heat soak

[h22a]

I've been getting ever increasing heat soak with climing temperatures over the past couple of months. Im considering a new intercooler, induction(pod etc..) and exhaust. In regards to the intercooler im stumped as to whether i should fit a top mount or front mount cooler. I'm told that a front mount will be much more beneficial for performance but will cost me close to three times more than a top mount. its basically the difference of $500 as opposed to $1500 and i guess it comes down to whether its worth spending the extra for what im guessing will be a minimal gain.

Sorry for my stupidity but i prefer to come to you guys as your explanations are simplified for mechanicly void brains like myself

also, are front strut braces(which are quite cheap)beneficial and easy to fit?

[pimento]

For your 03 WRX hatch (assuming your profile is still accurate) I imagine the top mount is cheaper because that's essentially what it's designed for. It's also more in keeping with the look and the 'ness of the car, so if you're that way inclined there's another angle to consider.

[clutch-monkey]

front mount will increase lag won't it? maybe get an air-to-water intercooler?
and a strut brace is a good idea, i fitted one to an sti a few weeks back, easy job

[h22a]

front mount will increase lag won't it? maybe get an air-to-water intercooler?
and a strut brace is a good idea, i fitted one to an sti a few weeks back, easy job

i believe it does increase lag(i have nothing to substantiate this) but peak power is increased at higher revs as opposed to the top mount which doesnt rely so much on high revs and high boost pressure to generate more power. but power gains are not as dramatic????. really i dont have a friggin clue

strutbrace: thats sweet news, I just started looking on ebay and their cheap as chips. Is it worth spending the extra for a branded strutbrace(eg hks or some shit) or are the less known brands just as worthy. surely the technology isnt progressing that much with braces

[clutch-monkey]

i believe it does increase lag(i have nothing to substantiate this) but peak power is increased at higher revs as opposed to the top mount which doesnt rely so much on high revs and high boost pressure to generate more power. but power gains are not as dramatic????. really i dont have a friggin clue

as i understand it you do get some power gain but there is lag the sti belonging to my friend simply has a slightly larger top mount and some ducting under the bonnet, and he's got close to 400hp apparently

strutbrace: thats sweet news, I just started looking on ebay and their cheap as chips. Is it worth spending the extra for a branded strutbrace(eg hks or some shit) or are the less known brands just as worthy. surely the technology isnt progressing that much with braces

well even the branded ones aren't particularly expensive, we used a whiteline one and results are good i'd reccomend it anyway

[whiteballz]

My car runs a "no name" front strut brace, i drove without it for about 30 minutes, and there is a huge difference. If the price gab isnt huge, I'd assume the branded ones to be a little better.

EDIT: as with the front mount, there is more piping required, so that presents a problem too.

[h22a]

cheers heaps guys very helpful. i'll opt for the top mount i think, go for no name struts and use the extra cash to get some silicon hosing or maybe an intake.
in guessing an intake would be the better spent money?

[charged]

A front mount wouldnt create too much extra noticable lag, probably a bigger top mount intercooler will draw less attention from the law. Another way of keeping intake temps lower is by fitting a squirter system with microjets that put a mist over the intercooler. We run these on the race cars and they take 40c out of intake temps. Its a cheap option that works well all you need is a water tank in the boot 20l, a decent pump, some micro irrigation piping and misters and its ready to go

[h22a]

i heard the makkinen evo 6.5 came standard with those squirters. i'll look into it. you mentioned fitting it to racing cars charged, do you know what the rough cost of fitting a similar system would be.

[clutch-monkey]

charged how much cutting would you have to do to fit a front mount in? or does it fit easily?
H22 if you put an intake on maybe look at fitting a heatshield or something

[charged]

i heard the makkinen evo 6.5 came standard with those squirters. i'll look into it. you mentioned fitting it to racing cars charged, do you know what the rough cost of fitting a similar system would be.

You would do it for under 50 bucks, we run them on the race cars mainly for extra cooling to the radiator on the starting grid as the cars run no fan. But the data showed us the inlet temps are cooler as well.

We run a 20litre container in the cab with a pump that runs to a switch, then just micro irrigation pipe and squirters, its very simple.


