Installing an Intercooler for Dummies Questions

[Myxalplyx]

Hey all,

 

I'd like to install an intercooler sometime this week. I've already done my homework and have the silicone and vacuum hoses that I need. I measured the turbo-intercooler and intercooler to throttle body length and have determined what length and diameter of piping I'd like to use. It's just a matter of me going to pick the piping up (hopefully tomorrow).

 

I just need some help from those that have already done this (or haven't but knows how I can go about this). I'd like the intercooler to sit a certain height upwards. I have it sitting in my engine bay now almost exactly how I want it mounted except that I'd like to tilt the part facing the throttle body slightly downward. So, here are my questions.

 

1. What can I use to help make the intercooler sit higher up?

 

2. I have a BOV (Blow off valve) mounted onto the intercooler. There are two places for vacuum hoses to go to. I know one is supposed to be routed back to the intake (the larger one). Where does the smaller opening go to and can I hook it up like you see in the pic below?

 

3. The stock turbo to throttle body piece has a place for a vacuum hose to hook up to. When I get the new piping to replace this part (turbo to intercooler), where can I route the vacuum hose that's suppose to go to the stock intake vacuum port?

 

I think that's all for now. Pics are below.

 

[Myxalplyx]

1. What can I use to help make the intercooler sit higher up?

 

2. I have a BOV (Blow off valve) mounted onto the intercooler. There are two places for vacuum hoses to go to. I know one is supposed to be routed back to the intake (the larger one). Where does the smaller opening go to and can I hook it up like you see in the pic below?

 

3. The stock turbo to throttle body piece has a place for a vacuum hose to hook up to. When I get the new piping to replace this part (turbo to intercooler), where can I route the vacuum hose that's suppose to go to the stock intake vacuum port?

Ok, I think I have #1 and #2 covered. Will gave me an answer to #1 as I can use rubber pieces to tilt the intercooler forward and have it sit a little higher. If you have suggestions then that's fine too.

 

#2 I found on the internet. The one piece to the BOV goes back into the intake I know but the little piece on top of the BOV, I didn't know where to hook it up too. Looking at the pic below, it has to go into the intake manifold somewhere post the throttle body valve.

http://us1.webpublications.com.au/static/images/articles/i21/2188_15mg.jpg

 

#3 I'm still weary on. What alternative can I use once I replace the stock intake piping with new piping from the turbo to intercooler? I don't want to have to drill a hole in that intake piece so I can hook a vacuum hose to it. If there's an alternative, please let me know. Thanks!

[subaru_styles]

the little tube off the BOV, does go to your intake manifold... if you search around on it manifold you will find a couple block-off bolts with a square head on it. un screw and attach a fitting to it, then plug in that vacume line.

[nkx]

is that an sti hood scoop? and bondo or something around the edges to stabilize it?

[Myxalplyx]

is that an sti hood scoop? and bondo or something around the edges to stabilize it?

Got me! *shrug* It was like this when I purchased the car.

 

Take a lookey at WJM's BOV setup.

http://consumer.inkfrog.com/pix/WJM/DSCF3522.JPG

 

He's cheating! It doesn't look like his BOV's vacuum hose is routed to the intake manifold. The little hose coming out of his BOV is routed somewhere over there pre-turbo, in the intake piping it seems. Yes.....I'm teh newbie at this.

[nkx]

edit: new stupid question. is the vacuum line from the intake manifold what actuates the recirc to open with the wastegate when you let off the throttle? couldnt you tap into the same line the wastegate gets its signal from?

[BobBrumby]

wastegates only open when there is to much exhuast to go through the turbo (at high rmp) so some exhuast bypasses tha turbo and just goes back through the exhuast as not to damage your it. so no i dont even think wastegates have vac lines and even if it did it would require a different "signal".

[WJM]

Got me! *shrug* It was like this when I purchased the car.

 

Take a lookey at WJM's BOV setup.

http://consumer.inkfrog.com/pix/WJM/DSCF3522.JPG

 

He's cheating! It doesn't look like his BOV's vacuum hose is routed to the intake manifold. The little hose coming out of his BOV is routed somewhere over there pre-turbo, in the intake piping it seems. Yes.....I'm teh newbie at this.

 

Its an 04 WRX hood scoop.

