it was completely knock free).

You can naysay all you want, I will reverify on my own. BTW..where did you come up with this 1.5psi offset? First it was 3 or 4...now its 1.5?

I know you and I have got into it in the past, but you dont have to attack me needlessly when I simply came in here looking for help WITH THE SENSOR ITSELF. So far you have offered none, you have only said that

1) I calibrated it wrong
2) I logged it wrong
3) Its not even possible (so which is it, not possible, or poor calibration?)
4) Then RUDELY demanded I post full logs, when the questions are simply about the boost sensor, and not my map in general

And not once did I say I wanted to hit 27.5psi, if that was the case, I wouldnt be in here posting asking about the sensor. And I wouldnt have posted new logs showing the car hitting 23psi

Relax man, seriously

 

Yeah, it is all my fault. Here in Ecuflash people tend to post their logs and not one variable out of the log so the reast of us know what is going on.

Do whatever you want. But do not make claims that you have not thoroughly verified and from a single unsubstantiated snippet of data. That is all we see from your log; a snippet of data.

Read what I said earlier. The JDMMAP sensor was off by ~ 1-1.5 psi due to pressure spikes from the manifold that the sensor is mounted on. I presented the raw data for all to see. You can read the raw data with logworks if you have it. Logworks can open dif files.

1. Well, you did calibrate wrong. Razorlab had to show you how to do it.
2. I do not know if you logged wrong, because you did not and would not post the log.
3. I assumed that you were running rich (I said pig rich) and running negative timing, because you would not post the log. I was close and the car did knock which you conveniently hid in the Evoscan chart. How convenient?

If you want people to give you a full answer, then you have to proivde them with a full spectrum of data.

 

double post..see next page