FMIC disadvantages
 

i have noticed the current trend in upgrading the stock intercoolers is to use v-mounts opposed too front mounting the intercooler. i understand that a FMIC may cause overheating problems because of the reduced flow to the radiator. but surely one of the aftermarket radiators which most of you with v-mounts already have could fix that. also realiase the advantages with shorter intake piping. what i'm trying to get at, what is the problem with FMIC?

the problem is that there are better options

well the since the ic is mounted in before the radiator , direct air flow is interrupted quite a bit. i have a apexi fmic but to deal with this problem i bought a koyo rad 1st and foremost, then i did the fan mod so i can control when the fans activate (stock is like 96c, i turn mine on at 81c)

but it has it advantages also, my intake temps are much lower!!!

but v-mount are the way to go, people just choose not to go that route cuz its lotz of $$$$$ about 1800-2400

but depending how deep ur wallet is, either choice is a great mod

mike

i've had zero problems from my apex fmic kit. never once thought about over-heating even sitting in traffic for long periods of time

as my car is used for track events i don't want to compromise cooling. a PWR radiator will be fitted with the HKS FMIC. does anyone have problems with a similar setup on the track?



yeah mate, care to elaborate on that

From my understanding, at some point ( track conditions not street) if your giving it 110% constantly you will at some point overtax the cooling system and it will begin to creep toward the red zone, nothing that a lap or two of regular/average driving cant control. So its like 5 or 10 laps of hard, fast etc etc then a lap or two to cool off, then again another 5 or 8 laps, then cool then again on and off. Also boost temps, twin or single, and water injection affect all of this.

Please use the search function, there's no need to start another intercooler debate, it has been discussed ad nauseum.

ok think about this....
with a v-mount:
when you are moving, the radiator is getting air.... correct?
the intercooler is getting air... correct?
when you are stopped, neither get air (without fan's)

with a FMIC:
when you are moving, the radiator is getting air.... correct?
the intercooler is getting air... correct?
when you are stopped, neither get air (without fan's)

the only time youu will have a problem overheating is if you are sitting in traffic for a long period of time.... i have never heard of anyone that was moving and overheated because the radiator wasnt getting air......... i have heard of people running hotter with a stock rad but thats what a koyo is for..

both have their pro's and con's but the only time you will have a problem is when your sitting in traffic!

think about it!

A friend of mine tracks his car a lot (he's an instructor, blah blah) and runs the Apexi FMIC. He does run hot, but doesn't overheat (he also has the Scoot hood). However, he said if he had it over to do again, he would go with a large SMIC like the ASP/M2 instead of the FMIC.

ive got a fmic, i constantly moniter operating temps and didnt notice any increase when i switched over to the fmic.

i havent done any track days though so i cant comment on that.

FMIC + stock nose + track events = trouble. Otherwise ok with larger rad.

with greddy fmic, manny/sleepR1 was seeing 240F+ at stock sensor (would be 250 at t-stat hsg). way too close to boiling point for egw. he had about 1E6 miles of track days with stock IC, and brief life with rebuild and nice cool charge air from greddy fmic.

Most FMICs block the already small mouth area by 50%.

To use fmic at track, consider and/ors:
1) new big mouth nose http://www.rotaryextreme.com/ms/sideview.jpg
2) twin upgraded ducted o/c's
3) back set fmic that allows substantial bypass air to big rad.
4) belly pan scoop or dam or splitter to get air to big rad.
5) npg+ coolant, if still hot with above mods.

without 1), for track days, air needs to bypass the ic. charge air does not have to be near ambient.

Most of the japanese workshops who circuit race have swapped over to the v-mount - it's universally conceeded that it's a far superior design for the task at hand. Those who still use a fmic set-up, use a very substantial radiator - we're not talking your average koyo here.

IMO, you're asking for trouble circuit racing (or daily driving in significant stop-start traffic) with a fmic (particularly with a non-vented bonnet/pre-98 spec bumper/crap radiator, etc). It's obviously been done, but it bumps up the risk rate.

If you're aiming for moderate horsepower levels, on a budget, then a strong smic would be a very sensible modification (though many can't go past the aesthetics of a shiny silver ic filling up the bumper).

but yeah, this has been covered at least twice :p

Except that with a FMIC, whether moving or not, the air going through the radiator is already heated quite a bit and therefore doesn't cool effectivly. With a Vmount, the air has not been put through a heating core.

First off, if you ever overheat on the street or even run hot, you have bigger problems than what IC you are running. So running low temps on the street is not a good indication of cooling system integrtity, IMO.

