70 replies to this topic

[Start]

Hey guys,

Im currently looking to upgrade my intercooler,

Have been looking at two options

1) V6 STI Intercooler $approx $150-200

2) APS Front Mount $approx $350-450 second hand (silicone pipes) for easier install.


Now im skeptical about going FMIC as people have mentioned, hacking front bars & cutting panels etc to fit them.

Can anyone with a FMIC confirm? also how would a FMIC benefit me? Is it really worth the extra $?

Im running standard 15PSI boost, on a VF29.

Thanks in advance.

[Shaz]

Top mount: Protected from damage, shorter intake tract for less lag, limited overall size restriction due to placement, more air to the radiator for better engine cooling.

Front mount: Better max airflow to intercooler, bigger overall size as well, engine will run hotter due to less flow and hotter air flow to radiator, can be damaged from road debris.

Basically, if you aren't pushing 400+hp you don't have a need for a front mount intercooler. An upgraded top mounted system with an auto water misting system and an STi hoodscoop will be more than enough for 350hp.

Each has its advatages and disadvantages. An intercooler is in essence a large heat sink. In the front of the car you can put a larger intercooler with very high surface area to volume ratio. This allows for the greatest amount of heat disipation. Also, with the large frontal area, cooling is helped by air passing through the intercooler.

However, to place the front mount on the car you need to add a large amount of piping from the turbo and back to the intake. This ads lag (less throttle response from the increased area the air needs to travel). Also, you can run into smoothness problems as the MAS calculates air flow some 10 ft from the actual engine intake. Also, with larger intercoolers there is an actual pressure drop that occurs which can also cause more lag and confuse the ECU (this can be worked around with software if neccesary).

Top mount intercoolers are good for a number of reasons. They need very little piping and are relatively cheap to make (less piping).

The front mount is really MUCH better if you are running high horsepower. But they are very hard to make and cost a good deal of money.


Cheers,
Shazza

[Start]

Thanks Shazza,

I just need enough KW to beat Scott.


The TMIC is looking a better option, as I can keep the stock airbox - and not have to cut and hack at anything.

[Delete This Account]

Dry ice intercooler.

/thread

[aekOne]

Haha look there’s only one right answer as far as which type cools best. A FMIC is better than a TMIC. BUT I guess the debate for you is is it worth the extra money. A TMIC will do the job to a certain point for sure but a FMIC will do it better.

What temp is the ambient air outside your car at the front of your bumper? What temp is the air directly above your engine while enclosed in engine bay with the bonnet shut?

Does the liberty splitter meet up with the v5 sti tmic correctly for maximum efficiency?

I hear lag get mentioned a lot as well but to be honest, I’ve got a front mount on my liberty and the difference really isn’t noticeable. You have to think that one on the main reasons for more lag is having a larger turbo as well, not the FMIC alone. Speak to all the other guys who have got an FMIC (not guys who have TMIC and have read on google or the forums about pro’s and con’s but ones who have ACTUALLY tried both) and I think they will all tell you that lag really isn’t an issue.

Generally the only people I ever hear say a TMIC is the best option is people who have a TMIC and have never tried the FMIC option. You hear people say look at group N rally cars, they have a TMIC and they get XXXkw etc but in the real world we sit in traffic, stop at intersections, stop at traffic lights etc etc. Heat soak might not be a problem when your flying through a forest in Denmark but in the real world it is an issue for our cars.

As for fitting one sure you will need to get rid of your airbox but apart from shaving about 3mm along the length of my bumper reo, there was no other cutting or modification required to fit it. Also you’ll need to add a CAI which is again proven to be a better air intake on a turbo car than having the stock airbox. You can only really win.

If money wasn’t an factor what would you do? Surely you’d go front mount. Why? Because its a better system.

For an extra $250 I’d be going for the FMIC FOR SURE. If you don’t can you please send me the details as I’ll buy it from my Legacy. I’ve been meaning to upgrade for a while and I was going to look into it next month so seriously if you don’t go that route I’m 100% interested.

A FMIC will improve your car weather it's a stocker making 150kw or a beast pushing big numbers.

[Shaz]

If you go flouirsh through the general laws of airflow and dissipation, the mathematics will tell you that on a TMIC, air will enter the combustion faster (As it doesn't have to travel as far), then it will a FMIC, which generally gives the effect of less lag. Whilst the charge may not be cooler, for a turbo pushing small amounts of air, a TMIC would appear to be a better option in terms of lag.

Once you start pushing enough CFM to fill 3" intercooler piping and a 600x300 cooler, then obviously, the FMIC would FAR outweigh a TMIC, simply because it can accomodate a much larger charge of cfm.


