R Xplicit

i would think that an upgraded rasiator WOULD bring down temps, right??/

turbojeff

iTrader: (30)

Did I miss the answers to these questions or do the "front mount" people not like to talk about this?

Jeff

RonKMiller

I have always been concerned that in addition to impairing radiator efficiency that airflow through the engine compartment would be seriously compromised with a FMIC, aftermarket air box mod, etc. It does not matter how big or how many rows or what your radiator is made of, if there is not enough air moving through it she ain't going to work. Especially at low speeds, and curiously enough, even at high speeds due to aerodynamic considerations.

Granted, fresh air moving through the engine "room" (as Mr. Chin is fond of calling it) is fourth on the list of cooling factors, behind gasoline, water and oil - but it IS still important none the less to help prevent hot spots...I think a vented hood (and one that is proven to extract HOT air vs. one bolted on for looks) is mandatory with a FMIC. I wonder if ANY of the aftermarket vented hoods been in a wind tunnel for some serious scientific evaluation.

I really enjoyed the write up! Good work. This is great stuff to see on the forum. Beats "How many chicks can an FD draw?"

RX7Elmo

For the Greddy 2 row, you must hack at the fiberglass bumper reinforcement considerably. You also have to shave/cut the factory bumper as well.

Water Temps on my car aren't a big concern to be honest. During this winter time, i'm actually have a hard time getting out of the warm up mode, ESPECIALLY on the freeway. During hot summer days, i can just turn the fans on and my temps are fine again.

On the topic of air going to the engine area. If air is going through the radiator, it's going to the engine. With stock or with an FMIC, air must go through the radiator before it hits the engine area. Or at least that's what i remmeber from looking at the front of the car.

Danny

SleepR1

No the RE V-mount is $2800. The RE HMIC is $1450, but you'll need a vented hood for the HMIC to work properly.

SleepR1

recommends the Greddy 2-row FMIC and Koyo radiator for his customers with sequential twins and ported motors (enlarged intake/exhaust ports, enlarged oil/coolant passages).

He says Greddy 2-row FMIC/ported motor water temps range between 90 and 95 C (191 and 201 F); stock motor and stock radiator, water temps range between 180 and 220 F, depending on ambient temp conditions.

I've overheated my motor once at Mid Ohio in '99 (odometer @60,000 miles). I blew the upper radiator hose; the motor was being cooled by the oil (280 F).

That motor now has 102,500 miles. Still runs but with low compression. The old motor passed a leakdown test, despite being overhead 4 years ago.

The water temp issue gets overstated, especially by FD owners with large SMIC kits.

How well does cooling air exit the radiator with a large SMIC core duct blocking the air exit?

How much cooling air does a large SMIC duct allow through the IC core with such a small opening in the duct?

The FMIC is the most efficient way to cool the intake charge air; and is less prone to heat-soaking.

If a LARGE SMIC core was such a great idea, why aren't there any Japan domestic market AEM standard mount IC Kits available for the FD Rx7?

Yes the Blitz and the Greddy SMIC kits are available. The Blitz SMIC core is no larger than the stock IC. The Greddy SMIC core is only slightly larger than the PFS IC core.

Nearly all the JDM AEM IC kits with LARGE IC cores are front-mounted ICs.

What are the ambient temps in Japan?

FMICs aren't just a hip trend.

Boostn7

>>The 3-row has too much pressure drop for the stock or Japan spec twin turbos due to the large IC core's volume.

2-row Greddy FMIC for Twin Sequential Turbos!<<

Hmmmm... I may argue with that !
too much pressure drop !!!! don't think so.......a little added lag due to the bigger piping (3"vs 2.75") and bigger core....possibly.

I can you argue with 122mph trap speed with stock motor and turbos.

But honestly....if you're planning on running the twins I would recommend the 2 row.......performance is about the same and less cutting.

turbojeff

iTrader: (30)

I asked more questions than just the water temp.

1. What happens to the power steering cooling loop? I know that there are several FMIC kits out there. I know they can't all keep the PS cooling loop. No PS cooling loop doesn't sound good to me.

