For consideration for all air to air ic users

[freds]

1. If the inlet side of the intercooler is not effectively isolated from the rest of the engine compartment:

a. there is going to be re-circulation of hot air from the engine compartment through the IC;

b. this is true irrespective of where external air is being ducted from;

c. also true no matter what fans (push..pull or whatever) are being used

Both b. and c. are true unless the fresh air is being ducted directly to and close coupled to the IC inlet ....In which case they are effectively isolated from the hot engine compartment air.

2. The passenger side IC inlet and side of the IC are pretty well directly above the Turbo and first 8~10 inches of exhaust pipe.
Without a heat shield between turbo/pipe and that side of the IC that RH inlet pipe and the IC itself the temperatures on that side of the IC run 40+ degrees hotter than the driver side (and yes, I've measured them)


Without addressing these two basic issues, in whichever or whatever way one chooses, all other "solutions" have to be sub optimal no matter how innovative and/or clever.

I started this new thread as it is not about how the ducting or isolation of the IC inlet is actually done.

I have posted my "isolation solution" a number of times and post here photos of my elementary heat shield which has reduced the right to left IC temperature difference by at least 30 degrees.




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[Flamshackle]

great heat shield and yes isolated fresh air is paramount.

[bimmerbill]

I haven't installed my engine yet. Is an air to water IC necessary? As in, my engine won't last for normal road use with out a better IC solution?

[matteo92065]

Do you Need an Awic or AAic? There are plenty of cars out there with no intercoolers. What intake temp are you good with?

[Hindsight]

Keep boost down to 5 or 6 PSI, run it rich, and be careful with ignition timing and you can probably get away with no charge cooler of any kind. Won't make much power like that, of course.

[RM1SepEx]

The stock location is stupid for a mid engine car with a windshield. Just rotate the turbo 135 (Craig ! ) and put an air to air in the side. I'm bringing air to my cone filter over the IC with simple aluminum ducting. I need to add scoops for the side duct and the right IC duct on the engine cover as I'll open up some airflow there to the air cleaner too.

The air cleaner air flows through the opening I'm pointing to over the AAIC

I ducted the IC fan towards the rear and boxed off the air cleaner

[Mechie3]

Do you Need an Awic or AAic? There are plenty of cars out there with no intercoolers. What intake temp are you good with?

http://blog.perrinperformance.com/your-sti-doesnt-need-an-intercooler-right/


Dan, right now you ahve the only 135 deg bracket in existence. lol.

[C.Plavan]

The stock location is stupid for a mid engine car with a windshield. Just rotate the turbo 135 (Craig ! ) and put an air to air in the side. I'm bringing air to my cone filter over the IC with simple aluminum ducting. I need to add scoops for the side duct and the right IC duct on the engine cover as I'll open up some airflow there to the air cleaner too.

The air cleaner air flows through the opening I'm pointing to over the AAIC

I ducted the IC fan towards the rear and boxed off the air cleaner

Do you have any temp numbers on this yet?

[billjr212]

Do you Need an Awic or AAic? There are plenty of cars out there with no intercoolers. What intake temp are you good with?

Not picking on you, but I had to quote someone. There are a few responses to bimmerbill that appear to have all misread his question. He is asking only if an AWIC is necessary for normal road use. Nothing about deleting the AAIC entirely (at least not how I read it). The answer, of course, is "no, an AWIC is not necessary" with an asterisk given that nobody has big miles on an 818 to be 100% certain. Also, ducting, isolation, heat shielding, etc are necessary to ensure the AAIC is at least somewhat effective for road use. There are other threads entirely dedicated to bimmerbill's question.

Thanks to Freds for the original post. I like that heat shield. Definitely follows the KISS standard. I am thinking of doing the same in combination with Craig's (Zero DB) heat shield, plus some gold foil tape on the bottom side of this second heat shield and gold foil tape on the bottom of the intercooler duct.

[RM1SepEx]

Due to my physical limitations I should be called pokey :p I'm hoping to put her on the dyno this week. For road use I "need" a scoop, however I'm not that enamored by the ones that you have, I just don't like the angled top edge cut.

Air flow is all about location and ducting. we can get the air pressure differential so that it sucks in the air, the 10 inch fan moves a ton of air. My intake will also be pulling in air from the side and the top. The IC is 40% larger and a bar and plate design, it has almost double the stock IC heat capacity. When you rotate the turbo the tubing runs get pretty short. I have less than 6 feet of 2.5 inch tubing, three 45 degree bends and three 90 degree bends.

