petrol

18th May 2012, 05:39

hey guys and girls, getting my car mapped in 2 weeks, if i put v power petrol in when its mapped does that mean ill have to run it on v power all the time? or would i get away with normal unleaded aswel as vpower? hope im making sense?

18th May 2012, 07:01

I would run it on V-Power anyway i do mine burns much more better and the car loves it.

18th May 2012, 11:37

Depends how they map it. If its mapped to use the extra octane then yes you should. Ask them when you go

18th May 2012, 12:03

Get it mapped on normal fuel and run it on v power
Then you know your not going to cause any damage if you can't get any higher octane fuel if you get caught short

18th May 2012, 12:34

Always map to lowest available octane for a road car as blackie says.
It will effect overall power but not by much.
A lot of standalone systems and even quite a few piggy back ignition/fuel systems allow multiple maps so you can switch between for different fuels ( never switch if you top up a tank ) I used swear by apexI safc for a piggy back road car that or the smt6 from perfect power great if they are compatable with the ecu ( don't know on French Cars I was a DUB/Honda tuner)

18th May 2012, 12:41

Quote:

Originally Posted by K567

( never switch if you top up a tank )

Ill have to remember this as i'm sure i've done it loads of times

18th May 2012, 13:42

Lol yeah I learnt from the mistake I had a car that had a map for street on 92 and for race on C16 accidentally ran the C16 map on 92 put foot down at a street race and put a rod through block. Not long after that I wired up LED's to show which map I was on ya know just in case

18th May 2012, 14:49

ah right thanks for the advise, does it make much difference, sounds silly but would i see a better bhp on the dyno lol

18th May 2012, 15:37

Higher the octane tighter the fuel ignition map can be making more hp lower the octane higher the risk of pre ignition ( knock ) to combat this you need to pull timing and add a little fuel, modern ecu's do a lot of this for you ( lambda sensor and knock sensors ) when they detect changes ie: different times of the year colder air vs warmer air, higher altitude can affect air density oxygen content there are lots of variables to look at. On the dyno is a hp at a given altitude, air temp, and other relative conditions ie when I would tune a turbo engine at sea level on a cold winters day I would make between 50 and in some cases 100 more hp than that same engine would see at 500ft and a hot summer day. ( these are big 1000 hp plus engines) with 100 to 200 its about a 5 to 10% varaition. With modern ecu's a lot of this is sorted with map/maf/ait/lambda sensors changing fuel and ignition parameters on the fly as you drive. So in summary and simples the dyno hp is for me a waste of time apart from bragging rights. A well tuned road car will always be done on the open road. But that's just my opinion.
Race ( drag for me ) engines are a different matter because it's always WOT tuning there's is no part throttle highway daily driver need, needless to say not the same for circuit track car.