Mapping

[309PUG 2 1 Cars]

When mapping my engine would it make any difference to the settings ie fuel / ign maps etc, dependant upon what fuel I used, ie super unleaded 98 RON as opposed to racing fuel on 105 RON or even higher.

 

Plus what are the implications if any of using 105 - 109 RON fuel as opposed to 98 RON forecourt fuel

 

Chris

Edited March 8, 2006 by 309PUG

[Dom9 2]

If you map the engine with higher octane fuel then you will be able to run more ignition advance... So, effectively, your ignition map will be different for each grade of fuel...

 

If your engine has a knock sensor then it could adjust itself for different grades of fuel but otherwise you should probably map to the lowest grade of fuel to avoid any detonation.... Unless you have a system able to hold two or three different maps, in which case you can have a seperate map for each grade, like some of the Jap cars do...

[pdd144c 0]

use superunleaded if you can buy it somewhere near you on a regular basis... but like dom inplied if its mapped on that you'll have to stick with it really.

[d-9 0]

If your engine has a knock sensor then it could adjust itself for different grades of fuel but otherwise you should probably map to the lowest grade of fuel to avoid any detonation.... Unless you have a system able to hold two or three different maps, in which case you can have a seperate map for each grade, like some of the Jap cars do...

 

Even if it has knock it would have to be mapped to detect that and retard the timing appropriatly, but apparently most aftermarket systems dont include knock, as there is so much engine noise at revs knock is near impossible to detect.

 

Getting it mapped on super unleaded and running it on normal would probably be ok, but getting it mapped on race fuel and running on normal would almost certainly cause lots of detonation.

[Butler 0]

Would it be right to say that if you map it for 98ron, running race fuel afterwards is pointless? IE it doesn't give you anymore power without advancing the ignition.

[Jonmurgie 2]

Race fuel isn't really going to add masses of power to an N/A car, though as stated you can adjust the ingnition map. Unless you have the right bits, running race fuel on a car mapped for super (optimax) would be a bit pointless...

 

In contrast, I've seen (MY06) Scooby's gain around 40bhp with the addition of just race fuel. The litchfield imports Spec C made 375bhp with exhaust/filter/race fuel... monster power for very little outlay!

[Alex G 0]

i would map for standard unleaded, and advance the ignition as much as possible. then i would run on higher octane fuel, as a safety factor in a turbo charged engine.

[Anthony 1,003]

Map the car on the minimum grade fuel you would normally use, which I would recommend being 97RON or higher on any modified engine.

 

Some ECU's do have a dual map facility, so you could have for example one engine map for normal unleaded, and one for race fuel. Without a knock sensor and the ability to automatically adjust the timing to match the fuel, you won't gain anything running higher octane fuel than the engine is mapped for.

[16v205 9]

I had mine mapped on tesco unleaded cheapo fuel at emerald. According to Dave Walker the amount of ignition advance that had to be removed was massive over his standard mi16 map on tb's, he guestimated I was between 5 & 10 bhp down a couple of ft/lb of torque down aswell.

 

Had it mapped on cheap fuel so i wont be worrying about trying to find higher ron fuels near trackdays, if the car never left redditch id of had it mapped on 99ron Tesco fuel or Optimax.

 

Rich

[DrSeuss 0]

Knock sensors are pretty simple to implement but only really used to sort the timing at lowish rpm. Its main role is improving midrange torque. But few ecu's have support because its an awkward feature to implement.

 

since its a race car, map it on race fuel. Too little ignition advance on a car running race fuel will lead to burnt out exhaust valves fairly rapidly.

[309PUG 2 1 Cars]

Thanks for the replys chaps, I understand the situation now, will mix 98 Ron + 105 Ron 50/50 all the time.

 

Chris

[pug_ham 245 3 Cars]

Thanks for the replys chaps, I understand the situation now, will mix 98 Ron + 105 Ron 50/50 all the time.

This is roughly what I've do in mine but it was mapped on 97*ron SUL.

 

Main difference I've noticed mixing them is the economy improves but i don't intend continuing to do this once I've used my current stock up.

 

I'll mention it to Wayne(chipwizards) when I get my new engine fited & ready for mapping though & see if he thinks its worth doing.

 

Graham.