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Discussion Starter #1
I hope this is info you can use. This is not meant to rip the water to air users.

This information is garnered from over 20 years of experimenting with stock location (in the engine compartment), front mount intercoolers (in front of the radiator), and water to air intercoolers) by some world record holders. (In the 8's with a stock block). It directly applies IMO to allforced induction applications.

The least effective intercoolers of all were the w/a's. I myself have had 4 different fms, 3 stock locations, and 1 w/a. You can search sites for more information. Look for american muscle cars of the 80's that came factory turboed. My Porsche turbo was also a/a.

It would seem that the proper size and type a/a would work in the rear wheelwell area of the Elise. I'd be interested in that type of setup myself. I wouldn't be surprised if it moved more air than the scoops on the Exiges. And it wouldn't be sitting on top of the engine. Is someone making one? :drool:

If worried about heat soak, a small fan would work during heavy traffic times.
Most of the people that I know pulled the stock factory fan that was run by the crank (muscle car). It was overall agreed that the cooling was reduced sufficiently once the car started moving at around 30-35mph. (The shroud helped big time). Many tests were done over the years by the dragster-type guys; check out what they are running nowadays. Many of these 10-11 sec cars are daily drivers to this day...a/a intercoolers are the norm.

This site should help---he's an incredible addition to the force fed crowd. http://www.rjcracing.com/RJC_Buick_Products/RJC_Megacooler/rjc_megacooler.html
 

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I do agree with you to a point, a front mounted cooler with enough exposed fronal area can provide excelent cooling, however there is not enough airflow on an elise\exige for an efficent system. The better air flow you can get greatly increases the cooling efficency so a front mounted heat exchanger and a rear mounted charge cooler will give you the most efficient charge cooling for the elise or exige.
 

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... It would seem that the proper size and type a/a would work in the rear wheelwell area of the Elise. I'd be interested in that type of setup myself. I wouldn't be surprised if it moved more air than the scoops on the Exiges. And it wouldn't be sitting on top of the engine. Is someone making one? :drool: ...
The ForcedFed system uses an a/a intercooler that pulls air from the side scoop. Someone on ET has also built a conversion kit to pull air from the side scoop and feed it to the stock a/a intercooler.
 

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There is more to performance of an intercooler system than just the cooling efficiency. For those trying to achieve the linear, quick throttle response of a N/A setup (just more power), the air volume inside the intercooler and its piping is an important consideration. Too much volume equals lag, even with a supercharger. The W/A intercoolers minimize that volume, and hence minimize the lag.

For this reason alone, I don't consider a front mounted A/A to even be an option for the type of driving I (and probably most) do with our Elises. There would be way too much air volume in all that piping, thus creating a lot of lag. Of course, if you are WOT at high RPM on a big, high speed track most all the time, and only care about peak horse power, not lag, then a front mounted A/A might work out fine if you can run the large diameter piping. (Large diameter to minimize air flow resistance, which would lower effective boost.)

Rear mounted A/A can be an option, but then one really has to consider (that is, test) what level of air flow you can get through the side scoops through an intercooler, and just how crowded you want the engine bay to be. You may also need to decide if you don't mind the noise of an intercooler fan right behind your head (or your passenger's head), which is a complaint of some of the people who have driven the ForcedFed turbo cars.
 

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The plan on my car was to mount an A/A IC in the passenger side intake, probably with a Spal behind it. For how much power I was running, I don't think I would need more than that and the trade off is less plumbing.

For autocross, I could spray it down with cold water before I took my runs.

The advantage is a very short travel for the air.

But the new owner may have different plans. I did put in the tubes toward the passenger air duct and it would not have been a big deal to source an IC and mount it to the diagonal brace with some flexible coupling.
 

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Discussion Starter #6
The plan on my car was to mount an A/A IC in the passenger side intake, probably with a Spal behind it. For how much power I was running, I don't think I would need more than that and the trade off is less plumbing.
Yes, makes sense. One guy had a switch that was activated by air flow and would shut the fan off when air flow became optimal---like I mentioned--- around 35mph for that particular car. It would seem perfect for city or autocross.

In the turbo I have dual Spals and rarely need both running. Great fans!
 

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The ForcedFed system uses an a/a intercooler that pulls air from the side scoop. Someone on ET has also built a conversion kit to pull air from the side scoop and feed it to the stock a/a intercooler.

i seached and nothing do you have the links handy?
 

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I was thinking the same thing, 'Ol Racer!

A/A beats the tar out of A/W for a track car... Drag racing is great with A/W since you can ice down the water, but heat soak is a major issue with water... Ronin's car:bow: is proof of that. His setup works great but he's got more radiator than the average semi truck just to cool his charge cooler water. Nothing wrong with it, but I just feel compelled to go back to what makes sense to me... not an easy task with our space constraints though:(

I've been tinkering with this A/A project for a while now. I don't have any hard data to show that it will work or won't work. I guess we can all theorize about it for a while though and arm chair quarter back it to death:D

Seriously though the passenger side vent seems to be a good spot. It has natural air flow as the air seems to get sucked through there via the low pressure over the boot lid quite well. I've been working with Bell Intercoolers on this and have the IC spec'ed out and Lotus S manifolds sitting on the work bench. Bell calculated that a 6x10x3 core would be sufficent for 330hp provided that it's in a good airstream and would be 80% efficient. And you don't get heat soak since there's infinite air at speed(unlike water). Heat soak in traffic is moot, since you're not shooting for peak power over sustained period while sitting in rush hour....so I'm not sure why that issue keeps coming up:shrug:....unless one is worried about AutoX, which I am not...

