vaughnc

I was talking to our new sponser BNR about an upgraded top mount intercooler.

Looks like they're going through with it

Front Mount may give you cooler air, but top mount is nearly as efficient when the car is moving.

And there's nothing like a bolt on/drop in that actually helps quite a bit

Here's their page:

http://www.lourdsmusic.com/bnrsupercars/ic.htm

FEDREX

I saw that last nite...looks good enough to add to the mod list.

Gene

iTrader: (1)

Doesn't help a lick when if car is moving. It's a low pressure area on the hoodm and all the fans and misting in the world won't change the fact that TMIC's suck, especially sitting on top of a hot as hell rotary. For that price I would get an FMIC instead. The current craze in Japan is a horizontal mounted cooler in the engine bay, with individual ducting for it and the radiator... that would be interesting because it has nice short runs to reduce lag, but also gets a nice fresh air stream

Scott 89t2

that is the same price as the new huge greddy front mounts... sorry bring it down to like 500 and maybe you will get some interest

Node

iTrader: (1)

Top Mounts suck no matter how good they are to any front mount.

vaughnc

I believe the hoodscoop is there for a reason

duehuynh

so if tmic sucks, why other cars like WRX uses it?

what about the porche turbo?

just asking!

BoostedRotors

Top mount is better than NO mount...eh, Node?

vaughnc

RETed

You ever priced ARC stuff???&nbsp I'd bet that's over $1,500US!

Why you messing with inferior top-mounts when a GReddy V-spec BIG-*** front-mount is selling street price for UNDER $1,000?!?!



-Ted

BLUE TII

iTrader: (9)

Boost response is better w/ TMIC than FMIC I suppose. I plan on doing the horizontal IC behind stock radiator position w/ a small NPR unit. Both FCs in Options #92 used this set up; it seems like a good compromise to me.

vaughnc

I believe FMIC have their disadvantages as well ....

(correct me if I'm off BOOSTD7 / RETED)

- adding turbo lag
- decreasing the turbo's efficiency/volume at the same PSI (which is partially offset by the cooler air charge and increasing the boost).
- requires moving the radiator
- adds weight (move the battery to compensate)
- requires an upgraded radiator as airflow to the OEM radiator is hampered by the FMIC

and most of all - for purists an upgraded TMIC is a bolt on that doesn't require cutting/moving/modding anything.

NZConvertible

Top mount is cheaper and easier for the manufacturer. Simple as that. It's compact and minimises the engineering expense. But if you look around you'll find many many more cars with their stock intercoolers mounted at the front (usually small ones off to one side) than on top of the engine. As for Porsche, they don't any more. The 911 Turbo now uses two smaller ones mounted low down behind each rear wheel fed by ducts from the side scoops.

cymfc3s

im rather partial to FM flavor. =]

vaughnc

Where's the TII has the brakes fed by the air ducks down below behind each front wheel

zyounker

The WRX has a low pressure zone infront of the scoop.. That is why it works..

A upgraded top mount /w a new hood would be good.. for a stock turbo car.. but for an upgraded turbo you would be better off going with a front mount...


-Zach

vaughnc

cymfc3s,

Never said the FMIC didn't look good

Wish I had a corporate website to stick my pics on for free hosting

I'll just get my pressure gague out and measure the hoodscoop....

all kidding asside I'm assuming Mazda's setup forces air in similarly to WRX. It does shove enough air through the TMIC that an upgrade would be effective and a kit upgrade would be a no brainer.

-- vaughnc

FEARED7

Whats up everyone. I thought I explained how to prove that there is enough air going through the core a while back?
Test to see if your intercooler is getting enough air to cool the intercooler..

1. Start the car up and let the intercooler heat soak.
2. Put your hand on the intercooler core and feel how hot it is.
3. Get in the car and drive it for 2 or 3 minutes at 40+mph.
4. Stop the car, pop the hood, then feel the core again.

The air duct is doing its job! This low pressure stuff doesn't prevent the air duct from working. You say there is a vacume above a certain MPH? And how come the intercooler is cooler than before? You say that the air come beneith the intercooler? then the air would be hot! There is lots of ai getting throught the core! If you don't believe me, go take the test! No more talking physics... I took that crap in college.

later all!
Bryan

Node

iTrader: (1)

Like I said before, DO NOT bother with a upgraded TMIC, just get a TMIC, greddy makes a nice model for fairly cheap (compared to some others), blitz makes a nice one, or do it right and get one custom built w/ some custom piping (probly same or cheaper in price for same or better performance).

Unless for some reason you cannot fit an FMIC in (theres most likely a way to fit one in)
Yes FMIC's have more lag to a very small point over TMIC's on account of them being directly over the compressor and intake of engine.
However it is meant to TAKE AWAY HEAT. Not add it on account of being DIRECTLY overtop of the hot rotary engine. It is also in a low pressure zone. Ditch the bitch, go for a very efficient FMIC that looks good and helps your boost.

And FMIC does not have a small amount of air redirected down onto the engine. It is rammed all the way head on, much bigger face for much more air.
Get a cowl hood and cool down your engine much more.