I have a fully "ducted" and sealed IC/rad setup. It keeps temps at the thermostat on the highway. I went to a track event a couple weekends ago and was seeing temps climb to 230F by the end of a 20 min session. I can't monitor AIT's (I'm sure they are low) but needless to say I am less than impressed with the FMIC set up. I am also running a stock front end, so that might be some of the problem.

First/original motor lasted 102,546 miles/10 years/70 track days in mostly stock config. KDR/Malloy motor lasted 18 months/18000 miles/7 track days.

My theory on the failure: hot spot formed on the rotor housing due to boiling coolant. The hot spot caused detonation in the front rotor housing (12 psi boost), chipping a front rotor apex corner seal.

Upon engine teardown, the water seals were in fine shape, so the boiling coolant did no damage to the rubber seals. I was running 85% water, 15% antifreeze. With 15 psi cooling system pressure, coolant with that much water will boil @ ~240 F. I was seeing temps in the 115 C (239 F)--definitely boiling the coolant.

To imagine a hot spot, watch how water boils at the bottom of a hot steel pot. When the boiling water vapor starts from a hot spot at the bottom of the pot, that hot spot is superheated. Imagine many of those hot spots on the rotor housing's coolant jacket, and it's not hard to imagine how detonation WILL occur, despite a solid 10.9 AFR tune on 93 octane pump gas.

The engine damage was ultimately caused by a chipped apex seal piece which lodged between the rotor/rotor housing, and scored the housing beyond salvage. The rotor was not salvagable either b/c the failed apex seal was press-fitted into the rotor, and could not be removed without milling past 3-mm apex seal specs. Thus I needed a new front rotor and rotor housing.

Sadly I don't have the money to convert to V-mount AND rebuild the motor, so all I can do is switch to Evans NPG+ (and run race gas at open track events). This coolant boils @ 375 F (@ zero psi). My cooling system will run at 10 psi max (I'm retaining the 15-psi pressure caps), so the actual boiling point is higher than 375 F.

Theoretically, I should not ever reach Evans NPG+ 385 F (10 psi cooling system pressure) boiling point. Engine cooling will be limited to how well the stock R1 dual oil coolers maintain oil temps @ 250 F. If the coolant stays in liquid form (does not vaporize), hot spots will NOT develop on the rotor housing cooling jackets. No hot spots mean you prevent detonation from boiling coolant--thus your motor can run hotter SAFELY with no ill effects. There are accounts of Evans NPG+ cooled rotaries running as high as 265 F with no problems.

Don't let my ill-experience turn you away from FMIC. FMIC's the best street rod setup, barnone. I'm an instructor-level open track driver, so my gas-pedal foot's on the floor OFTEN during my track sessions (you're going slow if your gas-pedal foot's not all the way to the floor LOL).

You should have very few problems on the road with Koyo rad/Power FC fan switch-on adjustment/Evans NPG+ with GReddy FMIC.

Best of luck!

I think the whole idea of this thread is more of the nature of "how is your money best spent"

With egw, assuming one can maintain 15 psi in the system (an rx8 type expansion tank helps), the bulk coolant temp at the oem gauge sensor (near plugs/chambers) should be at least 30F below the boiling point, to assure air bubbles from normal local boiling are quickly condensed. This would be 235F max at 50/50, and 225F max at 20/80. I think the pfc (stock thermo sensor) reads coolant at the pump, which is cooler than at the chambers.

I don't think you want to be the one to set record high temps with NPG+, but based on the flush mounted fmic, you could be:

http://opentracking.com/_borders/HoodOff.2.JPG (installed greddy fmic)

Not much cooling air flows through the side plates of the end tanks! Mazda did increase the mouth flow area on later non-US models. One low budget thing to do may be to find ways to move back / tilt the IC and perhaps rad & cond'r too, to allow some bypass of IC, and more total air flow through mouth. I assume the volume between the mouth and rad is sealed so air does not bypass the rad.

with npg+, 7 psi cap is more than enough.

I fully expect to see NPG+ coolant temps in the 130 C to 135 C (266 F to 275 F) @11 psi full tilt boogie on a warm day . What I need is for the coolant temps to stabilize over the duration of a 30-minute session. I won't know until I track-test. On the Power FC, I have to increase the ignition retard coolant temp setting from 110 C (230 F) to 135 C (275 F).

With the ethylene glycol water mix, the coolant temps kept rising to a peak of 121 C (250 F) highest I've seen with EGW.

Koyo rad core is sealed with foam between engine bay and rad core sides.

Evans tech rep says, that if I keep the 15 psi caps that are on my cooling system unmodified, the highest pressure I'll see from the Evans NPG+ will be 10 psi.

Even Mr Evans would cringe if he saw your installation.

Assume koyo is sealed at top too.

Evans rep is wrong. During expansion process 15 psi cap will relieve at 15 psi, cat piss or coolant. Pressure will then rise and fall a bit with temps during a session, peaking at 15 psi.

