Balrok

iTrader: (15)

There's been a struggle with Evo race cars and which gas to run. We all know both e85 and 110 work. SO what do you run and what have you found? In my experience e85 can get you through ~25minutes in the oem tank, which can cut your race short in most cases.

In my mind It'll all depend on your budget.

Figure:

Properly installed 20gal fuel cell ~3500
12 gallon well cell bridging the OEM tank ~ 1800
Custom surge tank ~ 1000

Or Race gas

E85 x 40 gallons at 3.50 a gallon = $140 in fuel for the weekend
112+ x 40 gallons at 9.00 a gallon = $360 for the weekend

Lets say you do 8 events a year.

140x8 weekends = $1120 yr
360x8 weekends = $ 2880 yr

There's pros and cons to both. Gas consistency is always a player because you can get e70 or e90 from one day/station to the next. 112 octane is always going to be 112 octane. But E85 runs cooler, cleaner, easier on your o2's, more readily available to the public etc. Let's discuss.

R/TErnie

iTrader: (32)

You didn't consider weight.

With the race fuel you have a higher energy density and therefore you can carry less on your vehicle. Means you're lighter at the start of the race and at the end of the race.

Depends on how your minimum weight rules work...if you scale before or after the race. Something to think about.

E85 is not as reliable as VP fuels. You do have a variation, but that should be compensated in your tune. Equip your car with an Ethanol content sensor and tune your engine based on Ethanol content. (yes that requires that you have a real ECU in your Evo) MoteC, VipeC, or ProEFI to name a few.

I personally would choose E85 for the following reasons
It's far cheaper than c16 ($4.00 versus $15.00 per gallon)
I can test my Ethanol content prior to purchasing it.
I can buy Ethanol 24 hours a day from known locations and they're rarely ever "out of stock"
Chemical cooling of the charge air
Better spool up on E85 (better boost threshold and transient response)
Setup costs are in fact much higher, but the operating costs are much lower... and at 15 dollars a gallon I think this discussion will be HIGHLY skewed by costs.
You might be able to get a sponsor for being "green"

skidmarq

iTrader: (6)

Thanks for starting this thread, as you saw I'm currently beginning my plans for the future as you are. Currently I'm running E85 and love the fact that it runs cooler, is cheaper than race fuel, and arguably easier on the vehicle as a whole. Obviously, it is a pain to have to bring 40 gallons each track day I attend (four twenty minute sessions and 30 mile round trip). Some of this burden will be lessened by the purchase of a dedicated tow vehicle though.

That said, I'm leaning more towards staying on E85 and developing a larger capacity fuel cell/tank setup...anxious to hear others' opinions though as I'm in no way set in that decision...

Balrok

iTrader: (15)

Lets make sure we look at this from a track only perspective, as most race tracks have 110/112/114 etc Sonoco fuel right there. So even if you lugged jugs, you could top off. Or not bring jugs at all.

Most of us in SCCA/NASA always weigh in after especially if your in the top 3. So if you added capacity to hold the cheaper content, could you put the weight in the right place to offset it all. I remember KevinD doing his fuel cell and stating it was a waste because he spent thousands and didn't save any real weight. If c16 is 15 something a gallon I think the scales tip towards the extra weight. But where do track fuels come in at? I've never seen it over $9.

boomn29

iTrader: (47)

I run 100oct unleaded. And I have no plans to change.

1) 100oct is always 100oct. No worries about different times of the year
2) Around Chicago I can get it at the pump.
3) It runs $6-$8 / gallon
4) I can run stock ECU
5) I can run stock injectors, rail and pump (AMS Tuned FTW!)
6) I don't have to carry 5-7 5gal jugs or buy an expensive secondary fuel tank to put in my truck for E85
7) I can run a cat if needed (certain 'street' rules) on my tune
8) I don't have a CEL
9) All tracks have 100 or 104 available. Almost 0 have E85; some stations are multiple states away!
10) Fuel mileage and surging as compared to E85

I've talked to several that did a all out fuel cell (KevinD included I think). Most said it's a waste of $$ if not absolutely necessary.

goforwand

iTrader: (132)

Potential stupid question

What's wrong with running 93 octane with a proper tune? Most of our cars see ~325-340 whp on an all wheel dyno for TTS/ST-2 classification purposes which I thought that 93 was just fine for that level......

