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Old 09-12-2012, 01:46 AM   #1
jraft00
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Default Front Mount vs. Top Mount Intercoolers

What are the differences between the top and front mount intercooler? Is there any kind of performance difference, or is it mainly to clear some space off the top of the engine? And what is the best time to change to the front mount if thats what I want to do?
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Old 09-12-2012, 02:07 AM   #2
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More power you want bigger intercooler you will need! Tmic will limit in size cuz of space, so Fmic will be better route in end for bigger power! Plus Fmic does clear up space and makes things little easier work on also.
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Old 09-12-2012, 02:20 AM   #3
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Old 09-12-2012, 07:22 AM   #4
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Did you even try to search for this?
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Old 09-12-2012, 08:09 AM   #5
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i think it pretty much comes down to personal preference bc in the typical street car they will both most likely perform the same. I will eventually get a TMIC bc i will never trim my bumper cover or remove the bumper core.
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Old 09-12-2012, 08:22 AM   #6
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Been talked about lots of times. Anybody who says TMIC are small obviously are not looking. Quite a few large ones some as large as 1000cfm. That is more than larger enough for a gt30 turbo or similar. But if you want to go larger turbo than yea FMIC.

FMIC does make it a little easier to work on the car since you don't need to remove TMIC to work on items.

FMIC require you to remove, cut or "replace" your crash beam. So what would have been a little accident is now a big accident if you hit something

FMIC you may or may not be able to keep fog lights and intake. Depending on model.

FMIC intercooler would allow you to use like an oil cooler in TMIC place if you wanted.

Personally I will keep or upgrade my TMIC. Compromising safety isn't worth it to me.
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Old 09-12-2012, 09:12 AM   #7
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FMIC will almost always perform better than a TMIC, mostly due to the vast increase in air flow over the core. The downsides are the extra piping required and the fact that you have to cut/remove your front bumper beam.
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Old 09-12-2012, 09:14 AM   #8
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Quote:
Originally Posted by talvai View Post
Quite a few large ones some as large as 1000cfm. That is more than larger enough for a gt30 turbo or similar.
CFM numbers for an intercooler core are worse than meaningless. CFM is not what matters, a straight section of 3" pipe has a higher CFM rating than any intercooler, but it won't cool the charge at all. What matters in an intercooler is efficiency, not flow rating, and the TMIC will almost always be worlds behind a good FMIC in this department.
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Old 09-12-2012, 09:28 AM   #9
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Originally Posted by the suicidal eggroll View Post
CFM numbers for an intercooler core are worse than meaningless. CFM is not what matters, a straight section of 3" pipe has a higher CFM rating than any intercooler, but it won't cool the charge at all. What matters in an intercooler is efficiency, not flow rating, and the TMIC will almost always be worlds behind a good FMIC in this department.

This man is correct, but I have to say with the downpipe and header wrapped a high quality TMIC can preform just as well as any FMIC. What it really depends on is the application. For any car that is simply street driven I always suggest a TMIC > and FMIC because the benefits of the front mount simply do not out weigh the risks. If you plan on building a strictly drag strip car where you will be sitting in line and have large possibility of experiencing heat soak a front mount could be really beneficial. If you are building a HPDE car, a good top mount with the correct ducting from the hood scoop and properly wrapped pipes might be a better choice.
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Old 09-12-2012, 09:53 AM   #10
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Personally, I'll stick with the TMIC due to some increased lag when going to a FMIC. I personally think TMICs are just fine for street cars.
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Old 09-12-2012, 10:20 AM   #11
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Is there evidence that the Fmic causes real lag? 500 rpms or more when comparing a quality Tmic (Process West) to lets say a (Turbo Sx/Perrin) Fmic?
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Old 09-12-2012, 10:30 AM   #12
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I have to say with the downpipe and header wrapped a high quality TMIC can preform just as well as any FMIC.
While I would say that a quality TMIC can perform adequately, I would not say it can perform as well as a FMIC. Even completely ignoring the heat soak issue, no matter how well designed the TMIC is, it's still limited by the relatively small amount of cooling air that can pass through the hood scoop. The FMIC has the entire front air dam to play with, and the TMIC just can't overcome that. With a TMIC you often see efficiencies around 70% at WOT (again ignoring heat soak). A good FMIC is usually over 90%, often over 95%, simply because it has significantly more cooling air at its disposal.

