Omex Wiring

[neil a]

I know its been covered before but never seen a post with a direct answer so dont flame me

Im going to be running a Omex 600 ecu so as far as i can make out the ecu will run semi stand alone needing

Direct Live
Switched Live
Earth
Coolant Sensor
Air temp Sensor
Lambda Sensor
Piggy backed into the CPS

What does the standard ecu still run.

Fuel pump
Fans
Dash


When removing the standard wiring is there anything that needs joined to complete a circuit ,or is it just a case of cut and cap all the unused wiring with shrink wrap individualy then tuck it back into the covering.


So far i have pulled all the unused (injectors,map sensor,air temp sensor,carbon canister )wiring back to the rear of the engine bay and had planned to terminate it here.

 

[Chip-mk1]

You can also choose to either leave the standard ECU running the dephasor or you can run that from the Omex, the latter being better IMHO as then you can alter the cutover point of course.

 

[neil a]

Thanks Chip I take it you would use the Aux 2 output rather than the VTech function on the ECU so you can set a cut in and cut out point.

 

[Chip-mk1]

If you are going to statically advance the inlet cam (which I would advise) you need to be able to turn it off at high RPM.
I cant remember off hand if the VTEC wire will let you do that or not, I dont think so though, Im pretty sure we used Aux2 on porkies, but it was Mike that wired it not me.

 

[Michael Woodford MST]

V-tec- The dephaser will become live at a set RPM/ Throttle angle and will stay live to the limmiter
Aux-2- The dephaser will become live at a set RPM/ Throttle angle but you can then switch it off again before the limmiter. You also have the option to leave it live the whole way.

id use Aux2

 

[Cup_Phil]

Aux2 - that's how my omex 600 is running my dephaser

As for the wiring - you're right the only thing you need to do is splice 2 wires off the TDC sensor onto the old loom - so that the standard ecu can run the rev counter
The standard ecu powers the fan (though that can be controlled from the Omex if you add 2 more wires into the omex loom and run them to the fan relay), and dashboard.

I pulled all my standard wiring back to where it comes from the main trunk at the back of the gearbox and just chopped it off. Taped it up to make it look a bit neater.

 

[Michael Woodford MST]

Aux2 - that's how my omex 600 is running my dephaser

As for the wiring - you're right the only thing you need to do is splice 2 wires off the TDC sensor onto the old loom - so that the standard ecu can run the rev counter
The standard ecu powers the fan (though that can be controlled from the Omex if you add 2 more wires into the omex loom and run them to the fan relay), and dashboard.

I pulled all my standard wiring back to where it comes from the main trunk at the back of the gearbox and just chopped it off. Taped it up to make it look a bit neater.

I always join the omex loom in the hairbrush. that way you can use the standard cars relays for powering up the Injectors and coil with 12v

It also keeps the loom neat and just looks standard.

 

[Cup_Phil]

Yeah - I don't really trust the standard loom, after taking mine apart some of it is quite nasty lol

Plus my plan is to bin all the standard loom and ecu, run a race tech dash off the omex.

 

[Chip-mk1]

If you are doign that, then TBH you could just as well bin the entire lot and not run the standard one at all as its a race car, and just run the fuelpump direct off the omex too.

and the fan you can either run from the omex as well, or just use a basic temperature switch in the rad to flick it on as its only in the pits it will matter.

 

[Cup_Phil]

Yep that's what I'm doing - fan and fuel pump from omex, full loom getting binned. Probably gonna keep the rear loom for the lights and the front lighting loom - and wire them into a fuse/relay box inside

The amount of wiring in the Clio is insane when you all you need is lights/indicators etc..

 

[Dan519]

Vtec output never works properly on the 600

 

[Michael Woodford MST]

Vtec output never works properly on the 600

In what way Dan? Can't say I've ever had an issue with it.

 

[Silent_Scone]

If you still need mine I'll send it out today for you recorded, I'll let you know what the postage is and we'll call it that!

 

[Dan519]

In what way Dan? Can't say I've ever had an issue with it.

