E85 on RS2: 22% more torque, 10% more power

[goinginzane]

Ive been looking for a thread like this some time. Glad i found it.

I have an audi 90 quattro with AAN engine, stronger rods, 650 cc injectors, stronger fuelpump etc. I was looking for 450 hp on 98 RON. Now i heard they started selling E85 at a local shop and this got my intrest.

If i read correctly the only thing i would need is a wideband and a adjustable fuel regulator. Im i correct on this?

The car has to be mapped yet. Is mapping on E85 different than mapping on 98 RON?

If this is all i think im going to buy Vems with wideband and an adjustable fuel regulator next month

[prosty]

What about the valve breathing, some ppl say that you have to change oil more frequently, and build better valve breating because the car runs richer and therefore goes into the oil more.

[EspenW]

Ive been looking for a thread like this some time. Glad i found it.

I have an audi 90 quattro with AAN engine, stronger rods, 650 cc injectors, stronger fuelpump etc. I was looking for 450 hp on 98 RON. Now i heard they started selling E85 at a local shop and this got my intrest.

If i read correctly the only thing i would need is a wideband and a adjustable fuel regulator. Im i correct on this?

The car has to be mapped yet. Is mapping on E85 different than mapping on 98 RON?

If this is all i think im going to buy Vems with wideband and an adjustable fuel regulator next month

Yes, you need a wideband and most likely an adjustable FPR.
You don't mention what kind of turbo you run, but I guess a 3071R or something of that size. with 650cc injectors (you sure they're not 630?) I guess that you will end up with a fuel pressure of approx. 3.8bar for an AFR of mid to high 11's.
MBT is pretty much equal for E85 and petrol, but you will be able to reach it or go way past it on E85. It is easier to simply increase the boost in order to take advantage of the sky high effective octane of the fuel.
You need approx 40% more fuel on straight E85

[EspenW]

What about the valve breathing, some ppl say that you have to change oil more frequently, and build better valve breating because the car runs richer and therefore goes into the oil more.

I have seen oil analysis done where the lab (Blackstone) was not able to tell that the car in question was running E85, so oil dilution is not automatically an issue.
The car will run basically the same lambda, so percentage wise, the same amount of unburnt fuel on WOT. Unless running WOT constantly, this should not be a problem.

[goinginzane]

How much km have you run with E85? No problems so far? How easy is it to switch from E85 to 98RON? (i have no idea how an AFR works)

Im running a garret T60-1 which should be capable of a good 500 hp according to ATPturbo.com.

Here in holland lots of people keep talking about rubbers that wont last but no one has any experience.

I think i going to think about this for a week or so.

Power gain is great but i dont want this to end up broken because i used E85.

[EspenW]

Cars made after approx. 1986 have alcohol resistant fuel systems, since they were obligated to tolerate alcohol (E10) since that year.

I have been running my 1986 Golf on it for almost 3 years, and the RS2 since last fall. Absolutely no problems.

The challenges are cold starts and the ability of the fuel system to deliver enough fuel.
High capacity fuel pump and larger injectors is what is required. Due to limited availability of the fuel, it is (in most countries) necessary to have a setup that allows straight petrol as well. Adjustable fuel pressure regulator and a wideband OXS with readout takes care of that.

[Bram]

For the bi-fuel setup; would you need a second ECU mapping as well I presume? How did you solve this? Or do you run E85-only?

[goinginzane]

i was thinking kind of the same bram. Do i need to maps?

When i decide to go for Vems it would be possible to make a map for petrol and a map for E85. I that case would you still need an adjustable fuel pressure regulator? in my opinion it would be possible to give less fuel in the map for petrol and more fuel in the map for E85 but would this be enough?

[A80Avant]

with vems you dont need an adjustable fpr.

Billman was using E50 in germany and 98oct.in greece. all you have to do is get injectors to cope and build 2 separate maps for the different setup.

The only thing is that with the current firmware of VEMS, it is not as easy as a switch adjustable maps.So you would need to have the laptop there to do the switch.Or you could have a carpc and do it instead

[EspenW]

On the Golf, with help of the Innovate LC-1, I have programmable closed loop lambda feedback at all times, so it can run any mix of alcohol and petrol.

On the RS2, I run a 1.7bar base map for 98 octane. On E85, I run 3.7bar fuel pressure. If I have to run petrol, I lower it to approx 2.2bar.

Just the fuel itself provides a huge gain, but the octane lets you increase boost and/or timing. Increasing boost is easy. Just make sure that your turbo can deal with it.

[Thuppu]

Interesting thread. About the emissions, the CO2 seems to drop quite much, but how about HC and CO?

[EspenW]

Interesting thread. About the emissions, the CO2 seems to drop quite much, but how about HC and CO?

I did a quick google, and average numbers based on controlled testing seems to be the following for E85 vs. petrol:
-22% for CO,
+ 12% for HC
-8% for NOx