# Madmax E85 tuning notes



## madmax199 (Oct 28, 2009)

The board has been asking lot of questions about E85 lately and since I seem to be the only one running an MK1 TT on corn juice, I decided to make a comprehensive thread that will cover what is really involve in the conversion.

There are a couple of other threads on the 1.8t technical forum that are great starting points and cover the basics. The second one I posted below, does a great job at going through the hardware install and giving basic settings to get the car runnning. I am mostly going to take it from where he left off, tuning wise, and go into the specifics.

http://forums.vwvortex.com/showthre...albro-Inline-18-Gurus-Come-all.&highlight=e85

http://forums.vwvortex.com/showthre...-run-on-E85-FlexFuel-ethanol-(in-4-easy-steps)

Before we even go anywhere, I feel that a little break down of E85 is in order.

E85, on paper, is 85% ethanol (mostly corn based in the US but could be made out of other things like sugar cane, algae or switchgrass) and 15% gasoline. In reality, most pump only supply about 83% ethanol in their summer blends and about 75% in winter blends but it will vary from pump to pump. 

*The question many may have is why E85?* 
In my view it’s a great alternative to race fuel at regular gas price, if you are looking for a performance boost. You can easily exceed the agressiveness of a tune pass what 116 octane race fuel would allow, safely on E85. It’s also a commitment because it’s not readily available at every station. I’d advise that you check availability in your area before you decide to attempt converting your car to E85. Can it be a real alternative and support all US demands? At this point, I don’t think so but that could change in future and I want to leave the politics involved, out of the thread.

*Why does E85 make more power?*
Part of the reason it makes good power is because it's highly oxygenated. That means you can use a lot more fuel which means more power. Remember gasoline's lambda is 14.7 afr, while E85 is ~9.8. That's 1.5 times the fuel. 

1.5 more fuel will make more energy even though unit per unit ethanol has lower energy content than regular gasoline.

*Gas is 114,000 BTU/gal
E85 is 81,800 BTU/gal*

However you burn them at a different stoichiometric mixture
Gas = 114,000/14.7=*7755 BTU*
E85 = 81,800/9.8=*8436 BTU*

We also want several other things out of fuel - fast burn and detonation resistance being the most important ones. High oxygenation and cooling are also some other very good qualities. 
All those properties in a fuel help it make power, and E85 exceeds gasoline in all of those.E85 combusts at a lower temp, and also draws more heat from the intake manifolds due to its higher L H o Vaporization. These effects cause most engines to run at 10-15degF lower temperature (at coolant) when using E85. I have also recorded lower EGT in an average of at least 200 degrees or more.

E85 can also tolerate much higher compression ratios and cylinder pressures safely without the fear of detonation. That means more boost, more timing (up to the limit of timing advance possible before torque loss is recorded also known as MBT).



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Another advantage to E85 is that is has more exhaust byproducts, mainly because of the higher volume flowing. More exhaust means more energy to spin the turbo blades and that results in faster, stronger spools (about 300rpm earlier than regular gas).

*Edit with the chemistry that shows how and why E85 produces more exhaust byproducts *

_"Combustion of ethanol and gasoline (octane) to determine how much more exhaust gas we are getting when running E85 as opposed to gasoline.

ethanol:
1 CH3CH2OH + 3 O2 ----> 2 CO2 + 3 H2O 

gasoline (octane):
2 C8H18 + 25 O2 ----> 16 CO2 + 18 H2O


So, if we standardized to the same unit airflow (O2), we get:

ethanol:
1/3 CH3CH2OH + O2 ----> 2/3 CO2 + H2O 

gasoline:
2/25 C8H18 + O2 ----> 16/25 CO2 + 18/25 H2O


So, for the same amount of mass airflow, we get roughly 4% more CO2 and 39% more water vapor in our exhaust. That helps explain why E85 helps spool our turbos sooner, burn cooler, but it also points the fact that exhaust restrictions will come into play sooner"_

*Drawbacks:*
Do not tell any regulatory (DMV) or police agencies that you are running E85 since it is technically not legal to do so per the EPA. Even though E85 does spew out fewer emissions, the EPA has not certified E85 conversion for a TT.
The rubber corrosion is a myth!! All cars after 1998 were mandated to be able to handle Ethanol in their rubber lines and I’m tired of hearing this crap.