 

Im not cheating! LOL The BOV's vac hose is routed over to where I have a T fitting in some vac lines....that go to the intake maifold.

 

The line thats on the bottom of the stock intake plenum is for the idle ait control valve....well, more like high idle valve. All you need to do is make sure its hooked into a place BEFORE the TB, but after the MAF...as long as its hooked up getting metered ar...the thing will idle correctly when cold and what not. Ive got mine on the side of that intake pipe I have...that yellow/orangeish hose on the left there.

 

And to go back to the IC tilting...it would really but alot better to make a bracket for that IC...cuz if you block off the bottom of that IC...you get a hot spot/no air flow thru it, and you loose IF efficiency. YOu can take one of those spare tire holder thingys with the turbo heat shield on it, cut it up, and reweld it and make some tabs on it and so on...the reaon I used what I did is the IC intake pipes are metal under the IC and there is plenty of room for the air to escape...i see you IC is one made for the 2.5 RS turbo kits...

[WJM]

edit: new stupid question. is the vacuum line from the intake manifold what actuates the recirc to open with the wastegate when you let off the throttle? couldnt you tap into the same line the wastegate gets its signal from?

 

Vac line from intake manifold controls recirc/BOV operation. Tapping into the wasteaget line would be a big no no....as the wastegate (here on, "WG") line is stright off the compressor housing...so it sees DIRECT compressor housing pressure. At part throttle, heavy load, the turbo can and will overspool/over boost if the WG line is to the intake manifold...thats one issue I have with the EBC...its hooked up to the manifold and doesnt see the pre TB presures...to the turbo is really cookin! No lag...but still...is stressing it. Anyhow, at part throt, the waste gate progressively opens as presure rises to keep the turbo from producing more than 6.5~8 PSI or so...when you let off the gas, TB closes, causing lots of air to go no where, compressor surge..and the wastegate opens fully...turbo despools FAST, and the intake charge air goes...somewhere...either recirc/BOV, some into the TB...the rest tries to escape back thru the compressor which=BAD BAD NEWS, and LOTS of stress on the turbo...thats why modern turbo cars have BOV/recirc valves...so the air can escape, turbo stays somehwat spooled, and no turbo death.

[oddcomp]

yeah what wjm said

 

also that large line on the bov needs to vent back into the intake system anywhere between the maf and turbo

since the air your venting has already been measured by the computer and calculated <somewhat> to have a matching amount of fuel injected to go with it

so venting it betwee the maf and turbo keeps it in the system

other wise you can expect some rough running everytime you gear change or let off after boost happens

 

of course if you change over to ms then it doesn' matter you can bolt on one of those nice a loud bov's and vent it to atmosphere and scare teh honduhs away

[Huck369]

Kevin,

I know nothing bout IC's, but don't raise it up too close to the hood, leave at least a half inch space to allow the body to flex with out damaging the IC, then put some 3/4" foam tape around the IC frame to seal it to the hood to make sure it gets all the air coming in, and make sure there is somewhere for the air to go out the bottom....

[Myxalplyx]

Kevin,

I know nothing bout IC's, but don't raise it up too close to the hood, leave at least a half inch space to allow the body to flex with out damaging the IC, then put some 3/4" foam tape around the IC frame to seal it to the hood to make sure it gets all the air coming in, and make sure there is somewhere for the air to go out the bottom....

Point taken Huck! Thanks! There is space between the intercooler and hood scoop now. I don't have anything but a box of sorts that is propping it up from the rear. It's all I have at the moment.

 

This morning, I went out to a local warehouse and picked up pieces of tubing for the turbo-intercooler and intercooler-throttle body. I was looking for aluminum but the warehouse only had this 304 stainless steel piping. Boy was that expensive. I don't think I have to worry about any rust for a while. Hehe!

 

Got home and put the pieces on and here's what it looked like.

 

 

 

I had to situate the piping at a weird angle because hey both would not go straight back to the intercooler without affecting the other one. Fortunately, the intercooler-throttle body pipe comes --><-- close to the hood but it doesn't hit. Make me think about the flexing you spoke of Huck. :-\ I seems to work for now though. Also, I thought I'd have to remove the plastic 'F' shaped piece near the throttle body and connects 3 different vacuum hoses. It seems to go under the throttle body piping without issue.

