[s-cars] E85 fuel

Sat Apr 15 09:16:19 EDT 2006

Hello,
We are several in Scandinavia using E85 fuel in our hot street Audi engines. I'll try to list some pros and con first based on my own original IMSA engine and the dyno session including both race gas( VP 102 octane) and E85 fuel (15% 98 octane+85% ethanol as bought from the gas station).

Engine specs:Original IMSA engine with 4 valves pr cylinder, two separate intake and exhaust runners pr cylinder, 81 mm bore x 86mm stroke, 7,5 CR, KKK 7634(wheel is OD 86mm-ID 65 mm(76 %) ) with # 9 and16  exhaust housing(wheel is OD 76mm - ID 67 mm)(turbo is equal to a T66 i believe), Inconel tubular exhaust manifold  10 pcs 650 cc Siemens low ohm injectors, Autronic SM2 ECU, two Autronic R500 CDI boxes, 5 pcs Mercury Formula 1 2,5 liter outboard ignition coils, Se link for pics and details. Power was stopped at 705 hp/760 Nm @ 2,0 barg boost(AUDI sport managed 736 hp at 2,3 barg boost in 1989) due to wastegate limitations and increasing backpressure in turbo exhaust housing.

http://www.gatebil.no/index.php?objectid=459&pageid=153&offset=10

E 85 Pros:
1) Exhaust temp is significant lower, approx 60-80 Degr C in favour of E85 to race gas on full load

2) Power is up 10-15% with use of E85 due to more oxygen molecules, (its like getting a new turbo with slightly increased airflow)

3) Price pr liter is around 1 USD/liter compared to 6 USD/liter in Norway

4) High resistance against knocking, at 2 barg boost with race gas we were limited to 20 degrees ign advance, with E85 we advanced to 40 + degrees with no signs of knocking(Dyno shop used a special electronic sensor with head phones)

5) No material problems observed due to alcohol mix, I were running Russel hoses and couplings, two Bosch 044 fuel pumps aluminium fuel rail etc

Cons:

1) Approx 30 % more fuel required pr horsepower, which sets high demand on the fuel system.

2) Unable to start engine with temperatures below 4-8 degrees celcius due to low atomization.

3) Normal Motronic with 5 Beru coils ala AAN or ADU will give misfires at 1,3-1,4 barg boost

4) Ignition system is real expencive in order to run high boost

So to sum it up, you could use pure E85 in the URS AAN engine if you increase fuel delivery approx 30% either by new injectors or adjusted FPR. Unless you use an engine heater in cold weather the engine will not start. Power increase will be limited due to low spark enegergy with Motronic and 5 coils.

Best regards Joern

Dyno results:

MAPPING of IMSA MOTOR 23.12.2005				VS-MOTOR				
BORE 81mm		STROKE 85 mm		Comp ratio 7.5/1				
Original IMSA KKK 3476 ,comp wheel  OD=87mm, ID= 66 mm,( equal to Turbonetic T66 )								
Autronic SM2, w/ign expander #5, 2 x CDI 500R,  5 x Mercury 2.0 F1 racing coils								
10 x Siemens 650 cc/min, 5 barg fuelpressure static- 1:1 fuel pressure regulator(adds boost incr.)								
102 Octane VTR Race fuel and E85 fuel 110 Octane(15% gas+85%ethanol)								
Note: on all test unable to force higher boost due to lack of pressure control on top of Waste Gate								

Test # 1, KKK 3476(equal to Turbonetic T66), and # 9 exhaust housing and race fuel 102 Octane								
Revolution	Power	Torque	Air-fuel	Boost	Ex Press	oil press	EGT	
r/min	PS	Nm	relations	barg	barg	barg	Celcius	
3000	96	205	 13,40 	 0,30 	 0,14 	 4,65 	794	
3500	108	212	 13,30 	 0,50 	 0,20 	 4,85 	800	
4000	235	346	 12,10 	 1,28 	 0,78 	 5,40 	825	
4500	284	402	 12,43 	 1,57 	 0,98 	 5,50 	828	
5000	379	502	 13,37 	 1,97 	 1,28 	 5,50 	841	
5500	484	622	 12,36 	 2,00 	 1,48 	 5,50 	865	
6000	558	652	 12,62 	 2,00 	 1,70 	 5,69 	888	
6500	611	673	 12,32 	 1,90 	 1,70 	 5,79 	917	
7000	620	639	 12,40 	 1,90 	 1,80 	 5,90 	914	
7500	631	604	 12,43 	 1,80 	 1,80 	 5,80 	913	
8000	628	570	 12,47 	 1,80 	 1,80 	 5,80 	912	
8500	625	540	 12,49 	 1,78 	 1,80 	 5,80 	911	

Test # 2, KKK 3476(equal to Turbonetic T66), and # 9 exhaust housing and E85 fuel 110 Octane								
Revolution	Power	Torque	Air-fuel	Boost	Ex Press	oil press	EGT	
r/min	PS	Nm	relations	barg	barg	barg	Celcius	
3000	95	211	 13,65 	 0,30 	 0,10 	4,65	774	
3500	109	218	 13,35 	 0,50 	 0,20 	4,85	780	
4000	239	352	 12,42 	 1,27 	 0,78 	5,2	803	
4500	293	411	 12,66 	 1,57 	 1,00 	5,2	808	
5000	408	533	 12,60 	 1,98 	 1,30 	5,3	820	
5500	514	664	 12,70 	 2,00 	 1,50 	5,4	846	
6000	584	693	 12,54 	 2,00 	 1,77 	5,59	859	
6500	633	706	 12,94 	 1,92 	 1,80 	5,7	818	
7000	643	676	 13,17 	 1,90 	 1,80 	5,8	828	
7500	677	633	 12,73 	 1,88 	 1,90 	5,8	848	
8000	650	591	 12,94 	 1,80 	 1,88 	5,7	852	
8500	633	566	 13,10 	 1,79 	 1,90 	5,7	853	

Test # 3, KKK 3476(equal to Turbonetic T66), and #16 exhaust housing and E85 fuel 110 octane								
Revolution	Power	Torque	Air-fuel	Boost	Ex Press	oil press	EGT	
r/min	PS	Nm	relations	barg	barg	barg	Celcius	
3000	85	188	 13,74 	 0,10 	 0,05 	 4,65 	761	
3500	95	190	 13,70 	 0,20 	 0,10 	 4,85 	768	
4000	186	279	 13,33 	 0,60 	 0,39 	 5,40 	789	
4500	221	314	 13,43 	 0,79 	 0,50 	 5,50 	794	
5000	291	384	 13,22 	 1,09 	 0,77 	 5,50 	798	
5500	467	561	 12,94 	 1,88 	 1,57 	 5,50 	824
6000	602	714	 12,93 	 2,10 	 1,89 	 5,69 	850
6500	663	730	 13,20 	 2,00 	 2,00 	 5,79 	872
7000	689	706	 13,24 	 2,00 	 2,00 	 5,90 	895
7500	705	675	 12,82 	 1,90 	 2,10 	 5,80 	912
8000	701	635	 12,69 	 1,88 	 2,20 	 5,80 	902
8500	700	630	 12,95 	 1,85 	 2,20 	 5,80 	896