Aek, you and I will have to have a run. I have a stock TMIC, and you have a FMIC, and so we'll see which is faster off the line.

And considering Gen3 > Gen2, you may have to wind the boost up a bit my friend.



Cheers,
Shazza

[Grant]

Oh no...not another one of these threads!
First of all, you don't need to get rid of the airbox, I've got ABS, my stock airbox, and a FMIC. Admittedly it took a bit of moulding and it's a toight squeeze, I've also got 2" piping both sides, but I did it!

Pros of FMIC-
Bitchez
Flutterz

Cons of TMIC-
No bitchez
No flutterz

But really, I went from a Water-air top mount to my FMIC and I don't regret it one bit. I didn't notice any less lag, it flows alot better, power delivery is more linear, and it pulls all the way to redline. Yes you get less flow to the radiator, but that just means the thermo fans kick in more often, big whoop! There IS a fair bit of cutting involved, but that doesn't mean it has to be untidy, check my build thread and try tell me it's a dodgy job!

Cheers, Grant

[Shaz]

Pros of FMIC-
Bitchez
Flutterz

Cons of TMIC-
No bitchez
No flutterz

Lmfao.

This is ALL you need to know right here my friend.

Cheers,
Shazza

[aekOne]

If you go flouirsh through the general laws of airflow and dissipation, the mathematics will tell you that on a TMIC, air will enter the combustion faster (As it doesn't have to travel as far), then it will a FMIC, which generally gives the effect of less lag. Whilst the charge may not be cooler, for a turbo pushing small amounts of air, a TMIC would appear to be a better option in terms of lag.

Once you start pushing enough CFM to fill 3" intercooler piping and a 600x300 cooler, then obviously, the FMIC would FAR outweigh a TMIC, simply because it can accomodate a much larger charge of cfm.


Aek, you and I will have to have a run. I have a stock TMIC, and you have a FMIC, and so we'll see which is faster off the line.

And considering Gen3 > Gen2, you may have to wind the boost up a bit my friend.



Cheers,
Shazza

Shaz as I said it’s easy for people to point to the theory of science or google (not saying you did but i've heard it before from idiots i know have never put it into practice ) for an explanation on the laws of airflow and dissipation (I understand the theory and also used to believed that a FMIC must be laggy as well) but in the real world (and again I say speak to guys with front mounts) the difference is basically unnoticeable. Maybe you’ll get a very very small jump (i’m still sceptical that it’s much if any) from a stopped start, say 900 rpm idle but with both cars doing a 5k launch there’s gonna be nothing in it. Again it’s guys with tmic’s that’ll argue black and blue that the TMIC is as good or better. Try a FMIC on YOUR subaru and tell me that lag is an issue. Try a FMIC on YOUR subaru and tell me you regret it. You’d be lying if you did.

Ok let me use this as an example. You have a VF23, larger rear housing, more top end. I have a VF24, smaller rear housing, faster spool, less top end. I get full boost before you BUT in the end of the day they are very similar and off the mark there’s not going to be much in it BUT you haven’t swapped your turbo for a VF24 for sake of a faster spool up have you?

I’m not a traffic light warrior and I don’t live my life a quarter mile at a time. I want over all efficiency and I’m sorry but a FMIC is superior to a top mount.

Again it’s up to Jamie but I wouldn’t sacrifice the effects of a FMIC for the benefit of a couple of foot jump on an identical car in the off chance I come up next to one at the traffic lights and they want to race.

I have FMIC on my Liberty not my Legacy. It wouldn’t be a fair fight. My boost level will be the least of YOUR problems. It’ll only prove that a gen 3 liberty wagon with a V3 STI conversion and a tmic is slower than a gen 2 Liberty sedan with a fully built motor, aftermarket engine management, upgrade turbo, full custom tank to injectors fuel delivery system and FMIC. We know this without running each other

ps: “Gen3 > Gen2, you may have to wind the boost up a bit my friend” - Gen 2 is lighter

pps: Shaz we're going for a fish on the lake tonight if your keen. probably hit it up at around 6:30 ish

[Shaz]

Shaz as I said it’s easy for people to point to the theory of science or google (not saying you did but i've heard it before from idiots i know have never put it into practice ) for an explanation on the laws of airflow and dissipation (I understand the theory and also used to believed that a FMIC must be laggy as well) but in the real world (and again I say speak to guys with front mounts) the difference is basically unnoticeable. Maybe you’ll get a very very small jump (i’m still sceptical that it’s much if any) from a stopped start, say 900 rpm idle but with both cars doing a 5k launch there’s gonna be nothing in it. Again it’s guys with tmic’s that’ll argue black and blue that the TMIC is as good or better. Try a FMIC on YOUR subaru and tell me that lag is an issue. Try a FMIC on YOUR subaru and tell me you regret it. You’d be lying if you did.

