I did a few searches and I didn't really come up with an answer to my questions. I see that the Alky or meth kits pretty lower IAT so you can fiddle with the timing.

Is there any way to actually decrease the IAT for high boost applications (>10psi) without running these kits? I'm guess there must be but it is cost prohibitive. Also, are these kits more common for supercharger applications than turbo applications (or vice versa)? Why?

Not looking to do this myself anytime soon, I just want to be knowledgeable and well informed about adding boost to our cars should the day come where I'd like to join the FI club. Never stop learning.

 

Living here in Houston this is an important question, the most logical way is a well designed Intercooler that gets maximum flow hence Andy's new design for his vortech kit. It mounts in front of the front braces instead of behind and if you read up on some of his earlier post or on the A&A website you can read about the changes internally to the intercooler.

Another way to drop intake temps is to add a blower cam and headers, if you are making 10psi right now and add headers and cam you will drop your psi down to 8 reducing the heat but will gain 60+ more horsepower because the engine is flowing easier without restrictions.

However meth is the safest way to run FI motors it adds octane well over 100, drops the intake temps, and keeps internal valve train parts clean also reducing the chance of detonation.

 

Several ways:

- Ensure your intake receives fresh air from outside the car. Relocate the filter or build a shroud for it if necessary.
- Ensure the intercooler is exposed to high velocity airflow and is of adequate size to properly cool down the intake charge.
- Insulate post intercooler charge pipes inside the engine by so they do not heat soak from high engine bay temperatures.

A well designed kit will have adressed all 3 of the above. Your next option then becomes to drop the boost (as mentioned by Vert C6), or you could spray water directly into the intercooler.
Most turbocharged cars made use of that. The Subaru STI and the Mitsubishi Evolution 8 / 9 / 10 all have I/C WaterSpray buttons that will spray the intercooler with water from a separate reservoir. Some racing versions also have automatic waterspray that will spray the IC once the intake air temperature becomes high enough. These systems are actually very effective and are mentioned in Corky Bell's "Maximum Boost" and "Supercharged!" books as viable ways of running more boost under high ambient temperatures by drastically increasing intercooler efficiency.
I am planning a similar setup for my car except I want to use the windshield washer reservoir and pump for it to keep things simple.

 

In extreme case, you can always run an air/water intercooler and place dry ice in the liquid cell.

 

Thanks for the feedback. If I'm reading you guys correctly, it seems that once you've reached a certain limit or boost level, due to reliability purposes, there is no avoiding some kind of spray whether it be in the form of an Alky kit or an air/water intercooler setup. Afterall, there is only so much frontal area on our cars and some must be saved for the radiator and A/C condensor.

 

Very bad idea unless you only drive 1/4 of a mile at a time... Air/Water intercoolers always have lower efficiency than air/air because you add the inefficiency of two intercoolers (the air/water that cools down the intake charge, then the air/water cooling down the water that just cooled down the intake charge) and adding dry ice to the liquid cell allows you to supercool the intake charge for several seconds at best; there just isn't that much heat capacity in a pound or two or five of dry ice.

 

10psi is the max I would go without meth and even that is pushing it. On a very hot houston day I would not get on it with 10psi. The meth really is very simple, it uses your wash fluid tank and runs up to the TB and the control panel mounts anywhere in the engine compartment.

 

One last common way without Methanol is N2O, there are two ways to do this one is a spray bar in front of the intercooler, second is a dry shot plumbed into the system... I personally run An ECS Methanol injection system and I also run a Dry N2O shot... Though I have NOT run the dry shot with my current setup, back when the car was 620rwhp, the Dry shot made roughly 120extra rwhp up to 740rwhp. Now that the car is at 713rwhp the extra 120rwhp would put me in the mid 800's and I'm not ready to test that just yet... notice I said "yet"... I want to take it to the Texas mile in October with the STOCK LS2 and see what she'll do before going with a forged 402 and larger head unit...

 

Not exactly... Even our limited frontal area is still worth several tens of thousands of CFM at any highway speeds...
Airflow = s*a
Where:
s = Forward Speed in MPH
a = Frontal Area in Square feet
E.G: 2 square feet frontal area at 60MPH:
Airflow = (60(mi/hr)*5280(ft/mi)*1/60(hr/mi))*2ft^2
= 10,560cuft/min
That's over 10 times what a Vortech S trim flows at peak power making over 680hp...

The bigger issue with running high boost is that as your boost level goes up the likelyhood of detonation occuring goes up disproportionately. Eventually you get to the point where detonation can't be avoided on pump gas unless temperatures are dropped considerably or octane level is increased.

