2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

FMIC vs. VMIC

Thread Tools
 
Search this Thread
 
Old 01-23-06, 10:49 PM
  #1  
We are the D

Thread Starter
 
InMyWhiteTII's Avatar
 
Join Date: Nov 2005
Location: Indianapolis
Posts: 492
Likes: 0
Received 0 Likes on 0 Posts
FMIC vs. VMIC

Which is the better intercooler arrangement, V-mount of Front mount? Why? It seems that in the FC engine bay, space would definately not the issue, and V-mount seems very efficient. Any ideas?
Old 01-23-06, 10:57 PM
  #2  
We come with the Hardcore

iTrader: (2)
 
Liquid Anarchy's Avatar
 
Join Date: Nov 2001
Location: Springfield, MO
Posts: 2,456
Likes: 0
Received 0 Likes on 0 Posts
v-mount just requires less pipe than a front-mount... and a vented hood... and new radiator hoses... and some sheet metal shrouding.
Old 01-23-06, 11:17 PM
  #3  
Passing life by

 
iceblue's Avatar
 
Join Date: Feb 2005
Location: Scotland, USA
Posts: 4,028
Likes: 0
Received 2 Likes on 2 Posts
I thought about it. I want a clean look so I am doind FMIC again so evrything isnt shoved under the engin bay and I want a smooth hood. Plus all the fabing for hte rad brackets and IC and stuff.
Old 01-23-06, 11:25 PM
  #4  
yessir

iTrader: (24)
 
First gen man's Avatar
 
Join Date: May 2005
Location: Sebring FL
Posts: 722
Likes: 0
Received 0 Likes on 0 Posts
i want a v mount but alot farther frontwards. kinda like a vmount but in the front lol...
Old 01-23-06, 11:28 PM
  #5  
Rotary Freak

 
Turbo II-FB's Avatar
 
Join Date: Nov 2004
Location: Austin-Houston Texas
Posts: 1,879
Likes: 0
Received 0 Likes on 0 Posts
v-mount is worthless unless for track use
can you sy heat soak
they are pointless unless going 40 plus
Old 01-24-06, 12:08 AM
  #6  
Boss

iTrader: (9)
 
superstock2's Avatar
 
Join Date: May 2003
Location: montana
Posts: 836
Likes: 0
Received 5 Likes on 2 Posts
^^ and a topmount's not?
Old 01-24-06, 12:08 AM
  #7  
Law Breaker

 
Carzy Driver's Avatar
 
Join Date: Oct 2005
Location: S.F. Bay Area, California 510
Posts: 3,333
Likes: 0
Received 0 Likes on 0 Posts
v mounts look nice but are a big pita. fmic look good, slightly more functional, and are easy installations
Old 01-24-06, 05:34 AM
  #8  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
I still haven't seen numbers to prove VMIC set-up's are just as efficient as an FMIC.

The one big problem with VMIC's is the vented hood that doesn't guarantee better airflow efficiency.


-Ted
Old 01-24-06, 09:55 AM
  #9  
knowledge junkie

 
vaughnc's Avatar
 
Join Date: Mar 2001
Location: Atlanta, GA
Posts: 5,595
Likes: 0
Received 6 Likes on 4 Posts
Adv: Less turbo lag, weight is further back, doesn't block radiator, slighly lighter with less piping, no cutting the subframe

Dis: Some fabrication for ducting & mounting, proper placement for optimal airflow in/out requires trial & error.
Old 01-24-06, 10:02 AM
  #10  
S5 TII

iTrader: (1)
 
RyoFC3S's Avatar
 
Join Date: Oct 2003
Location: Denver, CO
Posts: 826
Likes: 0
Received 0 Likes on 0 Posts
I have a completely custom VMIC setup installed in my FC. I chose to do this because I'm building a road racing/occasional drift/daily driver, and a FMIC is not even close to ideal for this. I can't give you any numbers, but all I can say is it works wonderfully, even without a hood vent. Contrary to common belief, it does not heat soak (or at least not enough to be able to feel it with your hands). On cool nights, the temperature difference between the intake and exhaust side of the intercooler is roughly from too hot to touch with your bare hand to COLD or luke warm! No joke! If its hot outside during the summer it doesent work as well; (although i doubt a FMIC would be cold either) there is not a very noticeable difference between the intake and exhaust side.

Keep in mind as well that mine is still a work in progress and is NOT sealed, has some small holes on the sides, has no hood vent, and has absolutely no shrouding other than what comes with the car from the factory. I have had ZERO problems with overheating of either the oil or coolant as well (i doubt any of you FMIC owners can say that).

