Race fuel

[mikem7709]

Can someone explain to me how a car that doesn`t have a seperate map for race fuel (like HPF) is able to make more power on race fuel ??

This might sound like a dumb question but I don`t understand it. If my car is mapped to run on 98RON(UK) and I put (95RON) in, the car will detect knock and retard the timing enough to prevent it and hence produce less power.

If I then take the same car mapped for 98RON(UK) and put MS109 in, what detects the higher octane of the fuel to advance the timing to take advantage of it ?

Surely to take full advantage of the MS109, it has to be mapped to run on it and then rely on the timing being pulled everytime its not running MS109 ?

Am I a retard ?:eek:

[SMGEEZ]

Im thinking because HPF uses a standalone or strong ass piggy back there is a switch or setting that they can activate for race fuel... There is no way for a car to magically read the octane of gas and deal with it accordingly. Your right, it can only take away timing and adjust if there is knock.

[Jeffxxx]

There is no way for a car to magically read the octane of gas and deal with it accordingly.

Yes it can. Our cars have a self adaptive ecu, I believe it can adapt up to 97 octane.

[bernstem]

The stock ECU will advance timing gradually until knock is detected then pull back a little bit. I don't think it will advance indefinitely, though, so there is some limit. Maybe somone with a bit more knowledge can chime in.

As for HPF, they have a switch that changes between different maps used by their piggyback. You put in the fuel you want to run +/- methanol, set the map selector to the approprite setting and you are good to go.

[BimmerDude18]

Its basically just pulling timing on the lower octane fuel. The knock sensors in the S54 are pretty awesome.

[mikem7709]

Thanks guys, I understand how the HPF cars are able to do it (2 seperate maps) what I`m trying to establish is what the cars running just 1 map need to be mapped for. How far can it be "pushed" to still allow it to pull back for regular pump. What is the adaptation value ?

[SUMOM3]

There are preset limits to how much timing is advance in our ECU. Im brainfarting right now but there is a certain word for it and when it does ill say it. But basically, for you to further your limitations, you will need to get someone to allow or "open" the parameters so it can read and allow more timing advancement. If its stock the OEM parameter is as far as it will go...

So for instance (just example): 93 octane is our standard here in states... You put 100 octane and it will advance timing and detect whether there is knock free of not. Lets say the parameter will only allow it to "advance" to approximately to a 97 octane gas.. You will see gains for sure till 97, but that addition 3 is not taken advantage of.

So, if you open your parameters to allow the timing to advance further you can take advantage of much hight octane fuels.

Out ecus are so adaptable that it takes only about 2 runs on your engine and it will fully adapt to whatever octane is in your vehicle.

So when someone other than HPF states they have a race map, that just simply means the parameters were changed and tuned at that time for whatever octane they were tuning with.

Hope that made sense...

[maxnathan]

Surely to take full advantage of the MS109, it has to be mapped to run on it and then rely on the timing being pulled everytime its not running MS109 ?

Am I a retard ?

I believe the PC term now is " disability" :rofl:

And no you`re not!:pimpin:

To answer this question using evidence based research, i believe Thorney MS did an article where they dynoed several types of performance cars using various grades of fuel including race........Overall Tescos 99 delivered the most consistant and higher bhp/torque figures ( if i recall correctly)

Read this on Piston Heads some time ago mike......

[mikem7709]

The HPF cars make roughly 30-40% more power on race fuel over pump (I can understand this and don`t dispute it in any way, as its running a proper tune designed for the higher octane when on its race map)

A S/C`d car only seems to make less than 10% more power on race fuel, without altering the software. So the ECU obviously isn`t able to adapt enough to take full advantage of the higher octane rating. What I want to know is where the cut off is, how far can the ECU adapt because anything over and above that is a waste.

Or have I missed something ?