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You need to check and change your oil more often as running higher boost may likely cause some oil usage. 

Cold start is the biggest issue I had with the fuel as the high alcohol content gives it a much lower flash point that conventional gas. In temperature lower than 35 degrees, starting need help but more on that later. Normally stations in cold area are suppose to take care of that by switching to winter blends with higher gas content but it’s not really enforced. 

As I understand it, ethanol mix is not regulated. The ethanol industry has established its own self-regulatory guidelines. 

Class 1 – Ethanol content min. 79% 
Class 2 – Ethanol content min. 74% 
Class 3 – Ethanol content min. 70%

Class 1 – Gasoline content min. 17%
Class 2 – Gasoline content min. 17%
Class 3 – Gasoline content min. 17%

Combining the above minimums creates the following range for ethanol content:

Class 1 – Ethanol content min. 79% - max. 83%
Class 2 – Ethanol content min. 74% - max. 83%
Class 3 – Ethanol content min. 70% - max. 83%

As you can see, these are pretty broad ranges. Buyers beware!

Some stations do their mix with 85 octane and other use 87 but the gas portion is so small that it doesn’t matter if they started with 85 or 87.

Blend w/ 85 octane
(113 x .85) + (85 x .15) = 108.8 octane

Blend w/ 87 octane
(113 x .85) + (87 x .15) = 109.1 octane

Now just in case lower octane is blended, here is what I came up with for summer blends

93 octane 109.6
91 octane 109.2
87 octane 108.58
85 octane 108.24
80 octane 107.39 

Now that we have established what e85 is, let’s move to fun stuff.
Hardware wise, you need to almost double your fuel flow capability to satisfy the demand of an E85 running engine. You need a pump that can flow 300+ gal/hour and bigger injectors (how big is going to depend on your boost level and turbo size). You can also, like most do, run a second external pump in series with the stocker (that’s what I have for my stock turbo car but I wouldn’t feel comfortable with it on a BT). 
Same with the injectors, a stock K04 will need around 630cc to have enough headroom for big boost and acceptable duty cycles (80% or less at full load).

The next thing needed is software changes to make it all work.
As far as I know there isn’t a dedicated E85 flash available so you need to get your hands dirty and use those adaptation channels to set everything up.

I am going to base my conversion notes on a TT running the stock turbo, since BT applications are the minority. 

I am not going to go into the details of installing the hardware (pump, injectors and a real time wideband gauge/controller) because it’s pretty straightforward and should be handled by a shop if you’re not sure how to do it. I am not including an adjustable fuel pressure regulator in my recommended list of hardware, for the simple reason that some of you may want to cut corners and raise the fuel pressure way high, as a substitute for running the right size injectors. In my book, that’s a recipe for disaster because you risk running too high on your injector duty cycles and run lean. The second issue is that you also risk exceeding the rail pressure capability (around 90psi for the stock fuel rail), if you increase the fuel pressure to say 4.5 bar (65.26 psi) your are left with only 24.74 psi for boost before that rail goes static ( another condition that would make you run lean up top).

*Hardware and software needed on a stock K0x to run E85*

1) 630cc injectors
2) External inline high flow fuel pump, running in series with the OEM pump
3) A wideband gauge
4) VCDS software and cable bundle for your logging
5) Unisetting, lemmiwinks or maestro7 or equivalent

USRT had a good deal on pump/injector combo and that’s what I went with:
http://www.usrallyteam.com/index.php?main_page=index&cPath=10

Once you have all your hardware installed and tested we can finally move to what everyone's waiting for, some in-depth *tuning*.


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## madmax199 (Oct 28, 2009)

_*Before we even start with the tuning, I need to warn everyone that certain modifications made, can be dangerous to your engine and should be done with caution. Careful logging and a wideband is crucial for success. I am also not responsible for what you do to your car. *_

*How do we tune for E85?*

Adaptation channels are built into the ecu by the manufacturer and they allow tweaks to be made to the engine operating parameters. These settings can be modified using Unisetting or Lemmiwinks (VCDS does the same thing but has low preset limits). I choose to use Unisetting because it is USB based and that’s what DougLoBue had to lend me since I don’t own one.

