yeah i dont drive it stupidly all the time i have the odd occasional blast but i drove it off boost as best as i could 1 week and got about 110miles out of it from 30quid but another week it was nice and wet out so was playing around spinning around in some open places and drifting about and only got 65miles to 30quid so yeah i def need to sort something out haha
here in the superior metric system (hehe), i consistantly get 10L/100km
(calculated it this morning, did 480km, to about 44L, so thats even closer to 9.1L/100)
which according to some online conversion guide is about 23.52miles/gallon. (10L/100)
i don't tend to drive like a grandma everywhere either, give it a bit of stick reasonably often. (standard s15, apart from exhaust and a bit of extra boost)
so i dunno how 23.52mil/gal compares to your 30pounds/100miles.
the only real way to check fuel consumption, is to fill it all the way up, hit the trip meter, run it low, then fill it all the way up again, see how much you had to put in, and check your trip meter again.
put a voltmeter across the feed wire and earth on the O2 sensor and get a mate to make the reves move go up and down, if the voltage reading is jumping all over the place when the car revs then its reading OK, if the voltage hardly moves or gets stuck at certain points then replace the sensor as its faulty.
Mine was the same last year (last time I drove it was December when petrol prices were better) I was getting about 100 - 130 miles to 30 quid.. and that was driving good, shifting below 3k and staying off boost a lot.
I thought it could be down to running a de-cat and mahoosive 3inch exhaust system but I think it could be down to something else which I need to have a look at when I have time.
where abouts are you based? there is a good mapper down this way who knows nistune inside and out as well as apexi. he wont map it for mpg or bhp figures, he maps it for where the car is happy. he charged me 250 bucks for the mapping last year, this may have even included fitting the nistune board, and my car has not missed a beat since. drop me a pm if you are close enough for this to be of interest to you....
i mean that every car has a point at which its perfect, ie not underperforming and not strained. finding this point should theorecticaly be the goal of a mapper, but many will just map a car to try and get as many horsepower as possible, this is not always in the best interests of the car and may end up causing damage to the engine over time.
mapping a car is not easy, i wouldnt just trust it to anyone....
ohh yeah ino what you mean mate.thats why im having trouble finding somewhere decent.although i have come across somewhere called horseham developments in berkshire and looks like they specialise in nissans.i have mailed them to see what its all about but no reply yet.
yep jez at horsham is well recommended here and elsewhere and knows the s15/sr20 well. if you go with them i would suggest you get them to fit and map a NIStune board rather than their own version, just because if they fit their own board then they will be the only ones able to map it in the future (i believe). for the figures you are looking at and beyond the NIStune is more than capable. i went direct to NIStune in austrailia and imported my daughterboard (much cheaper than purchasing here, even taking import duty into account) then found a mapper to fit and bespoke map it. for £500-£600 you can be upgraded, mapped, and smiling like a looney. always remember that driveability is FAR more important than bhp figures, 280bhp that is smooth and responsive is much superior to 320bhp that drives like a dog.