AS a matter of fact, yes I do have a Masters Degree in Mechanical Engineering. And, yes, I did own a turbocharged second generation RX7, the engine which I built from scratch which used an air/water intercooler. The intercooler worked great for drag racing when you could put ice water in after every run. Just like the Mustang I spoke of. But for road racing, it sucked. If you would do a little reading yourself, you might see why an air/air intercooler is better for a road racing car. You might start with these:

http://www.bellintercoolers.com/Pages/tech.asp#howcan

http://www.gnttype.org/techarea/turbo/intercooler.html

 

IMO, fperra is not hating, he is pretty much telling you guys the truth. Water intercoolers are not the best for daily driven applications. An air to air intercooler is better suited for a daily driver. Water intercoolers are not the best simply because the water can't stay cold for long periods of time. Do you plan on keeping a trunk full of ice in your trunk everytime you go somewhere? Water intercoolers do work great, but they only work great if the water is cold. Go to the races and check out the street, daily driven hondas. Just about all of them run air to air intercoolers because they are better suited for a daily driver that is going to be boosted on the street. Check out some of the race cars and yes, you will see more water intercooler setups. These cars get a bag full of ice before every run. You don't have to be corky bell to build a decent turbo setup. $6000 is just too much money for a setup like this, but that is my opinion. Also, please understand that bigger turbo setups are never as reliable as smaller turbo kits like the one offered here. Everyone needs to understand this. A greddy kit for a Bseries motor is alot more reliable than any Full-Race kit, but it is in no way close to being as good. It is simply made up of parts that are smaller(turbo), that usually run less boost and require very little tuning, that is it. With a price tag like this, you should at least include an EMS. $6000 for a kit and it still uses a FMU?

 

An Air to water intercooler is inherently more efficient than an air to air intercooler of similar construction. removing heat from air to water is actually a reasonably efficient transfer, but the opposite is VERY poor. Most luxury car manufacturers do it for packaging efficiency, look at performance cars (Porsche, etc) and you'll see a much greater prevalance of air to air intercoolers.

Sure, air to water sounds good. Water has a much higher specific heat than air does. It does a better job of taking the edge of a boost spike because of it's ability to pull heat out of the intake air. However, it does a much poorer job of transfering that heat from the water to coolant.

Tubing length is almost entirely irrelevant in pressure drop. proper sized tubing has almost none. Usually OEM designs have a steadily increasing piping diameter from turbine outlet to throttle body. If an air to air intercooler has more than a 1/2 psi of pressure drop, you are using a very poorly designed core or bad endtanks or too large a piping, etc.

You know how long it takes to pressurize 10 feet of 3" diameter tubing? 1.5 x 1.5 x 3.14 = 7.065in^2

x 10 ft x 12inches/1ft = 847.8in^3 x 1 ft^3/1,728in^3 = .49 ft^3.

Ok, and we have a 2.2l motor, or 134.25in^3

Using .83 for Ev, (a guess)
Cid X RPM X 0.5 X Ev / 1728 = 256.44 CFM or 4.274 CF/second.

That means it takes .11 seconds to fill up your 10 feet of 3" diamter pipe at 8000rpm, NA. Of course this ignores the friciton of the walls, etc, but you can see the magnitude of effect length of properly designed piping has. At 7psi of boost, it's even less.

Throttled volume makes a bigger difference, and it's irrelevant (the same in both I/C types)

Personally, I think the s2k has plenty of room for air to air intercooler piping. There are no packaging concerns. If you are worried about the radiator for an air to air setup, you still need to exchange the same amount of heat with an air to water intercooler and you need to do it with a much less efficient heat exchanger. For a street car, an air to water intercooler might work fine. I'm talking about the experience I had working with an air to water intercooler on a supercharged M3. It worked very poorly for me on the track, the system simply didn't have the heat capacity nor the ability to remove heat from the system for any kind of track use. In a single session I could melt 4 gallons of ice water to the point where the car was knocking under normal load.

 

if this kit can be available for 4500-5000 im sold on it..
i will sell my comptech kit (sorry shad!) for this..

 

for that much cost savings, I'd rather have the kit with an air to air intercooler. simplifies installation and makes it viable for the track guys...