Ahhh, 15 psi will mean a 400 F boiling point for Evans NPG+ LOL. Bring on the 275 F coolant temps!! Nope, top of rad core is not sealed up to the hood.

Note that I'm NOT advocating my FMIC setup for track use. I'm merely making do with what I have (a $3000 engine rebuild is forcing me to...).

Of course if Chuck Huang and Rotary Extreme want to sponsor me by sending me his/their Monster V-mount setup to track test free of charge. I'd gladly oblige :biggrin:

doesn't have to be sealed to hood. but, must have a top surface that forces air that has moved beyond the IC to go thru the rad, and not over it. someone had posted about making these sealing sheets from alum or cf.

goal: all air entering mouth must go through the rad.

don't have to have a V-mount, but you could do much better with what you have by getting more cfm through the front opening, and letting intake temps rise a bit.

thanks for the useful infomation, hepas of it there. when i bought the seven it came with a hks FMIC unattached. the fd runs fine with the standard radiator, standard intercooler and stock twin oil coolers, but this has only been tested with 2 sets of 5laps. if it's not a problem i will fit the FMIC and a PWR radiator, otherwise i will just sell front mount off


as for the search nazis, i did a search prior to posting this thread. FFS get over it. If threads wern't repeated once in a while there would be very little to talk about

If it were up to you guys noone would ever discuss anything after it has been discussed once before. Just dont reply if you dont like the topic. Geezzz The "search" reply is fucking older than the fmic vs. smic debate so there.
NannyNannyBooBoo :D

What new information has come to light since last week's debate about intercoolers? Or the one the week before that?

The FACT is that FMICs put more stress on the cooling system, no matter how well you duct things. The FACT is that FMICs have longer tubing than SMIC or v-mount, leading to more lag. The FACT is that many FMICs require hacking or removal of structural parts of the car.

Neither the SMIC or V-mount setup has any of these negatives. You give up a lot for slightly colder air intake temps -- to me, it's an unacceptable compromise. Especially when there are other mods, such as water injection, to keep intake temps low.

I would lay money down that the two major reasons that people buy FMICs are the bling factor and the lower cost compared to a good SMIC or v-mount. It's not for performance reasons. In most cases, getting a large intercooler is for show anyway, it's not like most FD owners track their cars these days.....

One of the most intelligent replies I've seen in a looooong time!!!! Well done! hahaha

Not true. For strictly streetrod use the FMIC is the way to go for big rwhp. And yes, I do like the toothy grin of the FMIC...the shiny grin let's dumb-ass C5 owners know not to screw with you at the light. FMIC is perfectly fine for open tracking in cooler ambient temps. It's only during the summer heat, that FMIC becomes a real problem. IMO, FMIC is getting an unduly bad rap. My advice to noobs, is to know what you're getting into, and what to expect. If the worst happens (as in my case), there are no surprises. Each enthusiast will have to reach his own decision as to which type of intercooler is the best the for his needs/wants. Hindsight is 20/20, and there's never enough money to do what's best. Choose wisely. It's this simple. If you don't track your FD, you live in a temperate climate, and have addressed all cooling issues, there's no reason to shy away from FMIC. If your FD is a bonafide open track car, go with V-mount or SMIC.

KevinK2, you're more than welcome to stop by Rx7 Store and share your ideas with Zavier. Oh, and your mods can't cost much, b/c, I'm already in deep with the rebuild. It's easy to criticize, and say I told you so, when it's NOT your car waiting on an engine rebuild isn't it?

Disadvantage is install. SMIC just drops right in. Are you trading intercooler heat soak for radiator heat soak? ...that's debatable. They are about the same price or even more expensive so i'm not sure where someone got the idea they are cheaper. V-Mount seems to be a good concept but it's incomplete to me. The closest to a finished product is HKS which can direct air flow. You will still need to fab shields for the sides and close all the gaps and maybe funnel the shields to cover all of the opening. The duct on the SMIC just doesn't make any sense to me. The opening is what 1" x 6"? Unless the car is moving the SMIC will get heat soak. So it's a trade off and figure out how to compensate for it (vented hood, etc) and there's nothing wrong with a visual preference on a street car.

Manny, your experience is not uncommon with what I've seen of Japanese tuners running hot laps with FMIC. And this was 6 or 7 years ago.

So the fact that you went head over heel b/c of the he-man factor of a front mount means that you're complicit in the destruction of your engine. In plain English, you screwed up tracking a car with FMIC when it's well known in the RX7 community here and in Japan 6 or 7 years ago that you don't run a FMIC in a road race car. That and the fact that you're running 240F with 85% water. What were you thinking? 240F would be fine with 50/50 but not 85/15.