These settings are stored in a serial eeprom and will not disapear or adapt back to the OEM or be flashed back to default setting. This serial eeprom is not he same as the regular flashed memory chip that has the main engine control program stored. Changes made to the adaptation channels will not affect the code checksums and other regular subroutines. However, just like a chip will change some of the preset ecu parameters to make the car go faster, you can use the available channels to do the same thing. These adaptation channels, I have to admit, have some limitations because they only make changes in percentage to the entire map and are not load specific, like let’s say Maestro7(the only software I would spend money on for my TT).

*This is what the unisetting screen look like*:
Most of the values should be pre set a 100% or 0%



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There are 14 channels and that's their basic definition:

*Channel 1: Additive Engine Idle Speed Offset *
This channel allows one to adjust the engine idle speed in steps of 10
rev/min. 

*Channel 2: Tweak on fuel enrichment based on increasing loads (i.e. accel pump) *
This channel adjusts a fuel enrichment term that is proportional to load
rate of change and that acts to enrich full when the engine load is
increasing. This is equivalent to an accelerator pump function 

*Channel 3: Tweak on fuel enrichment based on decreasing loads *
This is very similar in function to channel 2 but adjusts a term
that works to decrease fuel when engine load is decreasing. 

*Channel 4: Tweak on Startup Fuel Enrichment *
This adjusts the startup fuel enrichment term. 

*Channel 5: Tweak on Warmup Fuel Enrichment *
This adjusts the warmup fuel enrichment term. 

*Channel 6: Lambda Regulation *
This tweaks a lambda regulation system's narrowband oxygen sensor
cycle time in steps of 10 milliseconds. 

*Channel 7: Additive Offset On Speed Limiter *
This is allows one to adjust the speed limiter in steps of 1 kmh. 

*Channel 8: Secondary Fuel Tweak *
This adjusts the main fuel term. 

*Channel 9: Additive offset on ignition timing angle *
Allows one to shift the ignition timing angle up or down in steps of
0.75 degrees. 

*Channel 10: Primary Fuel Tweak* 
This adjusts the main fuel term. 

*Channel 11: Not used*

*Channel 12: Specified Engine Load Scaling Factor (Turbocharged cars only)* 
This factor allows one to scale the specified engine load. The default
value comes set at the maximum value, so specified engine loads can only
be reduced with this adaptation channel. 

*Channel 13: Control Bits* 
These control bits affect engine idle control. 

*Channel 14: Additive Offset To Idle Torque* 
This channel allows one to raise the minimum torque maintained at idle

_There are a couple of more channels that are purposely hidden and don't appear on both unisetting and lemmiwinks. One of them allow boost modifications but you have to open unisetting in Hex editor to manually have access and make changes to these ghost channels._



*All of the following channels are going to need some modifications to get the car running right on E85:
Channel 2, 3, 4, 5, 8, 9, 10*

If you have all your hardware installed and checked, go ahead and open unisetting with the ignition turned to the on position. Click read from ecu and your pre set values will show on the appropriate boxes. Once that’s done and you have read properly from the ecu, save your those values by clicking save to disk and name it default (in case you want to return to stock you’ll have the values stored somewhere). Now that you have succesfully read and save your default setting, it's time to modify them for E85.

Assuming you have already drained your tank and filled it with E85. Change the following channels as follow. They will get the car running pretty good but you will still need to get some extensive logging to fine tune everything.

*Channel 2*
Remove 10% for now(mine has 15% removed for a flat fuel curve). Most gas tune has the fuel curve taper considerably towards redline for safety. When running on E85, you don’t want that taper as it will be too rich on the top end and could cause knock. Your specific flash may have more or less taper than mine had(GIAC) and that's for you to determine through some logging.

Nasty fuel curve taper on my GIAC gas flash(from 14.2-10.5 is way too much).


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*Channel 3*
This channel, just like channel 2, has control over the fuel enrichment but under decelaration. After some logging if you have some throttle overhang you might want to remove 10-15% accordingly (I have 10% out on my car but I'm also running a 3" ID S4 maf).