Like you said though, it's all about application. For anything under a ~50 lb/min turbo on the street I think a TMIC is perfectly fine. For anything bigger than that I think a TMIC simply doesn't have enough cooling air from the hood scoop to keep up with that much flow. With my Turbo XS FMIC and a 30r going full tilt, it's rare to see the post-IC air more than 5 deg above ambient. You simply will not get that kind of performance out of any TMIC.
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Old 09-12-2012, 11:02 AM   #13
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Quote:
Originally Posted by the suicidal eggroll View Post
While I would say that a quality TMIC can perform adequately, I would not say it can perform as well as a FMIC. Even completely ignoring the heat soak issue, no matter how well designed the TMIC is, it's still limited by the relatively small amount of cooling air that can pass through the hood scoop. The FMIC has the entire front air dam to play with, and the TMIC just can't overcome that. With a TMIC you often see efficiencies around 70% at WOT (again ignoring heat soak). A good FMIC is usually over 90%, often over 95%, simply because it has significantly more cooling air at its disposal.

Like you said though, it's all about application. For anything under a ~50 lb/min turbo on the street I think a TMIC is perfectly fine. For anything bigger than that I think a TMIC simply doesn't have enough cooling air from the hood scoop to keep up with that much flow. With my Turbo XS FMIC and a 30r going full tilt, it's rare to see the post-IC air more than 5 deg above ambient. You simply will not get that kind of performance out of any TMIC.

I'll agree with you on that. My only concern is when you see NASIOC members running a FMIC on a vf turbo . I believe a majority of people run a front mount mainly for looks .

I still wish some company or shop would give some comparable results of a variety of different top mounts and front mounts with an IAT placed post intercooler to have some actual data on how well these intercoolers are actually cooling said air.

As far as the lag issue goes. In all the cars I've ridden in the extra piping will create some extra lag, but it's almost unnoticable in most applications. The worst case I saw was a 20Ged EJ25 hitting peak boost (23psi) only 300rpm later with the addition of a front mount. It was basically no issue though because a fair amount more timing was able to be added due to more efficient cooling capabilities.

In the end if you go top or front the best thing to do is use a quality core, or atleast something that your tuner has had good results with. Yo could slap on the biggest core in the best possible location, but if it has no actual ability to cool the charged air then it's useless.
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Old 09-12-2012, 11:07 AM   #14
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Quote:
Originally Posted by Source,LLC View Post
I'll agree with you on that. My only concern is when you see NASIOC members running a FMIC on a vf turbo . I believe a majority of people run a front mount mainly for looks .

I still wish some company or shop would give some comparable results of a variety of different top mounts and front mounts with an IAT placed post intercooler to have some actual data on how well these intercoolers are actually cooling said air.
Agreed. It blows me away how many companies publish the CFM "rating" of the intercooler, with no mention of how well it actually cools that air.
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Old 09-12-2012, 11:59 AM   #15
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Originally Posted by the suicidal eggroll View Post
Agreed. It blows me away how many companies publish the CFM "rating" of the intercooler, with no mention of how well it actually cools that air.

I can understand that the method of doing a true test that would be accurately repeated would be costly (wind tunnel and all), but there could be some simple road tests preformed on the same car with a variety of different intercoolers. The cost of a new IAT sensor is somewhere around $80 or so, and the cost of welding it post intercooler would be no more then $30-40. We just need to contact all the producers of intercoolers for subaru's and see if they are willing to donate some cores
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Old 09-12-2012, 12:02 PM   #16
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there has been so many debates about this...i say its all preference and looks. i prefer a top mount however im not going to run one until i upgrade my turbo.
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Old 09-12-2012, 12:07 PM   #17
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Quote:
Originally Posted by d0ugch0i
there has been so many debates about this...i say its all preference and looks. i prefer a top mount however im not going to run one until i upgrade my turbo.
Looks and preference?
Just READ some of the posts
I also want a fmic just to make clearece(swapped gc, no bellows from the scoop either)
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Old 09-12-2012, 12:08 PM   #18
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Quote:
Originally Posted by Dmochowski View Post
i think it pretty much comes down to personal preference bc in the typical street car they will both most likely perform the same. I will eventually get a TMIC bc i will never trim my bumper cover or remove the bumper core.
Its realy not hard to cut it if you have ever taken your front bumper off. Not as big of a deal as you make it out to be. Just a challenge..


Quote:
Originally Posted by the suicidal eggroll View Post
FMIC will almost always perform better than a TMIC, mostly due to the vast increase in air flow over the core. The downsides are the extra piping required and the fact that you have to cut/remove your front bumper beam.
True..FMIC will outperform TMIC when trying get extra HP.

In re: to the FMIC not having crashbeams depends on brands. TurboXS offers a crashbeam for 2012 wrx...

-BMH
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Old 09-12-2012, 12:13 PM   #19
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Originally Posted by EvoXtoWRX View Post
Its realy not hard to cut it if you have ever taken your front bumper off. Not as big of a deal as you make it out to be. Just a challenge..


In re: to the FMIC not having crashbeams depends on brands. TurboXS offers a crashbeam for 2012 wrx...

