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Another engine needed! 2 blown 350zs in 1 week


stuRS

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My brother told me that Mark at Abbey mentioned a sensor/detector that limits the car when lower octane fuel is detected. Apparently this works up to 4500 revs or so and then reverts to standard. Both cars blew with revs around the 6000 mark, any more info on this would be good, particularly for you fortunate soles with cars that are running.

 

I was saying the car's only have knock control up to 4800rpm as a stock after this RPM the car doesnt have knock control. This is all in the stock ECU. If the car see's heavy knock readings it will switch to the high detonation map which has around 5 degree's timing removed.

 

The car that we have here that has failed hasnt had a bottom end failure from what we can see , it has had piston failure. The car had a full service prior to dyno work. 1st pull on the dyno I noticed some wrong spoke to Scott saying I think the car is running 95 Octane fuel , he spoke to the customer that confirmed it was running on 95 octane fuel.

 

I have a feeling that the usage of 95 octane fuel may have caused weakening of the piston's maybe due to continual detonation over a long period.

 

Mark

 

Does this mean if your running 95 Ron you need to keep it below 4800rpm as the knock control is lost thereafter and you will be getting det but the ECU is not aware? As your more likely to get det with 95 Ron?

 

(Forgive me if I am misunderstanding)

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There is knock control under 4800 rpm. attached is a couple of screen shots from the UPREV software tuning package , should help you understand how the car runs knock control

 

In the 1st screen you see the normal ignition running map , the number aren't in degree's of timing they are in mille seconds before peak cylinder pressure. The number will change per RPM increase.

 

The high det map removes ignition timing if the car hears knock within the knock control window, on the 2nd screen grab your see green and red colouring when the car is running in the Red area we have full knock control , when it is Green area there is limited knock control which we have found will not prevent detonation occuring.

 

When we tune for either Super unleaded or unleaded we make a bigger difference between the normal running map and the high detonation map so the car will feel slow if it see's detonation within the control area.

 

We find when running on unleaded fuel (95 octane) even the high detonation map is to agressive re ignition timing for unleaded fuel.

 

I hope this helps people understand how your cars work.

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Does this mean if your running 95 Ron you need to keep it below 4800rpm as the knock control is lost thereafter and you will be getting det but the ECU is not aware? As your more likely to get det with 95 Ron?

 

(Forgive me if I am misunderstanding)

Correct. Go see Marks thread about UpRev mapping for 95RON. He has a dyno plot which shows the power go a bit mental after 5kPRM which is down to det :headhurt:

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Interesting to read that there's knock control up to 4800rpm....if you read your handbook in the section about setting the rev limit light you will read the suggestion that you can set it at 4800 revs to maximise the use of the engines torque,so I've got mine at this setting.

I would guess that changing up at about about 5000 revs when in a hurry as opposed to thrashing it into the red won't actually make that much difference to acceleration times...anyway,that's my policy and if it's helping to preserve my engine so much the better....and of course,on that special occasion,you can always ignore that light ;)

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Wrong I am afraid. :blush:

 

The refinery doesn't mix additives into fuels, a refinery only refines crude oil into its constituent parts.

 

ALL, additives are added at the tanker not before, not after. In actual fact fuel, or sprit, as its know on fuel terminals won't actually run a car anyway. Once the sprit leaves the holding tanks, it is pumped into the lorry, where all the additives are added.

How do I know this, Well, I service the additive plants on fuel terminals across the UK, and trust me, the stuff they add is not pleasant. It burns through steel toe capped boots within an hour, rots material and burns your skin within seconds. VERY NASTY STUFF. :scare:

 

Also rest assured, there is NO difference between any fuels apart from Tesco 99 ron. The amount of additive is exactly metered into lorries cargo, whether or not its going to sainsburys, BP,Esso Asda etc.

 

There is a lower limit to how much additive is added and a higher limit, but it must be dosed between these 2 limits from the additive plant, outside of these limits, there is an automatic cut off for the lorry loading.

Trust me, all fuel is brewed in exactly the same way. :snack:

 

 

sainsbury's super is bp ultimate :thumbs:

 

not true, I have heard that both supermarket plus fuels are mixed differently to BP or shell. The additives are literally added in the tanker rather than at the refinery so can be a bit hit and miss and not as well made with less additives. Sainsburys is sourced from BP but that doesnt make it the same as BP ultimate.

