My MKIII Supra conversion to e-85

By Figgie – Supramania.com and supraforums.com

The contents represented in this paper are the steps I undertook in my 87 supra Turbo to convert it from running on straight gasoline/Petrol to run with e-85 or gasoline/Petrol. This is based on my research with numerous fuel pump companies, hose companies and stand alone companies. Credit is noted where the information came from at the end of this paper.

Introduction

Well I have been a supraforums.com member and supramania.com member for quite some time. The objective of this project was to do something no one had ever done in the supra community and that was to run e-85 in the Turbo MKIII Supra as a daily driver. What this means is that I would use E-85 exclusively unless there was none available. For Minneapolis/Saint Paul, Minnesota this is not an issue as E-85 is available at 87% of all gas stations within the Twin Cities. The other reason for my undertaking of this project was to see if I could do it without any major help from any professionals. I am a Senior Server analyst by day time so this was a completely different that what I am used to

The guinea pig

The project required that the car was capable of running on E-85 on the original engine, meaning no custom head and no custom block. The recipient I chose was a Black with Grey interior, 1987 Toyota Supra Turbo. I am the second owner of this vehicle. I have owned this car since 1994 when I purchased it in Rapid City, South Dakota. It has gone to Miami, Florida a couple of times then from Florida to the Minneapolis, Minnesota where it currently resides under my ownership still. The car suffered an engine failure at about 200,000 miles from rod knock, so this is what got this project going.

Research

Digging through the internet was a valuable asset as there was ethanol conversion from the early 70 during the first initial oil crisis here in the USA. Of course back then all cars where carburetor based so it was a bit different but the fuel requirements stayed the same. With the introduction of E-85, ethanol started to become readily available and this made the conversion possible. E- 85 is slightly corrosive. No where near the level of Methanol or MTBE. Now with that said it is still corrosive to rubber and mild steel. So if there is no plating on the mild steel it needs to be replaced. Rubber will expand and become to soft to contain any pressure, meaning that all rubber hoses and O-rings (fuel injectors) need to be replaced. The fuel pump needs to be swapped to an e-85 fuel pump.

And now on to the project

This is where the fun begins.

(DISCLAIMER: This is a presentation only and not to be construed as a step by step on how to do this conversion. I hereby release myself from any damage caused by you, either by consequential or inconsequential use of this presentation. If you decide to do this, you do it at your own risk.)

Needed: Electrical know – howMotor operation TheoryEFI Operation theoryWideband sensor and guageE-85 compatible fuel pumpAlcohol compatible hoseSomeone that can TIG weld mild steelTools

Optional:MIG or TIG WelderStandalone ECU or piggy back (E-manage or MAFT-PRO)BuddyBeer or SodaPizza

Ok with this project there are certain aspects that we must address. Any mild steel that has not been plated has to be removed. Any aluminum where the E-85 is in constant contact has to be anodized (the fuel rail is an example, the head is not as the E-85 is in an suspended state and does not puddle in the head). Any rubber part has to be replaced with either Stainless lines or Teflon lines. Aeroquip hose will work but has to be inspected regularly. If the hose is Teflon lined it is Alcohol compatible.

With this in mind,

The first order of business is to remove the stock 7M Fuel rail. This is to address a couple of things here.

1. The rubber O-rings in the injectors NEED to be changed to Viton/Viton II based O-Rings.

2. The Aluminum fuel rail has to be anodized and preferably type III anodization.3. The fuel injectors need to be replaced with a bigger injector. Recommend at least

20% bigger which happen to be the 550cc/min injectors for the LEX-AFM mod.

Once the fuel rail is replaced and items addressed. The next part to be addressed is the fuel pump and the fuel lines. Neither the stock nor the walbro fuel pump can be used for this project. The fuel pump MUST be E-85/Alcohol compatible. The reason is a safety concern. Inside the fuel tank, when using Petrol/Gasoline the environment is too rich to

ignite (8.7:1 AFR = Lambda 1). This environment changes when using E-85. It goes to a near perfect stoichiometry value for the E-85 (9.7:1 AFR = Lambda 1) meaning that if the fuel pump is not sealed it WILL ignite the vapors inside the gas tank and that would not be good for your vehicle or for your life. Now the question becomes who has E-85 compatible fuel pumps? Simple, for not to much above stock power levels, General Motors, GMC, Dodge, Ford have Fuel pumps which are E-85 compatible. Which one are the right E-85 fuel pumps? Answer: The ones for their Chevrolet Suburban’s, Chevrolet Blazers, GMC Yukon, GMC Yukon XL or any of GM’s 5.3 Liter engines. For a current list of FFV vehilcles go to

http://www.e85fuel.com/e85101/flexfuelvehicles.phporhttp://www.eere.energy.gov/afdc/progs/search_type.cgi?1/E85_GSLN

This might or might not fit the stock hanger. More than likely it will not and will need to have the hanger modified to fit, the same with the electrical and fuel lines.

If going for big horsepower the entire fuel picture changes. Reason is that for high horsepower there are only several electrical fuel pumps that can support 1000 HP on the alcohol side. These are the following:

Weldon 2345

Magnafuel Prostar EFI SQ series

Product Engineering PE4600

Most belt driven fuel pumps from Aeromotive, Barry Grant, Magnafuel can also supply the needed volume at high pressure to run high HP on E-85.

With the fuel pump addressed we now go to the fuel lines. Not all fuel lines are alcohol compatible, some that are:

Icore/ProGold/BMRS convoluted PTFE hoses (Aeromotive Teflon hoseEarls Teflon HoseRussell’s Teflon hose.Goodyear Ambassador, BC Gasoline, Flexsteel Hardwall, Pacer

Any of these company’s rubber based Stainless steel hoses will not survive long with E-85. You have been warned.

I would recommend a minimum of -06 lines to the fuel rail and an alcohol compatible Fuel pressure regulator. The Aeromotivbe A1000 is alcohol compatible, is a good value and is widely available.

Using any of the aforementioned High HP pumps, the stock fuel tank must be sumped. This is easily done as the MKIII supra fuel tank is made of steel. There are two universal sumps currently available;

one is made by competition engineering

And the other is made by Aeromotive

Both require expert welding skills and the necessary purging to prevent an explosion. If you are not familiar with this do not attempt to install these sumps on your gas tank. Take it to a qualified welder.

After this part is done The fuel system is ready for E-85 and gasoline duties.

Now comes the harder part which is the ECU. The piggy backs that can work with E-85 are the MAFT-PRO and the E-manage. Both can change the apparently air flow to make the system read what It does with OEM. Reason being is that with the install of the 550cc/min injectors. You are throwing in about 20% more fuel which puts it roughly where it needs to be. Put gasoline and with the aforementioned piggy backs and you can change the air flow measurements to read less (like going to a LEX AFM) this will in turn make the car drivable with gasoline if E-85 is not available.

The ideal solution (and the route I took) would be a standalone that allows the use of multiple fuel maps. AEM, Motec, Haltec, Tec3, Wolf3d, EFI Systems, Autronic all support multiple fuel mappings. The trick is to adjust for the alcohol which all the standalones mentioned can.

I will not go over stand alone installs as if you don’t know how to do that you should not be attempting tackling this project by yourself.

If there are any questions, critiques or any improvements that can be made. Please PM me in Supramania.com or Supraforums.com.

Thank you

-Figgie

Credit

Fueling requirement – Weldonracong.com, tremendous pool of knowledge over there.Hosing and compatibility - Brown and Miller racing, suppliers of I-core PTFE convoluted hose.Standalone – Electromotive and Motec for their technical knowledge on tuning.