-BMH

Getting the front bumper on the newer models of is a breeze, its about 10 push clips and it pops right off.

Your statement concerning the crashbeam is incorrect. The beam TurboXS (and basically every other brand offers) is not a crashbeam, but just a support beam. The beams supplied are not crash test rated, and really will provide no sort of protection in an actual crash. Your front bumper beam is designed in according with the rest of the unibody and support system in order to decipate force of an impact in a calculated way. Removing a key component, like the crashbeam, makes the system all but worthless.
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Old 09-12-2012, 12:17 PM   #20
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Originally Posted by Source,LLC View Post
Getting the front bumper on the newer models of is a breeze, its about 10 push clips and it pops right off.

Your statement concerning the crashbeam is incorrect. The beam TurboXS (and basically every other brand offers) is not a crashbeam, but just a support beam. The beams supplied are not crash test rated, and really will provide no sort of protection in an actual crash. Your front bumper beam is designed in according with the rest of the unibody and support system in order to decipate force of an impact in a calculated way. Removing a key component, like the crashbeam, makes the system all but worthless.

I see what your saying but its also better than driving around with nothing at all true?? crashbeam...true front bump beam....I'd still feel safer knowing it was there. I didn't mean to take this off topic.

-BMH
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Old 09-12-2012, 12:27 PM   #21
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Not saying cfm is everything but does have some effect. Just saying their is a lot of nice tmic out there that do a great job still with bigger turbos.

Yes Turboxs and others offer crash beam replacements but have yet to see 1 crash test with it. So how do you know if that beam is worse or better than the OEM one. Granted you can use JDM beam with fmic too just again not the same as usdm one when it comes to safety standards.

For me if you racing the car all the time, go fmic. If you got some huge huge turbo then go fmic. But I see all the time people with vf turbos or like a 16-18g turbo running a fmic when its just not needed.

Just my take on it
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Old 09-12-2012, 12:28 PM   #22
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Originally Posted by EvoXtoWRX View Post
I see what your saying but its also better than driving around with nothing at all true?? crashbeam...true front bump beam....I'd still feel safer knowing it was there. I didn't mean to take this off topic.

-BMH

I guess it's better then nothing, but not by much. In reality if you a driving with a FMIC and you get into even a small front end collision your intercooler will be damaged, and as the speed of said collision increases so will a lot more. In my personal opinion I don't see any reason to drive a street car around with an FMIC. Even though a top mount may not be as efficient, for a daiyl driver or a mainly street driven car the potential risks are not worth the benefits.
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Old 09-12-2012, 12:32 PM   #23
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Quote:
Originally Posted by talvai View Post
Yes Turboxs and others offer crash beam replacements but have yet to see 1 crash test with it. So how do you know if that beam is worse or better than the OEM one. Granted you can use JDM beam with fmic too just again not the same as usdm one when it comes to safety standards.
I can say with 100% certainity that it is worse. As i stated in my earlier post the stock beam is designed to work as part of a system that provides disipation in the event of a crash. Simply bolting on another beam no matter the size, weight, or demensions will not worth the same as the crash beam. Also if you do a search of the beams demensions you will see all of the replacement beams are much smaller, not as thick, and are lighter. There is almost no way this could possibly act as a better beam then the OEM one, unless it was made of some super strong light weight material. Even then, again it is not engineered to work with the system as a whole.
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Old 09-12-2012, 12:50 PM   #24
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My 04 wrx with a Perrin stage 2 map dynoed at 238whp and 217wtq with the stock intercooler on a mustang dyno.

I uprgraded to a front mount and went back to the dyno. The only other change was the addition of a COBB SF intake, because of course you cannot run the stock airbox with the intercooler piping. I did NOT retune or anything. Made 271whp and 246wtq on the same dyno.

This is still with the TDO4. I just couldn't justify the price of an aftermarket TMIC compared to a FMIC. Even if I went with a bigger TMIC, I would still have heat soak.
Not taking sides, just providing my results.

Last edited by Talon4ever; 09-12-2012 at 12:56 PM.
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Old 09-12-2012, 02:26 PM   #25
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Quote:
Originally Posted by Talon4ever View Post
My 04 wrx with a Perrin stage 2 map dynoed at 238whp and 217wtq with the stock intercooler on a mustang dyno.

I uprgraded to a front mount and went back to the dyno. The only other change was the addition of a COBB SF intake, because of course you cannot run the stock airbox with the intercooler piping. I did NOT retune or anything. Made 271whp and 246wtq on the same dyno.

This is still with the TDO4. I just couldn't justify the price of an aftermarket TMIC compared to a FMIC. Even if I went with a bigger TMIC, I would still have heat soak.
Not taking sides, just providing my results.
Lag increase?
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