*Channel 8*
Assuming that you followed my recommendations for injector sizes (630cc for a K04), Add 15% to this channel. It controls the injector reaction time and is set for stock injectors at 100%. If you don’t change it, the bigger injectors will be seriously lazy. Why 15%? Well, after spying on Unitronics 630cc flash vs their lower injector sizes flashes, I found out that's what they use for 630s. I did a lot of testing and it woke my injectors up tremendously at around +15% so I left it there. Bigger or smaller injectors will need different tweaks, PM me if you need recommendations on ball park numbers.

*Channel 9*
Add timing by increments of 1.5 all the way up to 9* additional timing. I can not stress this enough, don’t fall in love with timing although it gives a lot of power. *Each time you add some timing go for a few logs to make sure your timing corrections stay under 5* on all 4 cylinders*. In my car, at the dyno, the car took up to 12* of additional timing safely with my torque curve ramping up each time and letting me know that I haven’t pass the point where extra timing increases cylinder pressures and lower the torque numbers(the point in the timing curve, right before more timing=less torque is MBT and you don't want to pass it). 

This is what my final timing curves looks like at 30+ psi (I have virtually zero timing pull throughout)
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*Channel 10*
Zero this channel out, and go for some logs. You want to start a zero for the new fuel and let the ecu adapt. Once you have some good short term and long term fuel fuel trim numbers you can tweak this channel for the target AFR. Your target AFR value (on a gas calibrated wideband) is *12.0-12.5* , corresponding wot lambda values should be *0.82-0.85*. E85 can go a little leaner still but I like leaving some kind of a safety net and you won't make much power past 12.5 AFR. If you are on the lean or rich side after some logs, add or remove to this channel until you reach the desired target. A real time wideband is important because the VCDS sampling rate is way too slow for comfort. Please do not cut corners with this because it will make or brake the tune. A fuel curve that is spot on, will ensure great power and longevity.

*We are not done because chanel 4 and 5 also need modifications but I will touch them later:beer:*


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## omerkm1 (Feb 23, 2010)

subscribed


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## madmax199 (Oct 28, 2009)

Tuning posted, will update/finish later


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## Marcus_Aurelius (Mar 1, 2012)

With the renewed interest on E85, I might as well bump this with some more info. I posted the following in a different thread and it would be a great addition to this one for the MK1 TT people (quoting myself):

"Here is a seasonal State by State breakdown of ethanol blends. It may only show minimum requirements, but gives a good picture of what you get as a worst case scenario. I would not use this as a reason to stop regular alcohol content testing but it's a good baseline. I thought it would be a good contribution to this thread! :beer:

Summer Blend: Class 1 (min 79% ethanol) 
Spring/Fall Blend: Class 2 (min 74% ethanol) 
Winter Blend: Class 3 (min 70% ethanol) 
State Fuel Region Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 