Now, back to your question of increasing charge cooling: Intercoolers, like any other thermodynamic device, are never 100% efficient. A good intercooler will do about 80% efficiency and a very good one will do maybe 85%. Intercooler efficiency is increased by increasing the number and the density of turbolators (internal sections), or increasing intercooler size and/or cross section. All those things increase intercooler pressure drop, which requires more boost from the supercharger in order for the original boost level to be maintained post intercooler. More boost from the supercharger equals more blower outlet heat, so the intercooler may be more efficient, but it also has to deal with more heat.
Now lets assume the intercooler you have is fantastically efficient and can do 85%. We will calculate the intake air temperature for two systems, one running 6PSI and the other one running 12PSI.
Temperature Gain = ((PR^.28-1)*Tabs)/.75
6PSI: Pressure Ratio = 14.7PSI + 6PSI / 14.7PSI = 1.41
Tabs = 550F on a standard 90F day
Temperature Gain = 74F.
So, on a 90F day, the blower outlet temperature will be 164F
For 12PSI: Temp. Gain = 133.4F. On a 90F day the outlet temperature of that supercharger will be 223.4F! That will boil water!

So we intercool the outlet charge... The intercooler is 85% efficient, so:
For 6PSI: 74F*(1-.85) = 11F
For 12PSI: 133.4* (1-.85) = 20.01

This doesn't take into account a few factors:
First of all the 85% efficient intercooler is not going to be 85% efficient at 12PSI, because the increase in airflow caused by that extra boost will leave the air charge with less time to cool down, reducing efficiency.
Also, as the outlet charge cools down from 223.4F to 100.01F it will contract, causing a reduction in outlet pressure, requiring more boost to be run to meet the 12PSI outlet pressure goal, which will create more heat, drive the compressor lower into its efficiency range, etc etc...

The point: Regardless of how efficient your intercooler is, there is no way around the laws of thermodynamics: a higher boost pressure will ALWAYS create a higher post intercooler temperature... So we try to "cheat" the laws of thermodynamics by using evaporative cooling through intercooler water spray or meth injection. Meth injection has the added benefit of increasing the effective octane rating of your fuel, although when it fails, your engine will go with it... For that reason I'm not a big fan of meth on vehicles that get driven a lot under boost.

 

But if you tune it safely and not turning up the timing I think the meth is the best thing you can do. As long as you are not adding it to make more power and only as a safety measure.

 

I will make this easy for you...

E85

You will need compatible fuel pumps, lines and upgraded injectors.

Effective Octane rating of 105. Cost less, runs cooler.

 

Costs less? Give me a break, you need twice the fuel.

E85 efficiency sucks. The price per gallon is comparable to gas. I'm not saying there isn't a benefit, but I am saying the benefit is akin to fondling a tree and making it feel good about itself.

 

Get cold air to the intake. Cartek ducted my procharger air intake to the brake duct inlet in the front wheel well. Tons of forced fresh air there....much better than sucking in the hot air from under the hood.

 

I understand the principles of thermodynamics well enough, just wasn't very versed with the where the limits commonly occur for our cars.

I will certainly have to keep these things in mind should I decide to go the FI route. Also have to keep in mind the other factors such as the head and humidity in the south and my car must be reliable (only car and DD).

 

There are things that can be done on the consumption of the E85. Also, If you are trying to build big power then the miles per gallon aren't really the issue, and lets face it... if you need to really keep your gas milage down, you probably aren't building a FI car anyway.

I wouldn't ever use E85 to make me feel good or to replace that valuable tree hugging time, but I would use it for higher octane ratings, more power, cold IAT's and less detination.

I'll give up the loss in economy for the added power.

 

Well, you stated it "costs less," hence the argument.

But aside from it being more expensive to run, there's also the annoying little side effect of almost halving your miles on each tank. That would be the part that would annoy me the most, anyway.

 

You are certainly entitled to your opinion, but if I want to build big power, I see no reason why I cannot also have great fuel economy. I would not use E85, however, for the same reason I would not use Nitrogen in my tires, or Nitrous or Meth Injection on the engine. If I can't stop at any station and get it, I'm not interested. My car is my only driver.

 

hrmmm.. Mixing nitrogen and air isn't a problem, though. There really are no downfalls to using nitrogen in your tires. If you get a slow leak and have to add air, no problem.

 

Sure there is a downside. Nitrogen costs money, air does not.

 

Well, right now I am still on pump gas and haven't converted yet, but am still researching. Check out my post of what my car did, maybe this is enough for you I don't know.

I wouldn't be trying to do this kind of a build on a small budget though.

http://forums.corvetteforum.com/show....php?t=2109777