If you want to increase lag so much just route your compressor straight into the intake. Right there, no intercooler lag but more heat, well not too much, Although I'm sure your compressor heats up the wheel spinning at about 50,000RPM (I guess, I have no clue on what it actually spins at)

rx7_turbo2

The stock hood scoop looks good, don't get me wrong but I don't think alot of air flows into it, the design just isnt right. FMIC is the way to go, unless you could get a mega sweet deal on a TM.

NZConvertible

At low speed and when stopped, the scoop acts as a chimney for the rising hot air, preheating the IC and dramatically reducing it's effectiveness when you accelerate off. I've seen a test on a WRX where after two minutes stationary and idling after a drive the intake air temp (measured at the TB) rose from ~40ºC to over 60ºC. Would you want to risk a high-boost launch then?
As for airflow at high speed, look at the cross-sectional area of the scoop and tell me how that can compare to the opening under the bumper.
Yes the intercooler works, but it's not nearly as effective at cooling as it would be out front. It's just a typical mass-production compromise.

NZConvertible

I saw a very interesting IC set-up on an FC the other day that addresses most of the compromises of both the stock mounting position and the traditional front mount. The car had a TO4 and external wastegate, and had a custom ~65mm thick IC mounted in the location of the stock radiator. It was about the same size as the stock radiator too. A custom 3-row radiator (stock width and height) was then mounted on top of the IC like a sandwich. There was room for this because the stock fan and shroud had been replaced by a 16” thermofan. (The stock radiator might work fine, but this guy had plans for even more power!) The battery was in the boot, the A/C was gone and the PS pump had been lowered by a custom mounting bracket. This gave heaps of room for the very short and direct runs of 2½” HPC’d pipe to and from the IC. The only thing that needed attention on this car was ensuring none of the incoming air leaked around the sides of the coolers, but that’d be easy to fix. So we have short, straight pipe runs, no metal cutting, no heat soak, a much bigger IC and you can’t see it from the front if stealth is your thing! I think this is pretty much the ideal set-up for these cars.

FC300BHP

My Top Mount is working pretty good, granted I don't have as much power as some of you guys but my FC is putting out 300 FWHP with the stock TMIC and I'm not having any engine problems at all. 11 to 12 PSI of Boost on the HKS SPORT TURBO UPGRADE. I'm looking foward to the UPGRADED TMIC if it will work even better then stock, I just don't want no FMIC near my radiator!

NZConvertible

EVERYBODY READ THIS!

Intercooler theory

It'll help you understand why your TMIC won't be working as well as you might think it is.

RETed

Your turbo's too small.

Your turbo is too small or run smaller intercooler pipes.&nbsp Running 2" intercooler pipes, I bet you can't tell the lag.

Now, this is totally false.&nbsp Not one of the kits I know of (HKS or GReddy) require moving the stock radiator.&nbsp They DO require cutting of the radiator frame though.&nbsp I'm working on an intercooler kit myself, and it'll be based on our own proprietery radiator and intecooler design.&nbsp This pivots the (stock) radiator top a little back, but will require an electric fan.

Just a little if you're talking strict weight of TMIC versus FMIC cores and endtanks.&nbsp Weight in front of the nose is a bad place to be adding weight due to increasing polar moment of inertia.&nbsp BUT, I doubt 99.99% of the people would even notice the difference.&nbsp If you can, you should be driving F1...

This is questionable.&nbsp In general, I would agree, but there are some very "radiator-friendly" intercooler cores out there.&nbsp A good example would be the A'PEXi intercooler core.&nbsp At this stage of the game, I would think you're running at LEAST a compressor upgrade running close to 300hp.&nbsp You SHOULD be running an upgrade radiator (no excuse with the $430 Fluidyne from http://www.absoluteradiator.com/), as the FC cannot take more heat from the increased performance.

The TMIC is in a "bad" spot.&nbsp Anyone with some common sense knows the FRONT BUMPER is one of the most highest pressure areas on the automobile.&nbsp Intercooler is all about airflow - high pressure airflow if the best.&nbsp If you can handle the slight decrease in efficiency to the radiator, then run the intercooler up front.&nbsp It's all about priorities; for me, 1st is engine cooling, then it's intake cooling.&nbsp This means WATER/COOLANT and OIL get the first priority.&nbsp The intercooler gets a very close second.&nbsp Brake cooling is minimal, as airflow after the intercooler and radiator is still in the 200F degree range - more than cool enough for brakes which can go over 500F!&nbsp I run 12.19" x 1.25" rotors anyways.

The top scoop of the FC is a very low pressure zone on the FC.&nbsp Any doubts, go check the airflow pressure diagram in the Jack Yamaguchi 2nd gen RX-7 book.&nbsp I believe there's an online pic floating around too.

Yes, an upgrade TMIC is a very efficient means of intercooling.&nbsp I'm planning to run 20+psi on a big 60-1 (minimum) to GT-TA45 Garrett in the near future.&nbsp I'm hoping 500hp to the wheels or break the motor into pieces (to test out the dowel theory).&nbsp The TMIC just won't cut it in my application...


-Ted