 

If fperra or anybody else has concerns about this kit by all means lets hear it. BUT, there is a decent way of bringing up concerns in a thread where it seams Wael has been up front in answering our questions, and then there is this way:

"fperra: This is the biggest bunch of BS I have heard on this forum in a long time. Water cooled intercoolers are fine for what they do, but with this post, its time to go buy a pair of boots to keep the BS from getting in my shoes."

No explanation, nothing other than screaming BS and waiving the flag. When called on it he provides minor explantaion with "I remember watching a dyno tuning session on a Vortec SC Mustang that had an air/water intercooler."

Here is my point, if you have the education you claim then put it to use, add something relevant to the topic and give us your concerns and logic behind them. Perhaps you might be the one to catch something they missed, something they could then research/correct before this kit goes to production. Maybe you could provide a better way of doing something that saves us all time and money. But, if you choose to come storming in like an ass people will call you on it, I just called you on it and on occasion others have called me on it. We all have our bad days. I have done my research, and for MY application this kit looks good, partially because it is unique in the S2000 world and I don't like having the same stuff everybody else does. However, I won't know for sure until the kit is complete, the specs are laid out, and the dyno sheets posted. If you want to whip it out and compare qualifications PM me or start your own "I hate Nate" thread in the off topic forum as it is not relevant here.

Nate.

 

All this talk of adding ice to an air/water cooler is totally irrelevant for the absolute majority of us who drive our cars on the road and track. Heck, the Comptech and Vortech systems don't even have a big enough opening to put ice in or tank to hold it. Why? because it's only for 1/4 mile runs.

Air/water intercoolers work but transfering charge heat to coolant and then coolant heat to air. If they have enough capacity to dissipate as much heat as they absorb they won't suffer from heat soak. Whether that is the case or not depends on their efficiency at removng heat vs. the amount of heat they absorb. A well designed system will work within it's specification. It's exactly the same for the engine coolant system. If your radiator can dissipate more heat than your engine develops you don't overheat.

The reason AW was chosen by Vortech and Comptech is that the boost and hence charge heat isn't much so a small AW system is more than capable of removing the heat and also because of the simplicity and hence efficiency of the piping.

Elda's intercooler is either up to the system's requirement (in specific usage) or it's not. It won't take an awful lot of experience to know one way or the other.

 

I talked to Corky about the IC selection and if he could put a list of pros and cons. for each. Here is his list.

Hi Wael,
This was a hot topic when we began laying out the system. There are a dozen factors favoring each set up.

The Air unit:
1. generally slightly more efficient. Usually in range of 70 to 85%.
2. generally more restrictive, which actually drives up the exhaust gas back pressure.
3. simpler
4. cheaper

Water unit:
1. Less restrictive ... usually the in range of 60 to 75%.
2. Slightly better boost response
3. "perceived" to be more efficient
4. "perceived" to be much more responsive.
5. competes better with the best S2000 received system .... Comptech

He also expressed his preference to air/air intercooler in general.

For those that think $6k is too much, I believe they're not considering the parts in the system, such as the larger injectors, the plug & play wiring harness, the e-manage, the GReddy pressure sensor, the larger radiator, the dual ball bearing, water cooled turbo, the 5 intricate heatshields, the airbox, the cast iron manifold, the water tank, the water pump...if anything, this system is cheap when you consider how much every other forced induction kits are market up. If you really examine what you get in this system, you will see that its actually a very good price.

cheers

W

 

Wael, how similar is the AW intercooler to the Comptech? I, and I know several others, are on the brink of ordering the Comptech AC upgrade. If your AC could be used in it's place and was a reasonable price you could increase volume by selling it to the likes of me.

I can't see from the pictures where the turbo compressor connects to the heat exchanger.

 

The cores might be very similar, however our castings for the end tanks and entire envelop are different. I would think it's a bad idea to buy any other air/water other than Comptech's if you're running their supercharger. I talked to Shad during Fall Colors and he informed me that they have 4 castings made for their intercooler. The unit is very nice and I believe they've sold about 100 units so far which is reassuring that if there were any problems we would have heard about it by now.

My advice is you should purchase their intercooler that works with their system as the inlet and outlets are different than ours. I also believe (haven't confirmed it) that the Comptech has a water tank while the Vortec does now, it simply runs the water from the IC housing to the heat exchanger and back.

We were very aware of this problem and made an approx. 3 gallon water tank.

cheers

W