If you can't properly duct a top mount, don't do it. Usually you have to make the air turn almost a right angle when it goes into the scoop, so you get strange pressure drop across different parts of the intercooler. There's a lot more design considerations than you may think. Also, you have to be sure that the scoop has the right shape, it's in the right part of the airflow, and the air under the intercooler has someplace to go. Remember, if the air is static under the intercooler, the air on top of it has nowhere to go. So you get no flow.
I'd stick with front mount, it's easier all the way around, and you know it's going to be in a high flow spot. Plus, you won't have to worry about heat soak.

 

heh im goin diy w00t. it wont be hard. and i think i have a good idea on how to make it look good.

 

I didn't read all the posts, but here's my thing. I've owned three Turbo2 RX7's, all with top mounts.
1) Those things get heat soak like a champ, after your first run, it'll be heating the air instead of cooling it.
2) The scoop that's on the hood is inefficient to start with. Once you start moving, it just keeps losing and losing effiecieny. Somewhere around 60mph, it becomes totally inept.
3) The stock IC is too small to begin with. Anything over 12psi is recommended to get a FMIC to handle the boost.
Go with a FMIC, it may be some extra piping, but that WELL outweighs the negatives of the TMIC.

 

So, Im the only retard that runs a water to air?

What about the first 15mph of a drag race? The air/air intercooler isnt dion its job, if you have a 2step ignition with full boost off the line, your goin to see a little problem when no air is flowing through it...

With water/air you can have cooler than ambient temps entering the engine, such as using ice in the resivoir, dry ice is even better...

Also, the entire core will see virtually the same temps, instead of an air/air which will see the coolest temps on the front part of the intercooler but as the outside air flows it too will be heated and the rear portion of the intercooler wont be as effiecent...


But do as you please.. Im not here to make believers out of everyone...

 

I'm surprise Carl(GTi-R) hasn't chimed in yet, he's been running a top mount on his 91 Sentra for a long while.

 

I'd run a water-to-air on a race car, but not a daily driver.

 

Air to airs are just simpler, and easier to make efficient than air to water. Air to waters definately have their place, but they are a lot more complex, sometimes it's just easier to get a big front mount A/A and call it a day.. The ice box argument is a strong one though..
If I remember right, an air to air will respond faster to changes in ambient air temp with speed, etc. because you don't have to cool the water first and then cool the air//water core.. Also, you can usually do REALLY short piping with an air/water, which could give better boost response..

Basically, both have their place, and it's a game of tradeoffs like everything else.
I'll probably do an air to water if/when I get an MR2 spyder, because it's easier for that car probably. I don't know, don't flame me Spyder owners..
I've always wanted a air/water unit, there's something hardcore and cool about it.. Kinda like that rear engine Sol that Top Fuel did, with the air/water unit and front mount radiator for it..

 

I dont think you can get much shorter piping than that...

And I garentee the water will never see hotter temps than ambient, unless you totally screw your self by putting the res in a heat soak place, or running too little water...


The only argument I agree with is the simpleness of air/air, but I will run a air/water any day of the week on any car that will see stop and go driving either daily or racing... a rally car or top speed car, would defently have a air/air with a N20 spray...

 

Big enough water res with a good sized radiator will have a really high thermal mass, yeah. I guess consistant temp is the best advantage of that..
What car is that, I don't recognize that engine bay.. ?

 

I'll take a guess at that and say a 2.3L Mustang SVO.