Don't be so quick to discard the efficiency of the VMIC. I think that it really depends on what you intend to use the car for. If you plan on only using it for drag racing, go with a FMIC. Its been proven time and time again. If you plan on using it for drifting, road racing, autocross or daily street driving, try to get a VMIC. Thats my opinion.

Pics: Pic 1, Pic 2, Pic 3, Pic 4 (Turbo), Pic 5

-Andrew
Old 01-24-06, 10:22 AM
  #11  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally Posted by vaughnc
Adv: Less turbo lag,
Your turbo might be too small.

weight is further back,
I doubt you could take advantage of this fact.
I could counter and say that the weight is now *higher* versus an FMIC.

doesn't block radiator,
Now, this is something if a misnomer.
Airflow is airflow.
For the IC to cool adequately, you need a minimum of airflow.
This airflow is STOLEN from the radiator.
So it's a matter if there is sufficient airflow for both the IC and the rad?
That's arguable.

slighly lighter with less piping,
Again, we're talking about ounces when it comes down to aluminum piping.
It's a weak argument at best, and I doubt you could take advantage of the weight difference.

no cutting the subframe
Untrue.
I will mount my FMIC without cutting ANYTHING very soon.
Someone had a thread on how I wanted to do this already.

8<


-Ted
Old 01-24-06, 01:58 PM
  #12  
And the Revolution...

 
DarkKnightFC's Avatar
 
Join Date: Apr 2005
Location: NC
Posts: 1,383
Likes: 0
Received 1 Like on 1 Post
Very nice setup Ryo. Soon enough I will have a Vmount as well. And it will not heatsoak. And it will not steal air from the radiator. BlueTII on teamfc3s has the best looking setup I've ever seen and I'm going to copy the **** out it, with one slight difference. I can see it now...
Old 01-24-06, 03:23 PM
  #13  
I break Diff mounts

iTrader: (1)
 
Digi7ech's Avatar
 
Join Date: Jun 2002
Location: Avondale, Arizona
Posts: 4,403
Likes: 0
Received 4 Likes on 2 Posts
I think ducting is the main thing needed to make either work correctly.

FMIC's cause some turbulence between the core and the radiator since the FMIC is usually placed far up front. Leaving a gap for air.

If the FMIC was placed a couple inches from the rad then it would smooth out flow BUT then you add the possibility of radiant heatsoak.


With Vmount your removing the core obstruction of the flow path. AT the end though it could get messed up as at the end it will have two paths to choose.

Thats why ducting is important. If you seperate the flow paths up front you shoudl have some good flow through both and one shouldn't rob from the other.
Old 01-24-06, 03:51 PM
  #14  
Endure Persevere Succeed

iTrader: (30)
 
Jaiyurai's Avatar
 
Join Date: Apr 2005
Location: Berkeley, CA
Posts: 1,693
Received 37 Likes on 30 Posts
RyoFC3S, I'm not quite sure that your VMIC setup is very accurate. In the 3rd picture, your radiator isn't slanting back far enough. Where the IC and rad meet is a little er.... You're losing 1/4 of your intercooler.

The gaps are a work in progress so no dings there. Also without a hood, you can't properly vent air from the intercooler. You probably haven't run into cooling issues because all the air is moving thru the front duct and mostly going thru the radiator, not the IC. Once you add the vented hood, it'll create a vacuum to pull the air mostly thru the IC. Then you'll run into cooling problems.

I'm sure you're running fine now, but I bet your turbo is working a bit harder than it needs to be.

And for future reference, a FMIC is MUCH MUCH easier to install and do than a VMIC. I don't think you can truly do a VMIC on the FC without cutting something. I admit I am doing a VMIC with a aftermarket 3" radiator and a XL 4" thick IC. I had to cut parts of the radiator support, relocate the oil cooler, and fab a bunch of brackets. This is all out of scratch because there isn't a real VMIC you can purchase for the FC. It hasn't been fun at all but I know in the end, all blood and money will be worth it.
Old 01-24-06, 04:06 PM
  #15  
Reverse Cerberus

iTrader: (1)
 
evileagle's Avatar
 
Join Date: Apr 2002
Location: Vancouver, WA
Posts: 1,788
Received 11 Likes on 7 Posts
Speaking of using a VMIC on a drift car...