Agreed. I've not driven a FMIC'd EJ20T, so i personally don't have any solid evidence to back my claim up.
If i start modding turbos and stuff, i'll prob eventually chuck a FMIC on, but for my application (>350hp) a TMIC is perfect for me.

Ok let me use this as an example. You have a VF23, larger rear housing, more top end. I have a VF24, smaller rear housing, faster spool, less top end. I get full boost before you BUT in the end of the day they are very similar and off the mark there’s not going to be much in it BUT you haven’t swapped your turbo for a VF24 for sake of a faster spool up have you?

I’m not a traffic light warrior and I don’t live my life a quarter mile at a time. I want over all efficiency and I’m sorry but a FMIC is superior to a top mount.

You so are a traffic light warrior. I've seen the way you drive, you got a heavy foot. You'll blow yourself to pieces!

Again it’s up to Jamie but I wouldn’t sacrifice the effects of a FMIC for the benefit of a couple of foot jump on an identical car in the off chance I come up next to one at the traffic lights and they want to race.

Jamie, if you're planning future power enhancing mods, a FMIC is a good supporting mod to get done now, so you don't have to do it later.

I have FMIC on my Liberty not my Legacy. It wouldn’t be a fair fight. My boost level will be the least of YOUR problems. It’ll only prove that a gen 3 liberty wagon with a V3 STI conversion and a tmic is slower than a gen 2 Liberty sedan with a fully built motor, aftermarket engine management, upgrade turbo, full custom tank to injectors fuel delivery system and FMIC. We know this without running each other

No chance of racing that my friend. I thought your wagon had an FMIC, but just remembered its a TMIC.
My cars just a work hack

ps: “Gen3 > Gen2, you may have to wind the boost up a bit my friend” - Gen 2 is lighter

Gen 3 is awesomer. True story.

pps: Shaz we're going for a fish on the lake tonight if your keen. probably hit it up at around 6:30 ish

Could be keen my friend. Will suss out the plans with the missus tonight.

[aekOne]

You so are a traffic light warrior. I've seen the way you drive, you got a heavy foot. You'll blow yourself to pieces!

Ok sorry let me clarify what I meant by that

I like a spirited drive as much, if not more than the next guy. I like trying impress girls with loud exhausts, bov qwoosh and flutter.

BUT for me, launches and speed of the line isn’t the be all and end all. Being quick off the mark doesn’t really cross my mind when I consider mods etc. Being quick in general does. A little (again debatable how much if any) lag doesn’t phase me

I live my life not a quarter mile at time but between 5000rpm and 7500rpm

Could be keen my friend. Will suss out the plans with the missus tonight.

I’ll give you a shout when I knock off see if keen

Hopefully I won’t need to buy dinner tonight haha

[Scott]

Thanks Shazza,

I just need enough KW to beat Scott.


The TMIC is looking a better option, as I can keep the stock airbox - and not have to cut and hack at anything.

biggest lol^^^

youll need to be running engine blowing boost to beat me

fmic>tmic

[Jimbo]

I have to disagree with Tints in his first post about FMIC Cons.

I have yet to see any evidence that a car will run hotter due to the FMIC infront of the radiator, the FMIC isnt solid so it isnt impeding airflow to the radiator completely. I've had both and had a negligable difference in operating temps which were monitered continuously.

Also, the theory that a FMIC adds "lag" is bullocks, the speed at which compressed air travels through a closed space is so great that you would'nt notice any change. What you're thinking of is pressure drop which again in the average joe's modified Subaru, you wouldnt notice. There is ALWAYS air in the pipework, your turbo is an AIR PUMP and will continuously flow air through the piping regardless. For example if you blew through a straw even if it was 10m long, the air would escape the other end instantly, not to mention you would be amazing if you could even blow 1psi through it with your lungs. Your turbo is pushing 15+ psi.

Also the need for a 600x300x76 whatever Kenworth core is overkill for our applications, everyone just uses it cos thats what everyone uses. You would be way better of using 2" hotside and 2" in/out core, then using a 2" to 2.5" joiner then 2.5" your cold side. Also you dont need a huge blinger core, something like 500x250x65 would fit perfectly and minimise pressure drop if anyone's scared of "lag".

