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Pinging,knocking,detenation


shockwavexr6t

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Shockwave did you get your car tuned and after pick up it started to ping, so the tune had to be backed off from 305 to 295kw. Or was this during the tunning process. If its the second then I cant see a problem, in fact this sound like a good safety margin has been built into the tune as the power loss was likely due to less advance.. At some stage all engines will ping if tring to extract more power than the fuel can cope with cylinder pressure wise.

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Shockwave did you get your car tuned and after pick up it started to ping, so the tune had to be backed off from 305 to 295kw. Or was this during the tunning process. If its the second then I cant see a problem, in fact this sound like a good safety margin has been built into the tune as the power loss was likely due to less advance.. At some stage all engines will ping if tring to extract more power than the fuel can cope with cylinder pressure wise.

<{POST_SNAPBACK}>

Hi philldub,

yes this was back off during tuning which is great and a good safety margin, but what baffles me is that having to change plenum and cold air setup as I already have a larger ic will enable to get more power with out pinging.

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Shockwave did you get your car tuned and after pick up it started to ping, so the tune had to be backed off from 305 to 295kw. Or was this during the tunning process. If its the second then I cant see a problem, in fact this sound like a good safety margin has been built into the tune as the power loss was likely due to less advance.. At some stage all engines will ping if tring to extract more power than the fuel can cope with cylinder pressure wise.

<{POST_SNAPBACK}>

yes interesting you mentioned to extract more power than the fuel can cope with cylinder pressure causes pinging.

then why have been advised upgrading fuel pump isn't nessary only plenum and cold air setup?

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  • Playing with Sports Bikes...
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As a real newbie to turbo performance it is brilliant to read threads like this... very informative and a great read for those (me) interested in how my car works now, and how my car will work and what to look for when I do get an edit or performance mods done...

Cheers to those who have posted with info!! Keep it coming...

Jack :spoton:

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I think shockwave you should read the post on the nizpro forum regarding Knock. I dont believe you are you are out of fuel supply, just out of fuel performance with the mechcanical hard ware you have at presant. As Simon surgests on the knock discussion there are many other factures. As far as I understand it, a better flowing inlet manifold makes more power at the the same boost level, this then has the effect of the waste gate being able to stay further open and reducing exhaust back pressure, this then reduces back pressure so less dirty charge re enters the cylinder of exhaust valve over lap. This then does not dirty the incoming charge so a better mixture is presant for the next cycle and the charge temp is also reduced as the hot gasses have not re entered the cylinder so there is then less chance of pinging and more timing advance can be added.

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It may have that power but it still slow as  :pooh:  :pooh:  I think you should join us another friday night so me and craig can laugh at you again

<{POST_SNAPBACK}>

I suspect the dodgy driver doesn't help...

Always happy to support laughter Adam.

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It may have that power but it still slow as  :pooh:  :pooh:  I think you should join us another friday night so me and craig can laugh at you again

I suspect the dodgy driver doesn't help...

Always happy to support laughter Adam.

Well said.

Well I have had pinging quite a bit lately and it was very noticable during the recent Snowies cruise.

Is pinging more likely to happen at say fuel tank only 1/3rd full? It was pinging quite badly just before we re-filled at Tarcutta. If so, I think my problem maybe needing a bigger fuel pump :pooh:

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I think shockwave you should read the post on the nizpro forum regarding Knock. I dont believe you are you are out of fuel supply, just out of fuel performance with the mechcanical hard ware you have at presant. As Simon surgests on the knock discussion there are many other factures. As far as I understand it, a better flowing inlet manifold makes more power at the the same boost level, this then has the effect of the waste gate being able to stay further open and reducing exhaust back pressure, this then reduces back pressure so less dirty charge re enters the cylinder of exhaust valve over lap. This then does not dirty the incoming charge so a better mixture is presant for the next cycle and the charge temp is also reduced as the hot gasses have not re entered the cylinder so there is then less chance of pinging and more timing advance can be added.

