Detuning a Zetec with Webers running Megajolt Lite Jr.

[Sonus]

I have just been told that my local SVA has approved my engine swap in my MGB:woohoo:
I'm using a Zetec running Weber 45DCOEs and igintion controlled by MegaJolt Lite Jr. otherwise stock engine.
This set up should produces something in the region of 160BHP, however I am only allowed the standard Mondeo 136BHP. So I need to detune the engine for testing purposes at the SVA and then restore the correct ignition values for 160BHP after it's been tested :liar: Can this be done through advancing the ignition only? And how safe will this be? The fueling will stay the same as for 160 BHP so I guess the engine will be running rich for the testing. Can this easily be spotted by the SVA?

Or do I need to have the carbs set up for 136 BHP and then have it set up again after I'm done the testing?

[Zetec_Escorts]

I will probably be better to fit smaller chokes to the carbs.

[graham bahr]

how will they know what power you have? wil it be subject to a rolling road power test?

trying to loose 24bhp with ignition timing alone would sem rather a dangerous thing to do to me, the engine would have to be either massively adavnce or retarded so much so your be in danger of wrecking it,

i presume you still have to pass an emmissions test? in which case you are going to be rather in difficalty, because again it will be hard to loose so much power with jetting and have the engine run cleanly, you could try fitting some 34mm chokes, idle mixture would be ok but it would be go rich at high revs.

the simplest and nicest way to hold back the power is to adjust the throttle linkage or stops so the carbs dont open fully, the jetting and mapping an stay as it is now and there will be no risk of an damage to the engine

[Sonus]

how will they know what power you have? wil it be subject to a rolling road power test?


If they suspect it has more power they will demand a power run on the rollers

i presume you still have to pass an emmissions test?

No, even though the engines newish the car's too old to be subjected to a emissons test :)

the simplest and nicest way to hold back the power is to adjust the throttle linkage or stops so the carbs dont open fully, the jetting and mapping an stay as it is now and there will be no risk of an damage to the engine


Basically not letting the engine breath properly and therefor limiting the power?

[dangerousdave]

You could always set the limiter low aswell as limiting the throttle. Zetecs are peaky and make their power high up around 5500-6000rpm (without looking at my graph for the exact place) so were you to limit the revs using the ecu to around 5000rpm and limit the throttle travel i recon you could be well under, you can get them to check when you are at the rolling road getting it set up :thumb:

[graham bahr]

Basically not letting the engine breath properly and therefor limiting the power?
__________________

yeah, if the engine only gets 3/4 throttle it will never make full power, i cant see them taking your filters and ram pipes off so they can look up the carbs with a mirror to see if you get full throttle

[graham bahr]

You could always set the limiter low aswell as limiting the throttle. Zetecs are peaky and make their power high up around 5500-6000rpm (without looking at my graph for the exact place) so were you to limit the revs using the ecu to around 5000rpm and limit the throttle travel i recon you could be well under, you can get them to check when you are at the rolling road getting it set up :thumb:


they might smell a rat though if the rolling road it and find a rev limiter at only 5K

[seventynine]

spud up your exhaust :D

[Sonus]

Axel Foley style :lol: