Toluene, Xylene, methanol and thinners. Octane boosters!
 

I hear of a lot of people using a mix (15-20%) of methanol on a fill, typically this requires a retune.
However I don't hear of anyone on SN using A mix of petrol with toluene or xylene or even thinners (which is a mix of the two and a tiny amount of methanol)
The above don't require a retune as it is a similar hydrocarbon to petrol and is not an alcohol like methanol, so AFR remains the same.
A 10% mix typically raises octane to that of race fuel 105-110 depending on the fuel you start with.
What's the thoughts here? Facts please no scoobynet scaremongering!

Surely you would need a map for the extra ron of the fuel?

I run methanol, I dont see the advantage of using thinners etc?

Why would you need a map? The AFR is not going to change, only the knock supression qualities of the fuel.
That's exactly the advantage over methanol, add any of them (toluene, xylene or thinners) to petrol and you get 105 octane pump fuel. If that was available at the pump for the same money as normal unleaded I know I would use it.

Right, so the way i understand it is you get better knock supression the higher the octane, to take advantage of that you will be able to add ignition timing and more boost etc.

So why would you not run two maps to get more power out of the better fuel?

I understand running better fuel on the normal map will make things safer but it wont necessarily see a major increase in power. To take full advantage of that you need a map.

I can run the methanol in my non-meth map, but it doesnt give me a significant power increase over the normal pump fuel, it will make it safer though...

Does it not run leaner on methanol? As you need twice as much meth compared with petrol for the same AFR? What does your wideband say?
Yes you are correct, not necessarily more power, but safety. Of course you could map more power in, but you could also map your car for 95 octane fuel.

Well that is beyond my knowledge to answer, I was told to use the normal map when there is only a bit of meth left etc.

As for the technicalaties of that I am unsure.

Im going to go out on a limb and say its the same principal though, as with the methanol and on the meth map there is more ign timing and boost etc....

On the normal map this is wound back, so it may run leaner but the parameters on the map mean t is still safe. This could be complete rubbish but I dont know lol.

Mine is all closed loop AFRS etc so without logging into the computer I dont know, it corrects it its-self :)

i would wonder if there would be corrosive element to fuel system?

you would have to run 30% toluene inclusion to raise octane to 105 and 50% to 110.
20% meth raises V-Power to 101 ron.
Trev

There definitely is with methanol...

Thanks for the info, I trust your source is correct.
What does 20% toluene raise the octane to? More than methanol's 101? I suspect so.

There is toluene present in petrol just now, it is after all a hydrocarbon. There is more toluene in super unleaded. V power etc.
Yes I'm sure it's not good for rubber, neither is methanol (a lot more so) but petrol and rubber are not best mates anyway.
A good valid question all the same

Get a wideband ya tart ;)
If you ran straight methanol you would need TWICE as much for the same power, so adding 20% means you defiantly need more fuel for the same power, so runing on the normal map on a bit of methanol will be leaner, how much leaner depends on the ratio of methanol of course. Like you say probably harmless with only 5% meth.

meth is just under 109, toluene 121 so 103.4 with V power.
It would have quite an impact but I'd want the map done to get the best out of it

On the flip side you could run 10% toluene/xylene/thinners and have the absolute best of the map you have (no retard due to knock) and it would be safe as houses.
No harm in running a good quality fuel in that way.
Yep I'm sure lots more power is available if you put the timing in, but in a way the aggressive knock advance map in an impreza would advance the timing and make more power anyway?
Just thinking there are so many threads quibbling about 1 octane here and one there, v power or momentum oh no not ultimate etc. When all you need is 5 litres of toluene/xylene uhhum thinners. And your well above any fuel available at the pump? Or am I being a retard as usual

I'd want to be certain of the reliabilty of anything I put in the tank, personally I'd stay away from thinners but 10% toluene might run without issue.

Yep 20% methanol might run without issue too

Would a 10% toluene and 10% meth mix with vpower give better results than just 20% meth?

Think so, but 20% toluene would give even better results

But toluene itself costs more so was wondering if a mix with meth would be better

All depends on the quantity you buy either. Thinners are £1 a litre for 25 litres.

Had a look at toluene online for around about £38 for 20 litres? Where u getting prices from?

eBay, toluene is £42 for 25l delivered. Similar price to xylene.
But thinners are £25 for 25l delivered and do the same thing

What "fuel additives" was Andy forrest running to get 440hp out of a 2.0 RA with a 20g?????

I'm pretty sure Andy was running a high methanol mix and at one point straight methanol. Although straight methanol may have been on a different turbo.

Would have to be something wacky to get 440 out of it!

http://bbs.22b.com/forums/showthread.php?12987-Is-temperature-the-only-downside-with-toluene

Quote Andy forrest;
"I have used Toluene for as long as I have been using Methanol (over 5 yrs) with no ill effects on the engine or fuel system.
20% of both in V-power is hard to beat. Very few race fuels can match it with regard to detonation resistance and power output capability."
Says it all really

Read it carefully again though. He isn't saying 20% of either, he's saying 20% of both otherwise known as Scottimax ;)
He turned away from it long ago and now uses proper race fuel in his car, that really says it all. If he still rated it as highly he'd still be using it as it's far cheaper ;)

In my experience 20% meth added to Vpower or Tesco 99 yields approx 10% more power from most setups assuming they are knock limited on pump fuel alone.
It isn't all about the octane content either, don't get hung up on that as meth has more to offer in terms of it's cooling properties over toluene or xylene.

I like that you're always looking left field and admire greatly your work on the Audi gearbox, but when it comes to fuel additives it isn't necessary to experiment when everything you're trying has been done to death.

So that means 20% meth is better than 10% toluene and 10% meth?

Scottimax is 60% Vpower, 20% meth, 20% toluene.