Octane Boosters????

[vxrphantom]

Guys I appreciate that these so called octane boosters you can buy are not going to markedly add to performance, but is their any benefit to them as they add to the octane rating? Its just with VMAX looming and lots of high speed runs high temps etc wondered whether they would at least offer something mildly valuable albeit in terms of knock protection.

[after_shock]

I tried it a couple of times in my old car (modified turbo engine) and can honestly say didnt see a single difference!

Have a bottle of the stuff in the garage but have not tried it in the Monaro so cant comment on the V8's.

[Magic919]

The way I see it your engine doesn't need any knock protection as the ECU will pull timing when the intake temps get high. Failing that it'll head towards the timing of the low octane map if it detects knock.

I'd just run the tank a bit low and fill up with your favorite high octane juice near the venue.

[k15tox]

personally i think there a load of bobbins, i think it was 5th gear that did a test, and some of them actually lost power!!! overated waste of money.

in my previous skyline i used v-power, well because i had to due to japanese fuel being 100 ron.

i can see a benefit with high revving or modern turbo engines, but with a simple v8 like ours there is absoulutey no need on a standard map.

i think on the 6.0l vxr vauxhall advise you use super??? (correct me if im wrong). i think its just a money making agreement they have with the oil companies. like ford recommends bp ultimate......in a 1.25 8v fiesta?? p**s off!!

obv if your going down the forced induction route you may get more power off super with the correct map.

dont the yanks run ls1's on 93 octane or something???

[vxrphantom]

Magic919 said:

The way I see it your engine doesn't need any knock protection as the ECU will pull timing when the intake temps get high. Failing that it'll head towards the timing of the low octane map if it detects knock.

I'd just run the tank a bit low and fill up with your favorite high octane juice near the venue.

Yes thought as much, but surely if I can prevent knock then the timing will not have to retard and therefore power will stay available?

[stigmundfreud]

if you want to spunk money up the wall then by all means buy some

[monkfish1]

vxrphantom said:

Magic919 said:

The way I see it your engine doesn't need any knock protection as the ECU will pull timing when the intake temps get high. Failing that it'll head towards the timing of the low octane map if it detects knock.

I'd just run the tank a bit low and fill up with your favorite high octane juice near the venue.

Yes thought as much, but surely if I can prevent knock then the timing will not have to retard and therefore power will stay available?

If your using decent fuel, then you wont get any knock if its set up right - which it is

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k15tox said:

i think on the 6.0l vxr vauxhall advise you use super??? (correct me if im wrong). i think its just a money making agreement they have with the oil companies. like ford recommends bp ultimate......in a 1.25 8v fiesta?? p**s off!!

dont the yanks run ls1's on 93 octane or something???

Factoid of the day, but the atual reason for the "super unleaded advised" is that when testing for the brochures etc the engine in benchtested on the best fuel available for the local market. Thus when the car specifications are released the engine will only develop the advertised power when on super unleaded. This is to prevent anoraks bringing lawsuits against the manufacturers saying my car doesn't get xxx bhp. Hardly surprising - the rules don't dictate that super unleaded shouldn't be used for this so why handicap yourself when every other manufacturer is using super unleaded on it's figures!

The yank system is better than the european <shudder - can't believe I said that>.
Fuel has several different specifications but two of them are RON and MON. Ron is the resistance to knocking (relative to a standardised combustible liquid) under low/moderate engine speeds and load. So 97Ron fuel is 97% as effective at preventing knock as the standard.

However MON is the same standard but under heavy engine speed and/or load (which is by far more relevant to performance cars).
Most fuels in the UK are about 86-88 MON.

We only advertise the RON value (and the MON can be quite hard to find) however in the US they take the average of the two.
So a fuel that is 98Ron/88Mon (the old optimax stuff) would be advertised as 93 Octane in the States.

It takes a fair bit of tuning on NA to start needing anything more than 98/88 fuel. Obviously FI can dramatically reduce the effective knock resistance by increase the cylinder pressure. Knock also reduces the higher up you go too.
I had a NA car with an engine tuned to 98/88 and it did make a bit more power (was a track engine) but not worth the hassle.

Oh, steer well clear of the octane boosters.

