can i run E85 fuel in my RX7 FD3?
 

hi, I live in Illinois were E85 fuel is very common. I was wondering if i could run E85 in my Rx7 right now. if not, are there any modifications i can do to make it possible? considering E85 has an octane level of 105 it would be good for the engine so.

it also has better cooling properties, what u would have to do tho is run some bigger injectors, so bassicly get urself an rx7store or a-spec (believe they are in chicago area) fuel system, pump, lines, rails and injectors, 850 primary and 1600 secondaries, get rid of ur acv (have to with any fuel upgrade) and would pick up a power fc for ur engine management, and get ur car retuned, with all that done u can run e85 and later on down the road can upgrade to a single turbo and run a decent amount higher boost then on pump alone, because of its higher octain and better cooling properties, u will see a decrease in fuel milage tho because it requres more e85 then it does 92 octain pump gas to burn effiesiantly.hence the reason u need bigger injectors, any questions tho about it call groundzero motorsports here in oregon, if ralph is around ask to talk to him hes running e85 in his pt67 single turbo fd putting down 500 rwhp, hope that helped

To clarify the previous post, you need to retune with E85. To maintain a safe AFR you need a good amount more E85 than gasoline, so you will need a separate tune for E85 and one for gasoline.

didnt i already say he would have to retune?

If you have to ask, you shouldn't even try. There are lots of things that must be done to run E85 safely and effectively.

would you like to share what need to be done or are you gonna just sit there?

what would i need to do to run a stock set up on e85 i have a 255lph fuel pump already do u think i would need to go bigger in jectors?

Yes you need larger injectors. The stock ones barely do the job on regular 91.

1. you MUST have larger fuel injectors
2. i recommend a FPR to go along with it.
3. new lines arent totally necessary, but also recommended
4. then you need some way to control the fuel ECU wise.

in my perspective, unless your building your car for performance sta away from e85. its good for power, not so much a DD. BUT depending on what gas prices are like around you, the price of 91/2/3 octane vs. E85 may balance out so that your paying about the same for fuel either way. e85 is ~25% less efficient than normal gasoline.

so figure it out for you and make a plan.

in ireland e85 is 92 cent and nomal 95 is 1.23ish

by any chance does any one have the cold start setting for e85 for normall primarys and 1600cc secondries

having a cold start issue

You guys are also going to have to switch lots of part in terms of raw material. The high ethanol use products tend to blow fuel pumps, valves. The cooler temperature property is helpful though. I'll actually ask around since my company manufactures small engine parts in Brazil. There are also lots of places that will help you convert your vehicle for E85 use. I think the government also gives you tax cuts or something of the sort for it.

Not much needs to be done, you can use your stock fuel lines, tank etc. etc.

Just make sure you've got enough fuel delivery

so if i wanted to run e85 on my stock twin turboed 3rd gen.. I could as long as I upgrade to a lot bigger injecotrs and get it retuned with my PFC, and of course swithch to a walbro or denso 255 fuel pump and then i can go straight to e85 when i get tuned?

Yes, bigger injectors and more pump is required.

well heck im already buying 850cc primarys and 1600cc secondarys just cause.. and i never plan to stray away from the stock sequential twins! so i should be able to do plenty on e85 running 15psi on the stock twins.. hmm i like my idea!!

oh yeah those turbos will last real long.

they will...

You need to stop hopping on the bandwagon. Testing has already proven that E85 doesn't eat up fuel pumps.:wallbash:

These cars also have no valves unless they are swapped.:scratch:

just wondering if i throw a set of 1300cc injectors in to the secondary rail do u think it would be enough to run e85 in an fd 93

Depends on your mods but your primarys will need more fuel as well. You need to add 30% more fuel as a base to your injectors so do the math.

On a side note, switching to E85 on many other (non RX7) cars requires no change in injectors, and causes no seal issues. I have done so with two other (NA) cars running splash blends of 50-75% E85 without any modification. Of course I will go to straight E85 when I get around to doing the simple mod of "fooling the air to fuel mixture"...and can also bump up ignition timing for a little extra power. I cannot see why a stock FC or FD would not be the same.

On the other thing - E85 (or any ethanol heavy blend) will only accelerate failure of old, brittle seals in the fuel pump, injector seals, etc - not cause it. Gasoline tends to gunk up these things, but when using heavy E mixtures, it cleans these seals out, effectively shrinking them somewhat. So this means the E85 (or E98 if you are lucky) tends to "find" those old seals that were already on their way out.

Admittedely, they would have likely lasted a few more years on gasoline, thanks to its gunking effect. Regardless, E mixtures are a good way to find any weak spots in the fuel system's seals...and a good way to clean the tank, injectors, etc. Just make sure to initially blend at rates of, say 1 gallon per tank and increase gradually a gallon at a time...or you will break loose everything at once....stopping up injectors, fuel filter, etc.

Finally, all rubber parts made since 83' are "supposed to be" ethanol safe by government mandate. However, I cannot speak for cheap (non-OEM) replacement parts, etc. but IME, I 've seen no leaks so far with two old-ass cars running E85 with original everything. Heck, these seals should be leaking on pure gasoline by now, lol.


LOL X 2. Gotta love those Chevron sponsored tests that tell you how ethanol will eat up the engine, destroy all seals, kill fuel mileage, kill puppies, etc.

So did you end up running e85 while retaining a lot of the stock fuel system setup? If so how did it go?

So has anyone ended up running e85 with the stock fuel system? If so how did it go?

Personally I have used E85 around stock power levels, I have a standalone and larger injectors but hardly any other mods (stock airbox, stock twin turbos, aftermarket downpipe, stock cat converter, stock muffler). ECU datalogs show that fuel pressure was dropping off even at stock boost... this was with the crappy stock fuel pump wiring and a stock fuel filter that had at least 15k miles on it. With a re-wired fuel pump and a fresh fuel filter, you might have a chance to keep up at stock power levels but I wouldn't hope for much more than that without an upgraded fuel pump.

Hi Scotty, thanks for the information.
So in terms of actual compatibility with e85 fuel the stock fuel pump and stock fuel lines have had no problems?
How long have you been using e85?