1FooknTiteFD

how are you planning on driving the car? If you are going to road race then use the stock mount or V-mount. If you are going to just cruise the car and do an occasional burst on the highway or drag race then go for the fmic. With single turbo, the water temps and the air intake temps decrease dramatically since the turbo is oil cooled. You may even get away with road racing with a FMIC

RETed

Funny, this has nothing to do with stock-mount versus front-mount...
If it's not obvious, this has everything to do with core dimensions, core design, and a little with end-tank design.


Was these numbers published somewhere publically?&nbsp The only "test" I've heard of is the article in Sport Compact Car magazine by Shiv Patak on the M2 intercooler(s).

Can you say "inferior stock mounting design"?&nbsp This is not inherent to the front-mount IC itself, but moreso a badly engineered and designed cooling "system".&nbsp Do you profess to claim the stock radiator and it's design and mounting are "satisfactory" for a "modded" FD3S?


Funny, the top Autospeed article QUOTE:

"By far the best location for an intercooler is in front of the engine radiator. The car manufacturer will have aerodynamically tested the vehicle to ensure that large volumes of air pass through the engine cooling radiator, and so an intercooler placed in front of that is sure to receive a great amount of cooling air. Note that the intercooler should be in front of any air conditioning condenser as well!"


doh

Bottom line - the stock (mount) intercooler sucks.&nbsp The stock radiator, design and mounting sucks.&nbsp If you want to get serious, get a true front-mount intercooler, and (larger) upright radiator, and make sure all the incoming air is ducted to go through both cores efficiently.


-Ted

Silver93T

Also, someone said that the duct is what determines how well a stock mount intercooler works? If that is the case then the duct for the M2 sucks. How is it supposed to get enough air from ann opening that is maybe 1"-1.5" high by 16" or so wide?

Mr rx-7 tt

iTrader: (5)

I know Corky Bell and talked to him extensively about IC's before purchasing mine. Front mounts have very large pressure drop which the M2 large IC doesn't have.

"Funny, this has nothing to do with stock-mount versus front-mount..."

*Yes It does..We were comparing the greddy 3 core front mount vs the M2 race...

"If it's not obvious, this has everything to do with core dimensions, core design, and a little with end-tank design."

*No kidding, It had to do with core design, and length of tubes..ie PRESSURE DROP...

The M2 also has almost a 90% efficency rating according to the figures Corky ran. (He didn't like the front mount and said so after we went through the numbers.) We came to the conclusion using math that the M2 was fantastic (full race car efficient) and it wasn't worth him building me a custom IC....



Was these numbers published somewhere publically? The only "test" I've heard of is the article in Sport Compact Car magazine by Shiv Patak on the M2 intercooler(s).


I usually don't publish my conversations with Corky. But it's basic math, run the figures. (actually I think the efficiency ratings are published on the site I gave).

There are also other issues such as the radiator cooling etc when installing a front mount.

"Can you say "inferior stock mounting design"? This is not inherent to the front-mount IC itself, but moreso a badly engineered and designed cooling "system". Do you profess to claim the stock radiator and it's design and mounting are "satisfactory" for a "modded" FD3S?"

*No I never said that did I..? This is why the stock mount works better on the RX-7 than a front mount.



Read this also:
http://www.scuderiaciriani.com/rx7/intercoolers.html

Funny, the top Autospeed article QUOTE:

"By far the best location for an intercooler is in front of the engine radiator. The car manufacturer will have aerodynamically tested the vehicle to ensure that large volumes of air pass through the engine cooling radiator, and so an intercooler placed in front of that is sure to receive a great amount of cooling air. Note that the intercooler should be in front of any air conditioning condenser as well!"

*Yeah, Thats great but read on. It is a general statement but has zero to do with the RX-7. Mazda didn't design the front facia to handle both a front mount and a radiator.( Not enough air flow). Look at the cars that are tracked with front mounts (road courses) they have over heating problems.