However if you have a diesel car a small amount of acetone (nail varnish remover) works reallly well.

[Windy Miller]

Essential on mine (04 CV8 - Wortec Sport Pac)

It doesn't make any noticable difference on performance, but with the dinosaur piss that is sold up here in Orkney (at great cost!) as an excuse for petrol, its essential to stop the pinking sound. Boot it with ordinary (95RON - Its the best we've got!) and it pinks like mad. Maybe not enough to activate the knock sensors, but certainly enough to hear it. Bung in a bottle of Millers Octane Booster every fill up and it sounds like it should.

Have alternated between using it and not to prove conclusively that its making the difference.

[stigmundfreud]

I thought wortec were tuned to 95 octane?

Glad I tuned to 95 then!!

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The problem is that all 95ron means is that this is the minimum level the fuel must be to meet the regs.
As such there is a safety margin built in so most petrochem companies actually supply 96/97 ron fuel branded as 95 to ensure that they always meet the standards. There are preople that go around spot checking and the fines can actually be quite large.

So if Wortec tune to a decent 95 ron fuel which is actually say 96/97 but the fuel where you are is much closer to the 95 limit then it could still legitimately pink.

[stigmundfreud]

the other issue being how regular is the fuel used at the station. Would you buy 98 or 95 from a station that sells a st load of 95 but only sells a few litres of 98 every few weeks?

[Boosted LS1]

What's the stuff people get from spray shops which raises octane? Tuolene or something that sounds like that. I've never used it but some racers like to chuck a bit in the tank.

[TerryS]

Toluene Mike, I used to keep 205 litre drums of the stuff in the Garage. It was great on Supras upto a 30% mix after which the plugs fouled badly. There is simply no substitute though for proper race fuel like Klotz, VP etc but Toluene if purchased as a paint thinner & not for Motor sport use is much much cheaper.

Edited by TerryS on Sunday 10th May 19:44

[stigmundfreud]

You can still get 5 star in some places, I think BP or Shell do a special mix which is sold near brands and silverstone

[TerryS]

stigmundfreud said:

You can still get 5 star in some places, I think BP or Shell do a special mix which is sold near brands and silverstone

Yeah BP do a high octane unleaded at a limited number of garages but the price is just silly.

[Boosted LS1]

TerryS said:

Toluene Mike, I used to keep 205 litre drums of the stuff in the Garage. It was great on Supras upto a 30% mix after which the plugs fouled badly. There is simply no substitute though for proper race fuel like Klotz, VP etc but Toluene if purchased as a paint thinner & not for Motor sport use is much much cheaper.

Edited by TerryS on Sunday 10th May 19:44

Thanks Terry. Some friends used to use it for road and drag strip use Not sure how risky it is though.

[stigmundfreud]

TerryS said:

stigmundfreud said:

You can still get 5 star in some places, I think BP or Shell do a special mix which is sold near brands and silverstone

Yeah BP do a high octane unleaded at a limited number of garages but the price is just silly.

considering it used to be widely on sale even when I was a kid

[ringram]

My understanding is that you want the fuel with the most energy content that lets you atain MBT. Which is best timing for max torque. Higher octanes have less energy content but resist knock better.
So you wont really know unless you try different fuels and retune to see which one works best. The stock setup tells you in the manual what to use. So if you are stock and run 98 when it says 95 then you are just wasting money.

Im currently tuning for 95 octane to save ~7% on fuel Im not sure if I would gain 7% retuned on 98. I might give it a go one day. In the mean time Im still messing around with 95 and it seems fine with timing around 23* at full whack and no sustained knock.

[the muppet]

Boosted LS1 said:

TerryS said:

Toluene Mike, I used to keep 205 litre drums of the stuff in the Garage. It was great on Supras upto a 30% mix after which the plugs fouled badly. There is simply no substitute though for proper race fuel like Klotz, VP etc but Toluene if purchased as a paint thinner & not for Motor sport use is much much cheaper.

Edited by TerryS on Sunday 10th May 19:44

Thanks Terry. Some friends used to use it for road and drag strip use Not sure how risky it is though.

Toluene can swell and dissolve some rubber components, ie o-rings and seals