Why isn't toluene used for race cars?

[Stevisiov]

I am doing a project on rally cars. One of the problems that came up is power loss with attitude. I am aware this is around 3% for every 1000 feet in naturally aspirated cars, however this power loss is significantly reduced by forced induction. The more pressure added by forced induction, the less net power loss (providing the forced induction maintains efficiency).

From what I can work out, the problem with running a high boost turbo is that if you add too much boost you get pre-ignition. The solution would be to get higher octane race fuel. From what I can find, high octane petrol based race fuels allow you to run around 25 psi of boost, whilst methanol will allow you to run almost 30psi. I then stumbled across toluene, which apparently was used in the F1 turbo era. In qualifying they ran with up to 73 psi boost with allowed them 1000hp per litre.

Presumably there is something fundamentally wrong with toluene but I can't work out why it is. Is it banned from most series? Are there reasons why it isn't used in say road cars?

Its the first time I have really looked into fuels so I will admit I am pretty ignorant about the subject

 

[TB]

From the wiki article:

Toluene can be used as an octane booster in gasoline fuels used in internal combustion engines. Toluene at 86% by volume fueled all the turbo Formula 1 teams in the 1980s, first pioneered by the Honda team. The remaining 14% was a "filler" of n-heptane, to reduce the octane to meet Formula 1 fuel restrictions. Toluene at 100% can be used as a fuel for both two-stroke and four-stroke engines; however, due to the density of the fuel and other factors, the fuel does not vaporize easily unless preheated to 70 degrees celsius (Honda accomplished this in their Formula 1 cars by routing the fuel lines through the muffler system to heat the fuel). Toluene also poses similar problems as alcohol fuels, as it eats through standard rubber fuel lines and has no lubricating properties as standard gasoline does, which can break down fuel pumps and cause upper cylinder bore wear.

Sure it'd be easy enough to do something similar to Honda and warm up the toluene first. Then you could replace the rubber gas lines with metal, but depending on how quickly the fuel pump and engine breaks down because of not having a lubricant, that could be part of it. Of course, that would be if they were running 100% toluene and if they were, I would imagine that something could be used as a lubricant.

Edit: I'm not sure why it took me so long to realize where I had heard toluene before, but it's one of the main components of TNT, which might have more to do with why they aren't using it than engine wear...

 

[Alex.]

Amended.

 

[wfooshee]

^^ Which has what to do with toluene?

 

[Alex.]

Damn I thought It was the general question thread when I clicked.

Ill edit, and repost in that thread.

 

[Stevisiov]

From the wiki article:

Sure it'd be easy enough to do something similar to Honda and warm up the toluene first. Then you could replace the rubber gas lines with metal, but depending on how quickly the fuel pump and engine breaks down because of not having a lubricant, that could be part of it. Of course, that would be if they were running 100% toluene and if they were, I would imagine that something could be used as a lubricant.


which might have more to do with why they aren't using it than engine wear...

Cheers, I should have looked at wiki a bit more closely. I hadn't heard of toluene octane boosting until today. I guess the reasons above are clear cut enough. A bit too impractical and expensive.

Edit: I'm not sure why it took me so long to realize where I had heard toluene before, but it's one of the main components of TNT,

trinitrotoluene, although IUPAC nomenclature means we have to call it 2,4,6-trinitromethylbenzene in chemistry doesn't have the same ring to it.

Why isnt a race style steering pinion used on road cars? Surely it'd be alot easier to have 90 degree steering lock rather than 270 ish.

Easier for parking yes but a bit tired to work with all the time since its a lot more sensitive, a twitchy road car isn't what most people want.
In racing cars quick racks are great, but remember race cars also have limited steering angle, usually to allow them to run with big fat tyres. You don't need to parallel park a race car so they don't need much angle lock to lock.

Put simply if you gave a race car the amount of lock a normal car has but you could achieve it all within 90 degrees turn of the wheel the cars steering would be hyper sensitive and scrubbing off speed cornering form to much turn would become all too easy to do. (I tried it in Live for speed believe me ) If you significantly reduce the amount you turn the wheel, you will have to reduce your maximum steering angle to compensate.

So while race cars need less turn of the wheel to go from lock to lock, you also have to take into account that the maximum steering angle is reduced also.

Personally I would love a quick rack in my car so I can keep the same maximum steering angle for less turns of the wheel. I would like the high sensitivity, most people however would not.

 

[Alex.]

Thanks steve, I understand
(even if it was in the wrong thread)

 

[Pupik]

The FIA started to ban certain substances from racing fuels around mid-1992; I recall the ban it was more about reducing potentially detrimental heath effects from exposure (skin contact and breathing the fumes) than slowing the cars down (an immediate 50-100 horsepower loss).

 

[TheCracker]

The FIA started to ban certain substances from racing fuels around mid-1992; I recall the ban it was more about reducing potentially detrimental heath effects from exposure (skin contact and breathing the fumes) than slowing the cars down (an immediate 50-100 horsepower loss).

👍

From the FIA regulations website:

FIA regulations state that the rules are “intended to ensure the use of fuels which are predominantly composed of compounds normally found in commercial fuels and to prohibit the use of specific power-boosting chemical compounds.

I would think that the WRC regs follow these quite closely too.

Once upon a time we bought a barrel of 'special' fuel from a guy who worked for a team that ran one of the F1 outfits as well as one of the works World Sportscars teams. Even when heavily diluted with normal fuel it made a noticeable difference to the Cortina's performance. Trouble was, even when stored in metal cans you couldn't transport the stuff in the van because it stank dreadful and made you feel quite sick. My dad was happy when it eventually ran out, he'd been storing it in a brick shed by the side of his house and on a warm day you could still smell it when indoors, it must have been pure evil.

 

[Keef]

Cracker, you should rig up a separate nitromethane injection system on your racer. That'll motivate her.

 

[Casio]

Because too much toluene will blow the welds on the intake manifold hotshot.

 

[niky]

Are you allowed to use Water-Methanol injection on the project car? Methanol injection allows you to run a whole lot of extra timing or boost, but it can be problematic if it runs out... (heavily modified turbo set-up plus clogged methanol injector = boom).

 

[Jay]

A friend of mine started making his own Toluene mixes for his 800hp+ SR20 (2.0L Nissan engine) street car, he was using pump fuel prior, I never questioned him about it much so I am not sure on the mixes he used but I know he was able to add timing and boost and he was happy with it (well happy as he could be). Since then the engine is going in another car (the first car rolled off a car trailer) so not sure what fuel he will use.