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All 97/98/99RON fuel must be made to a certain British Standard, so anything you put in from anywhere will be fine. Some may be marginally 'better' than others, but it's going to be practically unnoticeable. It's almost irrelevant whether the additive is added at the refinery, the tanker, or the station, as long as it all meets the requirements of BS7800 it will be perfectly fine. :)

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So whats different with Tesco 99RON? Better or worse than the others? :shrug:

 

Tesco 99Ron has slightly more additive to further prevent detonation, but honestly, would the average motorist ever notice 1 Ron difference between fuels. :shrug:

Thats good to know as my car is mapped on 99RON by Abbey hence why I was curious :thumbs:

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I am sorry to hear about the two zeds!! :console:

when i got my roadster a few months ago- someone told me i didnt need to put the expensive stuff in! i thought they meant i can therefore use 95ron. So the first month and more i was buying that. then after another chat with them they said by 'expensive stuff' they only meant shell v power! i was very scared then that id been putting 95 ron in! however after alot of reading- it seems poss half of the forum (maybe less) use 95......

i switched to tesco 99 as i like the clubcard points and its closest to me. Then i switched to shell v power because alot of friends said they notice a difference and tesco fuel still isnt all that great :wacko::wacko:

i would rather use tesco - for my reasons above- plus its cheaper than v power... BUT if v power is def better for the running of my car- ill continue with it!

is there a right or wrong answer whats best for my 350z? i would like to use what the car would prefer! :lol: but she wont answer me :lol:

am i just panicing - is tesco 99 perfectly fine ? i assume so!?

is v power only diiferent because its slightly cleaner fuel (or something like that ive read.)

 

aslong as tesco 99 wont harm her, i think im happy! but if theres definate advantages to v power- id like to know. i am poor haha.... but i will put the best in her, cause i worry!

 

help! :doh:

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She'll be fine on Tesco 99RON. I ran my 350z to over 90K miles with no problems at all on Tesco 99RON. 370z has now done close to 15k miles on the stuff too and no problems there either - Abbey remap saw me with 308HP@hubs (~350HP@flywheel) :thumbs:

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Sju not just reine for 95 rhen?...

 

T9 fail... Why not just retune to 95?

any chance of sharing that in English please Anders ?

second line :D

 

Why do you guys worrying about ron95 not just retune the car for ron95 instead of its 98 super duper fuel :teeth:

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If something is designed to run with something specific in mind, then it should be ran with that.

You wouldn't make pasta in a rice cooker would you...

 

Never thought of that might try it :lol:

 

I think moral of the story is always try to run your car on super. If you cant get super and your using regular dont take it above 4.5k revs. :thumbs:

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Haha,

 

I must admit, from time to time I rag the sh*t out of the zed. That's what it's for, the rev limiter is there to be used - to protect the engine from danger-revs.

 

 

Also, I do enjoy dropping a gear or two and sticking my foot down, but it's the clutch/gearbox that has to cope with that, not the bottom end.

The zed seems to beg for big revs and dropping cogs, I do bean it every now and then, but I like to think it's done with at least a degree of compassion for the thing. I've been rebuilding bike engines since I was 10 and have ridden bikes for 21 years, so I do know how to look after an engine and know what can happen if you don't.

 

It just shocks me that two engines have gone within a week. I can't help wondering if there's a local petrol station to blame for this, because a Japanese V6 should be bomb proof, not sh*t itself when running on 95 Octane unleaded.

 

Rothers - if the top end goes (where that magic spark happens and directly linked to the fuel used) it can upset the bottom end, causing it to eat itself. I've seen little 2 stoke bike engines with a top end seizure damage the big end bearing, f**k the crank and turn itself inside out. That's a single cyliner, so with 6 the forces are much greater and the risk to the bottom end are increased.

 

Saying that - my first thought was oil starvation - so I'm with you on your logic.

 

Stu

 

IMO with an attitude like this against the car, along with poor maintenance I`m not suprised you have killed 2cars. I`m not here to argue your points even though you contradict yourself within the same post with reference to "ragging the s**t out of the zed" & "so I do know how to look after an engine and know what can happen if you don't" Clearly you need to adjust your approach to the way you drive & mainain your vehicles :thumbdown:

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