Alabama 2 2 2 2 2/1 1 1 1 1 1/2 2 2 
Alaska Southern Region 3 3 3 3 3/2 2/1 1 1/2 2/3 3 3 3 
Alaska South Mainland 3 3 3 3 3/2 2/1 1/2 2 2/3 3 3 3 
Arizona North of 34 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
Arizona South of 34 latitude 2 2 2 2/1 1 1 1 1 1 1/2 2 2 
Arkansas 3 3 3/2 2/1 1 1 1 1 1/2 2 2/3 3 
California North Coast 2 2 2 2 2 2/1 1 1 1 1/2 2 2 
California South Coast 2 2 2 2 2/1 1 1 1 1 1/2 2 2 
California Southeast 3 3/2 2 2 2/1 1 1 1 1/2 2 2/3 3 
California Interior 2 2 2 2 2 2/1 1 1 1 1/2 2 2 
Colorado East of 105 longitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
Colorado West of 105 longitude 3 3 3 3 3/2 2 2/1 1/2 2/3 3 3 3 
Connecticut 3 3 3 3/2 2 2/1 1 1 1/2 2 2/3 3 
Delaware 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
DC 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
Florida North of 29 latitude 2 2 2 2/1 1 1 1 1 1 1/2 2 2 
Florida South of 29 latitude 2 2 1 1 1 1 1 1 1 1 1/2 2 
Georgia 3 3 2 2/1 1 1 1 1 1 1/2 2 2/3 
Hawaii 1 1 1 1 1 1 1 1 1 1 1 1 
Idaho 3 3 3 3/2 2 2 2/1 1/2 2 2/3 3 3 
Illinois North of 40 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
Illinois South of 40 latitude 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3 
Indiana 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3 
Iowa 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
Kansas 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
Kentucky 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
Louisiana 2 2 2 2/1 1 1 1 1 1 1/2 2 2 
Maine 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Maryland 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
Massachusetts 3 3 3 3/2 2 2/1 1 1 1/2 2 2/3 3 
Michigan Lower Peninsula 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Michigan Upper Peninsula 3 3 3 3 3/2 2/1 1 1/2 2 2/3 3 3 
Minnesota 3 3 3 3 3/2 2/1 1 1/2 2 2/3 3 3 
Mississippi 2 2 2 2/1 1 1 1 1 1 1/2 2 2 
Missouri 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3 
Montana 3 3 3 3 3/2 2 2/1 1/2 2/3 3 3 3 
Nebraska 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Nevada North of 38 latitude 3 3 3 3/2 2 2 2/1 1/2 2 2/3 3 3 
Nevada South of 38 latitude 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
New Hampshire 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
New Jersey 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
New Mexico North of 34 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
New Mexico South of 34 latitude 3 3 3/2 2/1 1 1 1 1 1 1/2 2/3 3 
New York North of 42 latitude 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
New York South of 42 latitude 3 3 3 3/2 2/1 1 1 1 1/2 2 2/3 3 
North Carolina 3 3 3/2 2 2/1 1 1 1 1/2 2/3 3 3 
North Dakota 3 3 3 3 3/2 2/1 1 1/2 2 2/3 3 3 
Ohio 3 3 3 3/2 2/1 1 1 1 1/2 2/3 3 3 
Oklahoma 3 3 3 3/2 2/1 1 1 1 1/2 2 2/3 3 
Oregon East of 122 longitude 3 3 3 3/2 2 2 2/1 1/2 2 2/3 3 3 
Oregon West of 122 longitude 3 3/2 2 2 2 2/1 1 1 1/2 2 2 2/3 
Pennsylvania North of 41 latitude 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Pennsylvania South of 41 latitude 3 3 3 3/2 2 2/1 1 1 1/2 2 2/3 3 
Rhode Island 3 3 3 3/2 2/1 1 1 1 1/2 2 2/3 3 
South Carolina 2 2 2 2/1 1 1 1 1 1 1/2 2 2 
South Dakota 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Tennessee 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
Texas North of 31 latitude 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
Texas South of 31 latitude 2 2 2 2/1 1 1 1 1 1 1/2 2 2 
Utah 3 3 3 3/2 2 2/1 1 1 1/2 2/3 3 3 
Vermont 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Virginia 3 3 3/2 2 2/1 1 1 1 1/2 2 2/3 3 
Washington East of 122 longitude 3 3 3/2 2 2 2/1 1 1 1/2 2/3 3 3 
Washington West of 122 longitude 3 3/2 2 2 2 2/1 1 1 1/2 2 2 2/3 
West Virginia 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Wisconsin 3 3 3 3/2 2 2/1 1 1/2 2 2/3 3 3 
Wyoming 3 3 3 3 3/2 2 2/1 1/2 2 2/3 3 3"


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## Marcus_Aurelius (Mar 1, 2012)

Again, adding info I posted elsewhere!

The question was: "How do you test for ethanol content"? I answered the following:



madmax199 said:


> Simple, a graduated cylinder with a preset volume that you fill with water. The rest of the cylinder is then marked 0-100% after the water line, based on it's volume. You then add Ethanol to another volume line and shake it. The water and ethanol will mix together and the gas portion will separate and sit at the top. Since you already know the amount of water that was mixed in the ethanol, you can accurately find the ethanol content in percentage.
> 
> They sell these ethanol content graduated cylinders with the lines already marked but I like to play mad scientist in my garage and made my own. I used a bigger clear can that makes pouring, mixing, and reading the content easier and more accurate.
> 
> ...


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## Marcus_Aurelius (Mar 1, 2012)

This is what Jeff used as a starting point for timing increase on E85. A timing increase of +7.5* throughout the curve is pretty potent on top of what was preset in the base file.