 

 

So now I'm left with two problems. Problem #1 is that the BOV vents right into the turbo to intercooler piping. If it was to vent to the atmosphere, it would be ok but it needs to go between the maf and turbo like those of you said. There is little to no space here. It may be able to be rotated 180 degrees and face the intercooler-throttle body piping so it can have more room.

I don't want to vent it to the intake just yet. I want to temporarily keep the BOV disabled. With it on the intercooler the way it is, how do I go about that? I took the BOV piece and changed it out for a little piece I have with an air filter on it. It doesn't make a difference but I wanted to see what it looks like. It's in the last pic. Do I HAVE to do something about the piece that's supposed to connect to a port that's after the throttle body plate? I mean, can I just leave the BOV just like this and it be non-functional until I hook up the two vacuum hoses to it? Trust me, I'll be working on it this week.

 

 

Problem #2 is that with the way the car sits now, I still have that vacuum hose that connects to the stock intake between the turbo and the throttle body. Where can I tap it into now or can I just cap it off until I'm ready to use it?

 

 

 

Finally, here's how the car sits now with the BOV having an air filter on it.

 

 

 

Remember guys/gals, I know this is a simple procedure but to the majority of us out here, we don't know how to go about this. This stuff may be as simple as scratching your back to many of you but trust me, there are way more of us back in the shadows that are clueless and don't care for the 'use the search' response or other stuff. I've been here for ages and know about this stuff (in theory). I just never went about doing it. I thank all of you for your help. It seems to be coming together ok.

[Subarutex]

Ok. First off kevin... That is a beautiful intercooler.

 

Second... I downloaded a motorweek video the other day, about the 22B. Saw a guy on there named kevin leaning up against a turbo'd and NAWS'd OBS with black racing stripes... twas this you?

 

Thirdish... The BOV has 2 ports for hoses. A large and a small. The small needs to be hooked to the vaccuum system. This actuates the diaphragm inside the BOV/BPV. Now, the large end is where the excess pressure will be bled off. With just the air filter on the big end, and the small hose hooked to it, you will be venting to atmosphere. It will give you a cool whoosh sound when you shift. Some people have trouble with the car idling like this, some live with the rough idle for the sound. If you wanted to run completely without the BOV/BPV just unplug the small vac. source, make sure that the line is capped so it doesn't leak.

 

In my opinion, the best thing you could do, is leave it hooked up as is, with the air filter on it. It will vent to atmosphere.

 

Fourthly... Problem #2 you refer to vac. hoses. Those fatter lines are not vaccuum lines, they are PCV hoses. These vent your crankcase. In the FSM it shows how the system works to keep the pressure out of the crankcase (oil system). The line that is left free in your picture (use to connect to intake piece) is what draws air into the system. Since this air isn't part of the combustion process, it doesn't need to be drawn in from a point after the MAF. It would be in your best interest to simply put another mini air filter on it. At schmucks they sell these, i think they are labeled as PCV breathers, or something to that effect.

 

Fifthly... I have some pictures of that scoop being done "in progress" if you'd like them. On that note, how is the bondo holding up around the edges of the scoop? Is it cracking? Shrinking?

 

Good luck, and don't blow it up!

[Myxalplyx]

Ok. First off kevin... That is a beautiful intercooler.

 

Second... I downloaded a motorweek video the other day, about the 22B. Saw a guy on there named kevin leaning up against a turbo'd and NAWS'd OBS with black racing stripes... twas this you?

Thanks Tex. The compliment means a lot coming from you. And yeah, that was me on the motorweek video. Met lots of people and had a good time. Those were the good ole days. Surprisingly, the car is still running quite well albeit N/A now.

 

Fifthly... I have some pictures of that scoop being done "in progress" if you'd like them. On that note, how is the bondo holding up around the edges of the scoop? Is it cracking? Shrinking?

 

Good luck, and don't blow it up!

Sure, that'd be great to have the pics. It seems to be ok. The scoop gets kinda jittery post 80+ mph (Don't ask, I was just getting a feel for the new tires). Tex, I just got back from driving around. The BOV was left as is (like you suggested) but I had put a rubber plug into that other piece you spoke of. I was going to wait until hopefully I got some responses tonight but I couldnt' wait so I warmed up the car and drove around the neighborhood. To my surprise the BOV was working just fine. I was expecting either nothing to happen or if it did work, clouds of smoke to be made between shifts and the car run super rich and stall. None of that happened. The car ran just fine like it did prior to the install. Man, I'm sooo happy. I know I had major problems on my OBS trying to vent to the atmosphere and so I thought most other cars would have the same problem. I'll try to make a little video of the Blitz BOV doing its thing tomorrow after picking my son up from school. I'll let him handle the camera but he's only 9yrs old.