2. What were the REAL COOLANT TEMPS? This was glossed over in the original post and never really addressed. This is the major concern with FMICs. I personally know a auto-xer with a RX7 Fashion FMIC and a Mazdacomp radiator. His car DOES overheat when driving in higher load, lower speed conditions. IE, going up a steep hill, esp following another car. Track conditions will cause it to overheat also.

3. What did he have to cut off the car? I know that some of the FMIC kits completely remove the bumper support or really hack on it. This is bad for a street driven car but people will say they will never bump anything. OK fine. Some, maybe all, FMICs require that an actual part of the body struture be cut off. I'm not talking about the bumper support, I'm talking about STEEL that is part of the body. Now the front of an FD is really "fragile" in an accident. Remove the bumper support and you might find a 5mph bump will crush everything up front. Remove the steel and you'll find hitting anything at all will crush your FMIC and rad back to the crank pulley.

What is going on in Japan. Good question.

It seems to me that there is a larger profit margin on FMICs. No ducting.
The cars in Japan surely don't see the desert heat. High humdity helps cooling. They don't see a lot of high speed driving. Japan has 50% of the population as the US all packed into California. FDs are toys for only the very very rich there and they aren't driving them in condtions like we are.

FMICs are a hip trend IMHO.
Reason #1 for getting a FMIC many guys won't admit to:

People want a FMIC so you can see it through the bumper slot.

I can believe if you remove the AC, and to a lesser degree the PS, the cooling issue of a FMIC becomes mostly a moot point on a twin boosted car.

Single turbo seems to also work well with a FMIC.

Jeff

rxrotary2_7

Jeff, the coolant loop is rerouted. its not very hard to do. i will take a pic tomorrow of the new placement. i did not have to do any structrual *cutting* to my FD. BUT...the bumber cover went on over top of this just the way you see it.

turbojeff

iTrader: (30)

Thanks for the pic! Some FMICs require cutting off the piece of body that your IC butts up against.

It is interesting that they have such a large core, obviously the top ~2" are blocked on the back side.

Thanks again for the pic.

Jeff

SleepR1

1. The PS loop gets re-routed. The Greddy 2- and 3-row FMICs kits come with the braided hose to do the re-routing.

2. I already stated what the water temps are based on KDR Perf's experience, 191 to 201 F. This is with the Apex Power FC kicking on the radiator fans at 180 F. If your friend had high water temps BEFORE adding the FMIC, it will only be exacerbated with an FMIC. Also what do you define as overheating? The stock water temps for a 13B REW can run between 180 and 220F. I've run mine up to 290F with no consequences (or maybe I was just lucky)?

3. You have to trim ~1 inch off of the front bumper opening, for the Greddy 2-row, and ~2 inches for the 3-row. According to KDR the 2-row FMIC has no affect on the 5-mph crash-worthiness of the bumper. Dave did mention that in an off-set frontal impact of greater than 5-mph could damage the FMIC core.

There has to be a few Japanese FD enthusiasts who road race with FMICs, although many pro teams use the V-mount IC/Rad combo which is a variation on the horizontal mount IC.

You mean the FD Rx7 is used a daily transport HERE IN THE USA! I know I use mine that way, but I get the impression that many of you use the FD Rx7 as "toys" also?

No American or Japanese FD enthusiast will argue about the aesthetics of an FMIC (vs a SMIC). The FMIC is cool, no question. BUT the FMIC also works better for cooling the intake charge air temps.

FWIW the Greddy 2-row and 3-row FMIC tilts the A/C condenser up and in front of the radiator core, and you do NOT need to evacuate the A/C lines!

The twins apparently work very well with the 2-row Greddy FMIC, but the 3-row FMIC presents too much boost pressure drop for the little twins to work effectively.

inukai

Cool Post !!

SleepR1

SleepR1

Thanks

What's been your experience there in Japan with FMICs?

OC94Rx7

The FMIC and SMIC issue has always been kind of interesting. I have started my own SMIC project for my FD. I have already spent a good amount of time and money so, I won't be changing for a FMIC anytime soon.

I do think it is interesting how M2 Performance / Pettit Racing (US tuners and road racers) use SMIC while, in Japan we see FMIC ??? It can't only be because, M2 and Pettit sell SMIC so, they have been tested and they work. If FMIC where better? I am sure they would use them and sell them.

