Intercooler Ducts

[john g]

Do the intercooler ducts help direct air to the intercooler? I am hesitant to install them unless they have a significant benefit since they block access to the engine. As background, I use my 818 on local pleasure drives and don't plan on autocross or other racing.

John

[billjr212]

By themselves they are virtually worthless because there is a huge gap between the top and the deck lid. You could always install them with some small rivnuts instead of rivets to make them fairly easy to remove. You will need to add additional aluminum and a bulb seal if you want them to do anything meaningful in any event.

I ran about the first 200 miles on the street without them, but wasn't logging data to find out if I was having heat soak issues. Certainly didn't notice any issues.

They are pretty obnoxious to try to work around. On the plus side, I got a nice princess bandaid from my daughter after swapping turbos this week.

[freds]

By themselves they are virtually worthless because there is a huge gap between the top and the deck lid. You could always install them with some small rivnuts instead of rivets to make them fairly easy to remove. You will need to add additional aluminum and a bulb seal if you want them to do anything meaningful in any event.

I ran about the first 200 miles on the street without them, but wasn't logging data to find out if I was having heat soak issues. Certainly didn't notice any issues.

They are pretty obnoxious to try to work around. On the plus side, I got a nice princess bandaid from my daughter after swapping turbos this week.

+1 (Actually +1,000) They are useless!

Take a look at what I did, which is working well, for the kind of moderate driving I'm doing. http://thefactoryfiveforum.com/showt...se-of-stock-IC
I don't know how well my set-up will perform under race conditions, and I don't intend to go racing. Also don't intend to spend on an AWIC set-up.
I installed temperature sensors in the IC inlet and outlet streams to check performance.
There are other threads on this subject too.

fred

[Mechie3]

You will want some sort of ducting. Just having an intercooler with no airflow isn't good.

[redfogo]

What if we moved the turbo further back or down a little(might help keep the heat lower down or away from the motor) and angled it so the air intake would not be running through the motor(might help bring in some cooler air)? Then we install a puller fan under the IC? it looks to me like in the 818c we might be able to raise the IC a lot higher away from the enigne, but in the S I am not sure if there is any more room to raise the IC?

[john g]

Thanks for your replies. I decided to install the FFR-supplied ducting. It nearly seals with the mid engine cover, and I am planning to modify as Fred has when time permits.

[Mechie3]

What if we moved the turbo further back or down a little(might help keep the heat lower down or away from the motor) and angled it so the air intake would not be running through the motor(might help bring in some cooler air)? Then we install a puller fan under the IC? it looks to me like in the 818c we might be able to raise the IC a lot higher away from the enigne, but in the S I am not sure if there is any more room to raise the IC?

The issue isn't as much the heat coming off the turbo heating the intercooler (but that is something good to address to prevent heat soak) but the fact that as the turbo compresses air it drastically raises the temperature of the air. Hot air in the engine loses power but can also lead to detonation.

[redfogo]

The issue isn't as much the heat coming off the turbo heating the intercooler (but that is something good to address to prevent heat soak) but the fact that as the turbo compresses air it drastically raises the temperature of the air. Hot air in the engine loses power but can also lead to detonation.

Right and I agree with this coming from tracking my Turbo MR2 I have had to deal with mid engine set up and heat soak of the intercooler. However given the size of a standard STI intercooler or a front mount IC I don't see why it would not be sufficient with cooling if we could relocate it or get more air to cool it down. All of the engine bay heat is only warming up the intercooler, and adding the fact the fresh air being drawn into the turbo is already being nicely warmed from the engine and intake manifold. Mix the fact the turbo is heating up the intercooler right above it its no wonder we are heat soaking we aren't drawing any good amounts of fresh air it seems. Sure the turbo is pushing out hot air but the IC is meant to cool it so it itself needs to stay cool as possible no different then a radiator. I think some high CFM puller fans under the IC should help a lot with this. I did something similar in my turbo MR2 with a trunk mount intercooler and puller fans it improved temps tremendously as air went through the IC.

Having the turbo lower down could help get the heat away possibly or at the very least allowing us to move the intake from being stuck between the intake manifold and engine so it can possibly draw in cooler air.

[Bob_n_Cincy]

I had success autocrossing this fansetup when I was running go kart mode. The fan was pushing cool air down through the intercooler. I am running AWIC now.

P1050110fan.jpg

[mikeb75]

These plans are still early and a bit untested, but here goes:

Since we're going to be running the hard top, and the latest update showed the air inlet from the roof scoop & air tubes coming down in the engine compartment, we've been assembling an airbox/plenum for our IC.

We're running an '08 STI IC, so it's oversized -and we still had significant heat soak issues at our dyno tune. There are 2 ebay 8" rad fans put on the plenum. The plenum is made from Kydex (thermosoftening plastic) and sealed onto the IC with weather striping. A top box will be assembled with inlets for the air ducts. The fans are run off a simple toggle on the dash & relay, later when I get the opportunity I'll add some logic to control the fans off temperatures (maybe) with toggle overrides.

