NGK AFX vs. AEM 30-0300 CAN Comparison

[Gelf VXR]

That has been one of the advantages of using teh MPVI with the 30-0300 w/ the OBDII re-flash. The MVPI will record CAN data ( if present ) even on pre-CANBus cars. So, everything stays synched.
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I have an E40, pre-CANbus, EFILive FSV2 and two LC-1's, using stream fast mode with 24 pids I can log at 10 frames a second / 10hz. Serial and annologue inputs are polled at the same rate. The LC-1 serial out is 12hz or anologue out is instant, 1/12, 1/6 or 1/3 with offset compensation, serial is better because FSV2 can only poll 10hz?

The AEM 30-0300 can eliminate offsets completely, and in independent testing its response time is 20ms. I think I read that you have said the aem has T63 time ~10ms and the Lc-1 ~20ms, if I am correct, this is response time between the sensor and the aem gauge / LC-1 controller.

The question I'm trying to answer is what I have already optimum with the E40 PCM, or whether I could consider upgrading to two aem and HPT MPVI to log 24 pids at higher than 10hz, I think I read elsewhere that the MPVI can poll 100 Hz or would I still be limited to 10 Hz of the class 2 network of the PCM? Can you connect two aem to the CANbus?

[dr.mike]

As far as I know, only the HPTuners MPVI can log CANBus data simultaneously with pre-CAN protocols like J1850, etc.

I read that you have said the aem has T63 time ~10ms and the Lc-1 ~20ms, if I am correct, this is response time between the sensor and the aem gauge / LC-1 controller.

That is the time it takes for the sensor and controller, together, to get to 63% of the proper reading. For example, if lambda suddenly went from 1.00 to 2.00, the t63 time is how long it takes for the reading to catch up and get to lambda 1.63 . It takes about 2 and a half times as long to get to 90% ( Lambda 1.90 ) etc.

From my own measurements, the 30-0300 is about 10ms and the LC-1 is around 17ms for t63. The independent lab included the solenoid opening time in their measurements, which adds about 10ms to all of the units tested. Which seems to work out about right.

What I, and some others here, have found is that there is much to be gained by logging at higher polling rates. Specifically, with the 30-0300, 100Hz works especially well. I'm pretty sure this is because of what I call "cell velocity". This is the rate at which changes in RPM and manifold pressure cause the current "cell" of the VE map to change. If the current cell changes 30 times a second, then lambda data from 100ms ( @10Hz ) ago can be 2 or 3 cells off.

The question I'm trying to answer is what I have already optimum with the E40 PCM, or whether I could consider upgrading to two aem and HPT MPVI to log 24 pids at higher than 10hz, I think I read elsewhere that the MPVI can poll 100 Hz or would I still be limited to 10 Hz of the class 2 network of the PCM? Can you connect two aem to the CANbus?

I think the polling rates are independent, per channel. But, obviously, the ECU limit still applies for those channels.

Yes. Multiple AEM gauges can connect to the CAN bus. Specifically, this would be th 30-0333 version of the AEM gauge ( OBDII version ). Depending on your setup, you may need to add in a terminating resistor ( 68ohm ). But, that should be easy

[Gelf VXR]

Is anyone using AEM 30-0333 with an E40 that can confirm the polling rates of the wide band on the CANbus vs other pids on the J1850 VPW connection?

[Michael_D]

How does this thing work if it plugs into the OBDII port, and you also have the HPT interface that needs to plug into that port?

What do I need to order? I'm a bit confused by the different part numbers, as shown on AEM's website, and what you see on vendor websites. I think the 30-0333 is the newest gauge version, but what's that come with?

[schpenxel]

They don't do a good job of showing it, but I'm almost sure the cable they include allows you to plug the WB into the OBD port then HPT into the WB. Kind of like this connector. It's called a "pass through" connector. Ignore the bare wires, etc. on the right.. this is just meant to show the connector itself.




https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


Page 2 of the manual

http://www.aemelectronics.com/files/...tion%20Kit.pdf


Worst case you'd need an OBD Y cable off Amazon or eBay

[Michael_D]

Thanks! I had no idea such widgets existed.

