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S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 4:53 am
by SMR
Hi All,
Wondered if anyone can help?
My car runs a total-loss power system so the wideband system I've installed is powered by it's own 12v battery (triggered by a relay to turn on when the ECU is on) to avoid a drain on the main engine battery.

Is there any way i can monitor/log this additional 12v supply in my S100 to keep an eye on when I need to remove and charge the WB battery?

Looking at the analogue input settings, I appear to be only able to input 0-5v so this wouldn't work.

Any ideas?
Cheers
Steve

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 5:37 am
by Rob Stevens
Steve, you could make a potential divider made out of say 1 1000ohn and 1 3000ohm resistor across the 12v supply and feed the centre tap back to the ecu for logging. You would need to calibrate the response somehow and also ensure that the ground is common.

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 5:57 am
by SMR
Cheers Rob - I had thought of doing something like that but was hoping for an almost plug-and-play option.
The battery lasted all weekend at Harewood no problem, so it probably boils down to just making sure it's fully charged before each event.

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 6:19 am
by Rob Stevens
I think I've said this before, just fit an alternator :)

I know there is little room however, perhaps from the diff or final drive sprocket if you can't get on the crank.

Is the sequential all working ok?

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 8:50 am
by SMR
We never got the sequential going - the base mapping took a while and we ran out of time (slightly aided by finger-trouble/lack of experience with the DTA). The cam sensor is working though - nice repeatable trace on the scope test so the plan is to get the car on a rolling road at sometime over the summer and finish the mapping.
We couldn't fit my airbox or exhaust system on the dyno which will also alter the mapping needs.

I've been logging lambda from the WB and have played wth the fuel map accordingly; Fintray this weekend will be an experimental meeting to play with the fuel map.

I also need to play with the gearchange settings as it does kick a bit when engaging the next up gear; I suspect I'm using too much ignition retard (65 deg) so plan to try reducing this.

And no chance of me fitting an alternator................not until the mapper can convince me I'm losing spark power due to low voltage. Just too much added weight and complication for the moment. As it is, the new ECU and gearchange kit has added 3kg's to the car.

Steve

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 8:57 am
by Rob Stevens
3kg when the car only weighs about 38kg is a large increase. I did suggest to Alex that he offers a lightweight ecu without the same environmental protection, i.e next to no case to save weight as the case does look substantial.
Regarding the gear change try the option to make it come back on softly via the ramp retard feature

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 2:10 pm
by stevieturbo
A 38kg car ????

Re: S100; monitoring another 12v supply?

Posted: Wed May 16, 2018 4:32 pm
by SMR
Rob is taking the piss a bit - the weight addition is just over 1% (For those mathematically challenged, the car weighs in at 219kg fully wet and ready on the line). A bit of a coincidence; each front corner weight is 38kgs!

Rob - I'll try the ramp-up feature first before reducing the full retard value and see how I get on.

The new loom for the Raptors was 1/2kg lighter than than the combined MBE/Geartronics one, but my old loom was already pretty minimal. Just that the S100 is 3 times the weight of the old MBE967 and the new gearchange hardware is also slightly heavier.

Re: S100; monitoring another 12v supply?

Posted: Sat May 19, 2018 1:50 pm
by SMR
Rob - I tried a 100ms ramp-up time today (still with 65 degree retard) which did help with smoother upchanges.