On a VMIC you really really need to have the air going in the front of the car, being pushed in... now what I don't understand I guess... is how would it get in there if the car is going... sideways..?
Old 01-24-06, 05:12 PM
  #16  
We are the D

Thread Starter
 
InMyWhiteTII's Avatar
 
Join Date: Nov 2005
Location: Indianapolis
Posts: 492
Likes: 0
Received 0 Likes on 0 Posts


this car actually has intakes for the IC on the sides of the car. its an....RMIC O_o the damn thing is in the trunk!
Old 01-24-06, 06:35 PM
  #17  
Rotary Freak

 
Join Date: Apr 2002
Location: Boulder, CO
Posts: 1,739
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by InMyWhiteTII


this car actually has intakes for the IC on the sides of the car. its an....RMIC O_o the damn thing is in the trunk!

no, the radiator is in the trunk, and the IC is where the radiator normally is...


as for how V-mounts bring air into the car while going sideways... first of all, its not going at a 90 degree angle(I doubt even 45 degrees most of the time, for most cars), so air still comes in the front. the air that comes in the front is directed to the IC/radiator by the ducting. on a FMIC setup, the air may hit the IC, but at the angle its hitting at, how is that air going to travel THROUGH the IC, and then the radiator?

they both have their advantages and disadvantages.
Old 01-24-06, 07:57 PM
  #18  
Passing life by

 
iceblue's Avatar
 
Join Date: Feb 2005
Location: Scotland, USA
Posts: 4,028
Likes: 0
Received 2 Likes on 2 Posts
Here is a simple fact, Air flow will always chose the path of least resistance.

Second without ducting there is no way air will go up the VMIC. The only way to properly force air into a VMIC is with proper ducting, and a well-designed hood vent to cause a vacuum over the IC forcing the air through like a fan.

For the dude that has his without a hood vent or ducting and holes on the side. There is zero air passing through your IC and it is basically doing nothing, sorry.

The RAD in the trunk is a very common mod for racecars and cars with engine swaps that need room. The added cooling capacity is extremely effective.

SonicRat did a FMIC without cutting anything. He bolted custom brackets to move the RAD back. www.1300cc.com

A VMIC setup cannot be done without building custom mounts of the RAD or welding these mounts up.

The most important thing for proper cooling on both FMIC and VMIC setups is good ducting.

So far the only advantage to VMIC that has been documented on here so far is less turbo lag. The shorter the distance the less lag you have. But when most cars see full boost by 3.8kRPM I really don’t see the need. When you are racing how often are you below 4grand?

Last edited by iceblue; 01-24-06 at 07:59 PM.
Old 01-24-06, 09:06 PM
  #19  
S5 TII

iTrader: (1)
 
RyoFC3S's Avatar
 
Join Date: Oct 2003
Location: Denver, CO
Posts: 826
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by iceblue
For the dude that has his without a hood vent or ducting and holes on the side. There is zero air passing through your IC and it is basically doing nothing, sorry.
Well you can 'speculate' all you want. If you dont believe me drive to CO and i'll give you a long ride and show you how much difference there is between the intake and exhaust side of the intercooler. I'm not making it up.

Originally Posted by Jaiyurai
RyoFC3S, I'm not quite sure that your VMIC setup is very accurate. In the 3rd picture, your radiator isn't slanting back far enough. Where the IC and rad meet is a little er.... You're losing 1/4 of your intercooler.
Indeed. The intercooler I purchased was too tall.

Originally Posted by Jaiyurai
The gaps are a work in progress so no dings there. Also without a hood, you can't properly vent air from the intercooler. You probably haven't run into cooling issues because all the air is moving thru the front duct and mostly going thru the radiator, not the IC. Once you add the vented hood, it'll create a vacuum to pull the air mostly thru the IC. Then you'll run into cooling problems.

I'm sure you're running fine now, but I bet your turbo is working a bit harder than it needs to be.
That may very well be the case. I plan on running some stainless steel ducting to the radiator once I get the hood I need- but for now it cools just fine.

Originally Posted by Jaiyurai
And for future reference, a FMIC is MUCH MUCH easier to install and do than a VMIC. I don't think you can truly do a VMIC on the FC without cutting something. I admit I am doing a VMIC with a aftermarket 3" radiator and a XL 4" thick IC. I had to cut parts of the radiator support, relocate the oil cooler, and fab a bunch of brackets. This is all out of scratch because there isn't a real VMIC you can purchase for the FC. It hasn't been fun at all but I know in the end, all blood and money will be worth it.
I had to do all of this and more. Its definatly, definatly easier and cheaper to go with a FMIC.

-Andrew
Old 01-24-06, 09:25 PM
  #20  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally Posted by Digi7ech
FMIC's cause some turbulence between the core and the radiator since the FMIC is usually placed far up front. Leaving a gap for air.