Consider this, I'm running a Fluidyne with NPG+. At 90F and 80mph, I turn on the AC which drops the interior cabin temp about 20 degrees. Guess what? My water temp 200F at the filler neck goes up 20 degrees b/c of the AC radiator transferring heat into the Fluidyne. Now imagine your IC which must drop air intake temp about 100 - 150 deg F; that's alot of hot air that will be transferred to your Koyo whether or not you're running NPG+. From my search, there was a guy in Kansas who ran a FMIC with NPG+ and he reported 280F.

Regardless of the finger pointing, consider the $3000 as your up front tuition for a learning experience. If it were me, I would sell the FMIC, get a used SMIC and run Evans NPG+.

Nothing like the weekly SMIC Vs FMIC debate :)

Past 8 years I have run front mounts with no overheating issues. We have installed the greddy front mount probably 40 times and not one customer has had an overheating problem.

Look at it this way.
ASP SMIC $1500
Vmount setup $3000 ( To take advantage of the Vmount you need a vented hood so add $600)
Greddy FMIC + Koyo Rad + Vented Hood + Water Injection = $2250 Nuff Said :)

Jason

Manny,
A good investment would be a vented hood. That made a huge difference in temps when I put one on my car.

Jason

FMIC will cool your intake temp more than a V-mount. Cooler air first hits the IC and warms up a bit then it hits the radiator. V-mount the cooler air hits the radiator first.

This real simple people.

Jason, let's be honest. Do you or any of those 40 customers track the car (not drag strip, road course)? Manny had a well put together machine and it overheated, plain and simple. This can happen with SMIC too, no doubt about it.

Manny, I see plenty of high hp cars with SMIC or V-mount. FMIC is not necessary for high hp. I see no point in reducing the cooling ability of the car to get intake temps a few degrees cooler (which water injection would make up for anyway). There is a reason that most track guys don't run FMIC. Manny, we agree on many things, but not this...:)

I would have to agree with running a smic setup with some spray or possible co2 charges.

If the shop were 15 miles away, and not 1500, I would. You can always give him copies of posts which he can think about or use as toilet paper, I don't care it's your car. Fact based suggestions are not intended as criticisms of you, and don't remember saying I told you so. I do recall the blitz and/or true apexi are set back designs, and allow air to bypass ic (cew uses one of these at texas track days). This may be possible with the greddy also.

and what a debate it is :)


no water injection, would like to keep things simple.

PM zayrx7, rotarded, and Jason about your ideas on how to address GReddy FMIC setup for better air flow to my Koyo radiator.

The GReddy sits right out front (it's not set back like the Apexi'). There's a large air gap between the front bumper support, and the rad core. Perhaps there's a way to cut slits in the undertray, and mount a deep air scoop that will divert under car air into that air space, for more direct air flow to the rad core? Just a thought...

Yes, that reason is, most Rx7 track guys don't have the balls to try FMIC on track LOL ;)

Is there a "Manny discount special" for a vented hood, and perhaps Mocal 19-row oil coolers LOL?

If you can get intake temps where you like with a stock mount or v-mount why is there even a need to consider a front mount that robs the radiator of cooling air?

Well you're not me, but thanks for your opinion :)

If I lived in Austrailia, I would stay with stock mount IC/rad or go V-mount IC/rad. FMIC/rad might not be the best choice for you, especially if you live in the Outback LOL :)

Good question! Cuz GReddy FMIC looks so cool LOL :biggrin:

THis reminds me of women wearing high heels or lung-aphyxiating corset: It hurts like hell (in your case $3000) but it looks great.

I'll bet some Iraqui Dinars that you're going to see coolant temps in the 280+ range and after a year of tracking, you're going to see coolant seal problems.

Place your bet now. Face it. You like hot chicks with high heels so STFU LOL...:biggrin:

I'm going on my third engine. So what? That's par for the course. The car has over 80 days of track and 122,000 combined street/road course/autocross/drag race miles. That's averaging 61,000 miles per engine (from both failed engines). That's pretty much within the average lifespan range of 13B REWs that are driven hard eh?

$PRICE$ :D

So...what did the Aussie decide to do? We need closure on this topic, dammit?!

FMIC looks soooo rice.

;)

didn't get much sleep last night hey? :lol:

well considering i'm not going to do too much modifications to the boost or engine for that matter, i'm thinking of selling the FMIC and upgrading the stock SMIC with a larger item from avo. (pic attached) i'm fairly certain its the same IC used on the SP model. little expensive though ;) i really don't want to spend bucket loads of cash on fixing the cooling system, although i will still upgrade the radiator.

thanks again for the help guys. no problems with heat atm guys, it was -2deg C this morning in the outback :D

Just do a FMIC...