.








49) *Updated 3/10/10*



This is what I was able to squeeze out as far as timing advance on E85 at 30+psi (+13.5*). My results shows the potential but are not recommended to the noob just getting his feet wet, and can't properly monitor AFR, EGT and the TQ curve simultaneously in a controlled environment.








This is what my additional Unisetting +13.5* timing advance did to the curve overall (it is to be noted that my timing curve nowadays is more optimized but there are newly introduced variables that contributed to the improvement).




A dyno that shows what E85 can accomplish in terms of WHP with the boost and timing it allows! If you can keep the IAT sensor from raining on your parade, the cooling properties of the fuel will accept a lot of heat without a hint of detonation. (the dyno was taken with a slipping OEM clutch that was not holding the power like it should, but illustrates the potential on a stock turbo).


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## SteveCJr (Aug 3, 2008)

Hawaii 1 1 1 1 1 1 1 1 1 1 1 1

Summer all year round. Not important, just thought it was funny.


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## jedge1.8t (Jan 27, 2012)

Do you think E85 will bend a rod on the stock 225 TT if setup correctly?


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## Marcus_Aurelius (Mar 1, 2012)

jedge1.8t said:


> Do you think E85 will bend a rod on the stock 225 TT if setup correctly?


I don't think it will, I know it will! 

How do I know? I've pushed it myself and experienced it in my own car at around 360 AWTQ. The AFR curve was ironed out at .085-0.82 lambda on-boost, the timing was nowhere as advanced as it is now (original curve is posted), EGT was low (in the low 800*C), so everything was in good order. The OEM rods (they are cast) just weren't designed to take the massive TQ that E85 was producing.

Unless you're not running any significant boost and timing, upgraded rods are needed, there is no way around it! I know you've been inquiring all over about cutting corners, but there are only two scenarios:

a) you don't run any significant boost/timing on E85 to save the rods (which makes the whole conversion pointless)

b) you ignore the forewarnings and try your luck. Who knows, you may have a different outcome than the others who have tried it and all report the OEM rods been too weak to handle the TQ loads.


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## jedge1.8t (Jan 27, 2012)

lol no thanks im scared to put race gas in my car. I would have done this conversion a long time ago if i werent to get bannanas in doing so. 

I think it should be added this mod is only worth it if you have rods or just wanna do it for the smell.


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## BeasTToftheEast (Sep 20, 2007)

I'll be running Maestro, so how conceivable is it that I could set my car up with 2 tunes? One running e85 and the other running premium, obviously I would set the fueling up for the e85, but would want to configure the tune to be able to switch to normal premium since e85 isn't too available in NYC where I'll be living.


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## 20v master (May 7, 2009)

Marcus_Aurelius said:


> The OEM forged rods


The what rods? :sly::what:


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## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> The what rods? :sly::what:


Sorry, EVO moment! Sometimes it's hard for me to change things in my brain that have become reflexes from over a decade of 4G63t experience. *Our rods are cast*, our pistons are what's forged! Post fixed for you Adam! :thumbup::beer:


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## 20v master (May 7, 2009)

Marcus_Aurelius said:


> Sorry, EVO moment! Sometimes it's hard for me to change things in my brain that have become reflexes from over a decade of 4G63t experience. *Our rods are cast*, our pistons are what's forged! Post fixed for you Adam! :thumbup::beer:


:laugh::thumbup: Actually, they're sintered powdered metal, aka not forged so that's all that matters.


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## tedgram (Jul 2, 2005)

Just found this link will be getting an after market fuel rail. This is going to help me with tuning even runing gas.:thumbup: Thanks for your info Max


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## Marcus_Aurelius (Mar 1, 2012)

tedgram said:


> Just found this link will be getting an after market fuel rail. This is going to help me with tuning even runing gas.:thumbup: Thanks for your info Max


:beer:


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## 1fast2liter (Apr 4, 2005)

macx wondering here.. running e85 on a apr tune what would be power gains you could see? maybe running this with a w/m set up? say at 22psi on both a ko3 and ko4?


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## Marcus_Aurelius (Mar 1, 2012)

1fast2liter said:


> macx wondering here.. running e85 on a apr tune what would be power gains you could see? maybe running this with a w/m set up? say at 22psi on both a ko3 and ko4?