Are you running higher boost on the car, then inlet temps increase. The stock turbo on the subby will probably need to be upgraded as they are near their efficency when boost is increased.

You could also go water/methanol injection, these systems work well for controlling inlet temps. Though its usually used on higher spec engines but it works well

Boost Cooler

[hightower99]

Unfortunately top mount ICs are inefficient compared to front mount ICs.

Top mount ICs get alot of heat soak from the engine (remember heat rises).

Top mount ICs try to force air down through the heatsink forcing heat under it which tries to come up again (remember heat rises) creating more heat soak.

Top mount ICs are typically smaller (due to obvious space restrictions) than front mount ICs.

I would go for a front mount IC as it doesn't get anywhere near as much heat soak as a top mount, it doesn't make the system lag any more (if installed correctly) and all the help systems that have been mentioned can be used aswell.

However Front mounts are alittle more work and more expensive.

A top mount will probably be good enough but a front mount will allow greater boost (because intake temps will be lower) and better power (as the intake air should be more dense).

[clutch-monkey]

You could also go water/methanol injection, these systems work well for controlling inlet temps. Though its usually used on higher spec engines but it works well

how does that work? i wonder if i could fit it to my shittily placed intake

Unfortunately top mount ICs are inefficient compared to front mount ICs.

Top mount ICs get alot of heat soak from the engine (remember heat rises).

Top mount ICs try to force air down through the heatsink forcing heat under it which tries to come up again (remember heat rises) creating more heat soak.

Top mount ICs are typically smaller (due to obvious space restrictions) than front mount ICs.

I would go for a front mount IC as it doesn't get anywhere near as much heat soak as a top mount, it doesn't make the system lag any more (if installed correctly) and all the help systems that have been mentioned can be used aswell.

However Front mounts are alittle more work and more expensive.

A top mount will probably be good enough but a front mount will allow greater boost (because intake temps will be lower) and better power (as the intake air should be more dense).

i was working on an sti yesterday and a front mount will be a lot more work, cutting, piping etc
imo a bigger top mount will work fine for him. although will a water to air intercooler work?

[charged]

[QUOTE]

how does that work? i wonder if i could fit it to my shittily placed intake

Hers the FAQ on the site, it lowers the inlet temp, so more timing etc can be run, also the a/f can be run leaner
Boost Cooler

i was working on an sti yesterday and a front mount will be a lot more work, cutting, piping etc
imo a bigger top mount will work fine for him. although will a water to air intercooler work?

Front mounts will always work better than a top mount, because usually bigger surface area and better location for airflow. Water to air are ok but air to air is much better. Water to air run at 80c where a good air to air runs at ambient usually 20c-40c depending on ambient. I know guys with the GT4 celicas, one of the first mods was to convert to a front mount air to air and get rid of the top mount water to air intercooler

[hightower99]

i was working on an sti yesterday and a front mount will be a lot more work, cutting, piping etc
imo a bigger top mount will work fine for him. although will a water to air intercooler work?

I did mention that a front mount is more work but there are good benefits.
I also agree that unless he wants to do some pretty major tuning then a bigger top mount should be fine.

Water to air ICs when designed and installed correctly can cool the intake air cooler than ambient temps, however it is difficult to do and if a front mount is too much work then you shouldn't consider water to air ICs


AFAIK top mounts tend to keep the intake chilled to about 10-30 degrees C hotter than ambient (depending on design) and the longer you run the hotter the intake temps get (due to heat soak)

Front mounts maintain about 5-20 degrees C hotter than ambient (depending on design), bare in mind that air-to-air ICs act as large heat sinks instead of your typical radiator.

Water-to-air (no ice) can maintain ambient (sometimes slightly cooler) to about 10 degrees C hotter. Water-to-air ICs act more like radiators if you have alot of water or like heatsinks if you only have a small volume of water.

Water-to-air (ice) if you put ice in the water resevior you can cool the intake air down about 15-20 degrees C less than ambient (however you should never try to feed an engine with air that is colder than about 5 degrees C (as fuel will not atomize properly and milage will drop like a rock.