with the aem ecu do you still need a three bar map if so at what psi?

Yes, if you plan on boosting over 16.8psi.

Chris, He used that setting because He probably zeroed the PFC before He tuned the car. If You play around with the setting the PFC can be set to zero, BUT if it is zeroed all the fuel maps will change.

Hi Sub, the offset is set to zero. It is showing .06-.07kg/cm^2 (nearly 1 psi) of boost with the car off, and when the PFC shows 15.33psi my other two boost gauges indicate 14.01 and 13.98. Even if I zero the sensor with the offset function it's still 1/3-1/2 psi off.

Dee and I are discussing this problem. He has apparently used this setting with all the cars that he tunes and has verified that it is accurate on several occasions. However, most of the people I have spoken to have the value set to 41800. Is this one of those cases where there is more than one right answer? Does anybody know what these numbers represent?

Assume I want to start from scratch and come up with a value to enter without using trial and error.


Agreed. I'm not going to implement any changes until we do some more tuning.

Ok, I can't get my datalogit to work to make these setting changes. How bad will the car run without the scale and offset changes? I can go to option 2 via the commander, but I can't even get the car to run good enough to drive out of the garage.. And the boost readings on the commander are all over the place.. ?

Is the datalogit 'not communicating' with the ecu? If so try unplugging the datalogit box from the ecu and reconnecting it with the ecu turned on.

It's actually "interface not responding". But I have tried just about every combination of plug/unplug, on/off tricks I can think of.. Thanks for the response Chris. :)

Interface not responding well discussed on Datalogit Yahoo group
 

If you are a registered datalogit user, you can get lots of assistance on the Yahoo group that supports it. This error has been discussed many times and appears to be com port setting related. If you don't make the settings via datalogit, the options on the commander will only work with the Apexi 3-bar, not the GM unit, and even then they need to be adjusted ever so slightly.

Beast

back from the dead
 

Ok, I just installed my gm 3 bar map sensor as per instructions in this thread. I have a couple of issues regarding the values inputted to set this thing up. Like the original map sensor I am seeing 33mmhg with key on and car off. I used 41800/0 for my numbers. This is resulting in a slight vacuum reading according to the pfc. Much the same way as the stock sensor read before I adjusted the offset. The problem is that the pfc will not let me input an offset # lower than 0 to bring that 33mmhg back to 0. The stock sensor uses a really high # for offset which allows you to go up or down. The gm 3 bar is already at 0 so I can ony raise the setting which puts me further into vacuum. As mentioned above, someone has played with the scale but without knowing what this does, I do not wish to experiment on a new motor.

As an aside. The before and after power difference from changine the map sensor is unbelievable. I know it should't make a difference but I noticed a substantial increase in power from just changing out the stock map sensor. My gut would say that it must have been malfuctioning. However, It always tracked propperly and the voltages were in spec. I relaly do not see anything wrong with it. The only difference from before and after install was the vacuum reading being back at 33mmhg. For the longest time, I have been running with stock map reset to read zero. After putting in the gm and driving it with out recalibrating it the car drove like a totally different animal. Power and torque are up. The car pulls harder all the way to redline and comes out of the hole stronger.

Someone should try putting their stock offset back to its original value and see what happens for comparrison.

I have always known that the PFC was off. I can watch my boost gauge read 17/18 lbs. but the PFC reads 1.10 bar.

mr rx7 you ever get any results with the new mazda 2mm seals
my engine was fine we did ~10 pulls 22psi was the most

I only had two motors that had any problems. One we found was running 15 plus psi without premix or oil injection. (Can't blame the seals) The other is tuned to high 10's (afr) working oil pump and it did have warped seals.

I believe Mazda had a small batch of bad seals or they changed their manufacturing process because they were aware of the warping problem after it was brought to their attention.

Chris

anyone know a good source for in stock official Apexi plug and play 3 bar map sensors? its kinda crunch time :(

Why not just use the GM sensor with connector? I know Gotham stocks them, and there is a rightup on installation here on the forum.

agree to Goodfella, why to spend more money for something which work the same way, when you can get this lot cheaper?

I use both sensonrs on my cars. My FC running PFC has an apexi 3BAR map sensor installed (this one comes with the PFC as a kit made for FC from AP) and on my FD I'm using GM3 BAR map sensor with connector I got from ATP turbo. I see no issue with both of sensors, except the GM unit is not a direct plug in, but the installation took me about 10 mins to splice the wires and set the setting on PFC as well to mount the sensor.

From the point of view about the function, both sensors are fine and will provide all you need to go past limitations of a stock unit.

They are many places to get the GM unit for about 70 USD. Check atpturbo and summitracing.... just as example.

hope this help.

REgards
Iwan

If you don't wish to do the install steps these other fella's have described, I got mine via Motorsports Dynamics in Sacramento. It took a while, but the cost wasn't much more than what is being quoted for the GM unit. That was about three years ago, however. I started with the PFC but now use the Wolf 3D unit since my tuner is the West Coast distributor, and it calibrates just fine.


Beast

MSD also has a 3 bar with connector for less than the GM unit. Though it looks like and I have heard its a reproduction of that GM unit.

+1
http://store.streetspeedusa.com/5055.html

yes... ive been on the path in the past of getting the gm map sensor. im just spending a lot of money on my new setup and im not going to go cheap on a map sensor. its a very important part of the system.

Now that is some interesting info. If that is correct, for those who plan on driving their FD into areas with extremes in altitude, or those who live in areas such as that, the apexi sensor would be a good choice.

What if I take the Apexi 3bar from my AVC-R and plug that in and use that for the PFC and then just tap off of it for the AVC-R......any issues with that?

i knew it was money well spent... take that haters :)