Power gains on E85, just like other fuels, would depend mostly on the agressiveness of boost and timing. Mostly boost, and timing secondarily at about a 2:1 ratio (say 5 psi gives you 20 HP -- 5* of timing advance gives you 10 HP). Obviously, any higher oxygenated fuel like E85 will yield some power in itself; and the BTU released per combustion event will have a bearing, but nothing like boost and timing. 

I'm saying all this so it can be understood that you really need to take the tune (AFR, boost, and timing) a step farther to really take advantage of the potential - or going to all the trouble may not make sense IMO. Running on an APR tune at 22 psi with water/meth injection already in place is not the way to get a good return out of the conversion. Now, say you were proposing to run E85 on an APR tune, water/meth but adding 5 psi of boost and 5 * of timing throughout the curve, Id say that the gains would be very substantial. Ethanol is like liquid gold for forced induction, so if you run it you might as well take advantage of its properties and mind-boggling capacity to make power safely.:beer:


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## 1fast2liter (Apr 4, 2005)

very intresting


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## 20v master (May 7, 2009)

1fast2liter said:


> very intresting


Yes it is. Your question is similar to asking about power gains of running race gas on a pump gas tune with w/m: minimal. You need more boost and timing, just like race gas, to make it worthwhile.


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## 1fast2liter (Apr 4, 2005)

Your right and I wasnt thinking that way. 

Sent from my SCH-R950 using Tapatalk 2


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## Marcus_Aurelius (Mar 1, 2012)

Bumping this to add this post:



Marcus_Aurelius said:


> Here is a study I stumbled upon that was conducted at MIT in 2010 by a student for partial fulfillment of his ME degree. It compares and contrasts some major effect of E85 VS pump gas on a 4 cyl turbocharged engine (happens to be a motor running a twin scroll BW K04 turbo variant which made it even more relatable). The only difference would be that the motor tested was directly-injected, but the findings are usable to our port-injected 1.8t motor.
> 
> 
> http://dspace.mit.edu/bitstream/handle/1721.1/59952/676953430.pdf
> ...


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## 20v master (May 7, 2009)

Ah ha! I've always tried to tell you MBT was more dynamic than you would admit!


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## un1ko (Apr 6, 2004)

Great information! I'm going to read this a few times to understand it and then figuring how to apply this using the maestro. Thanks for the info!


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## Doooglasss (Aug 28, 2009)

:thumbup::thumbup:

Great data Max!

So what you're saying is for my upcoming retune I should be going for bigger timing numbers and feel confident in the fuel as my IAT's are always far below 100' C.


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## 20v master (May 7, 2009)

Doooglasss said:


> :thumbup::thumbup:
> 
> Great data Max!
> 
> So what you're saying is for my upcoming retune I should be going for bigger timing numbers and feel confident in the fuel as my IAT's are always far below 100' C.


You need to do it at steady state RPMs on the dyno only varying load and ignition. It's easy to model the hardware configuration, aka amount of force applied to crankshaft pin based on crank angle, but it's much harder to model flame kernel and flame front propagation, aka the speed of the combustion and the resultant peak cylinder pressure based on where the piston is in the bore when the highest amount of pressure is reached (piston moving down, so volume is increasing, so time window for peak pressure is a spec in time). In simple terms, you can crank timing way past the point of pumping losses/diminshing returns on E85 and need to find that gives the most torque for your motor at various RPM points on a dyno.


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## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> Ah ha! I've always tried to tell you MBT was more dynamic than you would admit!


Guilty as charged!!! :laugh:


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## Marcus_Aurelius (Mar 1, 2012)

Doooglasss said:


> :thumbup::thumbup:
> 
> Great data Max!
> 
> So what you're saying is for my upcoming retune I should be going for bigger timing numbers and feel confident in the fuel as my IAT's are always far below 100' C.


Always told you there was plenty of headroom. As Adam stated, tq monitoring on the rollers is a hassle-free way to find MBT and optimize the curve (can be done on the road with EGT and backpressure monitoring, but is much more involved). We should rent the dyno again when it gets warmer for some good test-n-tune, I'm sure Jeff and Don have things they want to play with.


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