[BimmerDude18]

The HPF cars make roughly 30-40% more power on race fuel over pump (I can understand this and don`t dispute it in any way, as its running a proper tune designed for the higher octane when on its race map)

A S/C`d car only seems to make less than 10% more power on race fuel, without altering the software. So the ECU obviously isn`t able to adapt enough to take full advantage of the higher octane rating. What I want to know is where the cut off is, how far can the ECU adapt because anything over and above that is a waste.

Or have I missed something ?
Supercharged cars don't change boost with race fuel, they only change ignition timing.

HPF cars change boost, if you want to compare pump/race for an HPF car you need to do pump+meth vs race or race+meth. It will be closer.

[SMGEEZ]

Yes it can. Our cars have a self adaptive ecu, I believe it can adapt up to 97 octane.

I still dont think it work like that... If timing is Set at X advance, it will only back off so to speak from there... THE ECU doesn't write or change its timing values... If you are running 97 octane for example you will stay closer to X pre programed value of timing. The Stock Timing curve of my car when I dyno'd it showed the highest timing advance of 22 degrees.... lowest was around 18 19 degrees in the middle and it had gone back up toward the top end of the rpm.

The way It was described to me is that there is only a value set in the ecu for say 25 degrees of advance MAX... its can't magically rewrite itself to go higher... if you run higher than 94 Octane (what I use) maybe you can take advantage of those pre set and fixed values... It won't ever change, there will just be less detonation thus the ecu WON't pull timing from its set point.

These ecus adapt yes, but they don't rewrite themselves so they can't adapt any better than they are programmed.

[MathiasM3]

Sorry for the threadjack mike7709! But this came across my mind while reading your thread

I was wondering , I was reading some threads and some say 91/93 in US is the same as 95/98 in Europe. I'm a little confused here...

Since you guys have 91 and 93 octane in US and we have 95 and 98 and Shell sells RON 99 and here they say octaan to it...

What's the story with this?

If I send my ECU to US to be flashed by AA , will it work perfectly on Shell V-power RON 99?

[mikem7709]

Some BP stations here are trialling 102 RON but its around £2GBP a litre and only around London at the moment.

Mathias, CA Automotive is the UK distributor for AA and offer a custom tune for euro cars, speak to AA and see if you could send it to them instead of stateside.

[MathiasM3]

Yes I could do that!

but is RON same as Octane in US ?

is 99 ron here almost the same as race gas (100octane) in US

[mikem7709]

Yes I could do that!

but is RON same as Octane in US ?

is 99 ron here almost the same as race gas (100octane) in US

No our 99 is probably equivalent to 95/96 there.

[MathiasM3]

Oh okay! so IF AA would flash the kit for 93 octane it would be a little bit off but when reading all the above my ECU will adapt itself and run fine?

I just mailed Jean@AA with the Question regarding CA , that would indeed make it alot easyer AND quicker!

Thanks Mike!

[SMGEEZ]

No our 99 is probably equivalent to 95/96 there.

95RON is the same as 91 in north america... Canada's 94 (our premium) is the same as 98RON.

The reason our numbers are lower is that we use a different index we use AKI (anti knock index) which is an average between RON and MON (research octane number and motor octane number)

[SMGEEZ]

Oh okay! so IF AA would flash the kit for 93 octane it would be a little bit off but when reading all the above my ECU will adapt itself and run fine?

I just mailed Jean@AA with the Question regarding CA , that would indeed make it alot easyer AND quicker!

Thanks Mike!

If you run higher than 93 octane there won't be any problems. You octane level will be more than enough and you will not experience any pinging. If it were the opposite, you had a tune for 98 but were running 91, you would get pinging all the time and you would constantly have timing pulled. It will go back to "original" timing when the knocking stops, but it will be knocking quite a bit and your ecu will always be retarding.

[Matt Q]

Does anyone out there know what gas we are running in South Africa???

I know everyone refers to Octane over here.. standard Pump is 93 and I can get 100 race.. but how does that compare to US / UK??