FMIC wins every time. The only drawback about FMIC is it can be costly depending on which way you go and having to modify the car slightly, but man the hell up and get your grinder out! I did a FMIC install from scratch on my Gen1 in a night. As long as your pipes are tailored right and you have everything, its simple.

TMIC's are merely a cost saving thing implemented by Subaru, and due to the design of the boxer engine it all fits perfectly and would be too expensive to fit FMIC like EVERYONE ELSE. How many sports cars other than Subaru have TMIC's? Not many. Theyre all front mounted or side mounted in a wheel arch. I can only think of Mazda MPS's having a TMIC.

Anyway, man up and get a FMIC, it can be done so cheaply these days. JustJap core for peanuts and a zorst shop to knock some piping together. Easy.

[Alex]

Aww fcuk.


Here we go again.



FMIC > TMIC


amen.

[Scuba-Roo]

Oh no...not another one of these threads!
First of all, you don't need to get rid of the airbox, I've got ABS, my stock airbox, and a FMIC. Admittedly it took a bit of moulding and it's a toight squeeze, I've also got 2" piping both sides, but I did it!

Pros of FMIC-
Bitchez
Flutterz

Cons of TMIC-
No bitchez
No flutterz

But really, I went from a Water-air top mount to my FMIC and I don't regret it one bit. I didn't notice any less lag, it flows alot better, power delivery is more linear, and it pulls all the way to redline. Yes you get less flow to the radiator, but that just means the thermo fans kick in more often, big whoop! There IS a fair bit of cutting involved, but that doesn't mean it has to be untidy, check my build thread and try tell me it's a dodgy job!

Cheers, Grant

QFT



Look at the size front mounts XR6 turbos have, or even EVO's. their certainly not big or illegal.



If you did a NA>turbo conversion yourself pluming up and mounting a cooler should be simple as.

[skillionaire]

Alex,

How can you say that? My mate used to walk the dog of a guy who once fed the goldfish of this bird whose uncle went to the same highschool as this dude that used to do drag shows with AMS at a club owned by a midget running 400kw@tw RELIABLY with a stock TMIC.

IRON CLAD BRAHHH.

Cheers,
Nik

[aekOne]

Also, the theory that a FMIC adds "lag" is bullocks, the speed at which compressed air travels through a closed space is so great that you would'nt notice any change. What you're thinking of is pressure drop which again in the average joe's modified Subaru, you wouldnt notice. There is ALWAYS air in the pipework, your turbo is an AIR PUMP and will continuously flow air through the piping regardless. For example if you blew through a straw even if it was 10m long, the air would escape the other end instantly, not to mention you would be amazing if you could even blow 1psi through it with your lungs. Your turbo is pushing 15+ psi.

Anyway, man up and get a FMIC, it can be done so cheaply these days. JustJap core for peanuts and a zorst shop to knock some piping together. Easy.

THIS.

[Shaz]

Yeah, but, the amount of time it takes for a FMIC system to pressurized to it's designed efficiency is longer then a simple TMIC system, hence lag.

If you had 1m of bent steel piping, which ran through an intercooler, the size of a STi TMIC and punched a CONSTANT 15psi of air pressure through it, it wouldn't take as long (in theory) to feel a constant 15psi of pressure at the other end, then if you done the same through 2.5m of steel pipe and a larger intercooler.

Sure, there always will be air inside, but as above, it does take longer to fill a bigger area with pressurized air, if both of the above examples were not only pushing the same pressure, but the same volume of air.

(The above example I'm comparing is a standard TMIC EJ20T, to a EJ20T, with a 600x300 and 3" cooler piping. Obviously the smaller the diameter of the piping, the faster it is to fill)

The faster you can FILL the piping with a constant pressure (ie; a bigger turbo) , the less noticeable the delay will be.

Whether or not the above is noticeable on a mildly tuned EJ20T, I don't know, as ive not had any first hand experience.

Bear in mind, all I'm stating is that the TMIC will have better responsiveness then an FMIC, and I'm not debating the other long list of benefits a proper fitted FMIC system will have (Getting cooler air into the engine is better for power, and reliability, then a couple of hundred rpm of responsiveness)

In any case, great discussion guys. Would be good to actually see some tests and results put forward to compare.

Cheers,
Shazza

[Richo]

Aww fcuk.


Here we go again.



FMIC > TMIC


amen.

quote for the truufs

[Richo]

responsiveness

I giggle at this

I have a boring 600*300*76 plate and fin cooler.. so like the worst you can get for "lag" and "responce". get me 3.5k, 2nd or 3rd gear and if im not smooth on/off the throttle, the SoB is jerking (from acceleration/deceleration) around like a $2 hooker.