So I figured I'd start a thread on this since it pops up from time to time and I thought I'd share my thoughts on this.
Part1
E30-40 Theory
Part 2
Testing
Part 3
Full E85
Part 1
While I don't suggest that you run FULL e85 on a stock setup, however, running around e30-e40 on a stock car is defiantly doable. I have a completely stock fuel system below is what I've done for the last 2 years.
For the last 2 years, I've been adding 5 gallons of E85 then filling the rest of the tank with 91. I always fill when near empty to ensure a similar mix. It's important to be generally around the same E-content unless you always want to watch your AFR's. You should immediately notice quite a bit more torque if running stock boost or even a few pounds more. Even if the pump outputs less than E85, it's no concern since you'll just be rich. However, still leaner than just 91.
Theory since ethanol requires approx 30% more fuel to keep stoichiometric by adding 30-40% E85 you effectively reduce fueling by about 10-15% at the same boost level while increasing octane.
This is a great double-edged sword. By going leaner, you'll get more power and response. Stock computer is extremely aggressive on timing and 91 cannot keep up to these requirements and often times will pull timing. Adding E30-40 will enable running full timing without knocking.
I've tested up to 12 PSI (stock boost cut on a 57 trim CT26) without any fuel computers or piggyback, and kept a good AFR.
Once you pass this you'll have to be very careful. Since you effectively made your stock injectors about 10-20% smaller since you require more fuel to have the same ratios.
Running 14-17 PSI or around 350 WHP estimated* seems to be the absolute limit of this, as I run out of injector on my stock fuel system and start getting really lean.
Part 2
I have 3 dynos over the 3 years
252WHP and 274TQ in 2017 @ SIV 91 octane
Stock car and boost, except for downpipe and catback, (Stock cat)
274WHP and 300 tq in 2018 @ SIV E30 mix
Stock car and boost, except for downpipe and catback, (stock cat)
300WHP and 357 TQ in 2019 @ SIV (after main dyno session)
57 trim CT26 Stock boost and 3" cat carb legal
E30 mix
(no video did the run after-hours SIV)
I figure I gained 15 from the new cat and 15 from the 57 trim.
Part 3
To run full E85, it's recommended that changes to the factory fuel system are made.
#1 First you'll want to change all the rubber items on the system to E85 rated hoses.
On the stock fuel system that would be 2 lines. The feed from the firewall to the rail should be replaced, and the return lines that connect to and from the Jpipe down on the block. I sued PTFE because the rubber E85 compact lines usually go brittle and break in a few years. PTFE will outlast the car. There is an adapter that DM sells to connect to the firewall line and then just run a PTFE -6 line to the hardline.
#2 Changing the pump
You'll want to change the pump form stock to something like a Walbro 450 which is ethanol rated, also using a corrugated plastic feed hose instead of the gates rubber E85 rated line is recommended as the rubber hoses seem to break down when submerged (Gates barricade). However, the stock pump will work just seems to be out of flow @ 325-350 WHP as with 850CC injectors I was still going lean at 15 psi on stock pump.
#3 Changing your stock fuel filter, is a good idea since it's probably old and needs doing, but not required. This is the one I used for my walbro 450 pump
I used the Denso 952-0006
#4 Injectors and O rings. I recommend changing the o-rings but i think they are nitrile already which means they should work anyways. Generally, all the old school top feed metal injectors seem to be ok with E85 so I don't think there is any concern here.
#5 Fuel rail, from my talks with others I think it's already anodized so it SHOULD be ok. I ended up just re-using mine without coating I'll see how it holds up.
One of the most comprehensive threads is found here.
www.supramania.com
Part1
E30-40 Theory
Part 2
Testing
Part 3
Full E85
Part 1
While I don't suggest that you run FULL e85 on a stock setup, however, running around e30-e40 on a stock car is defiantly doable. I have a completely stock fuel system below is what I've done for the last 2 years.
For the last 2 years, I've been adding 5 gallons of E85 then filling the rest of the tank with 91. I always fill when near empty to ensure a similar mix. It's important to be generally around the same E-content unless you always want to watch your AFR's. You should immediately notice quite a bit more torque if running stock boost or even a few pounds more. Even if the pump outputs less than E85, it's no concern since you'll just be rich. However, still leaner than just 91.
Theory since ethanol requires approx 30% more fuel to keep stoichiometric by adding 30-40% E85 you effectively reduce fueling by about 10-15% at the same boost level while increasing octane.
This is a great double-edged sword. By going leaner, you'll get more power and response. Stock computer is extremely aggressive on timing and 91 cannot keep up to these requirements and often times will pull timing. Adding E30-40 will enable running full timing without knocking.
I've tested up to 12 PSI (stock boost cut on a 57 trim CT26) without any fuel computers or piggyback, and kept a good AFR.
Once you pass this you'll have to be very careful. Since you effectively made your stock injectors about 10-20% smaller since you require more fuel to have the same ratios.
Running 14-17 PSI or around 350 WHP estimated* seems to be the absolute limit of this, as I run out of injector on my stock fuel system and start getting really lean.
Part 2
I have 3 dynos over the 3 years
252WHP and 274TQ in 2017 @ SIV 91 octane
Stock car and boost, except for downpipe and catback, (Stock cat)
274WHP and 300 tq in 2018 @ SIV E30 mix
Stock car and boost, except for downpipe and catback, (stock cat)
300WHP and 357 TQ in 2019 @ SIV (after main dyno session)
57 trim CT26 Stock boost and 3" cat carb legal
E30 mix
(no video did the run after-hours SIV)
I figure I gained 15 from the new cat and 15 from the 57 trim.
Part 3
To run full E85, it's recommended that changes to the factory fuel system are made.
#1 First you'll want to change all the rubber items on the system to E85 rated hoses.
On the stock fuel system that would be 2 lines. The feed from the firewall to the rail should be replaced, and the return lines that connect to and from the Jpipe down on the block. I sued PTFE because the rubber E85 compact lines usually go brittle and break in a few years. PTFE will outlast the car. There is an adapter that DM sells to connect to the firewall line and then just run a PTFE -6 line to the hardline.
#2 Changing the pump
You'll want to change the pump form stock to something like a Walbro 450 which is ethanol rated, also using a corrugated plastic feed hose instead of the gates rubber E85 rated line is recommended as the rubber hoses seem to break down when submerged (Gates barricade). However, the stock pump will work just seems to be out of flow @ 325-350 WHP as with 850CC injectors I was still going lean at 15 psi on stock pump.
#3 Changing your stock fuel filter, is a good idea since it's probably old and needs doing, but not required. This is the one I used for my walbro 450 pump
I used the Denso 952-0006
#4 Injectors and O rings. I recommend changing the o-rings but i think they are nitrile already which means they should work anyways. Generally, all the old school top feed metal injectors seem to be ok with E85 so I don't think there is any concern here.
#5 Fuel rail, from my talks with others I think it's already anodized so it SHOULD be ok. I ended up just re-using mine without coating I'll see how it holds up.
One of the most comprehensive threads is found here.
Figgie: E-85 conversion for the MKIII Supra
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...
www.supramania.com
if the road is a big cup / bowl how does that factor in
