Subaru EJ25 Race Fuel or e85?

J

JBL

Well-known member
Joined
Jun 6, 2021
Messages
305
Reaction score
312
Hoping to run into Jon from Outfront this weekend at Glamis so he can school me on my Subi sand rail.  But thought I'd start learning from guys who have converted either way from race 110 to e85 or vice versa.   All I know is e85 burns more per tank and can be harder to start but also makes more power.  The car us tuned now for 110 but lets face it $8.50 per gallon vs $3.80 is a damn big difference.  Spoke to Jon briefly and he said he can tune it, so Im making an appointment for late next week. 

So I bought this car to get me through till my other car comes in next fall.  I will be reselling it once that happens so also looking at resale value and demand if I did switch fuels.  Appreciate your thoughts on my topic. 

 
Well I am going to be doing that same switch here real soon as well. A few things I am going to do,

Switch fuel lines to PTFE lines 

Change to bigger Injectors to run more fuel (Injector Dynamics)

Adding a bigger Fuel tank to hold approx 4 gallons more I only have 10 gallons now.

Have my Car dyno'd for E85

 
Everything @FIREMAN said. 

I made the conversion last year from race to e85.  E85 can be a cold hearted beech but with the proper tune its nothing

 
For cold weather starts, that can be fixed by a proper tune.  Most people that have hard starting cars are due to the tuner not tuning it much for cold weather starts.  Meaning they spend hours on the tune, car is warm and such the entire time.  Most don't wait until the next day to throw back on the tuner when cold from overnight and do a cold start tune.  My car starts perfect every morning, my buddies doesn't and we are both E85 and had the same tuner, he picked up his car as soon as the tune was done. 

10 gallon tank is small, you need 15 gallons.

 
Thanks guys.  I hear alot of good tuner things coming from John at Outfront Motorsports who first did this build and he is only 35 minutes away from me.  I'll make sure he does cold start tunes as he rides a subi and is in Glamis a ton. 

As far as 10 gallon tank, I dont think I want to do that.  I dont mind topping off after every ride as we do that for bikes and when I had my SXS.  How many duning time do you guys get off that 10 gallon or 15 gallon tank?

 
We went back and forth with the 2.5 John built us for my boys car. We decided on using 110. At Red Earth it’s at the pump $8.50 gl. I didn’t want to mess with testing pump E85 to make sure it’s correct and adding 91 to get it right, draining the tank at the end of the season, using more fuel and having to haul more fuel.
 

I had a funco tuned on E80 and it used about 1-1/2 time the fuel of the race gas car. So you take the $3.85 x 1.5 your at $5.77 gl its not a big leap to $8.50, $50-60 bucks a trip. I guess if you burn a lot of fuel it can add up but race gas smell is worth something 🙂 

 
Pennywise said:
We went back and forth with the 2.5 John built us for my boys car. We decided on using 110. At Red Earth it’s at the pump $8.50 gl. I didn’t want to mess with testing pump E85 to make sure it’s correct and adding 91 to get it right, draining the tank at the end of the season, using more fuel and having to haul more fuel.
 

I had a funco tuned on E80 and it used about 1-1/2 time the fuel of the race gas car. So you take the $3.85 x 1.5 your at $5.77 gl its not a big leap to $8.50, $50-60 bucks a trip. I guess if you burn a lot of fuel it can add up but race gas smell is worth something 🙂 
Click to expand...
And don't forget the expense of making the swap as well. I'm sticking with 110. 

 
I will be in gecko at the first bathroom until Saturday night. I use e85 as I have burned 100 gallons in 2.5 days. Heading out in the morning with a full tank (23 gallons) and an extra 100 gallons in containers   With great weather.3-4 good dune runs a day at 10-15 gallons a run

 
cold start corrections for e85:

all cold start compensation maps are based off of the base tune.  therefore trying to tune cold start "before" a dyno is futile.  

the main tune needs to be done first then coolant temp must get cold again before this could be adjusted.  there are some base values, however there are quite different settings among the different ecus out there.  so even if i tuned two different ecus on the same day, once cold it could be a different story.  some ecus have a "first injection" that can occur when key is turned on or ecu powered up, other may have only 1d table or 2d tables to adjust fuel enrichment when warming up.  the other issue we have is that at my shop it seldom gets below 60 degrees, in the dunes it can be far colder, so the "cold start up" the next morning may not even closely represent the real world the buggy may see

 
  • Like
Reactions: JBL
I picked up a 2 seater 2.5 subi tuned for e85 last month.  New car and setup to me.  Running an old megasquirt 1 computer. Has a 10 gallon tank. I hear they burn 30ish% more than pump gas. I picked up a 55 gallon tank and filled it for this weekend. Still trying to figure out how to transport it, so it's staying behind. Bringing 45 gallons for 1.5 days. More worried about running out on a long run. Already thinking I need at least a 15 gallon.  Paid 3.29 per gallon last Sunday in West phx.