[Trackman101]

They don't do a good job of showing it, but I'm almost sure the cable they include allows you to plug the WB into the OBD port then HPT into the WB. Kind of like this connector. It's called a "pass through" connector. Ignore the bare wires, etc. on the right.. this is just meant to show the connector itself.




https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


Page 2 of the manual

http://www.aemelectronics.com/files/...tion%20Kit.pdf


Worst case you'd need an OBD Y cable off Amazon or eBay

I am considering 2 30-0333's. I would need a splitter or a couple right angle adapters to make it all connect compactly. Would it slow down the response time?

[schpenxel]

The adapters won't make any difference---whether having two connected will effect response time, I have no idea. Dr.mike might know

[dr.mike]

Technically, you would not need a splitter cable. As the pass-thru connectors can be "stacked". But, a chain of pass-thrus can be a bit unwieldy.
Adding a splitter will not affect transfer speed. And, will probably make the installation cleaner.

[Trackman101]

Thanks for the quick response guys!

[10_SS]

Since I was hiding all the wires and Gauge anyway, I peeled back the two wires for Can H and Can L and soldered direct. Also thinking about cutting the constant 12v wire on the OBD connector and running it to switched 12v. That always drives me nuts for many reasons..

#1 being when you plug the OBD cable into the MPVI box while the other end is in the OBD port and your short out the constant always on 12v pin to ground on the MPVI box, blowing a fuse, and usually leaving you without ability to tune or scan. And yes this is because I bought a 2nd cable and burried it under all the trim so the MPVI sits under the drivers seat, all tucked away.

#2 being that is drains your battery being plugged in like that.

#3 There is no reason for this.

[10_SS]

Somewhere there was someone asking about the accuracy of the MPVI analog inputs... this is something I put together last year playing around using a calibrated power supply.., I dont question the error shown is the MPVI since the power supply used goes clear through 22volts, and only tested 0-5v, and you can see how the MPVI falls off above 4.5v. The power supply was verified to be under 0.3% error overall, and 0.1% or below between 0-5v shown here. I used to wonder why it was SOO heavy yet it only supplies 2amps MAX power... well now I know why.

Analog Input Accuracy.PNG

[Michael_D]

I want to buy one of these. Is there a particular part number or kit I should be looking at? I would like the latest/greatest version.

[schpenxel]

30-0333 Is what you want

[GHuggins]

Schpenxel, yours ever show? Mine's been on order for a couple weeks now and still doesn't show to have shipped... Just wondering - I want to do some comparisons with it - won't be 100% accurate since it will be in a different bank, but never the less Anything that helps, is accurate and will hold up is good in my book...

[schpenxel]

Mine finally shipped Friday.. Going to be here today actually

Will probably be this weekend before I can install it though. I'm hoping to do the same comparison...

[Michael_D]

Where did you guys order them from? Direct?

[schpenxel]

I got it off amazon but it shipped direct from aem

[Michael_D]

Thanks.

Checked and found it. Then got the typical "cannot ship to your address". One of the joys of living in Alaska - shipping. Oh well, I'll find it somewhere else.

I want to compare it to my NTK-AFRM.

[gmtech16450yz]

Thanks.

Checked and found it. Then got the typical "cannot ship to your address". One of the joys of living in Alaska - shipping. Oh well, I'll find it somewhere else.

I want to compare it to my NTK-AFRM.

Off topic but where do you live in Alaska Michael? Our daughter is a dispatcher/911 operator in Fairbanks. She and her husband actually like it up there. Not many places you can be sitting in your living room and see a giant moose casually walk through your front yard! The worst part for her is how hard it is on their car and truck.