dumb intercooler question

from what i've read.... E85 cools combustion chamber and creates less heat sink up to the blower.

People say it lowers IAT. After the sensor, of course.

Nevermind... forget I said anything! this is the dumb question thread, right?




From some other forum on the net...
It has more oxygen in it than gasoline, much more. This allows you to get more oxygen in the combustion chamber than you normally would. Even though this oxygen is bonded to the rest of the ethanol molecule before combustion, it's still burned in the cylinder, just like nitrous. The stoichiometric ratio of e85 is approximately 9.6:1 and gasoline's is approximately 14.7:1, so not only do you have more fuel to burn, but more oxygen, too! This is why most cars will make 15-20% more power on e85 than with even the highest octane race gasoline. (Chemically, the most power you could make would be 27% more than gasoline, but that's hard to reach due to other restrictions).


It reduces intake air temperatures four times more than gasoline when injected into the air fuel mixture at proper air-to-fuel ratios. This is because alcohol requires more energy to evaporate than gasoline does and you're also injecting about 35% more of it into the air fuel mixture than you are with gasoline. To prove this to yourself, imagine (or actually do it, safely!) dipping your fingers in gasoline and placing them in front of a fan. Your fingers would get pretty cold. Then imagine dipping your entire hand in alcohol and placing it in front of the same fan, it would get much, much colder.


e85 has an American octane rating of approximately 105, but the American test for octane rating (MON) uses a preheated air-fuel mixture at 300 degrees! This means that they inject e85 into the air and then heat that mixture to 300*F. This is why the commonly known octane rating of 105 is innacurate for e85. Preheating the air-fuel mixture doesn't accurately model intake temperatures that are so significantly lowered by e85 in real world applications. Because of the heat-lowering effectiveness of e85, it's more accurate octane rating is between 112 and 118. Because of this you can run higher compression, more boost, or both!

Lol, you mean after the injector (is it still called "intake air" at that point?)

The ratio of air to E85 is ~11:1, so it'll be a bit tough for that mist of warmed fuel to chill all of that hot air. But E85 is magical, so anything's possible. Some even believe it makes more power!

AA wrote:

Lol, you mean after the injector (is it still called "intake air" at that point?)

The ratio of air to E85 is ~11:1, so it'll be a bit tough for that mist of warmed fuel to chill all of that hot air. But E85 is magical, so anything's possible. Some even believe it makes more power!

Its either intake air or exhaust air. Am I right or am I right?



you can measure intake air temps an infinite amount of places but where does it matter most? In the combustion chamber? Probably.

since i moved my IAT sensor from fender well to right next to throttle body, my IAT readings  jumped super high. That was to be expected.

It's all relative, tho.


It makes perfect sense how injecting 30% more (and alcohol) into the combustion chamber would cool the chamber and air thats in the chamber.

You guys all think of IAT to be anything coming through the throttle body that passes by the IAT sensor but the intake air is the same air that goes all the way into the combustion chamber.

Who cares at what point it's cooled.

Charlie's right - it's still intake air up to the valves. Since the injectors fire into the LIM, I can see some cooling happening before combustion. You won't see it on your IAT reading, though. Need to install an EGT sensor - that's how you'll know.

People are saying on the net e85 lowers EGT by ~200 degrees.

charlieRobinson wrote:

Who cares at what point it's cooled.

The sensor (tune) does big time. But of course you can change that to suit. IAT is a very important component to what airmass is coming in and needs to be accounted for. I like to see how hot the air is as far downstream the intake as possible for my purposes but the original tune is modeled from where the IAT is located from the factory.

From what i've seen in HPT, the only factor IAT sensor readings affect is the table that pulls timing.

Is that right or are they incorporated anywhere else in the tune?

I dont see how they would affect fueling because MAF and MAP takes care of all that?

It's way more critical on cars that work on a speed density tune because the IAT chiefly determines the density or worth of the incoming airmass. Before starting to read those tuning books I just sorta figured the IAT spark table just kinda helped keep knock in check but really that adjustment it makes to timing is quite meaningful as it compensates timing for an air - mass condition.

It's not something to worry about because our tunes seem to be pretty loose on the IAT spark strategy but the point is the sensor placement can change things

Has anyone ever considered an A2A intercooler instead? I would think it would be more effective than an A2W because you could use a massive front mount, but could introduce some lag because the air has to travel farther. It has claims of larger temp drops than any W2A system could even dream about. There are claims that it is an issue to tune due to the lag and the MAF positioned so far behind the air that's actually going into the engine but that could be solved by moving it inline with the IC piping. Thoughts?

http://www.ebay.com/itm/AIR-TO-AIR-INTERCOOLER-PLATE-2-SUIT-L67-SUPERCHARGED-V6-/400935388418?pt=LH_DefaultDomain_15&hash=item5d599c8502&vxp=mtr

The Holden Commodores have had that mod option for years, because their engine is longitudinally mounted. That plate wouldn't point the correct direction for our cars. It would need to be modified, but should be highly effective. Oh, and SO MUCH plumbing!

