Introduction
Bio-Ethanol
Frequently Asked Questions
Fascinating Facts

EEMS caught up with Triple Eight Race Engineering’s Raphael Caillé for some answers for those considering running bioethanol in race engines.

Raphael has been Triple Eight’s Engine Special Projects Manager since 1998. He now lives in England with his English wife. He has a degree in Mechanical Engineering, first became a teacher and then went into motorsport, working on the Paris Dakar Rally Raid and then with Sodemo with engines for the Williams BTCC team before moving to Triple Eight Race Engineering.

He is responsible for the engines in the E85-fuelled Thurlby Motors Boston Bowl Astra that runs with EEMS support in the British Touring Car Championship with driver Fiona Leggate. E85 is a blend of 85% bio-ethanol and 15% petrol. The EU Guidance Note for the specification of E85 as road fuel is being used as a starting point by the MSA to set an E85 motorsport specification.

What are the main aspects to consider with Bio-Ethanol in a race engine?

It’s a matter of the calibration of the ECU, its mapping, the camshaft timing for the injection time to let more fuel through, because the mix of fuel to air differs. With petrol, it would be one gram of fuel to 15 gms of air. With ethanol, it is one gram of fuel to just 10 grams of air.

How long does it take to build the engine?

It takes one person one week to build this race engine. The present Astra engine has five years of development from the road engine, from which we took the original block, the head and the water pump. There is even aero work on the engine as well as outside of the car. On the dyno with ethanol in the engine, it developed 285Bhp, which would give a potential top speed of 260kph (162.5mph). We do engine rebuilds every 1700 kms, and then we replace the valves, springs, pistons, rings, bearings of the con rods and camshaft timing chain.

How difficult has it been to convert the engine to Bio-Ethanol?

I waited a long time to do this, as other people told me it would be difficult and complex. With my experience now, I would say it was easy and I wish I had not waited so long!

If You're running Bio-Ethanol fuel in a racing engine, what components have to be different?

In our experience building the Astra engine, you don’t have to change any hardware, but the fuel map for the ECU has to be recalibrated by the engine builder. If it was a road car engine and you could not do this, you would change the injectors so that they flow 30% more, to allow for the change in energy density. Bio-ethanol needs 30% more volume to give the same amount of energy.

The Saab Flexi Fuel Vehicle (FFV) can run on varying mixtures of bio-ethanol to petrol – how can it do this then?

Saab has developed ECU software which adapts the fuel map to suit once it senses what fuel is going through.

As this is an alcohol fuel, what do you have to watch on rubber materials such as seals?

Our experience is that it causes no problems. Any race car standard system is perfectly able to handle the aggressivity of the bio-ethanol, including the fuel bag in the fuel tank.

What about the storage of the bio-ethanol?

This has proved important. Bio-ethanol does attract water. We always leave the tank either completely full or completely empty so there is no chance of water ingress, and we make sure the drums are stored in a dry place.

How about the power and reliability?

The power would be the same without further modifications to the engine. But you will have room to make modifications and get more power because of the high octane rating of 107.1 RON. In the BTCC, compression ratio is fixed at 12:1. For other championships, to gain power, there is a possibility to increase compression ratio depending on the octane rating of the fuel, whether it’s pure bio-ethanol or a blend. As for reliability, the combustion happens in the same way as with petrol, the mechanical stresses are identical.