Hmmm...How about a Air/Water Intercooler, or other aftermarket options?

[FFR-ADV]

Alot of the Subaru WRX crowd loves the benefits of a FMIC, but that probably wouldn't work out very well on a mid-engine 818. I am looking forward to seeing how air will be ducted over the factory WRX TMIC, and whether there would be room for a STi or even bigger aftermarket intercooler? This is not intended to spark any criticism of the FFR 818 design. In fact I am excited to get one into my garage as soon as possible. My newly aquired WRX donor is on the road and ready once the tear down/exact part list is fully defined. Just looking at performance mod options.

This further made me wonder what options are out there for an air/water intercooler with an additional small radiator up front that worth the extra cost and effort? Looks like this could neatly pacakge in. I know we have alot of Subaru experts in this forum who could expound on various intercooler options, cost, benefits, drawbacks, sources for solutions, etc...

What combinations of performance mods are you planning?

Thanks for your inputs! Have fun!

Cheers!

818R front clip.jpg

[Rasmus]

Things I like about Air-Water Intercooling. Easy to package. Short runs from turbo to heads. Efficient. Rare.

Things I don't like: Heavy (water, pump, water tubing, two heat exchangers); Complex thus more prone to failure from all the additional parts; Spendy(nope, changed my mind on "Spendy").

My thoughts. Run a top mount (OEM) style air-air intercooler with a custom shroud and a puller fan. If you need more cooling than that, run water/meth injection. It's your build though.

[FFR-ADV]

Thanks for the reply Rasmus.

I am favoring an aftermarket TMIC. There are even many good used examples on the market, Not much to wear out, but I guess in the WRX world some will step from stock to upgraded TMIC to FMIC... Good news for us. I might upgrade my Donor right now and get things working well there before tearing down for the 818. I am thinking catless up-pipe, turbo upgrade, catted downpipe (NH state inspection requirement) fuel rail, injector upgrade and tuning tool (perhaps RomRaider or "other"? any experience here?

I am concerned that the aftermarket TMIC which is designed to fit (without much room left anywhere) and workrs under a WRX hood will do the same in the 818.

I tend to agree with your assesment of the drawbacks on the air/water intercooler.

Cheers!

[NevaLift2Shift]

My thoughts. Run a top mount (OEM) style air-air intercooler with a custom shroud and a puller fan. If you need more cooling than that, run water/meth injection. It's your build though.

This is probably the best way to go. Snow Performance makes some of the best water/meth kits out there. Definitely more efficient than just an intercooler and more power too.

http://www.snowperformance.net/stage...st-cooler.html

[305mouse]

I have a Perrin TMIC that I no longer need. Really it's the same size as the OEM, just more efficient. I was planning on doing a water cooled system, but came to the conclusion that when I do build my 818 a few years from now it will be N/A.

[papajon1000]

I stumbled upon this a while ago. If you are still kinda thinking a water to air this is a pretty good write up.

http://www.iwsti.com/forums/water-me...-ic-build.html

but in reality it depends on what you are planning to do with your 818. If it is going to be a weekend fun street car than I wouldn't see a reason why you couldn't run an air to air.

just my 2 cents

[FFR-ADV]

Thanks for the replies!

Many great options!

Cheers!

[StatGSR]

I stumbled upon this a while ago. If you are still kinda thinking a water to air this is a pretty good write up.

http://www.iwsti.com/forums/water-me...-ic-build.html

but in reality it depends on what you are planning to do with your 818. If it is going to be a weekend fun street car than I wouldn't see a reason why you couldn't run an air to air.

just my 2 cents

Just had to say that people need to take a look at that link because those results are freaking amazing. While it does add some weight, you can still more or less add it where you want to (front of the 818 / passenger seat of 818R). i just don't think it is going to be possible to get those kind of air temps at the back of the 818 with a top mount air to air. i suspect those temps are hard to get with any Air to Air setup in a subaru.

[rjh2pd]

You could also run an intercooler spray of water or something else i forget what it is that could help a lot.