Lazy phone typing..... Doesn't work properly on clios. no hysteresis control for switches etc. Was also told not to use it as there was a glitch in the code but can't remember details (talking a few years back now)

 

[Cup_Phil]

If you still need mine I'll send it out today for you recorded, I'll let you know what the postage is and we'll call it that!

Is that a loom for sale?

</vulture mode>

 

[neil a]

Im already on it Phill :rasp:

 

[neil a]

Just waiting on my loom turing up from Omex today hopefully, one think I havent checked is what Lambda sensor is needed to work with Omex?

Also does anyone have a calibration for standard engine with cams, jenvey 48's I could use to drive the car to be mapped(10 miles) Omex are sending me out a start up map so I can check everything is wired and working.

 

[Cup_Phil]

The lambda sensor I use is from a ph1 172 - it plugs straight into the plug on the omex loom
I can try and rummage out a part number/ebay link if you want - it was cheap and it's an NGK one

When I got my ecu it had a map for a 182 on 48's - my mate took a load of ignition advance off of it to make it nice and safe for me to drive on until I got it properly mapped - happy to send you that if you want. It's not for cams but as long as you keep the rev's low it should get you there

Have you got a wideband and gauge fitted at all? I find it very handy for keeping an eye on the mixture - just in case

 

[neil a]

Ive not got a wideband Phil I sold all my guages when I got rid of my cosworths.
I had heard a MK1 16v lambda plugs straight in so that may well be the same one used on the phase 1, if it is my mate has one lying that I will get tonight.
If you could email me that map that would be great, my plan is hopefully get the car started this weekend on the omex, balance the bodies then fit the cams and timing belt next week, before dropping it off for mapping.

 

[Cup_Phil]

That's the one sorry yes - Mk1 16v - like the williams style

http://www.lambdasensor.co.uk/main/ntkprice/price.pl?item=OZA446-E8

It's a 3 pin plug and plugs straight into the omex loom
Lambda is optional - some people map without them, but it's massively beneficial for getting it through an MOT and for low revs fuel economy
Mine has lower emissions now than it had when standard on tick over lol

 

[Dan519]

That's the one sorry yes - Mk1 16v - like the williams style

http://www.lambdasensor.co.uk/main/ntkprice/price.pl?item=OZA446-E8

It's a 3 pin plug and plugs straight into the omex loom
Lambda is optional - some people map without them, but it's massively beneficial for getting it through an MOT and for low revs fuel economy
Mine has lower emissions now than it had when standard on tick over lol

saying it's optional isn't sensible. It's as important as an air temp sensor IMO,

 

[Cup_Phil]

Most of the mappers I've spoken to disagree with that - in fact Omex themselves recommended I didn't bother with it

It's only used sub-4k rpm to trim the fuelling for better economy. If you're mapping the car for performance than the lambda sensor isn't really required.
Ran mine for 3 months without one - the car I took the bodies from ran for 3 years without one lol

In fact when I had mine mapped the mapper told me the Lambda control on the omex is so s**t it's causing a few problems with very low rpm running. He said if I wanted it to be smoother I'd be better off ditching the Lambda but then I might struggle with MOT's

 

[Andyrg@ ClioTurbo]

i wouldn't bother with the Lamb, if its mapped correctly and ran in closed loop it should be fine. ive nver ran this as always had a Wide band fitted tho

 

[Chip-mk1]

saying it's optional isn't sensible. It's as important as an air temp sensor IMO,

Couldnt disagree more, lambda is useful for economy on part throttle cruising but an air temp sensor is important at full throttle for both peak power and reliability

Car mapped well with air temp and no lambda = fuels well at part throttle and well at full throttle in all temps
Car mapped well with lambda and no air temp= fuels perfetcly at part throttle and badly at full throttle at some temps


Lots of us were managing to get cars run very well and very reliably long before we had access to closed loop lambda control, its a nice addition but its far from essential unless economy is your primary concern.