AA wrote:

The Holden Commodores have had that mod option for years, because their engine is longitudinally mounted. That plate wouldn't point the correct direction for our cars. It would need to be modified]

I don't think we would have to touch a thing on the plate. All that theoretically would need to be done is a relocation of the coils because they would sit exactly where the hot air outlet of that plate exits. The only other headache would be the vertical position of the cold air inlet, but some ingenious thinking would solve that. There is otherwise plenty of room for everything as far as I can tell. Just some tricky piping bends and tuning.

I read somewhere that the holden guys find that the A2A plate is extremely hard to tune properly, it gets a bit "surge-y" having basically a massive pressurized plenum.  The Ford supercoupes have a similar arrangement and the same issues. Perhaps moving the MAF around could help...

Karma wrote:

I read somewhere that the holden guys find that the A2A plate is extremely hard to tune properly, it gets a bit "surge-y" having basically a massive pressurized plenum.  The Ford supercoupes have a similar arrangement and the same issues.  Perhaps moving the MAF around could help...

You'd think that someone would've made some sort of blow-off valve to help that problem. That setup is damn close to a turbo setup....

As far as lag, someone was explaining to me that there would be none since the whole system would be under pressure all the time. Not really sure how reliable of a sourvmce he is.

Air-to-air intercooling shouldn't cause a supercharger to act like a turbo. The blower is still mechanically driven, so no lag. Turbos lag because of spool time before exhaust pressure develops. For the same reason, there shouldn't be any surge in boost pressure to require a blow-off. While a turbo continues to spin when the throttle closes (building boost), a supercharger is mechanically linked to RPM, so it won't build boost when the throttle is closed.

Not that it wouldn't be difficult to tune, just saying A2A doesn't change a blower into a turbo.

AA wrote:

The blower is still mechanically driven, so no lag

You don't think the distance the boosted air has to travel would introduce some lag? It might not be as bad as waiting for a massive turbo to spool but still. Then again we could go T-Bird/Subie style and use a top mount, granted I have no idea where you would put it.

I don't think lag is the right word. And what I ment with "surge-y", isnt boost surge, but the engine surging. The issue with this setup is you have a massive plenum post MAF. That makes it interesting to tune, according to the Holden and ford sc guys. Funny enough their forums end up with the mirror thread to this, wondering about w2a.

Quote :

You don't think the distance the boosted air has to travel would introduce some lag?

I think it would might be measurable in tenths of secs, but not noticeable like a turbo's boost response during spool up. Based on MAF, intake air speed is very, very fast.

for those with experience. (I know the golden era of this forum has passed so I think I am only addressing this to what I believe may only be Mr. Turtle, Kamesennin, Cody) What gainz do you estimate happen when an e85 build is then intercooled?

My knowledge base is composed of a couple forum reads that noted they saw gainz when they had both and removed their IC. And a forum post or 2 that noted IC makes negligible gainz when paired with e85 and may not be worth the $. On the contrary I have heard from only 1 source, a machinist 3800 enthusiast, state that an intercooler makes substantial gainz when paired with e85. Even a short stack would make a remarkable increase in power.

So, in your experience. how much more power/ WHP do you estimate adding an intercooler to my current build would make? Not sure if it would be worth the weight to intercool and maybe resources would be better utilized with a set of ported heads instead.

I've never heard anything but good from E85 + IC setups. I think the amount of power you would make depends strongly on what intercooler you get. If you get ported heads first, you could get LIM with ported runners without worrying about the size difference causing turbulence.

There's this stuff that comes in a blue bottle with an orange label... I think that's what you're looking for...

An IC creates a slight airflow restriction, but at the same time creates cooler air. So is your problem airflow or heat? The increased octane of E85 lets you get away with a lot more heat before an IC is needed, but even still you can be more aggressive with timing if the air is cooled.

So basically, an IC should help in all situations. If you don't re-tune pretty much everything after you add an IC, you don't have the proper fueling and timing maps for the cooler air. So it's very possible that some people lost performance by just adding an IC, especially if they just dropped pulley sizes and didn't retune.

deekster_caddy wrote:

An IC creates a slight airflow restriction, but at the same time creates cooler air. So is your problem airflow or heat? The increased octane of E85 lets you get away with a lot more heat before an IC is needed, but even still you can be more aggressive with timing if the air is cooled.

So basically, an IC should help in all situations. If you don't re-tune pretty much everything after you add an IC, you don't have the proper fueling and timing maps for the cooler air. So it's very possible that some people lost performance by just adding an IC, especially if they just dropped pulley sizes and didn't retune.

If KR is a sign of heat issue then I have no heat issue. I just dont know if I want to drop the coins on an IC if the gainz will be minimal on top of E85. I'd rather use the resources on heads/transmission/body work.