Bottom line - the stock (mount) intercooler sucks.

*Ignorant comment and the math shows you are wrong.

The stock radiator, design and mounting sucks.

*Yep...

If you want to get serious, get a true front-mount intercooler,

Depends on the design...and your set up...

and (larger) upright radiator,

and make sure all the incoming air is ducted to go through both cores efficiently.

You make a lot of misinformed remarks based on knowledge you don't have.

Give Corky a Bell a call and straighten him out...lol

rx7tt95

I spoke at some length with the editor of RX7 Magazine (Japan) when he was in town covering the 4-rotor Auto Exe entry at the Sebring 12 hours. He's been present at many of the "tuner" race days in Japan that are often featured in videos like Option (you know, where the 400hp FD schools the 800hp GTR :-). The general emphasis in Japan is on road race versus that of drag race yet thumbing through the magazines, you'll notice virtually ALL of the big players that field pro roadrace teams use front mount IC's. The only exception is PanSpeed which uses something like a V-mount.

I asked him how they get away with running front mounts on their road race cars. His reply was "they don't. It's actually quite funny, after a few fast laps, they have to come in and cool down".

Like Mr. 7 said, the third gen (generation most of us are referring to here) doesn't have the frontal area to properly cool a rotary engine with double the specific output of a stock setup. The hot nature of the rotary doesn't help either.

Personally, I feel the ideal setup would be TWO top to bottom flow(short runners) IC's arranged to the left/right of an upright radiator. If designed correctly, the IC piping would be just a bit longer than an aftermarket SMIC and shorter than a front mount (although the GReddy design seems to have very short IC pipes for a FMIC). Picture it like this: /------\ Each vertical line represents an IC (not quite the right angle, LOL, and the center portion represents the radiator. EACH would feed off of a properly designed duct. A vented hood would be used to expel air out the back side of the radiator and relieve high pressure in the engine compartment (less frontal lift). The IC's would be ducted to the sides and exit behind the front wheels, similar to the oil cooler vents now. This setup would be even more viable with a 2 rotor moved 6-8" to the rear. Another scenario, albeit expensive, would be to use a curved radiator to shorten it's overall length, thus allowing for more IC room.

RETed

The original poster didn't specifically state this, and the mention of "GReddy" didn't pop up till several posts later.&nbsp I assumed we're talking The M2 versus ANY front-mount IC, which would negate all of your assumption on the front-mount.&nbsp I don't specifically recommend the GReddy front-mount myself - I build all front-mounts for FD's from raw cores and run custom built radiators that are moved upright.


See above...


I thought this was the reason for this debate?



Funny, Mazda *DID* redesign the ducting behind the front nose on the Series VII and redesigned both the front nose and ducting AGAIN for the Series VIII.&nbsp The Series VII ran from '96 - '98; the Series VIII ran from '99 to '02 - neither we imported into the U.S.&nbsp Mazda knew something was wrong.


I'd bet I could design a front-mount IC and custom radiator that will beat the "numbers" on the M2 unit.

Some "facts"...
Airflow efficiency is greatest when IC core face is perpendicular to airflow vector, UNLESS you can create a vacuum behind a slightly slanted IC core.
The area behind the stock IC design is a slightly high pressure area, mainly due to the aerodynamics of the airflow going over the hood and "hitting" the base of the windshield.
The differences of the SMIC versus FMIC in terms of dynamics of airflow behind it are very minimal - if anything the advantage would go to the FMIC due to the airflow being able to redirect itelf back downward for an easier exit.
This is assuming stock hoods.
This is assuming no electrical fan assist.
It's obvious that engines idling with the vehicle stationary would quickly heat the SMIC over the FMIC.

Therefore, it all comes down to piping design/efficiency and IC core design/efficiency.&nbsp I am not restricted to the GReddy FMIC kit - the original posted did not explicitly state that.