 

I'll try to get an air filter like you suggest to put on that PCV line like you suggest rather than leaving it plugged up. I really appreciate the advice. I hope the piping holds together well since the turbo to intercooler pipe seems fussy. Off to work in 15 minutes.

 

Oh..of special note: The turbo boost didn't spool up as quickly as it did prior to the intercooler install. It was noticable. I guess the difference in piping length and maybe the pressure drop inside the intercooler contributed to the slower spool up. No matter! I'm happy!

[Subarutex]

Once you get all the little bugs figured out with the IC, definately consider a MBC. Even if you set the MBC at pretty much stock boost (8psi or so) it will come on a lot sooner.

[rallyruss]

hmm I think the line that went to the old aluminum was for the idle air control like Will stated. could be wrong mine has not been stock for quite a while.

 

the blow off/bypass valve needs the vac line hooked up to it or it will leak boost unless you bluged the outlet too. simply T into the line that feeds the vacume canister BEFORE the check valve.

 

I ran mine open for about a week. got to be a real pain espically on long drives. not good for the mixture either. it shifts alot better with it hooked up properly too.

 

tubing looks real good. nice intercooler too. let me know the details on that thing again. I know you did already but I forgot. sorry.

 

I would be a little concerned about the hoses you used and fixing the intercooler to the body. I dont see enough flex alowed at the hoses. most stock systems use a flex or bulge hose to let it have more freedom of movement. I would show you mine but the wife broke the camera good this time.

 

check out www.turbohoses.com

[WJM]

 

damnit! thats the high idle valve hose! i certinly believe it needs to be plumbed in somewhere post-MAF....

 

And thats certinly the best looking n00b IC install ive ever seen. Looks way beter than mine. :cool:

[Myxalplyx]

Well, looks like the job is finished. Just want to thank everyone who helped me out in this thread and in PMs.

 

The intercooler air guidance is is controlled by ghetto cardboard I had laying around in my garage. I went to Home Depot but had 'writers block' and couldn't think of anything else to use. So cardboard and duct tape it was. Seems to work ok as the intercooler was icy cold after a few runs.

 

I simply routed the BOV vacuum hose to the high idle hose and the car seems to idle and drive well. No more hissing noise coming from the BOV at idle. I think I'm done with this for now unless that BOV vacuum hose can cause an explosion or something.

 

 

 

 

Believe it or not, the part directly over the cardboard is part of the hood scoop itself. It should do ok but I don't know for how long. Oh well!

 

 

 

Oh yeah, I tried hooking up a crankcase air filter to that high idle vacuum hose in a failed attempt. It looked pretty for all of 5 seconds. That's because the car would die because it couldn't hold idle. Yeah, I don't know what I'm doing but I'm trying. I thought I read somewhere in the thread I could do this. Oops!

[Subarutex]

Sorry Kevin, thats my bad on the Aux. Air Valve. I've had mine off for so long...

 

If you can't get it plumbed into the intake track (somewhere between the MAF and the throttle body) you can always plug it. Thats how mine was forever, then I just removed it, and plugged the port on the intake manifold.

[rallyruss]

just sent you a PM and I see the pic now too. your BOV will not work like that. it may leak boost and then not vent properly. it needs a proper signal. It has to see MANIFOLD vac and boost after the throttle body. otherwise looks like some good progress. keep it up.

[WJM]

just sent you a PM and I see the pic now too. your BOV will not work like that. it may leak boost and then not vent properly. it needs a proper signal. It has to see MANIFOLD vac and boost after the throttle body. otherwise looks like some good progress. keep it up.

 

thats what I said.

[archemitis]

i love the pics of all your mods, but damnit man! pressure wash your engine bay! =]

[calebz]

I know I am using a different IC than you, but mine had a 2-3 vacuum lines plumbed into it. One of them was the exact same size as the Aux Air valve line, so I just bought a longer hose and plumbed the AAV right into the back of the IC.