i hear what your saying, 11.5 to 12 fine, although I would stick to 11-11.5 (cause I like safety/dont know how to tunei would say 12.5 up 5K rpm and 12 to red line..
11.5 is on the rich side keeping things very safe but makes slightly less power.
mine used to run at 10 on full boost, didnt notice any black smoke though, then again its difficult to look when your driving!
Its just I was reading on Nistune website (IIRC) that Nissan always overfuel there cars down to the 10`s, so first job is to take much fuel out of the top end map??
Is that based on a N/A or turbo car jim? Couldnt see it specify anywhere.Good guide on target AFR's:
http://www.max-boost.co.uk/max-boost/internet_articles/Air fuel metering.htm
As I already said, you are looking at settings not actuals.
It doesn't specify turbo or NA, its more to give a flavour for the different areas of a map and why you might target a different AFR at different fuel settings. Turbo's affect timing more significantly than fueling. It is the interaction between timing and fueling that often causes confusion.Is that based on a N/A or turbo car jim? Couldnt see it specify anywhere.
Best ratio is going to depend on individual set ups and amount of ignition being run and only way of confirming actual best would be comparable runs on a dyno with the same car at different ratios.
The ECU was created by a software engineer at Nissan who probably copied the software from another car before handing it to the engine department who defined the map on a dyno.I though with them being target AFR`s they would be reasonably close, why is actual vs target so different?
It doesn't really work like that I'm afraid Chris. By moving from 440cc to 660cc injectors you are already adding an extra 30% fuel everytime the injector fires. At 1.4 Bar on a 3071 you would be out of range of the standard map so you have probably changed the standard MAF? This means the amount of fuel your ECU thinks it should be using bears little resemblance to the standard map.standard map at the top end, 4.5% extra. Im seeing 10.8a/f on full boost of just under 1.4 bar on a 3071 and 660 injectors, so id say that the standard map on a standard car would def fuel into the 10's.
Interesting stuff Jim.It doesn't really work like that I'm afraid Chris. By moving from 440cc to 660cc injectors you are already adding an extra 30% fuel everytime the injector fires. At 1.4 Bar on a 3071 you would be out of range of the standard map so you have probably changed the standard MAF? This means the amount of fuel your ECU thinks it should be using bears little resemblance to the standard map.
This answer links back to Steve's question on why the target and actual value are often different.
Wideband should be ok, only done about 500 miles. Am using it to simulate the narrowband aswell and closed loop its running around the 14.7 mark so should be functioning correctly.It doesn't specify turbo or NA, its more to give a flavour for the different areas of a map and why you might target a different AFR at different fuel settings. Turbo's affect timing more significantly than fueling. It is the interaction between timing and fueling that often causes confusion.
Below is a graphical way to look at AFR's:
On a turbo car you go to 12 to 12.5 but you are still in that peak HP hump area. Ultimately, a car fuel management system is very simple as you have 4 cylinders with different CR's and only one MAF, one lambda and generally common timing. This is before you add in a constantly changing environment and differences in fuel injectors. People like to argue over it but it is a rough science.
If your car is 10.8 at peak HP (between 6K and 6.8K?) then it is about 10% too rich. Even in the greyness of tuning you would find very few people arguing for that AFR when using decent petrol.
Before you start taking out fuel, when your MOT comes round and if you know the people, check your installed sensor against the testers. Handy way to get yours checked once a year ;-) Good engineers rule of thumb is before changing a system, always double check your instruments readings first. (Measure twice, cut once as the carpenter says)
Cheers,
Jim
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@Chris. part of the problem with the internet is in the states they have rubbish fuel whilst most of us in the UK run Optimax or equivalent. They can be seriously knock limited on their "pump gas" whilst we in blightey are not. This can lead to people talking about all sorts of safety margins and knock issues that we don't see.
Though not great here is a typical discussion on the internet:
http://www.sr20-forum.com/tuning/16...82-lambda-why-you-should-too-all-welcome.html
I think its worth pointing out that an average target AFR needs to be checked against the max and min value as well. For example, if your average seems okay but your max is too high then it might be worth considering targetting a lower average AFR.
Your lamda sounds new which i good. Do you have a timing gun? have you checked your measured IGN value equals what you read with the gun?
Your IGN reading sounnds sensible. As you are running more boost over stock then you will have to retard the ignition. This is normal and as we don't know what your base map really is this amount is in the range.
Are you planing too map the car yourself?
Bob, have you still got the emanage that came off the Hiteq care you had recently and what injectors was it running. If you have is there any chance of getting the settings off it to see how it was mapped? Its basically the exact same spec as mine but running a bit more boost.i dont know much about tuning chris but ive never heard of ignition being retarded coming on to wot, if anything some tuners add too much ignition to boost the bhp readings on dyno, but in doing so you have a car thats not very drivable through the rev range.
this is one definate problem that a few people have had from no.....names lol and no its not ed;-)
perhaps as you say they were being ultra safe when mapping the car:?