I guess the debate will continue on!

//Oliver

SleepR1

My preference would be to trust the Japanese tuners over the USA tuners when it comes to tuning the FD Rx7.

The argument follows the other way. Why trust a Japanese tuner with a C5 Vette, when we could go with Mallet or Lingenfelter in the USA?

RonKMiller

Let's not forget Callaway. I belive they had/have a production car that you can buy off the shelf that will do 250mph. Truly scarey.

OC94Rx7

Good point , I agree with you


Like Al Holbert w/ Porsche and Dan Gurney w/ Toyota (back it the old days) drive and prepare their cars and did very well for the Factory cars in the States. Might be getting off topic here...sorry.

It would be nice if we had some answers "why" the US tuners don't use the FMIC? From what I have seen. The tuners in Japan started with SMIC and use front mounts now. No doubt, that is for a reason .... are they that much better? It seems most of the heat soak issues with the SMIC happen during traffic (not race related) or are they
both good enough for us? It seems the pro teams in Japan use V and H- mounts, C-west with the FMIC but, in the States they still use the SMIC. WHY??

I will stop here because, I don't have the answers...... just wondering


Again, interesting topic. Always enjoy hearing your veiws SleepR1

rx7tt95

Just a few interjections here...I just installed a GReddy two row for my big single, replacing a CWR LARGE stock mount. I've had the GReddy in for a few weeks now. I also have a vented hood, Knight Sports design. Differentiating from the original poster, I noticed my two-row R-spec core was MUCH thinner than the CWR IC core which measures 3.5" off hand. The two row, I think, is about 2.75 to 3" thick at most. My fluidyne is thicker. Core length, naturally, is much longer. So how do you like them? Thick or long. Snicker.

For those that are using the PFC to monitor intake air temps, it's "sort of" innacurate. You'll see a larger drop in IAT temps by eliminating the coolant running through the throttle body (not recommended in cold climates!) than switching to a front mount. I believe the original poster used an aftermarket thermocouple to get measurements, albeit in a similar location. So the temps you're seeing aren't exactly accurate. Which scares me.

My experiences. Yes, coolant temps, initially, were high. Why? Air in the system. I now have them down to where they were before which is usually around 87 celcius for me. I've burped the system repeatedly and no problems, even at low/high speeds. I have not sealed the radiator with ducting yet and the AC condenser is still in front of the radiator. I however, did not replace the PS steering loop. I have a 96 (made in December of 95) and for the life of me, the GReddy supplied line would not fit. I'd like to see a pic if someone has it! All I had to do was unbolt it and reposition in a few key places. Works fine.

Besides the front bumper, there's no hacking with the GReddy FMIC. I have an aftermarket front end, meaning no bumper support, and thus, installation was a bit easier. Due to a mixup, I received the two row instead of the three row if you're curious. If you have Widefoot swaybar mounts, be prepared to fab up two brackets to hold the radiator at the bottom. The Widefoot tounges aren't as long as stock and thus requre an extension easily accomplished with some semi-thick aluminum. Use a dremel to cut it.

The FMIC does cool better, no doubt. It isn't a huge difference, especially at speed. I tend to see a 15 degree difference between ambient and IAT's with the front mount.

One thing I have noticed, I pull less vacuum with the front mount. Additionally, I had to adjust the boost solenoid duty cycle up a few percentages with the FMIC to hit the same boost level. I have not ruled out a defective GReddy Type S BOV on that last issue however, and it's being replaced with a proper Type R. Heck, the motor could be getting a bit soft too. But let's not go that route.

Spool up seems to take a hair longer. Might be the BOV. The original 3 row 19R core had much shorter piping than the newer redesigned units which air enters/leaves at the bottom rather than the top.