Since I'm not planning on any racing beyond an occasional autox data from me won't be much help. I'm hoping for 240 WHP with a Cobb stage II 91 octane tune. My driving has been limited to my street and a large parking lot. Bottom line, for a street car, you don't need the turbo, this thing flies.

I'm basing my design on my college education, fluids which I loved and heat transfer which I hated! The FFR aluminum ductwork just can't be effective, it's shapes suck, it can't really seat to the IC with engine movement and the stock IC has those terrible double tubes and Y assembly blocking airflow.

As far as "needing" an IC of any type... the stock tune requires an IC. Without detuning... BOOM

[matteo92065]

I'm not taking as a pick on. I was trying to ask the question of when is an intake system acceptable?
I've been driving my car hard for thousands of miles now, in the heat of Southern California summer. I have very large side vents (no scoops), and semi large rear venting. I've been watching the intake temp, pre and post IC temps, and water temps. Based on the intake air temps (pre turbo), the engine compartment never gets enough air flow. It's always about 20 degrees higher than ambient when moving, and up to 40 when in stop and go traffic. I only drove my car with the stock AAIC for a few miles. I have an AWIC and I don't know how you could do any better in terms of having air go into the engine at near ambient temps, at any speed, and at any boost level.

Original question: Is AWIC necessary for normal road use? YES, with asterisk of you can't drive this car easily, its too much fun to keep your foot out of it. If you had to drive it to keep it cool, it would not be fun. Second double asterisk: Dan, RM1SepEx, is the closest to having an AAIC that will work; his system could make the answer a "NO".

[Kurk818]

Due to my physical limitations I should be called pokey :p I'm hoping to put her on the dyno this week. For road use I "need" a scoop, however I'm not that enamored by the ones that you have, I just don't like the angled top edge cut.


FYI, I plan on making a pair of scoops with a curved top to more or less mimic the curves of the rear quarters. Ill be working on the this winter.

[RM1SepEx]

FYI, I plan on making a pair of scoops with a curved top to more or less mimic the curves of the rear quarters. Ill be working on the this winter.

in CF please

[freds]

Actually the original post was about the principle of isolating the inlet side of an air to air intercooler from the hot air in the engine compartment.

We seem to have move right back to scoops etc. which are discussed in many and various threads. And if IC's are necessary or what type of IC is best etc.

I had hoped to read some discussion on the topic of preventing recirculating hot air from the engine compartment through the IC

Even the second part of my own post about heat shields was a bit of a distraction and off topic (my apologies!). Heat shields are just heat shields... are just heat shields......

I would like to hear more about isolating the inlet side from the IC from the engine compartment hot air. Not where the fresh air is coming from, no matter how clever or elegant. That comes second, in my opinion.

Thanks

fred

[CNC_Geek]

Has anyone tried this?
45697

Could be placed right above the IC. There are several sizes and shapes available. Too much?

[RM1SepEx]

still too low with the windshield! :rolleyes:

[DodgyTim]

This will fix it:cool:45702

[Bob_n_Cincy]

To All
I am doing an AWIC because water is a very good thermal conductor to move heat from the intercooler to the nose heat exchanger. Plus the fluid thermal capacity is significant the fast surges of heat are effective cooled. I think this is the best way for auto crossing or road racing.

If I were going to do an AAIC, I would add a flat grill (vent)right above at AAIC. This grill would have a 12" radiator type fan on it sucking air into the engine compartment. A bellows would seal between the fan and the intercooler. The air coming out of the bottom of the intercooler would take engine & exhaust heat out of the engine compartment.

Exhaust wrap and turbo blankets are very important on an 818 along with force ventilation of the engine compartment.
Bob

[freds]

To All
I am doing an AWIC because water is a very good thermal conductor to move heat from the intercooler to the nose heat exchanger. Plus the fluid thermal capacity is significant the fast surges of heat are effective cooled. I think this is the best way for auto crossing or road racing.

If I were going to do an AAIC, I would add a flat grill (vent)right above at AAIC. This grill would have a 12" radiator type fan on it sucking air into the engine compartment. A bellows would seal between the fan and the intercooler. The air coming out of the bottom of the intercooler would take engine & exhaust heat out of the engine compartment.

Exhaust wrap and turbo blankets are very important on an 818 along with force ventilation of the engine compartment.
Bob

Thanks Bob....on topic!

