E85 Questions
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 565
From: Clearwater Florida
E85 Questions
....... E85 recently moved in to the area and I am pondering the change ... I know several of you have switched ... what all is needed to accomplish a successful and rewarding change ? Bigger injectors ? ... Fuel pump ? ... Its my understanding that it takes more volume vs. gas , like around 30% ... I'm also hearing octane in the 104 range , so that means higher compression ratios too ! ... How high is still safe ? ... The car's primary use is drag strip related with moderate street useage ... I'd like to keep it that way .......
Drifting
Joined: Feb 2013
Posts: 1,465
Likes: 12
As I understand it, you need 30 % more volume than what your running on pump gas. I am making the switch to E85 and going with 90 lb injectors and a way bigger pump.
E85 burns way cleaner and is about equivalent to 110 octane gasoline. The crazy part is how cold it is and how hard it is to get detonation in the engine. It is awesome in FI cars and engines with High compression.
Also from what I understand, Nobody running it in a c4 has had any corrosion problems. Guess I will find out for sure here in a month or two!
E85 burns way cleaner and is about equivalent to 110 octane gasoline. The crazy part is how cold it is and how hard it is to get detonation in the engine. It is awesome in FI cars and engines with High compression.
Also from what I understand, Nobody running it in a c4 has had any corrosion problems. Guess I will find out for sure here in a month or two!
Race Director
Joined: Sep 2003
Posts: 16,836
Likes: 337
From: Database Error Indiana
You will need big injectors and a good pump. Im not making big power so I did not have to get crazy. Already had a 255 Walbro and it got the job done. I ran my 24# Bosch IIIs for a while they were maxed out on duty cycle with 70# FP. I went to 32s and 56# FP when it was dialed in. I went with 6 AN teflon core fuel line in front of the fuel filter and on the return line back to the same point. Just did not trust the 1987 lines under the hood. Rubber lines at the tank, I left alone. Ran the alky for 3 years, no problem.
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
I ran it for about 6 months or so. The only reason I switched back is availability of fuel. FWIW mine made 462 rwhp on 60 lb injectors and a 255 pump. That is the only thing changed on mine. Fuel lines are all orig. Pretty much everything you said, seems to be my understanding of e85 as well. I have no idea how much more compression you could run. I run 11.3 and that was set up for pump gas. I would think I could run at least 12 to 1 if dedicated to e85
Drifting
Joined: Sep 2002
Posts: 1,642
Likes: 0
From: Suwanee,Ga
Same formula as above here.
Pump: Walbro 255 will work. Aeromotive 340 is rated e85 and so is the new Walbro 400... But zero troubles with pump in two years of E85 use...
60# injectors w/ 400cc. See Jon at Fuel Injection Connection.. you need info for the tune...
100 Mircon filter!!!!!!!!! don't go cheap here.
COMPUTER................
Pump: Walbro 255 will work. Aeromotive 340 is rated e85 and so is the new Walbro 400... But zero troubles with pump in two years of E85 use...
60# injectors w/ 400cc. See Jon at Fuel Injection Connection.. you need info for the tune...
100 Mircon filter!!!!!!!!! don't go cheap here.
COMPUTER................
Safety Car
Joined: Sep 2001
Posts: 4,150
Likes: 552
From: Glenbeulah Wi
I switch back and forth between pump fuel and E85. The few things I did were as follows:
-Walbro 485 fuel pump and wiring harness from racetronics. The pump and wiring harness fit very well and the it is capable of supporting over 1000 HP on gas and 750 HP on E85.
-48 lb injectors, could be larger on E85 but that is what I have
-45 PSI fuel pressure
-Stock fuel system after that, no problems in 5 years of use (Replaced a few non E85 pumps before switching to the Walbro 485)
-Switching adapter on the ECM so I can just switch between E85 or pump gas with the flip of a switch.
-11.4 compression because I want to run pump fuel when needed. If you don't care about that then you could run 13 to 1 on E85 only. My 555 BBC drag car is 13.5 to 1 on E85 only.
-E85 added about 12 rwhp and no detonation (timing retard) which made the car more consistent. (On my 1986 vette, with the 406)
-Caution note E85 is E70 in winter, E78 spring and fall, and E85 in summer so you must tune accordingly, hence the use of the switching adapter to make tune changes very easy. (Other option make your own E85 from E98 and pump gas.)
-Walbro 485 fuel pump and wiring harness from racetronics. The pump and wiring harness fit very well and the it is capable of supporting over 1000 HP on gas and 750 HP on E85.
