mx5cartalk.com

Hey guys,

I'm about to have an engine rebuild done for my road registered track car shortly and have been considering whether or not to set it up to use E85 fuel. The car is primarily a track car but might be dríven on the road once a month if it's not being raced. I currently have a Platinum PS1000 ECU so it looks as though I'd be up for some new fuel lines, some bigger injectors and possibly a new fuel pump.

I'm aware of an E85 fuel discussion here: viewtopic.php?f=81&t=44582 but considering this isn't for a FI application I though I'd start a discussion here.

Thoughts?

I assume your going for E85 for the power gains?

First stop for me would be to investigate the rule book for your series / class and see if you are allowed to run E85. If you are will the injectors and aftermarket ECU alter the class you are in?

Yes I'm considering the E85 for the potential power gains and as far as I can tell because it's considered a "commercailly available pump fuel" then it's ok for our Production Sports Car class (CAMS 2F & 2B). Both aftermarket ECUs and injectors are "free" under the 2F rules.

Another advantage of running the E85 fuel seems to be lower engine temps which is always a good thing on a track car.

Fuel pump and injectors.
Fuel line may handle the volume which will be ~ 30% higher
'Rubber' in lines will not handle E85 but neoprene etc will.
A fuel filter change regularly will be required as the E85 will release all the gunk that petrol has deposited in the fuel system.
You may have problems as the gunk was masking problems.
10% power improvement over a well tuned petrol of 98 is not unrealistic according to my sources.

E85 will absorb moisture and separate with lack of use so if not a daily or at least weekly drive you'll need to drain and store in an airtight container.

Availability might be a problem atm but you can get 200litre drums delivered.
http://www.racefuels.com.au/newsDetail.asp?ID=129

Hey Paul,

Also keep in mind the consumption.... they drink the stuff with upwards of 30% more needed. For normal spring racing not a problem but for one hours at tracks with WOT a lot of the time you may find you run out near the end. We suggested adding a swirl tank for 2F cars in the regs but so far this has not been adopted....

It is the way of the future and something we will all need to adopt for racing when the bunny huggers get their way......

Yes, the extra fuel consumption would definitely be a factor in the 1hr races. I've heard of guys running a reserve tank for the 1hr races but never seen any of the setups in person.

in 2F you cant run a reserve/second tank. I dont think you can even run a surge tank??. You can replace the OEM tank with another one that meets all those fancy FIA regs (and the cost associated with them) and increase the capacity but due to space limitations this would probably only fit in the boot so not the best place for weight distribution.....

In 2B not a problem. We've just fitted one to the BMW before we go to PI next week. After Morgan Park we had just 2 litres left in the tank at the end........

Now we should be ok for Phillip Island.. and Bathurst

E70 - E85 from the Pump.

I am told to assist cold start that sometimes the Gas Stations will be selling an E70 ish to E85 percent blend.
Unlikely the station would even now.

If you get a hard tuned E85 setup make sure you use the race fuel.

I am told by the Honda boys that very high compression is possible with E85 would love to see an NA MX5 running 13 to 1 Pistons

mx5racing wrote:in 2F you cant run a reserve/second tank. I dont think you can even run a surge tank??.

Ah ok. Can't remember who it was that mentioned the reserve tank but it could have been a 2B competitor.

That could make things a little more difficult to run E85 in the 1hr races then. Maybe two different ECU maps to switch between E85 for sprints and 98 for the 1hr races?

TCR, not sure if you saw this very recent post from a thread other than above:

rjastra2 wrote:Motor has a test of a E85 SS Commodore this month. Power/Nm figures are near identical between the fuels

The surprise was the fuel consumption test they did

freeway run netted 9.3L/100km on PULP and 9.7L/100km on E85. Average price difference was 30c/L.

viewtopic.php?f=53&t=44539&start=15

Couldn't find the article online for more detail, but believe it's from Motor Magazine December 2010, but did see this:
http://www.ls1.com.au/forum/archive/ind ... 42984.html

Is a Catalytic Converter needed with E85 ?

I have heard stories about failures due to too much ethanol or they run too hot.

Not sure as they seem to be rumours but it would be good to hear from an expert as to whether these expensive restrictive devises are still required or need to be modified.

E85 will absorb moisture and separate with lack of use so if not a daily or at least weekly drive you'll need to drain and store in an airtight container.

+1

Found this very informative post
http://forums.turbobricks.com/showthread.php?t=73061

Im running E85 in newcastle right now. anyone who wants to have a look see can text me on 0401387968 and come have a look at the car and my old maps compared to my new maps.

Its worth 11ish percent based on the decrease in calorific capacity and increase in fuel pumped in due to air fuel ratio changes. But that doesnt account for the fact you can run heaps more boost and timing.

In other words, it outputs less energy per kilo burned than 98ron, but you actually pump in 42% more (by weight, 30% by volume cos its heavier) and because you pump in more you make more power. Nitromethane has less energy per kilo than 98ron but you pump in 5 times more for it to run.

You pump in more because every revolution you suck in a fixed amount of air (atr the same volumetric efficiency). Lets assume 1600cc for a 1.6L, and you need to get the right amount of fuel in so that all this oxygen is used, but during combustion E85 releases much more oxygen on its own, requiring more fuel... hence making more power.

Because its 105-110 octane you get not only 11% more from the fuel energy output, you also get the gains from running 40 degrees of timing in a naturally aspirated application, or stock rather than reduced timing with lots more boost, and this advantage gives you more power again on top of that 11%.

Cheers,
Dann

This post was a copy pasta of another post i just wrote in turbo/super forum cos i couldnt be bothered typing it up twice.

93_Clubman wrote:TCR, not sure if you saw this very recent post from a thread other than above:

rjastra2 wrote:Motor has a test of a E85 SS Commodore this month. Power/Nm figures are near identical between the fuels

The surprise was the fuel consumption test they did

freeway run netted 9.3L/100km on PULP and 9.7L/100km on E85. Average price difference was 30c/L.

Said Commodore's build thread on JDMST...
Linky

He covers his E85 stuff fairly well somewhere in there.