Author Topic: ground wires  (Read 16577 times)

Offline Seight-v8

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ground wires
« on: August 15, 2009, 03:31:25 pm »
hello all,

I am just starting to feel my way and get my head around the vems system.

But at the moment i am starting to build the wiring loom.

Looked a previous posts the try and find the best way to ground the ecu/sensors.

do i need to connect all the power grounds 100mm from the ecu or can i connect them all at the back of the cylinder head with a single ring terminal.

and can i wire all the sensor grounds together again to another ring terminal at the back of the head.

or is this not a good idea.

cheers

scott
Engine:Rover V8 4600cc
Vems Firmware:V1.2.38, GPS, SDcard, LCD & Dual lambdas, Wasted spark, 36-1 trigger, Cam Sync & Bluetooth serial.

http://www.vems.hu/wiki/index.php?page=MembersPage%2FScottRichmond

Offline rob@vems.co.uk

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Re: ground wires
« Reply #1 on: August 16, 2009, 04:39:28 am »
All grounds, power and sensors, need to join at a common point 100 to 120mm away from the VEMS, you then need to have a single thick wire lead from the common point to the grounding point - your suggestion of using the head is a good one as long as the rest of the block is grounded well.

Offline PeepPaadam

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Re: ground wires
« Reply #2 on: August 16, 2009, 12:30:55 pm »
My best practice so far has been using five 1.5mm2 ground wires, twist and soledr them together 100-200mm from VEMS and run them together to head. Connected sensor grounds to sensor GND wire a little bit closer then the main connection point and VR sensor ground as close as possible to VEMS.

It's a very easy way and so far proved to be very reliable (Audi V8 with sequential injection and passive COPs running in dual_out without a hitch).

Offline dnb

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Re: ground wires
« Reply #3 on: August 16, 2009, 06:36:45 pm »
My sensor grounds are all tied together very close to the VEMS, but the power grounds all go to a set of ring terminals on the back of the left hand head.  They are only 250mm long, so it was not worth having the extra joins.  (Joins are bad for reliability)