-48 lb injectors, could be larger on E85 but that is what I have
-45 PSI fuel pressure
-Stock fuel system after that, no problems in 5 years of use (Replaced a few non E85 pumps before switching to the Walbro 485)
-Switching adapter on the ECM so I can just switch between E85 or pump gas with the flip of a switch.
-11.4 compression because I want to run pump fuel when needed. If you don't care about that then you could run 13 to 1 on E85 only. My 555 BBC drag car is 13.5 to 1 on E85 only.
-E85 added about 12 rwhp and no detonation (timing retard) which made the car more consistent. (On my 1986 vette, with the 406)
-Caution note E85 is E70 in winter, E78 spring and fall, and E85 in summer so you must tune accordingly, hence the use of the switching adapter to make tune changes very easy. (Other option make your own E85 from E98 and pump gas.)
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Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 565
From: Clearwater Florida
....... Thanks to all who replied ... some good info here ... I'm looking to stretch the compression ratio to 12.5 and was looking for a less expensive alternative fuel to race gas at roughly $8 a gallon ...... the E85 is $2.89 here compared to $3.89 for 93 ... but with 110 or so Octane , E85 is looking pretty good ...... 
..........
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Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 565
From: Clearwater Florida
I switch back and forth between pump fuel and E85. The few things I did were as follows:
-Walbro 485 fuel pump and wiring harness from racetronics. The pump and wiring harness fit very well and the it is capable of supporting over 1000 HP on gas and 750 HP on E85.
-48 lb injectors, could be larger on E85 but that is what I have
-45 PSI fuel pressure
-Stock fuel system after that, no problems in 5 years of use (Replaced a few non E85 pumps before switching to the Walbro 485)
-Switching adapter on the ECM so I can just switch between E85 or pump gas with the flip of a switch.
-11.4 compression because I want to run pump fuel when needed. If you don't care about that then you could run 13 to 1 on E85 only. My 555 BBC drag car is 13.5 to 1 on E85 only.
-E85 added about 12 rwhp and no detonation (timing retard) which made the car more consistent. (On my 1986 vette, with the 406)
-Caution note E85 is E70 in winter, E78 spring and fall, and E85 in summer so you must tune accordingly, hence the use of the switching adapter to make tune changes very easy. (Other option make your own E85 from E98 and pump gas.)
-Walbro 485 fuel pump and wiring harness from racetronics. The pump and wiring harness fit very well and the it is capable of supporting over 1000 HP on gas and 750 HP on E85.
-48 lb injectors, could be larger on E85 but that is what I have
-45 PSI fuel pressure
-Stock fuel system after that, no problems in 5 years of use (Replaced a few non E85 pumps before switching to the Walbro 485)
-Switching adapter on the ECM so I can just switch between E85 or pump gas with the flip of a switch.
-11.4 compression because I want to run pump fuel when needed. If you don't care about that then you could run 13 to 1 on E85 only. My 555 BBC drag car is 13.5 to 1 on E85 only.
-E85 added about 12 rwhp and no detonation (timing retard) which made the car more consistent. (On my 1986 vette, with the 406)
-Caution note E85 is E70 in winter, E78 spring and fall, and E85 in summer so you must tune accordingly, hence the use of the switching adapter to make tune changes very easy. (Other option make your own E85 from E98 and pump gas.)
....... I have also been told to NOT use paper filters of any kind but to use stainless mesh ... are you guys still using the stock filter ? any concerns about the sock ?
Last edited by C409; Jan 18, 2014 at 07:36 AM.
Race Director
Joined: Sep 2003
Posts: 16,836
Likes: 337
From: Database Error Indiana
I was going to use a Delco filter for a 2003 GM truck that is flex fuel capable from the factory. Simple to do. The threaded end is the same as a C4 and the output has a quick connect nipple. You can get a 6AN adapter for that. Ended up not getting around to it. At the time I switched, my Delco was near new and it never was an issue.
I got an alcohol content tester from Summit to test the fuel. It was under $20.
The % change for the seasons depends on where you live. The octane change was not a problem for me but the difference will make you leaner or richer, depending on the mix.
I will add that, the stuff burns clean. Spark plugs stay clean and when I took a head off, I could not believe how clean the chambers and piston tops were.
I got an alcohol content tester from Summit to test the fuel. It was under $20.
The % change for the seasons depends on where you live. The octane change was not a problem for me but the difference will make you leaner or richer, depending on the mix.
I will add that, the stuff burns clean. Spark plugs stay clean and when I took a head off, I could not believe how clean the chambers and piston tops were.