So what is a good airstream? Bell says 3,000 CFM for this IC we've spec'ed... There's *no fan that can do that* in the space we have available... 800cfm is the best you'll find. So round file the fan idea *for now*... Do we have 3,000 CFM through the side vent? No telling, but probably not is my guess judging by the size of the opening and the fact that it's not true frontal area on the car.

A bigger core is needed to be 80% efficient if we have less than 3,000cfm... Now one has to ask what's the efficiency goal for this project. For me, it's 50% for the A/A setup while at the track. That simply means that on a 100F day on the track and blower temps pre IC of 300F, you'll have 200F temps post IC... That's a good enough change for me to build in some safety and a little more boost...

Back to the fan for a second. If you build the system with a fan, you MUST go to a much larger core since the fan motor takes up so much core space in our little cars. And at 800CFM, the fan isn't going to do all that much anyway--- 30% efficient or so is best case... I, proably a little like 'ol racer, am a bit spoiled by the massive frontal area I had in my old GN. My IC back then was 4" think and had front area on par with my radiator:crazyeyes. It was HUGE! I could do no wrong with that thing:cool: In our case, we need every bit of the little core we have to work with...working:huh:

The whole reason I did the clamhinge and a large reason for the Dash2 setup was for this summer's IC project---which is something my eastern friend "Dave" (east, being ohio;)) and I are tinkering with. I now have the body in a situation where I can work on the fabrication for the IC setup and enough monitoring gadgetry to tell just how well the future IC does or doesn't work. If it doesn't work as expected, then back to the drawing board. It's fun trying stuff though.:nanner2:

Just my .02 euros (I had to switch from the dollar, as it lost too much value)...

Best,

Phil
 
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So basically, Phil, you're going to pop the clam up on the hinge and drive around with it? The hinge will act like a big air scoop and feed the intercooler? Cool!

:D
 

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For A2A, the rule of thumb is that you need 8 x the ambient air to cool 1 x of the compressed air.
 

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Weird I still think you guys are missing the point, for a front mount air to air is probably better and certainly less complex, for the elise\exige it is not an option, there is no airflow better on an elise\exige than where the rad is so using a\w with the heat exchanger there is the best solution, I don't think Frank now needs 4 rads he has only got to that stage via R&D I suspect he would be fine with just the Proalloy rad as it is the correct place and is almost as big as the main rad. The main issue with using a/a is it is more complex and fitting is time consuming and costly. A system like this can't suffer from heat soak as the front exchanger uses the main rad fans for cooling the water.
After you have main your a\a work in the side pod I wonder how long it will be till someone makes an a\w the same size and runs a front rad? I know I would do that if I needed to ;)
 

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So basically, Phil, you're going to pop the clam up on the hinge and drive around with it? The hinge will act like a big air scoop and feed the intercooler? Cool!

:D
Correct!:nanner:
 

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I have to dissagree here. A front mounted air to air is better than air to water in most setup's.... however when you start putting an air to air the size you need somewhere in the back of the car it doesnt perform as well as a front mount. i have air to water and doing air to water on the next setup as well and will still stand by it over air to air like many other setups i have seen. Side by side, over and over air to water has worked better for me on the rear engine turbo setup's where airflow isnt great. Again, i am not saying it works better in all setup's, just for this type, if you asked me to build a setup for a car w/an engine in the front i would go air to air everytime.
 

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Question does anyone have the core dimensions of the a/a options out there Hass, forcefed, ect? I would like to run some numbers with them.
I don't have those, but bell recomends a min of 6x10x3 and 3500CFM of cooling air through that core for 325hp, which would get us in that 275ish whp range... Granted that's for a 90% efficient IC though...

It looks like that Exige's IC is about 50% efficient based on what I've seen in another thread. In my mind, I'd be happy to get 50% efficiency out of a simple, lower priced A/A IC in the elise hanging off the side of the engine in the airstream from the side scoop (would probably have to be ducted air, but that's not a big deal)...

Best,

Phil
 

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FYI, if you're concerned about the weight of the IC, HKS cores are a LOT lighter than the Garett cores which most aftermarket intercooler companies use. However, you'll pay a pretty penny for HKS...
 

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i'd go with Precision over any other A/A IC....just my 2 cents ;)
 

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I don't have those, but bell recomends a min of 6x10x3 and 3500CFM of cooling air through that core for 325hp, which would get us in that 275ish whp range... Granted that's for a 90% efficient IC though...

It looks like that Exige's IC is about 50% efficient based on what I've seen in another thread. In my mind, I'd be happy to get 50% efficiency out of a simple, lower priced A/A IC in the elise hanging off the side of the engine in the airstream from the side scoop (would probably have to be ducted air, but that's not a big deal)...

Best,

Phil
Yeah it sounds like those numbers are based on some assumptions but I wanted to derive it with some simple heat transfer simulations, or hand cals. From that perspective assume how much input you have raising the temp of the air (compressor efficiency) we could figure out the airflow required or tact time in the core. Does anyone have any core dimensions?
 
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