[305mouse]

If I lived in the South and doing a turbo build, I would run a water to air intercooler. Up North where I live, I would add an STI intercooler sprayer. I'm just sticking with a NA when time comes but it will be interesting to see some peoples builds and how different some of these will be.

[AJW Performance]

TMIC best simple option hands down of course, with a lot of options ranging from 200.00- 900.00 to meet anyones budget.
We plan on playing around with the air/water intercoolers as well, since it has been a topic we have been discussing lately.
FFR-ADV; where in NH are you located?
We are over in Bow.

[FFR-ADV]

http://www.iwsti.com/forums/water-me...-ic-build.html

Thanks, this is a great link papajon1000! I have bumped into some material but not as complete a package as this. Nice find!

Thank you for the introduction AJW Performance. I am sure many in this forum including myself will be interested in what you learn about air/water intercooler and other performance / aftermarket upgrades for the 818.

Cheers!

FFR-ADV
Windham, NH

[Rasmus]

Spendy.

Gonna have to say I'm wrong on the "Spendy" portion of my opinion. Found all major parts in kit form for $280. Marketed to handle 350 HP.

[FFR-ADV]

We plan on playing around with the air/water intercoolers as well, since it has been a topic we have been discussing lately.

Hi AJW Performance,

Have you done anything with an Air/Water Intercooler yet? Looking forward to seeing your various performance builds for both the 818S and 818R.

Cheers!

[Wayne Presley]

I plan on doing an air to water on mine. I do them on the lotus' that I turbo/supercharger with a 3 gallon tank, front mount heat exchanger and a lightning/cobra pump. After a 30 minute race the water temp is about 30°F higher than at the start of the race. On a street car you would be hard pressed to get that amount of heat into the water.

[Slatt]

I have to agree with what has been said. Those water/air units have some impressive specs. But water weighs a lot and you'd want to keep piping short to keep this car light (which is it's virtue, after all), so I'd put the radiator near the rear wheel vents. Personally, I'm still undecided about turbo vs NA but if I go turbo I'll do the fan/shroud like Rasmus mentioned. It would be easy to switch the fan on/off from a thermocouple in the intake pipe (plus an override switch on the dash). And kivex is easy to work with for shrouds and holsters!

[FFR-ADV]

Here is another thought of how to get a larger than stock Intercooler in the 818:

Perhaps a large FMIC could be mounted above the transmission behind one of the grills at the rear of the car. Several fans could force air over the FMIC (now a RMIC I guess) with air ducted from scoops at sides (or a WRX style hood scoop over the vent on the deck vent?). Looks like there might be enough room for the RMIC brackets and plumbing.

IMG_2279.jpg

Happy Holidays!

[Subarugears]

Why not just run the Factory Subaru water to air intercooler that was factory made for the Legacy Turbo cars? They have done all the hard work for you. Perfectly packaged, water pump, heat exchanger already done.

[PhyrraM]

Why not just run the Factory Subaru water to air intercooler that was factory made for the Legacy Turbo cars?

It doesn't fit the later intake manifolds (such as all 'proper' donor WRXs) without mods. The throttlebody is moved 'forward' in relation to the turbo outlet on the newer cars.

If your going to use earlier hardware (such as the EJ22T or the EJ20G) then it would be a bolt-on.

[FFR-ADV]

Why not just run the Factory Subaru water to air intercooler that was factory made for the Legacy Turbo cars? They have done all the hard work for you. Perfectly packaged, water pump, heat exchanger already done.

Thanks Subarugears! That is an interesting option.
Do you know what the stock Subaru Legacy water to air Intercooler is capable of supporting ( larger turbos, more boost to cool, CFM from higher RPMs, ie more HP)?

Happy Holidays!

[FFR-ADV]

Thanks PhyrraM!

[Subarugears]

It doesn't fit the later intake manifolds (such as all 'proper' donor WRXs) without mods. The throttlebody is moved 'forward' in relation to the turbo outlet on the newer cars.

If your going to use earlier hardware (such as the EJ22T or the EJ20G) then it would be a bolt-on.

