Shell 100 Ocatne

[r33_racer]

ME TOO! I want some 110-115 ron pump bp fuel...where do i get that?

For pump fuel you cant beat the shell optimax extreme...100 ron with some eth in it, get it tuned on that and its your best bet without going to race fuels Believe me, race fuel is frikken expensive....we were using martini 110 for a little while...at the time we worked out per litre $6.80 FARK!

Knock is due to too lean a mixture, too much ignition advance, too much boost-related to 1, heating issues, excessive oil in the intake...what happens is somewhere during the compression stroke one or various causes such as the ones listed interrupts the combustion process from occuring at its set time, normally going by the term PRE-ignition is the mixture ignites before its timed moment and rattles the piston side to side causing all sorts of wear n tear and costly damage. That rattle is what is referred to as a KNOCK or PINGING. Other form of knock can probably be more so referred to as PISTON SLAP, which is basically the same event of the piston rattling from side to side, but normally occurs on the power stroke and is more so due to the tolerances being too sloppy or loose and allowing the piston to move around too freely in the bore during normal operation. Both are bad for engine life...specifically piston life

[chrissso]

Jut thought I'd add my experiences with ethnol.

The 98 IFS ethnol stuff did make a difference in power in the wifes mazda, but the economy was not the same. I must explain that I filled a tank and drove normally for the whole tank to see the economy. Other tanks, I did tend to put the foot down to experience the noticable difference in torque.

Also, I have a friend that has a VW dune buggy fiberglass thing with a stroker kit, and was setup for drag. They used 100% alcohol in it and the aluminium and other metal component suffered from bad corrosion. Something you wouldn't get with regular fuel. Although that 100% alcohol, you still have to wonder what that extra 10% ethnol would do to some of the metal components in the fuel system.

[Sydneykid]

If you had done a search (“Sydneykid”, “Extreme” and “any date”) you would have found these posts;

February 2006

We have a new project car, an R33GTST that is in need of some TLC. One of the recent upgrades was a Power FC. As most people are aware, the default ignition maps are a little advanced for Optimax, Ultimate or Vortex 98. Not as bad as they used to be for 95 ron fuels, but still a tad. Obviously I will tune it properly eventually , but we have a few mods to go yet and I don’t have the time to tune it multiple times. So the idea was to stick the Power FC in and run it on the default maps for a couple of weeks. On Optimax and Ultimate (didn’t try Vortex) it was reaching knock of 60+ up our usual test hill in 4th gear as logged on the datalogit. The dash warning was also flashing frequently, as it is set for 60, in normal day to day driving around. When the tank was just about empty this week, we filled it up with Optimax Extreme (@ 5 cents a litre more than Optimax). Several runs up the hill and we are not seeing knock over 10. And zero dash warnings in 3 days of normal driving.

Now that is very worthwhile, there is not enough Optimix Extreme around yet for me to tune it exclusively for 100 ron, but it sure will be a useful for the odd track day or run down the ¼.

I will monitor the effects of the ethanol on the fuel lines, o’rings and seals over the next few weeks. The injectors and fuel pump will have to come out shortly so I will check their condition as well. I am not anticipating any problems, but it is still worth checking.

March 2006

After a month (~2,000k's) of running exclusively on Extreme in the R33GTST, I did a fuel filter change on the weekend. Cut it open and no sign of any foreign material, deteriorated fuel hose etc. That means zero effect from the 5% ethanol, as expected. So we will continue to use it.

Current status, after 8 months of running exclusively Shell Optimax Extreme 100 ron.

After 3 fuel filter changes I still haven’t found one sign of fuel system rubber or metal deterioration.

I cleaned the injectors last week and there is not one sign of any effect on them either. I also flow tested them and they performed exactly as they did last time I flow tested them.

Based on the results with the R33GTST, I have now started to use it in the Stagea, which I will be tuning again very shortly to take advantage of the extra performance on offer.

cheers

[Beer Baron]

Also depends if you're hitting rev limiter in which case knock value on PFC will show large numbers.

not if everything is working properly. I can nail the limit in my car and knock is no higher than normal.

[illusiVe]

u can get kegs of the 110-115 ron fuel from selected BP stores

ive only seen it in 3x places in NSW.. i asked my local to order in 2 for me.