If the FMIC was placed a couple inches from the rad then it would smooth out flow BUT then you add the possibility of radiant heatsoak.
That's not necessarily a bad thing...
Turbulent air implies the airflow slows down.
This could be advantageous, as long as the minimum cooling efficiency is attained.


-Ted
Old 01-24-06, 10:27 PM
  #21  
Passing life by

 
iceblue's Avatar
 
Join Date: Feb 2005
Location: Scotland, USA
Posts: 4,028
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by RETed
That's not necessarily a bad thing...
Turbulent air implies the airflow slows down.
This could be advantageous, as long as the minimum cooling efficiency is attained.
Turbulence also creates heat. So for the turbulence or air tumbling in the IC to become effective it must obtain more ambient cooling then it creates in turbulant heat.

Originally Posted by RyoFC3S
Well you can 'speculate' all you want. If you dont believe me drive to CO and i'll give you a long ride and show you how much difference there is between the intake and exhaust side of the intercooler. I'm not making it up.
There is no speculation; simple fact, air will always take the path of least resistance. With your hood there is no outlet path, thus no ware for air to come and go. Your non-exsistant ducting and air gaps create a huge amount of lower resistance.
Old 01-25-06, 12:06 AM
  #22  
S5 TII

iTrader: (1)
 
RyoFC3S's Avatar
 
Join Date: Oct 2003
Location: Denver, CO
Posts: 826
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by iceblue
There is no speculation; simple fact, air will always take the path of least resistance. With your hood there is no outlet path, thus no ware for air to come and go. Your non-exsistant ducting and air gaps create a huge amount of lower resistance.
There is about 2 inches gap between the IC and the hood. All im saying is despite all of the 'simple facts' what you've said still doesent ''disprove'' the fact that my IC does cool the air noticeably. I dont care how many equations and phsyically properties and air dynamics you can go on and on about-- the simple fact is my VMIC cools air, despite lack of ventilation/ducting/etc.
Old 01-25-06, 05:49 AM
  #23  
Lives on the Forum

 
RETed's Avatar
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 16 Likes on 15 Posts
Originally Posted by RyoFC3S
There is about 2 inches gap between the IC and the hood. All im saying is despite all of the 'simple facts' what you've said still doesent ''disprove'' the fact that my IC does cool the air noticeably. I dont care how many equations and phsyically properties and air dynamics you can go on and on about-- the simple fact is my VMIC cools air, despite lack of ventilation/ducting/etc.
I'd still like to see objective numbers instead of your subjective opinion.
In my experience, with Haltech datalogs with FMIC's:
Boost level: ~15psi
Turbos: GT35R / H-trim compressor upgrade
Air intakte temps prior to TB: 110F to 115F
Ambient temps: ~60F


-Ted
Old 01-25-06, 06:05 AM
  #24  
I'm a boost creep...

 
NZConvertible's Avatar
 
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes on 8 Posts
Originally Posted by iceblue
Turbulence also creates heat.
We're not talking about aircraft speeds here. Any heat generated by turbulence anywhere on a car is totally insignificant. Silly suggestion.

With your hood there is no outlet path, thus no ware for air to come and go.
Or course there is. The intercooler is not sealed to the underside of the hood, there's a at least a couple of inches between the two at the front of the core and even more towards the rear. A vented hood would obviously improve the IC's efficiency, but to say there's no outlet path is just plain wrong.
Old 01-25-06, 08:56 AM
  #25  
Passing life by

 
iceblue's Avatar
 
Join Date: Feb 2005
Location: Scotland, USA
Posts: 4,028
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by NZConvertible
We're not talking about aircraft speeds here. Any heat generated by turbulence anywhere on a car is totally insignificant. Silly suggestion.
Not suggestion fact. I have also experienced and documented enough tabulated flow and heat generated just from an air filter to cause misfire and knocking. "On an NA 13b"

Originally Posted by NZConvertible
Or course there is. The intercooler is not sealed to the underside of the hood, there's a at least a couple of inches between the two at the front of the core and even more towards the rear. A vented hood would obviously improve the IC's efficiency, but to say there's no outlet path is just plain wrong.
Sure there is an inch. There are large gaps and no ducting. So do you mean to say that the air is going to flow up and through the IC that is obviously the most resistant path?

Only if the amount of air coming in is forced in hard enough and volume is greater then all the gaps and paths elsewhere will it then flow through this setups IC.

Since this is obviously a nasi post. You are right. My point wasn’t so **** it was implying an effective amount of air the little that drizzles through it if any would be worthless and probably less efficient then the TMIC.


Quick Reply: FMIC vs. VMIC



All times are GMT -5. The time now is 07:10 PM.