In that case the only benefit would be in hot weather. The theoretically perfect car would remain perfect longer with E30.
7
Ethanol questions
- Thread starter alper
- Start date
In that case the only benefit would be in hot weather. The theoretically perfect car would remain perfect longer with E30.
chiefhiawatha
Ready to race!
- Location
- Chicago
I have no data whatsoever but when I was stock and now with the mild dinan piggyback I swear I could and can tell a difference with a few gallons of e85
alper
Ready to race!
- Location
- cloudy but not too cold
Hmm I think I confused boost with timing and retardation. Ethanol allows for more aggressive timing but not necessarily with running more boost then? Kind of thought more boost = more aggressive timing I guess, in which case Ethanol would allow the extra boost to be made.
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
Go read up on timing advance. Internet can explain it better than we can. Boost has only a small part to do with it. A lot more variables come into play in how much the ECU will advance it and why it retards it.
alper
Ready to race!
- Location
- cloudy but not too cold
Should do it no doubt but proper "free time slots" are sparse currently. Any suggested links would be welcome.
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
This is a good read.
https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/143753246/Volkswagen+Mk7+Tuning+Guide
E: Tuning for appropriate Spark Advance
Ignition timing tables - The main tables for ignition timing at WOT are "Ignition Timing Port Flaps Low". Main timing tables for light load and cruise are "Ignition Timing Port Flaps High". These tables are referenced by "Airflow per stroke" and "Engine speed". Logging "Air mass intake manifold per stroke" and "Engine Speed" will allow you to reference the specific regions of these tables that may need to be edited to produce optimized ignition timing.
The ECU will calculate base ignition from "Ignition Timing Port Flaps Low" under normal full load conditions. However, due to sensitivity to hot charge air temperatures large reductions can be made to the base ignition request. Referencing "Final Ignition Angle Correction IAT" will allow manipulation of corrections depending on IAT conditions.
Final Ignition Angle Correction CAT / IAT - CAT / IAT source bit switch
Final ignition timing is corrected for charge air or intake air temperature via the "Final Ignition Angle Correction IAT/CAT" table. The input to the x axis can be altered by the "Switch for Charge Air Source" bit located in the Miscellaneous Tables folder. When this value is set to 0 it will utilize the IAT (T-Map sensor) as the input while when the bit is set to 1 (stock setting) it will utilize the modeled CAT via ECU calculations.
Timing adjustments are currently limited to ~.38 degree increments.
Detonation based timing adjustment - Ignition timing is also adjusted in response to detonation or pre-ignition. The ECU actively reduces timing in response to detonation. The ECU has the capability to make individual cylinder timing adjustments, because of this monitoring a single cylinders timing correction will not result a global picture of engine operations. Timing adjustments in response to detonation are logged with the "Knock Retard 1-4." monitors. Each knock event results in a change of ~.38 degree increments depending on severity of the event.
Generally speaking, higher ignition timing supports higher torque and greater power. However, ignition timing should be increased with great caution. Higher timing yields higher cylinder pressures and this is limited by fuel quality and the mechanical limitations of the engine. Too much timing will produce knock correction when fuel quality is limiting. When fuel quality is high, ignition timing should ONLY be added when its addition produces a substantive increase in torque and power. If increased timing does not increase torque the extra cylinder pressure is simply producing unnecessary stress on engine components.
alper
Ready to race!
- Location
- cloudy but not too cold
Thanks, much appreciated!
alper
Ready to race!
- Location
- cloudy but not too cold
So, using an online calculator to see how much 98ron and E85 I should mix, the E30 mixture results in a mere 99ron rated fuel, just 1 more over the 98 pump fuel I usually use, which i guess is to be expected if you're using 98ron petrol to begin with and just 30% Eth.
So does it really make sense to bother with calculating mixtures, changing pumps etc. if all I'm going to end up with is a mere 1ron? Are there other non quantifiable benefits to using Eth (other than filling up with less money as E85 is 40% cheaper than RON98)? Because the result octane rating is nothing impressive really.
So does it really make sense to bother with calculating mixtures, changing pumps etc. if all I'm going to end up with is a mere 1ron? Are there other non quantifiable benefits to using Eth (other than filling up with less money as E85 is 40% cheaper than RON98)? Because the result octane rating is nothing impressive really.
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
That's not correct. E85 is equivalent to 105US which is 110RON. Assuming your 98RON has no ethanol in it then 3 gallons of E85 and 7 gallons of 98RON would make something close to 101RON. It's 3 points higher, not 1. Also, it cools the cylinders which reduces knock.
http://www.pencilgeek.org/2009/05/octane-rating-conversions.html
http://www.georgebelton.com/E85Calculator.php
Fuel #1
E85 (Gals)
3.00
E85 Octane
105
% ethanol
85
Fuel #2
Gas (Gals)
7.00
Gas Octane
93
% ethanol
0
Result
10.00 gallons
96.6 octane USA
25.5% ethanol (or E26)
RON MON USA
100 91.5 95.75
105 95 100
Hoon
Autocross Champion
- Location
- Rhode Island
This.
Using 93 octane and E85 blended to E30, we get about 97 octane (US method).
Also, straight E85 always punches above its weight on the octane scale when used in turbo applications.
It's only rated at 105, but actual performance in turbo motors is very comparable to 110-112 race gas. This has a lot to do with lower combustion temps working very well with boost.
Oldschoolmk7
Go Kart Champion
- Location
- Yonder
Corn 4 life! 
.
.I’m sure I will get flamed. I asked a VW master tech friend who is very mod friendly and he says VW states nothing over E10 should be used in our cars.
Not sure on the details. But for my car he said he would avoid it.
I’m Not after every hp either so I’m leaving it alone.
Not sure on the details. But for my car he said he would avoid it.
I’m Not after every hp either so I’m leaving it alone.
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
Brazil only has 25% minimum ethanol gas.....
Does Brazil get port injection aka ROW cars?
Diggs24
Autocross Champion
- Location
- de plains! de plains!
- Car(s)
- 2015 GTI
It does but I'm not sure how that is relevant if the concern is ethanol's corrosive properties to the fuel system. Having 4 more injectors won't solve that.