[32GTRB]

is 100ron with 10% eth any more expensive? or is it cheaper then say 98 ron

[Sydneykid]

is 100ron with 10% eth any more expensive? or is it cheaper then say 98 ron

Shell Optimax Extreme 100 ron is 5% ethanol and is around 5 cents litre more than Shell Optimax 98 ron.

cheers

Edited August 30, 2006 by Sydneykid

[TokyoTaxi]

Shell Optimax Extreme 100 ron is 5% ethanol and is around 5 cents litre more than Shell Optimax 98 ron.

cheers

In your opinion, is it worth it ??

[r33_racer]

Im psychic, he will say yes it is so long as its readily available so you dont have to drive 25km to get to a bowser that pumps it.

In brisbane were still like that...only like 4 or 5 stations on the northside that have extreme. Pain in the ass sometimes.

Slight comparison....bp 100 octane or (avgas) which comes in 20l drums works out at something like $2.50 per litre, so about 50bux a drum....thats still like 1 dollar more exxy then the extreme

Edited August 30, 2006 by r33_racer

[Sydneykid]

In your opinion, is it worth it ??

For the extra performance = Yes

That's not just max power but response from the more advanced ignition timing.

Enabling the use of standard Power FC maps = Yes

Let's face it, in performance car terms it's peanuts

60 litres X 5 cents = $3 a week.

cheers

Edited August 30, 2006 by Sydneykid

[jazza08]

As Gary has pretty obviously pointed out, you really need a re-tune to get the benifits of the ethanol. Ive seen a 22rwkw gain (modified r32 gtr..) from moving from 98 to 100 octane with ethanol in a HPI magazine, they explained that you can put alot more igintion timing into the motor, however it did run abit lean and make less power without being tuned for the new fuel.... something to keep in mind if you have a tuned modified car, if its a stocko it shouldn't hurt.

[tridentt150v]

"Also depends if you're hitting rev limiter in which case knock value on PFC will show large numbers."

'not if everything is working properly. I can nail the limit in my car and knock is no higher than normal."

If you use a std or walbro you may [stress may] get this effect..............they can run a bit lean at the top of the scale!!

[paulr33]

"Also depends if you're hitting rev limiter in which case knock value on PFC will show large numbers."

Please show an example of this, and explain why knock would be more at the rev limiter?

[Color_Of_Green]

Please show an example of this, and explain why knock would be more at the rev limiter?

Ok.

My understanding is that the PFC cuts the revs by cutting fuel. As the revs quickly approach redline the PFC cuts fuel but still maintains ignition timing as per usual. If this happens during an injector cycle and they are shut off prematurely then the air/fuel mixture is a little leaner for that cycle and pre-ignition may occur. The revs drop below the red line and injectors become active again for a bit before hitting redline and fuel cuts out again... etc... Each time this happens, the knock sensor picks it up.

So basically if you rev your engine and dont come off redline quickly you'll see your knock values increase the longer you hold your foot there.

Please correct me if Im wrong, but that is my understanding.

[chrissso]

Nah, ignition is cut, not fuel. That why you see big backfires on skylines sitting on the revlimiter.

I'm curious, please explain when, where, etc, you have seen high knock on a engine reving at the revlimiter?

Thanks

[paulr33]

ive had my car on revlimiter for long periods

no signs of any abnormal knocking

its probably just a case of a few cells near 7 grand

that have a bit too far advanced timing

[chunkylover]

so optimax extreme has its benefits when its properly tuned to it. Doesnt ethanol also acts like a detergent? i was thinking if i run optimax extreme all the time wont it wear out the cylinder walls and other compnents?

[paulr33]

no it wont do crap, its all wives tales. but yes putting optimax extreme in your stock ecu'd skyline is likely to achieve less detonation, but nothing more. i wouldnt expect much detonation on 98 premium anyway.

[Beer Baron]

Ok.

My understanding is that the PFC cuts the revs by cutting fuel. As the revs quickly approach redline the PFC cuts fuel but still maintains ignition timing as per usual. If this happens during an injector cycle and they are shut off prematurely then the air/fuel mixture is a little leaner for that cycle and pre-ignition may occur. The revs drop below the red line and injectors become active again for a bit before hitting redline and fuel cuts out again... etc... Each time this happens, the knock sensor picks it up.

So basically if you rev your engine and dont come off redline quickly you'll see your knock values increase the longer you hold your foot there.

Please correct me if Im wrong, but that is my understanding.

does this happen to you? Having spent a little time on the limiter (sometimes on purpose, ie burnout, and sometimes just brushed it on gear change) I have never experienced high knock levels. What knock level do you get in usual driving, and conversely what do you reach when hitting the limiter?

[assyrian4evaa]

just one more question about the knocking guys not that i have understood it but how do u find out if your engine is knocking?