[Buzz Skyline]

Actually the original post was about the principle of isolating the inlet side of an air to air intercooler from the hot air in the engine compartment.

We seem to have move right back to scoops etc. which are discussed in many and various threads. And if IC's are necessary or what type of IC is best etc.

I had hoped to read some discussion on the topic of preventing recirculating hot air from the engine compartment through the IC

Even the second part of my own post about heat shields was a bit of a distraction and off topic (my apologies!). Heat shields are just heat shields... are just heat shields......

I would like to hear more about isolating the inlet side from the IC from the engine compartment hot air. Not where the fresh air is coming from, no matter how clever or elegant. That comes second, in my opinion.

Thanks

fred

How hard would it be to mount the IC high enough that you could make it flush with the engine cover, or even sticking out a fraction of an inch? Then the cover would serve as the heat shield (it might look pretty cool too). I feel like you might still end up with a lot of air rising through the IC when sitting idle, so you would want to add barriers, heat shields, blankets, etc. inside the engine compartment anyway.

[Mechie3]

A bellows would seal between the ... intercooler.

I agree. We've discussed the same thing before that the best way is to simply make a plenum to seal the top of the intercooler and then use solid ducts (large diameter hose, sealed intake tracts, not open sided sheet metal) to force cool air onto the intercooler.

Secondary to this is keeping radiant and convective heat sources away. Wrap the exhaust, use heat shields, etc. Third is flushing the engine bay of heated air (as insulation only slows the transfer of heat, doesn't prevent it)

If you look at most OEM application of an intercooler, they all use a bellows to seal the inlet side and use solid ducts. Many racing applications do the same. The WRX rally cars put the radiator in the back and use massive 8" diameter (at least) hoses to bring in air from side scoops to a plenum sealed on top. Back at GE I was doing cooling studies of a Xenon lamp for use in a video borescope. Several engineers tried various ways of guiding the air with baffles and various vents and location of vents to allow a good pressure differential. I made a setup that was a solid tract with the fan mounted on the front and an open vent on the back. It was the only solution capable of keeping the cathode below 150C and preventing it from burning out. In order to create the best favorable differential, sealing the front works best.

WRX: Solid hood scoop with rubber bellows on intercooler
911TT: Plastic plenums and intake tracts with rubber bellows on intercooler
Exige: Plastic rooftop intake tract with plenum

The only examples I can think of when you don't see a sealed plenum is when the intercooler is front mounted (such as the turbo mini cooper S) because the amount of air coming in from the front of the car is at such a high volume and pressure than from other locations (like hood mounted) that a plenum wouldn't really help.

[508wrx]

Post 106 on my build thread. I sealed off my IC completely and still couldn't get efficient airflow. This was using 4" bilge blowers with the highest CFM we could find, 180 I think. If we had run ducts to the front of the car it may have worked, but it would have looked pretty terrible. I ended up going AWIC in the end.

http://thefactoryfiveforum.com/showthread.php?12615-508-s-stroker-build-thread&p=199960&viewfull=1#post199960

[freds]

Post 106 on my build thread. I sealed off my IC completely and still couldn't get efficient airflow. This was using 4" bilge blowers with the highest CFM we could find, 180 I think. If we had run ducts to the front of the car it may have worked, but it would have looked pretty terrible. I ended up going AWIC in the end.

http://thefactoryfiveforum.com/showthread.php?12615-508-s-stroker-build-thread&p=199960&viewfull=1#post199960

Great, on topic thanks!...I missed that. Did you by any chance measure the temp of the air after the fan(s) before the IC?
Also, were you drawing the air directly from the two"over the wheel arch" inlets? and do you have a photo of that?

fred

[freds]

I agree. We've discussed the same thing before that the best way is to simply make a plenum to seal the top of the intercooler and then use solid ducts (large diameter hose, sealed intake tracts, not open sided sheet metal) to force cool air onto the intercooler.

Secondary to this is keeping radiant and convective heat sources away. Wrap the exhaust, use heat shields, etc. Third is flushing the engine bay of heated air (as insulation only slows the transfer of heat, doesn't prevent it)

If you look at most OEM application of an intercooler, they all use a bellows to seal the inlet side and use solid ducts. Many racing applications do the same. The WRX rally cars put the radiator in the back and use massive 8" diameter (at least) hoses to bring in air from side scoops to a plenum sealed on top. Back at GE I was doing cooling studies of a Xenon lamp for use in a video borescope. Several engineers tried various ways of guiding the air with baffles and various vents and location of vents to allow a good pressure differential. I made a setup that was a solid tract with the fan mounted on the front and an open vent on the back. It was the only solution capable of keeping the cathode below 150C and preventing it from burning out. In order to create the best favorable differential, sealing the front works best.