Pretty easy to make it fit all of them. Easier then sourcing a completely different setup from scratch.
It will handle more boost and CFM than your rear tyres can handle!

[bugeye_fever]

I really like the idea of water to air on this chassis. Thin dual pass heat exchanger in front with your pump mounted between the passes(ZR1), tubes can be routed to the back with the engine coolant tubes. You won't need a reservoir as there would be a plenty of volume with the length of the system. Though if you needed some more, simply uses larger lines from the front to rear of the car. Yes, it adds weight to the car, but its spread out over the whole car and would be quite low to the ground except the rear exchanger, which doesn't have to be mounted where the stock top mount is. If airflow at the front of the car is managed properly, there should be plenty of airflow to cool a radiator and heat exchanger.

I also like the idea of mounting a larger "fmic" in the rear and ducting the airflow through the engine bay properly.

Obviously these would only suite a high hp applications. I feel the stock, or an sti topmount would suffice for any application in the low to mid 300's.

[narkosys]

I was thinking about installing a FMIC. not for high hp reasons, but for better air flow/cooling as I am still a bit leery about the amount of cool air the TMIC would receive. Though looking at the size of the FMIC I am not sure it would fit in the front of the 818 so maybe an air/water solution may be the way to go. I am not worried about being a weight weenie as this will be a daily driver and not a race car.

As time passes on and builds progress i will be better able to make a final decision on these options.

P

[armstrom]

Installing a front mounted intercooler on a mid-engine car is pretty much always a bad idea. It has been done, but man, it's ugly and throttle response suffers greatly. Adding that much additional volume between the turbo and the intake manifold is not a great idea. It's fine for drag racing where throttle response is pretty much irrelevant. But for regular daily driving or autox/road course racing it would be a nightmare. Then you have to figure out where to route the pipes! The system I saw installed in an MR2 literally had the send and return tubes running right through the passenger compartment above the center console.

Air to water has FAR more advantages and would also be cheaper than trying to a front mount setup. I have yet to see anyone mention one of the huge benefits for racing. If you're doing short races (only a few hot laps or a drag race) you can actually chill the water in your A/W system. That will allow you to achieve intake temperatures far lower than any other solution. Low intake temps = more power. Some drag racing setups don't even bother with water-to-air heat exchanger. They simply use a copper coil or secondary core in a cooler full of ice. Before each race they replenish the ice supply.

Also, if you're building a car from scratch adding an air to water setup is far less complex than trying to retrofit one to a built car. You will have complete access to run the water hoses exactly where you want (following the path of the radiator hoses would probably be best). You will be able to locate the reservoir and pump exactly where you want, you can properly wire the circulation pump when you wire the rest of the car. It's really a worth-while upgrade if you ask me. Especially on a mid-engine car. Front engine, it's tough to argue against a good size FMIC other than to say that most A/W setups will have a lower pressure drop due to the smaller, more free-flowing core.

[rjh2pd]

They were talking about mounting a front mount intercooler to the rear of the car above the transmission where the vents are and maybe running ducting there to get more air flow not mounting it in the front.

[Racebrewer]

"Perhaps a large FMIC could be mounted above the transmission behind one of the grills at the rear of the car. Several fans could force air over the FMIC (now a RMIC I guess) with air ducted from scoops at sides (or a WRX style hood scoop over the vent on the deck vent?). Looks like there might be enough room for the RMIC brackets and plumbing."

IMG_2279.jpg

FWIW: This could be a bit problematic. My experience with car bodies shaped like this is that the air wraps around the side of the car and the flat back causes a high pressure area rather than sucking the air out of the body. I'd test closely with string, etc, before shelling out the big bucks.

John

[armstrom]

They were talking about mounting a front mount intercooler to the rear of the car above the transmission where the vents are and maybe running ducting there to get more air flow not mounting it in the front.

I was replying to this statement:

Though looking at the size of the FMIC I am not sure it would fit in the front of the 818...

But in that case, yes, that's often a viable option. A similar modification was done to MR2 turbos back in the day only the large intercooler was mounted in the rear trunk. The mod could be made to work but airflow was always a challenge.

