MauricioGTI
Go Kart Newbie
- Location
- Brazil
Yes
7
Ethanol questions
- Thread starter alper
- Start date
Yes
Hoon
Autocross Champion
- Location
- Rhode Island
I personally think the risk is massively overstated.
I've been running straight E85 in my turbo GSXR for 4 years now.
I let it sit for 6+months at a time without draining the tank, in fact it has always had E85 in it for 4+ years. I did not use ethanol compliant hoses, injectors, or anything else in the fuel system.
The fittings still look brand new on the inside, and I've never had any issues with corrosion or anything else.
That’s good to hear and honestly I don’t know what the long term effects are. (No one does on the mk7 yet)
But that is certainly reassuring.
marauder
Go Kart Newbie
- Location
- Northern Va
Running E30 isn't going to negatively affect any of the parts on your car. That is why you run E30 instead of E85. Running full E85, would cause issues with our fuel lines and hpfp as they aren't rating for it. The lines can dry out and crack, and the hpfp can wear and seize due to improper lubrication. Running a blend prevents this from happening.
In the US E85 pumps can vary the E% by region/month. In colder states in the winter E85 pumps can be as low as E50. Some of the warmer states don't have to drop the Ethnaol% in the winter, but doesn't mean that it is always E85. If you're trying to hit a specific ratio, get a gauge or a tester. Otherwise keep your tuning a bit more relaxed to allow for variance in the ethanol grades.
Being IS38, on ethanol you'll start to max out your lpfp. With only a JB4 you'll max out the jb4's ability to provide additional fueling before this though. The JB4 can only take the reading so far before the car thinks there's a problem. So you'll be leaving a good amount of power on the table with just the JB4 on E30 IS38.
In the US E85 pumps can vary the E% by region/month. In colder states in the winter E85 pumps can be as low as E50. Some of the warmer states don't have to drop the Ethnaol% in the winter, but doesn't mean that it is always E85. If you're trying to hit a specific ratio, get a gauge or a tester. Otherwise keep your tuning a bit more relaxed to allow for variance in the ethanol grades.
Being IS38, on ethanol you'll start to max out your lpfp. With only a JB4 you'll max out the jb4's ability to provide additional fueling before this though. The JB4 can only take the reading so far before the car thinks there's a problem. So you'll be leaving a good amount of power on the table with just the JB4 on E30 IS38.
chiefhiawatha
Ready to race!
- Location
- Chicago
What ratio do you suggest?
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
The one that doesn't cause AFR to go lean. For your Dinan E20 should be fine.
Hoon
Autocross Champion
- Location
- Rhode Island
Stratified recommends 25-30% for MK7s.
With small turbos (IS20 or IS38) you reach a point of diminishing returns very quickly, and with IS38 you run out of fuel pump on E30.
alper
Ready to race!
- Location
- cloudy but not too cold
Arghhh, the US octane rating was the culprit. I was entering "98" as my main fuel's octane rating thinking 98ron but the calculator was assuming US units so that value should be changed to 93.5/94 which already creates more headroom. All fuels in Sweden include 5% Ethanol already and I was using the lowest rating for the E85 (100) as I'm not sure how much it's actually rated for.
Car was IS38 from factory so it's a R engine, haven't done just a turbo swap (if that's what you meant about the hpfp). By "leaving a good amount of power on the table with just the JB4" do you mean I would need a full tune?
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
Not that I like to push people away from JB4, but your car would benefit a lot from a flash tune. Getting rid of that overboost would be key as it is either too much boost or not enough with JB4 on top. Too difficult to tune something that changes how much boost pressure it generates.
jybyrd
Go Kart Champion
- Location
- Seattle, WA
Has anyone else found that fuel rail pressure is heavily affected by the amount of fuel in the tank? Running E35-E40, I am seeing drops in rail pressure when <1/2 full, but everything is peachy for the first half.
Just curious.
Just curious.
alper
Ready to race!
- Location
- cloudy but not too cold
Do you mean because of the overboost delete mainly or there's other benefits to be had also? To be honest that silly feature is the main reason I've been contemplating a tune for quite a while. And I could keep the JB4 for logging or fine tuning for further upgrades, it's so versatile anyway.
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
Better fueling with the E85 added, but mainly to counteract that silly overboost.
steddy2112
Go Kart Newbie
- Location
- Belcamp MD
- Car(s)
- 2016 GTI SE
The issue isn't the hoses and injectors. Also a little different on an aluminum blocked engine vs an iron blocked engine.
Like I said in another thread:
It does lower the life span of engine oil.
In the gixxer's case though so does having a bunch of clutches sitting in engine oil lol and load levels are significantly lower on a 400-ish pound motorcycle than a 30000-ish pound car.
steddy2112
Go Kart Newbie
- Location
- Belcamp MD
- Car(s)
- 2016 GTI SE
This is a big one here stateside.
E85 really isn't regulated all that much, if you're going to run it, you have to test it and pay attention to what's going on.
Another thing I haven't seen anyone else mention that's good food for thought is the reason why you run out of fuel using E85 or blends is because even though it has a higher octane, there's less energy per volume in E85 so you need more of it.
Oxygenated race fuels are the same way, which most unleaded race fuels are oxygenated.