Stepper motors
Discussion
Although the Cerb hasn't got any, the MBE unit sitting in the car seems quite happy to be driving four of them.
I was sitting thinking last night what I could press them into service for on the car, and thought I might open the discussion up to the Cerb collective.
I thought after seeing the Cerb at brands with the aerofoil on the back that he could use them to have a speed sensitive angle on the foil.
Excuse my ignorance but does this mean all RV8 engines have an MBE as well. If so were they graunched by TVR from standard?
I was sitting thinking last night what I could press them into service for on the car, and thought I might open the discussion up to the Cerb collective.
I thought after seeing the Cerb at brands with the aerofoil on the back that he could use them to have a speed sensitive angle on the foil.
Excuse my ignorance but does this mean all RV8 engines have an MBE as well. If so were they graunched by TVR from standard?
GreenV8S said:
julian64 said:
Excuse my ignorance but does this mean all RV8 engines have an MBE as well. If so were they graunched by TVR from standard?
English translation?Also we know the MBE941 was altered to suit the Cerb. If other TVRs are running them were they altered to suit them?
julian64 said:
GreenV8S said:
julian64 said:
Excuse my ignorance but does this mean all RV8 engines have an MBE as well. If so were they graunched by TVR from standard?
English translation?Also we know the MBE941 was altered to suit the Cerb. If other TVRs are running them were they altered to suit them?
For the AJP V8 the version of the box of electronics changed from 941 to 955 and later still the 967 I think. But the EPROM seems not to have changed that much (apart from the maps)
The AJP MBE uses shift light for rad fan and a spare ouput for the shift light. It also uses the oil pressure and intercooler spray drive for the air con ack/req functions. It also doesn't recognise anything other than 1 or 0 for the target lambda map - something done deliberately whilst they were developing the lambda adaptation of the standard 941. I think also there was some jiggery pokery to get the correct ignition offset since the ECU type is set to a value that isn't recognised by the standard Easimap configs. So an AJP8 Cerb definitely won't work with a standard MBE.
The speed six Cerbs had a later variant of the 941 (955?). I haven't investigated the speed 6 ECU at all. I'd like to have a look at the EPROM and the harness to see if there is much in the way of differnces to a standard MBE.
Think we are getting our wires crossed a little. No pun intended.
The Cerb MBE I have no current questions about. The thread was merely started to indicate there is a lot of unused potential in the MBE on the Cerb.
I have no idea what ecu the rest of the TVR world is using as I am getting a little Cerb focused here and am likely to move away from the marque rather than upgrade to an S6 engined anything.
Interesting you should mention the lambdas though. Sitting here at work at the mo, but remember from last nights work that the lambdas go through a buffer, then into a multi in/out select and finally one of the AtoD's on the processor. The interesting point was that at no point did the wiring to the processor preclude the ability to input wideband. The software therefore seems to be responsible for converting the voltage signal to a 1/0 not the hardware.
However I did rather wonder what a normal MBE looked like inside. Does it have an eprom NVRAM combo, or are they both NVRam. Is the map on the normal MBE in the NVRAM. Can the slave port function on the processor be made to alter the map?
I'm afraid I'm 90% there now on the circuit diagram but nowhere on the program yet. One rather follows from the other with me
The Cerb MBE I have no current questions about. The thread was merely started to indicate there is a lot of unused potential in the MBE on the Cerb.
I have no idea what ecu the rest of the TVR world is using as I am getting a little Cerb focused here and am likely to move away from the marque rather than upgrade to an S6 engined anything.
Interesting you should mention the lambdas though. Sitting here at work at the mo, but remember from last nights work that the lambdas go through a buffer, then into a multi in/out select and finally one of the AtoD's on the processor. The interesting point was that at no point did the wiring to the processor preclude the ability to input wideband. The software therefore seems to be responsible for converting the voltage signal to a 1/0 not the hardware.
However I did rather wonder what a normal MBE looked like inside. Does it have an eprom NVRAM combo, or are they both NVRam. Is the map on the normal MBE in the NVRAM. Can the slave port function on the processor be made to alter the map?
I'm afraid I'm 90% there now on the circuit diagram but nowhere on the program yet. One rather follows from the other with me
Hi Julian
I was just speculating on whether the Speed6 version was closer to standard than the AJP8 version.
The Lambda conversion from voltage to a value is definitely done in the software. The standard MBE has an option for selecting the type of Lambda which points it at the appropriate graph to map the voltage to a Lambda reading.
The generation of the desired (target) Lambda is definitely different to the standard MBE since the TVR version of the software only responds to 0 and non zero in the target map.
Its also possible the TVR version doesn't support the alternative Lambda sensors.
AFAIK the std MBE is the same as the TVR one - EPROM and NVRAM
I was just speculating on whether the Speed6 version was closer to standard than the AJP8 version.
The Lambda conversion from voltage to a value is definitely done in the software. The standard MBE has an option for selecting the type of Lambda which points it at the appropriate graph to map the voltage to a Lambda reading.
The generation of the desired (target) Lambda is definitely different to the standard MBE since the TVR version of the software only responds to 0 and non zero in the target map.
Its also possible the TVR version doesn't support the alternative Lambda sensors.
AFAIK the std MBE is the same as the TVR one - EPROM and NVRAM
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