 

[Dan519]

i wouldn't bother with the Lamb, if its mapped correctly and ran in closed loop it should be fine. ive nver ran this as always had a Wide band fitted tho

closed loop IS lambda controlled

 

[Dan519]

Most of the mappers I've spoken to disagree with that - in fact Omex themselves recommended I didn't bother with it

It's only used sub-4k rpm to trim the fuelling for better economy. If you're mapping the car for performance than the lambda sensor isn't really required.
Ran mine for 3 months without one - the car I took the bodies from ran for 3 years without one lol

In fact when I had mine mapped the mapper told me the Lambda control on the omex is so s**t it's causing a few problems with very low rpm running. He said if I wanted it to be smoother I'd be better off ditching the Lambda but then I might struggle with MOT's

that's a very out dated outlook. Yes it can do it, just as you can do without lots of other things, but it doesn't make it good or correct.

Sounds like your mapper struggles with the settings of the omex closed loop control, it's more complex than some systems as every setting is available rather than being defaults hidden from adjustment, but there's no reason it wouldn't run smooth with lambda if set right.

 

[Chip-mk1]

closed loop IS lambda controlled

I just assumed he meant run in OPEN loop and just made a typo TBH

 

[Cup_Phil]

that's a very out dated outlook. Yes it can do it, just as you can do without lots of other things, but it doesn't make it good or correct.

Sounds like your mapper struggles with the settings of the omex closed loop control, it's more complex than some systems as every setting is available rather than being defaults hidden from adjustment, but there's no reason it wouldn't run smooth with lambda if set right.

Lol he doesn't struggle with anything. He's a mapper for btcc, wrc etc cars
I don't see the point in lambda other than for better fuel economy and emissions

 

[Chip-mk1]

Lol he doesn't struggle with anything. He's a mapper for btcc, wrc etc cars
I don't see the point in lambda other than for better fuel economy and emissions

On high mileage road cars its useful for applying fuel trims as components wear etc, but on a performance orientated car on aftermarket its only use is those things you mention.

There is NO downside to it though, so while I obviously dont agree with Dan's statement thats its more useful than air temp correction (which he probably said in haste and doesnt even agree with himself I suspect, as he isnt that daft really im sure) I do agree with him totally that its better to have than to not have, if only for better economy driving to and from tracks etc.

Can anyone name a downside to closed loop fuelling under lambda control? Cause I cant personally, other than obviously taking a small amount of time to add, and a small amount of cost to add.

 

[Fred@BTM]

Twin webbers

 

[Chip-mk1]

Twin webbers

Yuck

Outdated and thirsty, and so are the carbs you are talking about.


With fuel prices the way they are these days, I cant understand why anyone would want carbs over bodies unless they have to do so for some motorsport rules etc.

 

[Fred@BTM]

comedy - you missed it

 

[Cup_Phil]

Lol

I agree lambda is worth doing for the extra £30 but its not necessary for mapping. You could add it in after

 

[Chip-mk1]

Lol

I agree lambda is worth doing for the extra £30 but its not necessary for mapping. You could add it in after

Ideally the car should be mapped to run as well as possible on open loop so that lambda corrections are kept to a minimum, so not a problem at all if the mapping is done first, in fact it should always be done with the lambda disabled anyway.

 

[Andyrg@ ClioTurbo]

Sorry i ment open loop always get muddled id as chip says have things like that installed before

 

[MG cup]

So its possible to remove all oe engine loom, just leaving a power feed to the interior part and you will be left with a basic engine loom & leaving the standard interior loom controlling lights and you can cut down interior loom to leave only lighting circuit getting rid of UHC/UCH whatever its called.

I have a omex race loom with fan control relays added in and a crank signal splitter also

 

[Chip-mk1]

Why not just fit an aftermarket dash and bin the standard ecu completely?

 

[MG cup]

£££'s for a start, will come to a total of around £1500 maybe some more with dash,sensors, interior loom rewire and then there's time aswell.

Running the engine purely on omex with just starter wires and basics left of standard loom and then using a chopped down interior loom for lighting and ignition circuit should work right?

is the uch passable without a rewire?

 

[neil a]

Final question hopefully

I got my loom through eventualy from Omex and the cam phase is just a single wire, wired into aux 2 on the ecu.
I called omex today and they said that this is a switched ground so I would need to run in another wire from an ignition fed live. Im going to cut off the orignal plug and crimp this onto the new wiring what colour is the original live to this plug?