Also we've added an aluminum heat shield over the turbo (under the IC) to try to address the heat soak issue.

So far the only testing results I can give are that the fans blow air through the IC. We will be testing pre and post charge temps soon(ish).

[redfogo]

Are you pulling or pushing the air, sound like your pushing? Idk how much a difference it will make for you but when I had puller fans on my other car it cooled better compared to pushing the air. Also ebay fans aren't the greatest spal is a lot better and worth the money. Try swapping your fans to be pullers you might have better luck.

[Bob_n_Cincy]

Are you pulling or pushing the air, sound like your pushing? Idk how much a difference it will make for you but when I had puller fans on my other car it cooled better compared to pushing the air. Also ebay fans aren't the greatest spal is a lot better and worth the money. Try swapping your fans to be pullers you might have better luck.

With mike's good ducting job, what ever goes through the fan will go through the IC.
When changing Ebay fan direction. You have to do 2 things:
1. reverse the wiring (obvious)
2. remove the blade and flip it over. (this step can be missed easily)
Bob

[mikeb75]

They're pushers. Bobs 2 steps have been done (good catch on #2).

Unfortunately, due to the configuration of the OEM IC -particularly the Y pipe that feeds air from the turbo to the top side of the IC, setting up a puller fan is difficult/impossible, there is no room under the IC core. So, again like Bob said, the ducting and sealing is the important part here. Without properly doing this (or having leaks at the corners like v1) the air will obviously flow through the area of least resistance... which is not the IC core.

I think the Chinese e-bay fans (they're apparently nearly all the same, there must be only 1 factory in China who makes all the fans of this size) are rated at 800CFM (psha) for a total of 1600 CFM (not holding my breath) across the IC core. Once the concept is proven (especially seeing a good charge temperature drop post IC) we can refine the concept with more efficient fans.

And, I think, using top dollar Spal fans is contrary to our build philosophy... we're using the finest -er cheapest Chinese ebay junk

[Mechie3]

I think Jeromes13 used fans on his IC....or was it wallace18? Been too many years and too many builds to track them all now.

[JeromeS13]

I think Jeromes13 used fans on his IC....or was it wallace18? Been too many years and too many builds to track them all now.

I did, can't recall if Wallace did. Hopefully having the coupe hardtop will help get more air in....

[bbjones121]

They're pushers. Bobs 2 steps have been done (good catch on #2).

Unfortunately, due to the configuration of the OEM IC -particularly the Y pipe that feeds air from the turbo to the top side of the IC, setting up a puller fan is difficult/impossible, there is no room under the IC core. So, again like Bob said, the ducting and sealing is the important part here. Without properly doing this (or having leaks at the corners like v1) the air will obviously flow through the area of least resistance... which is not the IC core.

I think the Chinese e-bay fans (they're apparently nearly all the same, there must be only 1 factory in China who makes all the fans of this size) are rated at 800CFM (psha) for a total of 1600 CFM (not holding my breath) across the IC core. Once the concept is proven (especially seeing a good charge temperature drop post IC) we can refine the concept with more efficient fans.

And, I think, using top dollar Spal fans is contrary to our build philosophy... we're using the finest -er cheapest Chinese ebay junk

Any update on how these work?

[Coolspot]

I had success autocrossing this fansetup when I was running go kart mode. The fan was pushing cool air down through the intercooler. I am running AWIC now.

P1050110fan.jpg

Rear radiator setup..why? Or why not...

[lennyspecv]

I am very interested to see what ends up being the solution for the stock intercooler setup. Would be nice if the AWIC did not end up being necessary for street-driven/daily driver 818's. It's a chunk of change and more hassle to get that setup.

[Bob_n_Cincy]

Rear radiator setup..why? Or why not...

There is about 4 reasons I went with a rear radiator.
rr.jpg

The biggest reason I went with rear radiator was the 2 high spots in the cooling system. Air bubbles can form from hot spots in an engine. Think about the bubbles at the at the bottom of pot before it starts to boil. The bubbles will accumulate a either the top of the engine or in the top of the radiator on an 818. You want them to make it to the degas/expansion tank. As more bubbles form, that expansion will push out the gas into the overflow bottle. Because the hoses have to run very low to the front radiator, it is difficult to get the air in the front radiator to flow down hill bact to the expansion tank.

Down side of rear radiator:
Air flow out the back of the car isn't as good as the ram air in the front. So fans may run more often.
There isn't much space in the back of the car. I had to design a custom side shifter on my transmission to get the radiator to fit.

On the upside, I have no special bleeding procedures. Same as a WRX.
Also, the fans running in the back keep my engine bay cool.
Bob

[mikeb75]

Any update on how these work?

So far I can only tell you that the fans push air through the IC. This box/plenum will be used in conjunction with a hard-top IC vent & hosing. Currently waiting on delivery of the hard-top to complete the upper plenum. Honestly, won't be able to do practical testing until next spring... sorry :|

[Coolspot]

Wow Nice idea, and with the rad in the back, you've got space in the front for a trunk ...

Is cooling efficient ? Summer are not that bad here in Quebec and I would enjoy having a front trunk.