You are correct about the small frontal opening of the stock nose - too much components (i.e. rad, oil coolers, brake ducts, etc.) fighting for very, very limited airflow.


-Ted

fdracer

ted, i'd be interested to know how you would go about designing a fmic and radiator to overcome these shortcomings?

RETed

All use "GT-R" sized cores - 24" wide (like 10" high).&nbsp This means some of the bumper support has to be modified; hell, if you crash the car, you're going to cry anyways. We run all double-pass radiators with 2.5" thick twin-cores for radiators, roughly 26" x 13".&nbsp Upgrade twin oil coolers are also a must.&nbsp Ducting and foam insulation is extensively used to carefully channel the airflow.

This barely keeps a monster 500hp FD temps in check.


-Ted

80-CU.IN.T

I would be very impressed if you could keep the temps incheck with a stock sized front bumper. (Not enough surface area for cooling with a fmic blocking air flow to the radiator.)

1FooknTiteFD

Why don't you all ask what Forcefed7 AKA Ray from PFS what type of intercooler he is running and how much power he is putting out in his 9 second race car?

jspecracer7

What, the M2 medium with Ice Tray?

wptrx7

rx7tt95: what was said about the panspeed design and wouldn't that work just the way you described in your design and if so everyone should be purchasing a v-mount design sense it seems to having better cooling for the rad and ic. just my .02 cents.

luigi

VTECthis

iTrader: (4)

First, with the small opening in the stock front nose, there is no way a stock mount is going to recieve as much air flow as a front mount, most of the "ducts" ive seen are about 1.5 inches by 8 inches, compared to 7 inches by about 20 inches for the nose opening.
Although, this matters not. The fact is, the stock mount intercooler sits directly above a 200 degree radiator. As air passes through the radiator, it is poured on to the intercooler, heating it up.
If you were constantly moving, a stock mount could be effecient, but we all know traffic lights and stop signs exist in this world, letting hot air rise off of the radiator and soak that under ducted stock mounted intercooler you have with heat.
If you want HP, go with a front mount, and an upgraded radiator. Nothing beats this.
If you want to believe companies who make stock mounted intercoolers, who say you'll overheat with a front mount, get a stock mount.
Most people cannot think for themselves on this forum, and dont realize that a company producing a product is trying to sell it. In order to make money, they claim lots of things, some true, some untrue. Bottom line is money, noone works on rotaries or any car for free, garunteed.
As for pressure drop, if you take a look at the apexi intercooler, its basically a stock mount moved up 4 inches so it sits in front of the crossmemeber, and then you remount the radiator, its fins are also made so air has less restriction passing through to the radiator. In a speed density system, and as quickly as the stock turbos spool up, you cant possibly get lag from longer intercooler pipes, just doesnt exist.
As for me, i use the apexi front mount, I have an upgraded radiator, but used the stock one for 40k miles with the front mount, with NO overheating problems EVER. If everything else in your cooling system works properly, you can use a FMIC with no problems at all.
Rob
93 RX
T-72BB powered.

Silver93T

The only problems with the front mount that I noticed is at sustained speed, say 85-90 mph+ temps will creep up. I believe this is due to the intercooler taking alot of heat out of the intake charge and dumping the hot air onto the radiator. Here is my proposed solution. The lip spoiler is lowered and the undertray is sealed to the radiator at the rear. It offers a direct shot of air to the radiator. I have yet to test it thouroughly but I'll get a chance at MADS this weekend

