Octane booster

[TTM]

Good morning gents,

As there are fewer people in diseasel-infested Euroland using petrol engines, even less so who fill up with fuel of the highest octane, I believe 98 RON has the lowest turnover at petrol stations and I seem to find myself sometimes filling up from various tanks with somewhat old-ish fuel.

Add to this that the car is being run with the airbox but without the snorkel (the turbo doesn't work if running with the snorkel), meaning sucking in warm air, I have been annoyed in the last days by constant (inaudible) knock with boost pressures no higher than 13psi.

-> would it be worthwhile to use some octane booster, if so which one?

(...and no I still don't want to fit a cone filter behind the left headlight...)

Thanks.

 

[zcacogp]

... or fill up from a garage with more high-octane trade, thus getting fresher jungle juice?

Or (and I'm ignorant of the un-bonnet shenannigins of a turbo, apart from the fact that they inferior to those of an S2 []) can you arrange some ducting or shielding such that you get a decent amount of good cool air to the intake?


Oli.

 

[944s2]

Would have thought that there a sufficient petrol cars on road to ensure petrol does not lie for a while in garages

Lets be honest it probably, unless you are high milage user, lasts longer in your tank that the garages tank

Which brand are you using?

The fact that your air intake is "non standard" is more likely to be issue

 

[idwoodvale]

Tesco seems best value - 99 RON at only a penny or so more than standard Shell etc. where I live.

 

[944 man]

Nitrous Formula works, others Id avoid on the whole. How many octane points (4 to the RON) will you need though, to make up for too high an intake temperature?

Im going to suggest water or water & methanol (more complicated) injection.

 

[sawood12]

I'd get some cold air piped into that airbox ASAP. That is probably the main cause of the issue rather than old fuel. But I guess adding Octane booster can't harm in the long run if it prevents the knock.

 

[Diver944]

Hi Thom, do Shell in France supply the V-Power 100 Ron yet?

I've never heard of an octane booster that raises the octane more than a whole RON, they all talk about fractions of RON []

Can you get easy access to Toluene over there? Very nasty, carcinogenic stuff if handled incorrectly but you can mix a veritable rocket fuel for a few quid when added to standard petrol. There are mixing quantities listed over on Rennlist

Or 50 litres of 102RON racing fuel can be had online for £170!!!!!!! www.atolfuel.com/index.php?pIDref=113

or 5 Gallons US of 109RON fuel for only £120 [] www.motorshack.com/acatalog/VP_Motorsport_109_Race_Fuel.html

 

[944 man]

NF is the only product Ive seen which will raise your octane by four points or more (one RON).

 

[Super_Marv]

ORIGINAL: Diver944

Hi Thom, do Shell in France supply the V-Power 100 Ron yet?

When I was in France in September, V-Power was 98 Ron. Couldn't find 100Ron V-Power in Switzerland, despite the Swiss Shell website saying it's 100Ron, it was all 98.

The only two countries I could find that sell 100-Ron V-Power were Austria and Germany. A litre of 100 Ron V-Power was €1.22 in Austria but €1.52/L in Germany []

I did hear that the V-Power in Italy is 100Ron, but I didn't drive much through Italy, so never saw a Shell garage.

Didn't make much difference in my 968 (maybe a bit more mid-range) but a turbocharged car will probably benefit alot more.

Aral in Germany also sell 100 octane fuel.

Time to nip over the border to fill up, Thom []

 

[marcoturbo]

Buy some Toluene or Xyene and do your own mix or wait a few weeks for VR selling a water injection system []

 

[TTM]

I have been leaning towards filling up at low costs petrol stations as I use the car almost everyday - it is such a pleasant drive with the new engine - and driving on narrow and twisty roads reflects in the fuel wast.. err... economy [&:]

Scott, I could not make proper ducting for the airbox.
I made an aluminium duct shim that I fitted inbetween the airbox and the (wide open) snorkel to compensate for the lack of room caused by the hard pipe from the IC to the throttle body, but even with some more ducting allowing forced air coming from the front bumper I get more knock than running the airbox with no ducting at all.
The next step is to cut the cover of the spare airbox and see if a Naca duct fitted on the hood can be made to fit both without touching (too much) the filter cartridge and alter the stiffeners of the hood.