WRX: Solid hood scoop with rubber bellows on intercooler
911TT: Plastic plenums and intake tracts with rubber bellows on intercooler
Exige: Plastic rooftop intake tract with plenum

The only examples I can think of when you don't see a sealed plenum is when the intercooler is front mounted (such as the turbo mini cooper S) because the amount of air coming in from the front of the car is at such a high volume and pressure than from other locations (like hood mounted) that a plenum wouldn't really help.

Thanks for your post ......."We've discussed the same thing before that the best way is to simply make a plenum to seal the top of the intercooler".....that is what I have done (so far) and it has definitely helped. See post #30 http://thefactoryfiveforum.com/showthread.php?17351-Air-to-Air-IC-solutions&p=200340#post200340

[508wrx]

I have pictures of it all set up. I just need to find them.

I had it set up to pull air from the side vents in front of the rear wheels. I didn't get any temp reading, but the amount of air that was flowing over the IC was not enough at all. Two ~180CFM bilge blowers did almost nothing when the car was sitting still. That alone was enough for me to drop the idea. If I had run the ducting to the front bumper then this would work. You need that high pressure air.

That box that sits on the IC sealed pretty well too, our only big issue was the size. It was less than an 1/8 from the fiberglass.

My Primary reason for ditching it was I have a freshly built motor. I dont want to blow it because I wanted to test my IC plenum.

[Mechie3]

Thanks for your post ......."We've discussed the same thing before that the best way is to simply make a plenum to seal the top of the intercooler".....that is what I have done (so far) and it has definitely helped. See post #30 http://thefactoryfiveforum.com/showthread.php?17351-Air-to-Air-IC-solutions&p=200340#post200340

The link on post 30 doesn't work for me. I sort of remember what you did, but not 100%. You somehow sealed off the front of the engine bay from the rear. Definitely better than the open sided FFR parts. It allows pressure to build on one side which lets flow go through and prevents back flow.

[508wrx]

I think there was a guy at the open house who did something similar to that. I think he said he had low compression on 2 cylinders so he doesnt really know if it help since he can get into boost...

I could be wrong but that is what I remember. He has a blue plastidipped 818.

[freds]

The link on post 30 doesn't work for me. I sort of remember what you did, but not 100%. You somehow sealed off the front of the engine bay from the rear. Definitely better than the open sided FFR parts. It allows pressure to build on one side which lets flow go through and prevents back flow.

Try this one showing my isolation effort Post #1
http://thefactoryfiveforum.com/showthread.php?16430-Max-use-of-stock-IC&highlight=freds

[904svo]

Here's how I,m doing air/air intercooler using a external fan control by the VSS signal. Which turns on the fan when moving.
45714
45715

[Buzz Skyline]

Here's how I,m doing air/air intercooler using a external fan control by the VSS signal. Which turns on the fan when moving.
Wouldn't it be good to have the fan on when standing still? Like when you're gridding up or waiting at a stop light with a hot engine bay.

[redfogo]

Having fans at X value engine bay temp or at X value engine temp would be the best bet I would think.

[Mechie3]

Rear mounted radiator too I see.

[Bob_n_Cincy]

Rear mounted radiator too I see.
I saw that also.
I'm just trying to see where the rest of his frame went.

904svo, Can you post a picture with a wider field of view.
Bob

[904svo]

Wouldn't it be good to have the fan on when standing still? Like when you're gridding up or waiting at a stop light with a hot engine bay.

Fan make too much noise when standing still, besides you don't need cooling when standing still.

[904svo]

The car is not a FFR kit, it a Beck's 904 but I have the same problems as a 818 with the engine in the middle. The radiator is mounted in the back of the car as
there is no way to mount the radiator in the front of the car.

[GS guy]

SVO - for reference what's the CFM rating on your fan? Do you feel it draws adequate air through the IC when it's running? Any fan off/on temperature readings?
I was planning to use something similar to 508wrx's "old" A-A set-up, ducts feeding into a plenum above the IC, blowing through. Adding blower fans if necessary (my set-up is a little different than typical 818). I googled some similar looking bilge fans and the rating appears to be about 270cfm each, about the highest I've seen for any mfg. bilge fan. That's about 500cfm total. Though about using larger Spal fans, but the 6.5" models only make 330cfm, not a whole lot more than the bilge fans. Some manometer testing will definitely be in order when I get on the road!

