2007 Mustang 225+mph e85 Questions

Hello Oh great ones!

I’m a GRM reader (cover to cover) and sometimes lurker on the board, But I don’t feel I have a whole lot to offer so I don’t post much.

But I have a “problem” to solve and you guys/girls are definitly the outside of the box go to crowd. I’m hoping you can get me sorted out here.

Quick background on the car:

2007 Mustang GT that is at this point more aftermarket/fabricated/custom then stock. It’s a jack of all trades car. It can be driven on the street no problem. Yeah, its loud and doesn’t have much as far as creature comforts go. But for what it is it is an amazing street car. It goes around corners in a big way. The car weighs as much as the QEII, but with stiff enough springs, big enough rubber and plenty of power it seems a lot lighter than it is. It flat out CRUSHES cars at the track it has no right too. It makes stupid power. 718rwhp on 93 octane and we are not done sorting out the race fuel/e85 tunes yet 100%. But were thinking it will make close to a 1000hp on e85. It has big brakes/big ducts, a bar, race buckets, trans cooler, diff cooler, bla, bla, bla.

Goals for the car are:

-Can be driven on the stret with some civility and won’t “melt down” in traffic. -Can go faster than 225mph in the standing mile (no nitrous, no meth injection, no ice chest). -Capable of running with the “fast” group at open track days, if not being one of the fastest cars out there. -Won’t go China Syndrome half way through a 20min session. -Smoke the tires off from a 75mph roll. Why you ask? Because it’s fun!

The biggest “problem” we have been having is keeping it cool. There is about a elevindy-billion sq in of heat exchanger/radiator in the car. All custom and “fenced” in. Fitting more HE in is not an option. We are also running two 55gpm Meziere water pumps on the intercooler (IC) system and a third 55gpm pump on the engine cooling system. I think we are at the point of diminishing returns in regards to more cooler/more pump.

I just spent the last hour and a half searching high and low for a concrete answer to this and I’m pretty surprised, I came up with nothing that makes me all warm and fuzzy.

I’m getting closer and closer to jumping on the e85 bandwagon, but there is a pieceof the puzzle that I would like an answer too first. And that is how much does e85 lower your IAT’s?

The way our IAT sensors are set up we can’t get a true reading of how much e85 drops our IAT’s. Our IAT sensors are before where the e85 is injected, so the IAT senso(s) don’t read that temp reduction.

I’m about to jump on the e85 thing for all of its advantages. But the number one advantage that has me sold is the reduction in IAT’s and my ability to raise the threshold where the ECU starts pulling timing. For example:

Right now my blue car starts pulling timing in my 93 tune at 136deg IAT, which doesn’t take long to get too, especially when it is hot out. But, lets say that e85 reduces IAT’s by 100deg (I think it’s higher though). If that were the case I could set the threshold where the ECU starts pulling timing at 236deg and have the same safety margin I have now because in theory a 236deg IAT with e85 added too it is 136deg. And therefore safe.

Does that logic track?

Of coursethere are all the other advantages to running e85. More timing, more boost andtherefore more power. Which I will be more than happy to take advantage of. Butwhat I really want is for the car to make the same power heat soaked on a 90degday as it does in a controlled environment like the dyno cell.

What I amlooking for is having all of my power, all of the time.

But to set the tune up to do this I need to know how much the e85 drops the IAT’s after the IAT sensor so the “correction factor” can be built into the tune.

Anyonehave this data? I google’d my tail off and only came up with half answers. Someof these “half answers” are below with links to the source material.

Thanksfor your help!

Reference#1 A paperwritten by a MIT student in 2010.

The data: The knocklimit for e85 is shown as being at a IAT 110deg C (230deg F) higher than gas.

Section6.1.2Peak Cylinder Pressure

http://dspace.mit.edu/bitstream/handle/1721.1/59952/676953430.pdf

Reference#2 E85calculator

Maybesomeone smarter than me can figure this worksheet out. I’m getting a IAT dropof 253deg F. That seems high, but not far off the results from the firstreference.

http://www.pcmforless.com/index.php?option=com_content&view=article&id=57:e8 5-calculator&catid=34:tuning&Itemid=56

Reference#3 FastForward Superchargers Forum 16thpost

Another fact is that the latent heat of E85 in thecorrect AF ratio compared to gasoline is four times as great. This means fourtimes the temperature drop. Since gasoline at a 12:1 AF ratio will drop the airtemp about 50 deg F, this means that E85 at the corresponding lambda for E85 , would drop the air temp about 200 deg... or an additional 150 deg F tempdrop. FWIW, that is about as good as an Air/Air IC running 15psi of boost withthe MP62...

http://www.fastforwardsuperchargers.com/forum/archive/index.php/t-1934.html

Found a good discussion of the issue here:

http://www.modularfords.com/threads/194918-What-Is-The-In-Cylinder-IAT-Drop-With-e85?p=1855759

Here someone says they got a 40deg IAT drop (I assume fahrenheit?)

http://www.yellowbullet.com/forum/showthread.php?t=560481

Another thread, someone observed a 50deg drop:

http://www.yellowbullet.com/forum/showthread.php?t=559690

Is there really no more room for heat exchangers? Thought about V-mounting? Post some pics of the engine bay if you can.

Did you see the cooling system on the 914 Porsche in the last issue? Not street friendly, but outside the box.

And it's good to see one more late model Stanger on the board.

To be honest, reading those discussions is a very good way to get the idea of how the combustion mixture behavior will become, but what happens exactly in your engine will depend on your compression ratio, camshaft design, timing, combustion chamber and piston shapes, and to some degree, injector placement. I fell like it will also change with engine speed, as the fuel has less time to vaporize on the back of the valve(s) before IVO.

With those papers and discussions, I think you're well on your way to understanding the trend, but you're going to need to do some Thermodynamic calculations and in-cylinder datalogging to get a "threshold" number.

With water/meth injection, it is easier to measure when it's injected before the IAT sensor.