Breaker
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| posted on 2/2/10 at 10:13 AM |
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ZX12R fuel quality
Yesterday I was labeling all the connectors on the loom of my 2006 ZX12R engine.
I already knew there is no lambda feedback from the exhaust, but apparently there is also no knock sensor on the bike. What is the minimum fuel
quality you use to avoid knocking ?
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TimC
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| posted on 2/2/10 at 11:37 AM |
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Sorry - can't help but would love to know how you get on with the wiring!
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cd.thomson
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| posted on 2/2/10 at 11:43 AM |
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very few standard vehicles sense knock, although I believe some BMWs now do and have ECUs which can adjust timing accordingly - giving a 10hp
difference between regular and premium!
you will be fine with 95 RON
Craig
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BenB
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| posted on 2/2/10 at 12:11 PM |
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quote:
Originally posted by cd.thomson
very few standard vehicles sense knock, although I believe some BMWs now do and have ECUs which can adjust timing accordingly - giving a 10hp
difference between regular and premium!
you will be fine with 95 RON
You sure about that?
When I went knock sensor hunting there were lots of options on pretty boring Vauxhall rep-mobiles etc etc...
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scootz
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| posted on 2/2/10 at 12:31 PM |
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... the RS4 V8 has 4 of the buggers!
It's Evolution Baby!
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cd.thomson
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| posted on 2/2/10 at 12:43 PM |
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my comment was based on my reading stuff in 2005.. so may be outdated compared to recent cars.
I stand by my statement that its still a small number of cars on the roads fitted with them!
back to the point of fuel quality. Even with a knock sensor fitted it must be very rare for a car to not run on standard quality forecourt fuels...
Craig
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Brommers
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| posted on 2/2/10 at 12:47 PM |
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Well both my tintops have knock sensors - in fact one of them has two. And if you run them on standard Unleaded the ECU backs off the ignition timing
as a result (up to the point where it's no longer detecting knock) or (in the case of the Scooby) lowers the boost pressure, so you get less
power.
To answer the OP's question standard 95 RON unleaded will be fine. No point in using anything else really.
[Edited on 2/2/10 by Brommers]
[Edited on 2/2/10 by Brommers]
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TimC
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| posted on 2/2/10 at 01:30 PM |
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quote:
Originally posted by Brommers
To answer the OP's question standard 95 RON unleaded will be fine. No point in using anything else really.
Interesting - even when racing you don't use Super?
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Brommers
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| posted on 2/2/10 at 02:17 PM |
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quote:
Originally posted by TimC
Interesting - even when racing you don't use Super?
Nope. The benefit of Super Unleaded is its higher octane rating, which means that you can run more ignition advance before you get
detonation/pinking. In some cases (albeit not all) advancing the timing can increase the power output from the engine. However, since we're
limited to using the stock ECU in RGB, which is tuned for 95 RON fuel, and since there's nothing in the bike ECU to advance the timing depending
on the octane rating of the fuel (as there's no knock sensor) there's no actual benefit in running higher octane fuel.
In fact, if anything, using Super Unleaded will be detrimental since the calorific value for Super Unleaded (i.e. the amount of energy released when
it's burnt) is lower for Super Unleaded since it contains oxygenates (such as ethanol) which increase the octane rating but have a lower
calorific value than the hydrocarbons making up the bulk of the fuel.
In fact, the lower calorific value is unlikely to have any real difference given that our engines run rich than stoichiometric and so are unlikely to
be limited in their power output by the amount of fuel being used.
However, there's certainly no benefit in running Super Unleaded in an engine which has been tuned to run on normal Unleaded. So I don't.
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Richard Quinn
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| posted on 2/2/10 at 02:28 PM |
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quote:
Originally posted by Brommers
quote:
Originally posted by TimC
Interesting - even when racing you don't use Super?
Nope. The benefit of Super Unleaded is its higher octane rating, which means that you can run more ignition advance before you get
detonation/pinking. In some cases (albeit not all) advancing the timing can increase the power output from the engine. However, since we're
limited to using the stock ECU in RGB, which is tuned for 95 RON fuel, and since there's nothing in the bike ECU to advance the timing depending
on the octane rating of the fuel (as there's no knock sensor) there's no actual benefit in running higher octane fuel.
In fact, if anything, using Super Unleaded will be detrimental since the calorific value for Super Unleaded (i.e. the amount of energy released when
it's burnt) is lower for Super Unleaded since it contains oxygenates (such as ethanol) which increase the octane rating but have a lower
calorific value than the hydrocarbons making up the bulk of the fuel.
In fact, the lower calorific value is unlikely to have any real difference given that our engines run rich than stoichiometric and so are unlikely to
be limited in their power output by the amount of fuel being used.
However, there's certainly no benefit in running Super Unleaded in an engine which has been tuned to run on normal Unleaded. So I don't.
So, that's a "no" then? 
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Brommers
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| posted on 2/2/10 at 02:39 PM |
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No, it's a 'nope'...
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G.Man
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| posted on 6/2/10 at 02:51 PM |
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quote:
Originally posted by Brommers
quote:
Originally posted by TimC
Interesting - even when racing you don't use Super?
Nope. The benefit of Super Unleaded is its higher octane rating, which means that you can run more ignition advance before you get
detonation/pinking. In some cases (albeit not all) advancing the timing can increase the power output from the engine. However, since we're
limited to using the stock ECU in RGB, which is tuned for 95 RON fuel, and since there's nothing in the bike ECU to advance the timing depending
on the octane rating of the fuel (as there's no knock sensor) there's no actual benefit in running higher octane fuel.
In fact, if anything, using Super Unleaded will be detrimental since the calorific value for Super Unleaded (i.e. the amount of energy released when
it's burnt) is lower for Super Unleaded since it contains oxygenates (such as ethanol) which increase the octane rating but have a lower
calorific value than the hydrocarbons making up the bulk of the fuel.
In fact, the lower calorific value is unlikely to have any real difference given that our engines run rich than stoichiometric and so are unlikely to
be limited in their power output by the amount of fuel being used.
However, there's certainly no benefit in running Super Unleaded in an engine which has been tuned to run on normal Unleaded. So I don't.
Actually this varies considerably with fuel supplier.
More advance also will generally give more power, despite the calorific value of the fuel.
Most pump 95ron contains around 5% ethanol anyway as a filler to reduce price, as a result, good super such as Shell or BP can give better results,
and I have seen rolling road results that prove it 
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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