Does the higher octane lead to significant improvement in engine component life?

chkmgnt59

iTrader: (3)

I kinda lean toward the 93 pump gas as well. Easier fuel system setup, and if you need the higher power, thats what bigger turbos are for...

KevinD

iTrader: (56)

we run E85 in all of our race cars for several reasons.


1) its way cheaper
2) its more readily available around here (although at the tracks its not, and 100oct is). we just bring a 55 gallon barrel since the cars are trailered anyway
3) it gets insanely hot here especially in the summer. and for TTA lugging around the aftermarket intercooler costs points and weight. so the cooling properties of E85 is a huge benefit to us.



and yes, having gone down the full fuel cell setup, it definately wasnt worth it. i just wasn't happy with the double pumper setups at part throttle, which would cause rich or lean spots. went to a fuel cell with the weldon fuel pump and a surge tank. car ran a lot better, but the cell (even went with the aluminum one from fuel safe), wasn't hardly any lighter then the stock tank was. it cost several thousand dollars to do. if i were to do it again i would have simply added our surge tank system to my evo 8 stock tank, and run the weldon off it.

KevinD

iTrader: (56)

i'm going to start my car in TTS next year. i built it for TTU but it has been so unreliable i figured i would start with less power. with that said, the engine is going to make a LOT more torque then power. power will be modulated by the 3 port BCS keeping it below the 270ish whp i'll be limited too . i expect 400+ftlb of torque though. i'm aiming for 450-500ftlb. 2.3L stroker, small cams, stock turbo, e85 then when i'm happy with the cars reliability again i'll put the AMS HTA86 back on and see what 600whp at 28psi feels like. last time it was scarey. very scarey.

awdboosted

iTrader: (30)

E85 is awesome but you will burn thru it so much faster then 110.

You will be consuming between 30-35 % more fuel and given that pump gas contains E10 and 110 fuels don’t. The math looks wrong. I personal had this dilemma. I decided to go with 110 because of how hard it is to find the fuel when racing and I don’t trailer my car to events and I can’t carry a 55 gallon drum in my car. I personal go thru 21 gallons with 4 session at 20min each.

AWD Motorsports

iTrader: (211)

I wouldnt consider any other fuel ever for road racing.. Id find a way to add capacity to my tank.. I ran the bastard evo in sebring and didnt have any issues getting thru 20-30 minutes with a full tank..

KevinD

iTrader: (56)

the real efficiencies we see with e85 is no worse then 20-25% of pump gas. we run it a lot leaner then you would with pump so i think thats where some of the economy is made back. you might want to try leaning out your fuel map on e85 if your seeing 30-35% worse mileage then pump gas.


i never used more then half a tank of E85 in a 25 minute session. my street car was tuned to around 380whp last time out. i could easily make 4 20 minute sessions with 20 gallons of gas in jugs.

goforwand

iTrader: (132)

I wish I had someone to tune my car like this locally...will have to haul it for a few hours to find someone that has a dyno and can work with the 3 port .

Exactly what I want my set up to be next year (a bit higher on the hp 'cause the car will be around 3200 at full comp weight)

Balrok

iTrader: (15)

I'd agree with both Kevin and Mike when it came to running regular sessions or TT, but the pace/aggressive driving in a real race plus the added laps made a difference. I did 11 race laps at Sebring, 3.7 mile circuit, including 1 warm up and 1 cool down so 13 laps - I had a little less then half a gallon left when I refueled it. Figure that's 1.1 gallons per lap. She was also running lean because it was tuned with a leaking throttle body seal which I fixed. I'd say if we can get a 2.5-4 gallon surge tank it's a win-win.

awdboosted

iTrader: (30)

KevinD, my numbers come from an estimate. I’ve never run E85 and from pass research everyone says you need to rich up your map about 30 percent. It’s nice to hear that you’re not using as much as they are saying. I do know that 110 has a heavier specific gravity and going from 93 octane here in IL to 110 Sunoco fuels, I do lean out the fuel map because the fuel runs richer then 93 because of the lack of Ethanol .

My problem is finding a E85 pump near the track. Also trusting that it really is E85 is an issue too. Until I trailer the car I will not race on E85. But I really want to run it and agree with it being a much cheaper and better fuel to run.

So it comes down to if you Trailer. Do IT!!! If not, then run 110 because you can fill up at the track.