VW Passat R36 flexi fuel

[eurobahn5]

Has anyone run E85 in their R36, could it be a possibilty for more power ? Any ECU's that will do this ?

[Martin]

E85 has less power than petrol

To make E85 produce more power on a NA engine you need to significantly modify the engine with a very high compression ratio - then you can't run it on petrol at all (it will detonate and die, quickly)

E85 works on FI due to the availability and manageability of boost

Read this...
E85 – Why is it so popular - Nulon blog

[brad]

E85 blend has less calorific value than straight petrol but has a lot higher octane. There are also other side benefits of running ethanol such as the cleaning properties, and the high oxygen content of ethanol.

You can run a lot more advance with e85 (which is what helps make power) but you'll need to ensure that the fuel system (fuel lines & seals) won't degrade with prolonged use of high ethanol content fuels.

You also have to ensure the fuel injectors have sufficient headroom to flow an additional 30% fuel.

If you move to E85 you either need to be able to run it 100% E85 or have a switchable map ECU. If you run it in your unmodified VW the o2 sensor will get confused and run the system rich and eventually kill the sensor.

We've had 2 flex fuel cars at home (V6 Captiva and some other abortion) plus I've had flex fuel Chryslers overseas and it really hasn't worked as the fuel maps are fairly primitive and not well implemented.

I have driven a couple vehicles with custom E85 tunes and they were very impressive.

try run E10 100ron. It's within the design parameters & will make a slight difference.

[eurobahn5]

Thanks guys for your prompt reply, it seems there are divided views. I think I wont worry about it for now...

[brad]

Thanks guys for your prompt reply, it seems there are divided views. I think I wont worry about it for now...

I don't think martin & I have divided views.

You need to prep the car properly & do a bit of work to optimise the map. You'll also be wedded to E85 or switchable maps as flex-fuel doesn't work well.

A mate of mine is one of the better Subaru tuners - he does lots of very successful E85 tunes on WRX & BRZ.

Suggest you do a bit more research although your biggest problem will be finding a tuner.

[Martin]

Brad and I are saying the same thing - just calling out different points

I agree that factory fuel-flex systems are very primitive

Personally I would find it very hard to justify the E85 cost on a NA engine given the limited power improvements obtainable

I have a friend preparing a Nissan 370Z for racing on E85 - he is targeting a compression ratio of 14:1 !!!

[NasirAzizii]

Yeah can anyone give me some info on it as well ? What would you need to change for the car to be compatible ?