<{POST_SNAPBACK}>

philldub,

me thinks you have hit the nail on the head thanks for feedback.

So does cooler conditions extract more power as well?

cheers

shockwavexr6t

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ben,

that being the case when bad fuel is used to tune a car yes the end result will be a average tune. But if no bad fuel is used then timing is controled by tuner then the only other reason for pinging would be air density or presure drop through ic pumping or heat right.

what I'm trying to figure out that if fuel supply is OK fuel quailty is OK and timing is controled by tuner whilist getting tuned then only other variable is air density.

Does that mean that we are able to achieve more kws with colder conditions.

so for example if you have achieved 331rwkws on a 98ron tune.  So you decide to tune your car say on a 9 degree day I would assume you could get an extra

5-8rwkws due to air density. SO then you have say 339rwkws. What happens on a hot day say 36degrees you would lose some power and may start to ping?

Does that mean your tune will need to be retuned or will the knock sensor kick and retart your cars tune and stop from pinging.....

cheers

shockwavexr6t

<{POST_SNAPBACK}>

Ok

Firstly - colder temperatures will result in a higher air density which means more fuel and therefore greater capacity for power. So yes an engine can and will produce more power in cooler conditions and when it is cooler. This may or may not translate to a larger power figure from a dyno due to temperature correction, but will be real in practice.

Now as to pinging...

It is important to distinguish between ambient air temperature, and the temperature of the air and fuel mixture in the cylinder just prior to, and during combustion. Detonation (particularly of good quality fuel) will only occur at much higher temperature and pressure than ambient (not sure of exactly at what point it will combust, but much higher otherwise we would not be able to handle fuels safely).

The air being drawn into the cylinder undergoes a number of temperature changes. The main ones are heating through the turbo and cooling through the intercooler. Fuel is then added and the charge drawn into the (hot) cylinder where it will mix with some of the still very hot spent combustion products, the mixture of which is further heated during the compression stroke. As a consequence the charge in the cylinder prior to combustion will be at a much higher than ambient temperature (someone better informed than I might be able to give us some indication of typical temps... ), so whilst say going from 10 degrees to 40 degrees C might result in around a 10% change in ambient air density, I would EXPECT the increase in absolute temperatures in the cylinder will be proportionally much smaller so not as big a risk of detonation as you might otherwise expect.

In short I would not EXPECT that much timing would need to be taken out to compensate for changes in air density - any tuners like to comment...

Cheers,

Ben.

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Well I have had pinging quite a bit lately and it was very noticable during the recent Snowies cruise.

Is pinging more likely to happen at say fuel tank only 1/3rd full? It was pinging quite badly just before we re-filled at Tarcutta. If so, I think my problem maybe needing a bigger fuel pump :pooh:

<{POST_SNAPBACK}>

hi Luke!

I also thought I might need a new fuel pump not so long ago (due to the go/stop/go problem I once had... ). I have been told I do not.

As you know I also had major problems with the car on the run in to Jindy.

I cant think of any reason as to why the car would be more suseptable to pinging on the last 1/3 of a tank (doesn't mean there are no reasons - just that I can't think of any... any one else??? ). In terms of fuel pressure, if memory serves the fuel pumps operate to supply fuel at 4 bar or 400kPa, change in pressure as a result in change fuel level in the tank will no more than about 1% so relatively insignificant...

Mine ran fine after adding the octane booster in Jindy, except for the fact that the exhaust manifold started leaking as we came into Melb at the inlet to the turbo. Now fixed

Simon from Nizpro has told me that the nulon Octane booster can have a detramental impact on the iridium/platium spark plugs. Poor spark could also contribute to knocking.

I would suggest you take the car in - either to Nizpro or back to HPF and have them check it out, but it would probably be a good idea to run the tank really low a couple of times and refil with fuel from a relable petrol station.

Good luck! :pooh:

Ben.

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