[Bob_n_Cincy]

SVO - for reference what's the CFM rating on your fan? Do you feel it draws adequate air through the IC when it's running? Any fan off/on temperature readings?
I was planning to use something similar to 508wrx's "old" A-A set-up, ducts feeding into a plenum above the IC, blowing through. Adding blower fans if necessary (my set-up is a little different than typical 818). I googled some similar looking bilge fans and the rating appears to be about 270cfm each, about the highest I've seen for any mfg. bilge fan. That's about 500cfm total. Though about using larger Spal fans, but the 6.5" models only make 330cfm, not a whole lot more than the bilge fans. Some manometer testing will definitely be in order when I get on the road!

When talking CFM. A 3"x 12" hood scope takes in 1320 CFM at 60 MPH.
Bob

[Buzz Skyline]

Fan make too much noise when standing still, besides you don't need cooling when standing still.

If the engines running, the compartment gets very hot even standing still. I would worry about heat soak from idling, if the fan isn't running. But if your set up works, more power to you.

[C.Plavan]

If the engines running, the compartment gets very hot even standing still. I would worry about heat soak from idling, if the fan isn't running. But if your set up works, more power to you.

+1!

[GS guy]

A slick set-up might be to run a 2-stage fan. Stage 1 runs all the time at ~25-30% output keeping the air moving through the core, then a boost-level activated relay (maybe at 7-8lbs) kicks is up to full output. Looks like the target value should be around 1300cfm thanks to B-n-C. Hmmm, a Spal 12" pusher is 1360, or a couple of 9" HP pushers will easily deliver that amount and more. I wonder how one could set up a 2-speed electrical feed for one of these? Came across this little logic controller board, with a relay or 2 could probably do the trick: http://www.autospeed.com/cms/article.html?&title=The-eLabtronics-Voltage-Switch-Part-1&A=110548

[904svo]

SVO - for reference what's the CFM rating on your fan? Do you feel it draws adequate air through the IC when it's running? Any fan off/on temperature readings?
I was planning to use something similar to 508wrx's "old" A-A set-up, ducts feeding into a plenum above the IC, blowing through. Adding blower fans if necessary (my set-up is a little different than typical 818). I googled some similar looking bilge fans and the rating appears to be about 270cfm each, about the highest I've seen for any mfg. bilge fan. That's about 500cfm total. Though about using larger Spal fans, but the 6.5" models only make 330cfm, not a whole lot more than the bilge fans. Some manometer testing will definitely be in order when I get on the road!

I'm using a Jegs 10 inch fan rated at 1000 cfm.

[GS guy]

Bring this back up to discuss control of an A-A intercooler fan. A simple on-off switch would be easy to do, and seem to be a poor option - with the noise and high current draw, needed or not. Thinking this through, it seems like an IAT sensor is the one to monitor and use to control the fan on-off. Then a PWM controller that provides a continuous low speed (maybe 20-30% output?) to keep heat soak at bay, then proportionally increases speed once the intake temperature goes above 110F or so? Full output at 130F and higher. With a hysteresis and delay (10 sec or so) to maintain fan speed when you're cranking through the gears and rapidly on/off/on boost. Unfortunately, doesn't seem like anyone makes such a controller. The typical (radiator) cooling fan controllers operate at much higher temp. set points although a couple might come close in some of the desired characteristics (but not all). Lingenfelter has a controller that looks like it can operate from an IAT sensor, but only on-off control. The defunct SPAL controller looked like it was close to what's needed - if you could alter the temperature input to typical intercooler IAT levels, but seems to be NLA. Delta Current Controls (DC) might have promise, but again need lower temperature input level. Same as the Autocoolguy controllers (they might be talked into creating a version of their controllers for this purpose?). I did find one specifically made for running an IC fan - and of course the most expensive, from Treadstone. It appears to be triggered by boost pressure, 3psi and above. Not too many details about this unit on their site.
I'm guessing everyone here hasn't gotten past the "trying it out-go-cart" stage and just has a simple switch installed? Maybe 904SVO has worked up a good solution? This seems like it would make for a slick home-constructed project in the Megasquirt category, as an inexpensive kit you assemble as a stand-alone black-box. I can't imagine the electronic components would be more than $50?
Anyone else gotten this far yet?