[FFR-ADV]

Thanks to everyone for jumping in with responses.

Happy Holidays!

[Etos]

Here is another thought of how to get a larger than stock Intercooler in the 818:

Perhaps a large FMIC could be mounted above the transmission behind one of the grills at the rear of the car. Several fans could force air over the FMIC (now a RMIC I guess) with air ducted from scoops at sides (or a WRX style hood scoop over the vent on the deck vent?). Looks like there might be enough room for the RMIC brackets and plumbing.

IMG_2279.jpg

Happy Holidays!

FMIC does not mean it's a better intercooler. All FMIC have the inlet and outlet on the sides- it would create 2 90 degree turns the way you described it. If the placement is good- the TMIC is still a much much better fit. All you're doing is moving the TMIC back a bit to be further over the trans(factory TMIC is already right over the belhousing).

Also I think alot of you are over thinking this a bit. A factory STi TMIC is good to about a little over 20 PSI. After that the metal crimps start to pull away. Here's a thread with quite a bit of detail about it:

http://forums.nasioc.com/forums/show....php?t=2348764

Regardless, at 20 PSI in an STi with a few bolt on items(TGV, turbo inlet) you are making 380HP easy in AWD. That's 460 crank, that's 400WHP easy in 2WD format. Point being is unless you want over 350HP in an 1800lb car a factory intercooler is more then enough. At 350hp you have a 5.1 P/W ratio. That's better then ZR1 P/W.

[FFR-ADV]

"Perhaps a large FMIC could be mounted above the transmission behind one of the grills at the rear of the car. Several fans could force air over the FMIC (now a RMIC I guess) with air ducted from scoops at sides (or a WRX style hood scoop over the vent on the deck vent?). Looks like there might be enough room for the RMIC brackets and plumbing."

IMG_2279.jpg

FWIW: This could be a bit problematic. My experience with car bodies shaped like this is that the air wraps around the side of the car and the flat back causes a high pressure area rather than sucking the air out of the body. I'd test closely with string, etc, before shelling out the big bucks.

John

Hi John,

I appreciate what you are saying. Testing airflow is wise before investing in the hardware. I will likely start with the stock TMIC and go from there unless I get a super deal on a STi or similar TMIC.

Interestingly, I just saw a Lotus 211 intercooler which uses air ducts from the left and right upper side vents (like the 818 has) into a plenum which forces the air thru a large intercooler which reminds me of a WRX FMIC (now RMIC I guess). The cool outside air is forced thru the intercooler into the engine compartment (not unlike the WRX). The heated air vents with the rest of the engine space.

211 rear intercooler plenum.jpglotus211 rear intercooler.jpg

Cheers!

Steve

[longislandwrx]

that's a real nice setup. that should not be hard to do at all with all the room in the back of the 818.

that ducting isn't expensive.

http://www.amazon.com/gp/product/B00...1&s=automotive

I bet with 12' you could go halvsies with someone, and that plenum should be easy to fabricate, I would probably start with the oem IC splitter and go from there.

[Nuul]

I will likely start with the stock TMIC and go from there unless I get a super deal on a STi or similar TMIC.

You can get the 04-07 STI TMIC for about $300 from NASIOC before shipping an PayPal fees. It's pretty cheap as upgrades go.

[apexanimal]

i've got a magnehelic gauge too to test some of these high/low pressure areas...

[freds]

Why not use a cars A/C unit to provide cold air to the IC?

[StatGSR]

^ typically because it is not free energy and not terribly cost effective. To create the the cold air, the engine has to use its power to run the compressor instead of sending it out the flywheel. It's been done, but is not common, i remember seeing kits out there for the supercharged mustang cobras....

[freds]

^ typically because it is not free energy and not terribly cost effective. To create the the cold air, the engine has to use its power to run the compressor instead of sending it out the flywheel. It's been done, but is not common, i remember seeing kits out there for the supercharged mustang cobras....

Thanks, I was sure it couldn't be a new idea!!!