The only essential mods needed for running E85 are a Walbro 255 high output fuel pump, 30% larger injectors, and an E85 tune. That should give you +50whp (with increased boost and timing) on the average lightly modded EVO; figure on getting 15mpg.
Good write-up here.
This thread is an attempt to bring together a list of additional and optional items that you might want to consider when converting to E85. I’ll update this list as ideas are added to the thread.
In no particular order...
1. I think it is pathetic that this disclaimer needs to be included, but unfortunately regulation is far behind reality:
Do not tell any regulatory (DMV) or police agencies that you are running E85 since it is technically not legal to do so per the EPA. Even though E85 does spew out less emissions, the EPA has not certified E85 conversion for an Evo. I'm still trying to find references on this. The only thing I found was that E85 conversion is illegal in CA.
2. Upgrade your stock ECU to the Tephra map switching functionality. This will allow you to run both a gasoline tune and an E85 tune, and simply switch between the two as needed. Here are two descriptive links:
Link One and
Link Two. And here is the
Tephra mod info.
2.1. Or, here is another idea. Buy an older used laptop and a cigarette lighter power supply for it off eBay, Craigslist, Laptop Trader, Classifieds, etc. Have the laptop all set up with ECUFlash, your separate E85 tune AND your separate 93 tune. Then pack it up real nice and well protected in a cardboard box and toss it in the truck. Now you are all set to make a map switch just in case you need to...whenever...wherever.
3. Do a boost leak test. If you are turning up the wick from, say, 22psi to 28psi, a
boost leak test is definitely in order.
4. Upgrade any OEM hose clamps on your I/C plumbing to stouter screw clamps, or to T-bolt clamps. This is simply a precautionary measure I took on my 5 year old EVO; newer cars, not so much. I used the high torque worm drive clamps
on this page.
5. Check your oil level more often as running higher boost may likely cause some oil usage.
6. Running higher boost may blow out your oil dip stick, so install a dip stick return spring. BR sells a
nice one.
7. Running higher boost may cause increased oil blow through the valve cover vent. You may wish to install a catch can. See RRE
item here.
8. Or you may simply want to get the valve cover vent out of the intake, so oil blow can't go into the I/C pipes and FMIC.
9. For track cars you might want to consider simply deleting the PCV valve. See the write up on RRE
site here.
10. Consider implementing the CEL flash on knock functionality and data log regularly to ensure your tune is operating as expected. See #11 for the reason why this might be wise.
11. Review, know and understand the
3 classes of ethanol. As I understand it, ethanol mix is not regulated. The ethanol industry has established its own
self-regulatory guidelines. See page 7.
Class 1 – Ethanol content min. 79%
Class 2 – Ethanol content min. 74%
Class 3 – Ethanol content min. 70%
Class 1 – Gasoline content min. 17%
Class 2 – Gasoline content min. 17%
Class 3 – Gasoline content min. 17%
Combining the above minimums creates the following range for ethanol content:
Class 1 – Ethanol content min. 79% - max. 83%
Class 2 – Ethanol content min. 74% - max. 83%
Class 3 – Ethanol content min. 70% - max. 83%
As you can see, these are pretty broad ranges. Buyer beware!
12. Check the
ethanol class schedule for your area. If/when a class change is made in your area, do some additional data logging to check your tune. You may need to turn down the boost when your area changes to a lower class ethanol – from, say, Class 1 to Class 2.
13. Consider a ‘colder’ spark plug:
If you have an EVO IX, consider Denso IKH24, they are one step colder than OEM.
If you have an EVO VIII, consider colder copper plugs. I use NGK BPR8ES gapped at 0.020”.
14. Consider more frequent oil changes, due to the extra stress of higher boost and the possible oil dilution from running 30% more fuel through the motor. Regular oil analysis might be a worthwhile investment. Oil Doc recommends
Oil Analyzers at $27.85. At
Blackstone-Labs the cost is only $22.50.
15. Consider adding a serviceable fuel filter in the engine compartment. Ethanol may act like a cleaning agent to your fuel system and “dirt” could clog up your expensive new injectors.
16. You might want to use ECUflash to raise 'idle' and to raise 'idle with A/C on'. Stock cams vs. aftermarket cams will have an affect on this as well. I increased my idle with A/C to 1,100 rpms.
17. It also seemed to me that the off-idle response was dampened a bit on E85 compared to 91. The motor just did not want to rev off of idle as quickly as it does on 91, so I am experimenting with the timing a bit to see if I can improve the off-idle response. I adjusted the idle block
like this, which is from
this thread. I am not really sure how much additional timing is beneficial. Anyone have any idea? I'm at 14* in the idle block right now.
18. Consider installing head studs if you plan on running boost +25psi and beyond. This is a controversial subject. SEARCH! READ! One-by-one? Pull the head? Oil the threads? Molylube the threads? Like I said, SEARCH! and READ! I’m on stock studs and plan to stay that way.
19. You might want to consider adding an
inline sensor and gage to read/verify ethanol content in your fuel system.
20. Fuel mileage is lousy!!! You may want to experiment with
open loop idle and cruse, and try leaning these out some.
Please share additional E85 hints and tips…