80-CU.IN.T

I personally like stock mts. and with the nozzles now available for water injection, I personally think it is the way to go for cooling.( Water injection into the intake stream not on the intercooler) I also think a larger front bumper opening for the radiator is necessary even with this setup.
I had one friend that used the APEX'i fmic with a stock radiator and he had major cooling problems on hot days in S. California. Another Friend that used a Apex'i GTR custom fmic with massive cooling problems. Both of these cars were street cars and used stock bumpers. They would not have survived on a track with their cooling problems.
I am running a Apex'i GTR cored fmic also (Home made). I cut up the front of my car and re-welded it to make it fit. I relocated my air-conditioning condenser to fit vertically behind it with new lines and have a 27" X 16" Griffin radiator with 2 rows of (1-1 1/4" tubes) vertical behind that fully ducked with aluminum. I really don't like the air-condition condenser in there but I need air-conditioning. Have you ever been suited up with helmet in the sun in your car staging when its around 110F. at Willow Springs. It is not comfortable. You are tired even before you start your event and your suit is soaking wet. That is why I have air. A human hair can not fit between my ducking so I will have maximum air flow through the assembly. I only have 1 - 15" flex light pull fan through on the radiator. ( I got it for free). That has to be my favorite term next to cheap of course. I don't think the fan will be sufficient for stop and go traffic on a hot day or at Willow in staging with my air on. If it isn't I will change it. I also am using 2 large oil coolers with carbon fiber ducts and an Apex'i front bumper that has been modified. Even with all this I don't think I will be able to run a 20 to 30 min. track session with NASA and not overheat. But WTF everyone is entitled to their opinion. Hell I even got you read mine.

wptrx7

is a vmount similar to a stock mount or does it offer better cooling to both ic and rad?

luigi

fdracer

you got pics of your fmic kit? how much is one?

1FooknTiteFD

nope, ray runs the peter farel race smic. If that thing is good enough on peter's road race car and also allows him and ray to run 9's in the quarter mile, it's good enough for me for both drag and road race..

There are several different types of V-mount intercoolers. Knightsports had the first original Idea where the intercooler and radiator were V-shaped. The radiator is relocated to the bottom, and the intercooler is angled on it, and there are two block off plates on the side. Later, panspeed developed their own V-mount kit. Again, the radiator is relocated on the bottom, but this time the intercooler sits horizontally parallel to the hood instead of at an angle like the knightsports style.

I don't know which one works best, but the knightsports one from www.rxecret7.com costs $2800!!

evot23

iTrader: (17)

funny how the debate I'm reading is the same one in my head, pros and cons for each side with no clear winner in my opinion. Looks more to depend on what you plan to do with the car and even then no clear winner.

Nocab72: that was an awesome write up for the install, makes it look sooooo easy though I know it isnt.

I'm leaning toward FMIC since I'll probably drag more than road race and to be quite honest, I just like the look.

I'm very happy with my current pettit large but am starting to be swayed over to the dark side. Looking forward to seeing the HMIC.

jspecracer7

Lol...I TOUCHED rays intercooler about 2 weeks ago...but I didn't ask him what it was...just know that he has it cooled with ice water with a container in front of the SMIC.

wptrx7

so i still don't understand why the v-mount won't be the ideal ic rad set up. both get free flowing air. no one can argue against that? no cons? besides price?

luigi

rotaryextreme

iTrader: (2)

It's the ideal IC because both the radiator and intercooler get cool air from the mouth without one blocking the other. No one says anything because no one has experience with it. I will post photos of my monster V Mount set up in 2 weeks and I will tell you about my experience.

Chuck Huang

evot23

iTrader: (17)

Looking forward to the results! I'll need a new intercooler when the hood comes in.

wptrx7

alright, gonna get an answer.

luigi

wptrx7

so here i am doing my homework and trying to decide which intercooler to go with my future set up. i am going single (god willing this winter, x-mas better be good), i am looking to get a gt35/40. i know i am not going to auto x the car and as far as the drag strip i'll see it 3-4 times a year if that. i am looking to see which intercooler smic, hmic or fmic will be the best setup for the street (3-4 tiimes a week driven and sees traffic maybe for a total of an 1 hour in that week). and max psi is 15lbs (around 450 rwhp is enough for me).

i am leaning towards a m2 large or r.e. hmic, which one will work best? what will work?

by the way (if it matters), koyo radiator installed.

luigi