 
  • Like
Reactions: JBL
Most dunes runs for us running e85 are 8-10 gallons.  If your running down to Duner's Diners, you could burn more than that.  We camp near Cement Flats, I can dune to Swingset, to China Wall, back thru Olds, to Vendors and dune back to Cement Flats on a tank.  This is not straight lining, all duning and moving at a good pace.  This ride will burn near 13 gallons.

 
  • Like
Reactions: JBL
what color are the spark plugs suppose to look like  at the center of the electrode on e 85 and a 2.0 subi

 
@JBL how was your weekend? Did you connect with John? Also what computer do you have?

All in all my weekend was surprisingly car drama free.  I ran mostly with quads/dirt bikes/sxs. Kept a close eye on my fuel level. On Sunday we ran from wash 6 to Oldsmobile hill, over to swingset and back. Then my boy ran it back to Oldsmobile hill over to sunset point and back. Had about 7/8s of a 10 gallon tank.  So for now just running it as is. I ran through about 30/35 gallons of fuel.

On a side not. My engine is a jdm and not the sti. Seemed like I mostly just cruised and was not really getting on it a lot. My boy on the other hand, was giving full throttle rides in the flats and at the hill as well as trying to get it to wheelie and jumping down the table top up top. Told him you break it you buy it....

 
basketcase said:
@JBL how was your weekend? Did you connect with John? Also what computer do you have?

All in all my weekend was surprisingly car drama free.  I ran mostly with quads/dirt bikes/sxs. Kept a close eye on my fuel level. On Sunday we ran from wash 6 to Oldsmobile hill, over to swingset and back. Then my boy ran it back to Oldsmobile hill over to sunset point and back. Had about 7/8s of a 10 gallon tank.  So for now just running it as is. I ran through about 30/35 gallons of fuel.

On a side not. My engine is a jdm and not the sti. Seemed like I mostly just cruised and was not really getting on it a lot. My boy on the other hand, was giving full throttle rides in the flats and at the hill as well as trying to get it to wheelie and jumping down the table top up top. Told him you break it you buy it....
Click to expand...
did not connect with John, and heard he had to leave earlier then planned.  Running a Stinger which John confirmed he can tune.  As far as my first trip with Car, it was just a shake down and it ran perfect.  Love the power and truth be told I only burned about 20 gallons if not less Sat rides and a long morning Sunday ride.  Was most modest fast duneing and nothing really wide open but only a couple times briefly just to feel the rush....it did not dissapoint.  My friend in his LS Car was behind me and he admitted my car accelerated quickly and impressed him when I opened her up. 

Now I am torn between sticking to race fuel or e85.  The big problem is having to install a 15 gallon tank and I dont want to go down that hole since I will be unloading it after this season or early into next season.  I really like shifting of a sand rail but I sometimes ride desert and rails dont do that well vs a SXS.  Also like opening a door and climbing in when jumping into a SXS.  

But we will see how things go this season.  Just so glad to have a vehicle to drive this season vs my dirtbike.  The dunes were so chewed up that even my son threw in the towel early riding his bike and rather be in the rail.  No wind in sight so this Vet weekend will be even worse.

 
JBL said:
did not connect with John, and heard he had to leave earlier then planned.  Running a Stinger which John confirmed he can tune.  As far as my first trip with Car, it was just a shake down and it ran perfect.  Love the power and truth be told I only burned about 20 gallons if not less Sat rides and a long morning Sunday ride.  Was most modest fast duneing and nothing really wide open but only a couple times briefly just to feel the rush....it did not dissapoint.  My friend in his LS Car was behind me and he admitted my car accelerated quickly and impressed him when I opened her up. 

Now I am torn between sticking to race fuel or e85.  The big problem is having to install a 15 gallon tank and I dont want to go down that hole since I will be unloading it after this season or early into next season.  I really like shifting of a sand rail but I sometimes ride desert and rails dont do that well vs a SXS.  Also like opening a door and climbing in when jumping into a SXS.  

But we will see how things go this season.  Just so glad to have a vehicle to drive this season vs my dirtbike.  The dunes were so chewed up that even my son threw in the towel early riding his bike and rather be in the rail.  No wind in sight so this Vet weekend will be even worse.
Click to expand...
If you’re offloading it this season you won’t recoup the cost to switch to e85. Leave it be and run it. 

 
I also would leave it alone if this is only going to be used for one season.  Went and got E85 the other day, it was $4.00 a gallon, WTH.  4 years ago it was under $2.00 a gallon which made the savings vs Race huge.

 
You must log in or register to reply here.
Back
Top