Morning all.

Not the usual "Do I need a front mount intercooler?" this time.

I'm interested to hear peoples' thoughts on whether or not changing to a front mount intercooler really does make a tangible difference to the amount of turbo lag.

Obviously, there's a larger volume to get the gas through, which could easily be more than 4 times the volume of the standard tmic on imprezas.

However, thinking about this logically, the speed at which a turbo moves air would surely fill up the extra intercooler volume in next to no time, wouldn't it?

 

Negligible for road use.

 

http://www.enduringsolutions.com/fmic-vs-tmic/

 

front mount gives colder air temps as top mount can suffer from heat soak. mapper can advance the timing a bit more with a front mount as the air is colder and denser so you gain a bit more power but with some added lag.

 

front mount causing any noticable lag is a myth or a poor setup/map

 

That's pretty much what I was thinking.

 

 

Depends on what BHP you want.

 

All depends on what power her hoping to achieve...

 

From an engine safety point of view it doesn't matter what power your looking for.

 

you've got me there mate,,,he's driving a WRX so max safe power would around 350bhp so fitting a fmic would be a waste of time and money just fit STI TMIC job done

 

Fine when constantly moving. Heat soak and ACT is what does the damage. So as per previous post.

 

no such thing, i was at 390 on an sti top mount and it had to be backed off becasue it wasnt coping.

Top of the engine is a really crap place for an intercooler.

 

I prefer the look of a TMIC engine bay over the 'Pipe City' look of an FMIC.


I've run 385 to 394bhp (it varied depending on whose rolling road) for 60k miles without issue. But I suspect that I was at the limit for my WRX block.

 

I am.. .one with a forged bottom end though.

 

Thanks all... sounds like I was thinking along the right lines.

One other question though.. having decided that there is little to no extra lag when switching to a front mount, what about the size of the piping?

From what I understand, for a given quantity of air, the smaller the i/d of the pipe, the faster the air has to move to achieve the same flow as it would on a larger i/d pipe.

if there any benefit to fitting 3" diameter piping, as opposed to 2.5" or 2"?
the only thing I can think of is that the smaller the pipe, the faster the air moves, and therefore the hotter it will be, so surely bigger i'd must be better, or is there more to it than that?