Some people say FMIC will overheat, some say its the way to go. Everyone has their own experience or opinion but I agree this could go on forever.

Regarding the aerodynamics. It's just a theory. Though it sounds logical, I don't think that if the V-Mount has such an adverse effect on downforce cars would run that setup in the JGTCC class. I am sure they have examined the possibilities already. You can drop a mail to HKS and ask them if their V-Mount setup causes understeer, I am sure they would help you! :-)

 

Efficiency does not equal power. Hotter engines will run more efficiently, but will make less power. I think the point of upgrading the intercooler and radiator is to make more power for racing, I don't think there is a big concern about the engine's efficiency. A cooler engine will make more power.

 

No you dont, the cores dont flow nearly as much as the opening in the bumper. At around 20mph your FMIC starts to pushs air, they can only flow a certain amount of air and the nose hole is much bigger than the spaces on your fmic. With a fmic your going to max your core out and thats all the air that the radiator gets. Your basically cooling the air charge AND the radiator with however much air your fmic core can pass, this is why they have cooling issues. You can help the cooling issue with a fmic by going with a lower fin count on the ic but then your just hurting your intake cooling. When they are setup as a V you can max them both out independantly. With the radiator having more surface are than a fmic in reality your going to be able to flow more than twice as much air thru the total available cores as you would with a fmic.

As for the downforce "issue" people are talking about....get real guys your not building a formula one car that its really going to freakn matter. There isnt THAT mcuh air that its going to make a hill of beans difference. Anyway....you can always do what I'm thinking about doing and harness the air as it passes thru the radiator and channel it to the brakes. Problem solved

 

No one has mentioned "heat soak: which applies to street cars.

Race cars do not have this problem as after they warm up they are always in motion except the short time in the pits. Drag cars cool off between runs and many racers even ice their IC.

V mounts and stock mounts have the IC right over the radiator which heats soaks more than a front mount. FMIC heat soak the least amount. The AC setup for V mounts is also the worst of the three. Race cars do not have ACs.

Which is best depends on your primary use and weather condtions.

Here in Texas heat is more of a problem then if you live up north. Since I only street drive and am on full power for short periods, I went FMIC for best intake charge cooling.

Last Saturday while on a dyno, the DYNO registered AT was 94F. After each run, my FMIC AT sensor was only reading between 104 and 108F. Water temps were about 190F after each run.

Cool between runs, water was about 186F and IC about 100F.

 

Where the heck do you think the air exiting the radiator is venting to with the stock setup? The only way out of the engine compartment is still out the bottom, unless you have an aftermarket vented hood.

 

Punctuation is your friend.

 

No offense to those that have V-mounts, but unless your car is used on the track you are pissing money right down the drain. Front mounts, even though they dont let as much air pass to the radiator as a V mount, they are passing enough to keep it from overheating. Thats all that counts! Period. Front mount is not going to heat soak in traffic like a vmount or stock mount and lower the charge temp alot quicker. Another advantage is you can buy a boat load of performance parts for the price of one V mount. Dont get me wrong, the Vmount is a nice setup if you got the money, but there is no advantage to it over a front mount if your car is a street car. Just my opinion

Jason

 

Exactly, I would have gone front mount also but I will be tracking the car soon and that's the reason why I went v-mount, if I did not plan to track the car and just take it to the dragstrip I would have gone FMIC...and as far as aerodynamics just like some peeps said we are not building an F1 car here and for the aerodynamics to take effect you have to be going at a preety high speed for it to matter like over 120 MPH how many people here drive 120 and over everyday...

 

I agree that the v-mount is better for a track car than a street car, but i still want one, bad. BTW, the insulation on the undeside of hoods is more to quiet the engine noise and, more importantly, fire supression.

 

I won't bother to talk about IC's, a person can do a search for that. I just noticed your comment about not going 120mph, well unless your car is broken you should be going over 120mph 20+ times a day at almost every track event you're planning to go to, unless it's an autoX size tight course. If a stock block RX can do over 120mph from a dead stop in 1320feet you should know what kind of speeds you'll see when you're carrying reasonable speed through a final turn before the straight instead of starting from a dead stop. For real track cars aerodynamics do play a real role, it's not just an F1 thing.

From a different post someone mentioned something like, ~"where do you think the air exits from a normal radiator?", well it actually exits by cooling the turbos and the other side of the block and follows the trans / driveshaft / exhaust tunnel out. There is a difference.

Sorry I don't have anything to say about IC's : )

 

I am not too sure about other V-Mount setups but the HKS kit has the fans mounted underneath the car so the hot air is sucked away from the IC and not blowing at it like in the SMIC. The radiator has to be repositioned in V-Mount setups. Which is why someone brought up the issue of downforce. Also the HKS kit comes with a block off plate to seperate the IC and the radiator so any IC heatsoak is restricted to mainly the intake pipes leading to the manifold which is the case for all IC setups.

Just to clarify

 

Yup V-Mounts cost a bomb. I went with V-Mount because I have some a friend here who runs FMIC with ARC Radiator but his car always overheats. It is a daily driven and other then the occasional "illegal" road race we don't have a drag strip or race track here. In theory it should not be as almost all turbo cars here run FMIC. Don't see why the RX7 should be that much different. Maybe its got to do with the climate here. But I chose the V-Mount as no one here bought it before and I figure I be the first to try. So far no regrets but the price was really hard to swallow.

 

Kevin,
Mine was the "where do you think it exits?" comment. The point i was trying to make was, I really don't see how angling the radiator such that it's high in the front, low in the back as it is stock (what is it, about a 30 degree angle or so?), and positioning it at approximately the same angle the other way around (low front, high back).

Even in the stock config, once you've place some combo of a large IC duct, battery tray, intake above the radiator, a significant portion of the exhausting air is going through the gap between the undertray, and the crossmember that the IC sits on... and in a V-mount config., that crossmember is approximately the point where the radiator mounts at the rear, so the exiting air is really likely to exhaust in a very similar way.... see the attached diagram (not exactly to scale):