As for Japan, MOST of the better tuning shops use a variation on the SMIC. RE-A uses a front mount and they're still the fastest, although they offer alternatives. RE-A is godlike to me, so Inukai, when I'm in Japan in August, you have to get me in to meet him! Anyway..... Panspeed uses a horizontal mount. Knightsports uses a V-mount. All the drag cars use a front mount. Look through all of the Japanese RX7 Magazine editions and you'll see what I mean. There's a lot of diversity. Which reminds me, I have to order the latest edition! Most of the road race cars use a variation of the the SMIC or put the radiator and IC on different planes with their "exhaust" pointed in opposite directions. I'd think modifications to the bottom of the car would be necessary to equalize airflow and eliminate pressure differences behind each unit. Air takes the path of least resistance. Although....a certain RX7 tuner told me that some resistance created by the radiator fins helps cooling, as in airflow that's horizontal to the direction of the radiator fins won't cool as well as one that's been tilted slightly, so the air has some initial resistance. Dunno if it's true, just thought I'd pass it along for discussion.

Anyway, my wholly unscientific study (just observation mostly) of my particular change to FMIC leads me to believe it wasn't worth the time and effort to switch. Of course I now have room to put a filter on the T78, LOL. The CWR is a really good IC as are other similar units, and the lucky bastard that purchased it from me is getting a great IC unit and a very good deal.

I also think part of the advantage to the FMIC's are the cast end tanks that GReddy, HKS and Apexi use. I have no idea what cores they use or how well they're matched to the "everyone" setup. Obviously, the best solution is your own design mated to your specs with cast end tanks. Not exactly realistic. We all tend to believe that the Spearco IC cores are the best (ok, maybe not all of us) but I'm sure the big companies in Japan are using fairly efficient cores. Good topic. Two thumbs up!

inukai

Hi SleepR1

We can have a good talk about RX7.
I will go to the States this year.
NY, Chicago, LA, Vancouber and SFO.
We will meet very soon.

By the way,

Horizontal Mount is the best for circle track FD and FC.
But it is very expensive.
These days in Japan, almost all the fast track FD and FC have HMIC.

Circle track FDs don't have big turbine.
T04, TD06, TD67 and so on.
Those cars don't need big intercoolers.
Most of them have 2 rows.
Circle track FDs need good response.
Then, 2 rows are better than 3 rows.
And HMIC is much better concerning water temp cooling.
Besides, it gives a car good handling.
HMIC reduces the overhang weight compared with FMIC.
As for RE-A products, air-flow is considered.
RE-A HMIC and AD hood9 gives a car good front downforce.

All the RE-A products are race proven.

As for Drag, FMIC is thought to be best.
Drag FD and FC have a big turbine.
T51, TD88 GT3037 twin and so on.
Those cars need big intercoolers.

A friend of mine, Okamoto and Uchino, who are the fastest
FD and FC dragger.
Both two friends have 4 row FMIC.
Their cars are over 650 PS.
HMIC is too small for their cars.

I hope I can help you.
Ask me anything.
If there is anything I don't know, I will ask Mr.A.

Thanks

ttb

does the pettit work with an efini y-pipe?

SleepR1

Not without hacking the cross-over pipe...

SleepR1

Interesting about the HMIC. Chuck Huang is designing one, but hasn't quite finished the product. Go to http://www.rotaryextreme.com/product.html for more info.

The HMIC or V-mount IC/Rad would be the way to go for dedicated road racing FD Rx7s, huh?

By "circle track" I presume you mean a "road racing track"; a track with many turns, but completes a circuit?

In my case, my Rx7 will see the track much less than before (when it was mostly stock).

Before I die, I plan on having a dedicated road circuit car, like the SR3 Supersport from Radical Motorsports UK http://www.radicalmotorsport.com/

OR perhaps a Diasio D962R (powered by a Rotorsports Racing 12A Bridgeport motor) http://www.diasio.com/d962rext.html

BTW, inukai, I've been trying to find a FD Type RS/RZ spare wheel/tire. Jesse Lau had no luck finding the spare wheel/tire. Perhaps you can bring one with you on the plane from Japan

Best of luck in the coming year!

inukai

Hi SleepR1

I can find FD Type RS/RZ spare wheel/tire easily.
Beacause Most of the FD owners changed their wheels.
And Most of them don't have enough room for keeping them. HaHa

I will find them and bring them to the States.

inukai

My friend has it.
Is it ?

SleepR1

no, I'm referring to the 1999-2001 RS/RZ temporary spare wheel/tire that goes in the trunk spare tire well