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Thread: B14 ECU differences?

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Posts: 11-15 of 15
2016-06-27 13:22:06
#11
B14 ECU differences?
If you cover the outer ring CAM sync it will not know TDC Compression vs Exhaust and sequential fueling I suspect will not work.. Not a big deal I think but far from correct .. Would not work with a COP setup as timing is either on or not .. As far as the speed to the ECU all that other BS about IACV adjustments at speed is not the case and it does it by RPM if it was by speed rolling stops would never be a problem with SRs and we know that's not the case ... You talk about boost by gear is not a fiction of stock operations and would assume he has a tunable solution and this question would never have came up ...


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2016-06-28 07:49:07
#12
Originally Posted by shagspeed
If you cover the outer ring CAM sync it will not know TDC Compression vs Exhaust and sequential fueling I suspect will not work.. Not a big deal I think but far from correct .. Would not work with a COP setup as timing is either on or not ..


Yep, it's only CG engines with classical distributor system that can be modified this way.

Originally Posted by shagspeed

As far as the speed to the ECU all that other BS about IACV adjustments at speed is not the case and it does it by RPM if it was by speed rolling stops would never be a problem with SRs and we know that's not the case ... You talk about boost by gear is not a fiction of stock operations and would assume he has a tunable solution and this question would never have came up ...


Sorry, but I was just answering to your post higher up that I bolded: "an engine doesn't need to know speed for any reason to run an engine" which is very untrue. We wouldn't want to go around spreading misinformation, speed is a very usable thing to feed into an ECU. It's just the stock ECU's that don't really do anything useful with the info.

Other things you can use speed input for:
-Fuel consumption calculation. L/100Km(mpg) can only be calculated if speed is known.
-Launch control. Limit RPM until x speed is reached.

Speed input is the shit! I'm currently working on a GPS speedometer conversion for 90's Nissans. Gone are soon the days where you had to match a specific cluster ->speedometer sensor.
2016-06-28 12:09:09
#13
Originally Posted by Storm88000




Cool man thanks for the info. With a 97 ECU in my 98, I'm getting two codes: 10, 3 (park/neutral switch) and 7,7 (rear 02 sensor) which is expected since its not connected. The park neutral switch code may have something to do with my B14 having a B15 trans in it.

The neutral switch of your trans outputs a path to ground to pin 22 of the ECM when the trans is in neutral. You can wire the B15 neutral switch to the original neutral switch wiring.
2016-06-28 13:57:40
#14
B14 ECU differences?
Originally Posted by Dala
Originally Posted by shagspeed
If you cover the outer ring CAM sync it will not know TDC Compression vs Exhaust and sequential fueling I suspect will not work.. Not a big deal I think but far from correct .. Would not work with a COP setup as timing is either on or not ..


Yep, it's only CG engines with classical distributor system that can be modified this way.

Originally Posted by shagspeed

As far as the speed to the ECU all that other BS about IACV adjustments at speed is not the case and it does it by RPM if it was by speed rolling stops would never be a problem with SRs and we know that's not the case ... You talk about boost by gear is not a fiction of stock operations and would assume he has a tunable solution and this question would never have came up ...


Sorry, but I was just answering to your post higher up that I bolded: "an engine doesn't need to know speed for any reason to run an engine" which is very untrue. We wouldn't want to go around spreading misinformation, speed is a very usable thing to feed into an ECU. It's just the stock ECU's that don't really do anything useful with the info.

Other things you can use speed input for:
-Fuel consumption calculation. L/100Km(mpg) can only be calculated if speed is known.
-Launch control. Limit RPM until x speed is reached.

Speed input is the shit! I'm currently working on a GPS speedometer conversion for 90's Nissans. Gone are soon the days where you had to match a specific cluster ->speedometer sensor.


Speed is not a function for the ECU to care about .. Traction control systems , boost control systems are all external devices from an ECU though you may find other external systems on the same PCB as the ECU doesn't mean it's required .. My point is that the ECU doesn't care about the car speed and all those don't need to be in the ECU they can work as external systems with the most simplest of ways handing ECU info to the external devices is CANBUS .. I do this with the ECUs I build ..

As far as external GPS Speed to the ECU .. There's many ways to do this and I have already done this .. Just I recommend using a 10Hz GPS for better update speed ... Best of luck ..

If you want a quick solution look at this ... It should work just fine http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=837/category_id=646/mode=prod/prd837.htm

Also I think your on the right track .. GPS is way better as it doesn't see wheel spin like the flawed method of trans sensor ... Though you could also use rear wheel speed sensors on the ABS hubs .. We do this to measure front vs rear speed as traction control


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2016-06-28 16:44:23
#15
Originally Posted by shagspeed

Speed is not a function for the ECU to care about .. Traction control systems , boost control systems are all external devices from an ECU though you may find other external systems on the same PCB as the ECU doesn't mean it's required .. My point is that the ECU doesn't care about the car speed and all those don't need to be in the ECU they can work as external systems with the most simplest of ways handing ECU info to the external devices is CANBUS .. I do this with the ECUs I build ..

As far as external GPS Speed to the ECU .. There's many ways to do this and I have already done this .. Just I recommend using a 10Hz GPS for better update speed ... Best of luck ..

If you want a quick solution look at this ... It should work just fine GPS Speed/ Compass Sender/ BIM

Also I think your on the right track .. GPS is way better as it doesn't see wheel spin like the flawed method of trans sensor ... Though you could also use rear wheel speed sensors on the ABS hubs .. We do this to measure front vs rear speed as traction control


Now we are on the same page!

The Dakota piece is nice and all, but that price is way above what most on this forum would pay. My simple atmega version will only cost 5% of that piece...

Using rear wheel ABS hub info would be another way, but would need some filtering for sure before you feed it into an microprocessor. I went with the GPS to create something that anyone could put together, so it wouldn't be exclusive to people with ABS equipped cars.

But now this is getting way offtopic, so I'll continue rambling in my other thread.
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