Region: WDCR
Car #: 04
Year : 1993 Posts: 519
Status: Offline
posted
Back when I raced my Factory Five Cobra, I rigged the master switch with a fused jumper that would provide a constant 12v to the ECU even when the switch was off.
Is this necessary or beneficial for an SM?
-------------------- Lee Tilton 1993 Meowta #04 Brimtek Motorsports/ Team Four Racing Team Four Racing
Region: chicago
Car #: 72 and ?
Year : 90 and 90 Posts: 1051
Status: Offline
posted
It would not be legal
-------------------- Advanced Autosports, The Midwests leader in Spec Miata Service, Parts and Rentals 608-313-1230 Authorised Spec Miata service center www.advanced-autosports.com
Region: WDCR
Car #: 04
Year : 1993 Posts: 519
Status: Offline
posted
Well I was looking for the technical answer, but it looks like we will go down the legality road instead. (where is the can-o-worms icon?)
In a stock configuration, the ECU has constant power. If anything, interrupting the power to the ECU via master switch would seem to be construed as modifying the circuit and therefore illegal.
-------------------- Lee Tilton 1993 Meowta #04 Brimtek Motorsports/ Team Four Racing Team Four Racing
Region: chicago
Car #: 72 and ?
Year : 90 and 90 Posts: 1051
Status: Offline
posted
The power is turned off by the master switch by design. Installing "a fused jumper that would provide a constant 12v to the ECU even when the switch was off" would be the illegal modification.
My initial reaction would be that you are doing something to the ECU that requires constant power. But your reason could also be inocent.
Dave
-------------------- Advanced Autosports, The Midwests leader in Spec Miata Service, Parts and Rentals 608-313-1230 Authorised Spec Miata service center www.advanced-autosports.com
Region: WDCR
Car #: 04
Year : 1993 Posts: 519
Status: Offline
posted
quote:Originally posted by davew:
My initial reaction would be that you are doing something to the ECU that requires constant power. But your reason could also be innocent.
Dave
It is very innocent. My EFI 5.0 did not like being reset due to power disruptions. It would have to "re-learn" some mapping/trims in order to idle well. I just wondered if the SM ECU was similar.
-------------------- Lee Tilton 1993 Meowta #04 Brimtek Motorsports/ Team Four Racing Team Four Racing
Region: Houston; SWDIV
Car #: 15
Year : 99 Posts: 680
Status: Offline
posted
Lee,
It won't do any harm to take power off the ECU. I have always taken the power off by turning off the master kill in all of my 4 SMs over the years. Never an issue.
-------------------- James York
sponsored by: Stan's Auto Center, Lafayette LA powered by: East Street Racing, Memphis TN set up guru: Gilfus Racing, Austin TX
Steven Holloway
Blue Eyes, Aquarius, hates being squeezed to the grass in SowDiv!
Region: Lonestar
Car #: 97
Year : 91 Posts: 740
Status: Offline
posted
You could also just leave the master switch on and turn the key off...just like stock. If it's that large of a concern.
-------------------- If you can't fix it with a hammer, it's got electrical problems.
JIM DANIELS
Guest
Status: Offline
posted
These ECUs will not lose anything by powering down so K.I.S.S.
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