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Installing Shift Lite

3K views 18 replies 7 participants last post by  cyow5 
#1 ·
Tried this under electrical and received no responses.

I am installing a shift lite on a 2011 Exige. I am wondering where I can pickup a tach signal in/around the dash.

Where are you guys picking up the Engine RPM signal for your data systems?

Thanks,
Eldon
 
#3 ·
I had to do an MSD pickup off my #1 coil pack. Im glad I ran extra wires when I did the oil pressure gauge.
 
#6 · (Edited)
Like Gunpilot, I use the same MSD module to pick up the rpm signal from #1 coil pack. The wire harness is routed from the engine bay, through the shifter cable opening, under the back panel carpet behind the driver's seat, under the driver's side sill and into the dash area. I installed a Shift-I light recessed into the instrument binnacle (Dremel).

The Shift-I serves as a volt meter pre-ignition, and the light sequencing is fully programmable.

For me, it is a nice thing to have and has been a helpful tool on track since the display is easily picked up through my peripheral vision.
 

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#7 ·
I have purchased the same shift lite. I just hate to only pickup one ignition pulse because, from the data signal process side, it sucks. I use to design and sell motorsports data loggers so I always hated this approach. I take it that the MSD module is an inductive pickup or is it piercing the wire?

Later,
Eldon
 
#9 ·
Thanks for the suggestion but Lotus did not use any of the "Vendor Option" lines for Tach, MPH, etc. They did use one for the ABS and one for SRS(Seat Belts).

There must be a crank or cam trigger on this motor. I will have to check that out.

Thanks,
Eldon
 
#10 ·
Thanks for the suggestion but Lotus did not use any of the "Vendor Option" lines for Tach, MPH, etc. They did use one for the ABS and one for SRS(Seat Belts).



There must be a crank or cam trigger on this motor. I will have to check that out.



Thanks,

Eldon

Try gunpilots method first - those signals are shielded. If you introduce noise to them, you could realistically do some damage


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#12 ·
Subscribed for future modifications to my car...possibly. :D
 
#14 ·
Actually, that is not correct. The CAN bus in our cars update around 10Hz. Picking up one injector or plug pulse @ 6000 RPM is 50 Hz. The only difference is that some filtering will have to be done with the pulse because of variations in the actual pulse frequency. The advantage of using a microprocessor is that you can factor in acceleration to do some predictive shift lite alerts.

Later,
Eldon
 
#15 ·
The OBD is a bit slow, but the primary CAN bus is faster and around 500Hz (I think. I have the dbc file sitting around here somewhere so I can doublecheck. I know it was either 125,250,500 or 1,000). Edit: mixed up Mbps and Hz. I believe the frequency is more like 100. Still need to check though

Let's say it was slower at 10Hz, the factory shift light is ran by that CAN, too, so a light tapped into that bus would at least be no worse than the factory light.


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#16 ·
The 0x400 messages that run the dash are indeed only broadcast at 10Hz. I think that's just fine for shift lights... I guess some people disagree!

p.s. the datarate is 1Mbit on older cars and 500Kbit on the newer black dash cars. I'm pretty sure they made it slower to support OBD-over-CAN scantools. The older cars use K-line for the OBD-II diagnostics so using the faster CAN speed and breaking tools didn't matter for them, although they never sent enough to come close to saturating 1Mbit anyway...
 
#17 ·
My file doesn't have an 0x400 message - it has engine speed at 50Hz on a different channel, so I think we are looking at different buses. I have files for the ABS module, so that deals with engine speed at a higher (naturally). This also only applies to the Bosch ABS cars, and I'm not sure what year they changed over. I got this file from a friend who just knew I had a Lotus, so he didn't have much info on it, so I don't know a lot of the specifics.


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#18 ·
My file doesn't have an 0x400 message - it has engine speed at 50Hz on a different channel, so I think we are looking at different buses. I have files for the ABS module, so that deals with engine speed at a higher (naturally). This also only applies to the Bosch ABS cars, and I'm not sure what year they changed over. I got this file from a friend who just knew I had a Lotus, so he didn't have much info on it, so I don't know a lot of the specifics.
Man, that would be awesome! Sadly...

Bosch ABS unit first fitted at VIN: BH_10931. (the powertrain can be identified by the letter ‘X’ as the 7th digit of the vehicle VIN) Note; there are no changes to the 1.8 litre 2ZZ Elise or Exige range.
The good news is I'm feeling inspired by this thread and am going to build a set of lights run off of the diagnostic port. I'll post when I have something working!
 
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