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heat shield?

Posted: Sat Jan 04, 2003 10:35 pm
by vypa
ok right now i just have a short ram intake on my car and was curious if it would be worth it to fabricate a heat shield out of some sheet metal or somethin? the airbox has been removed but the snorkus and all has been modifed to force air under the hood... would it help my low end at all? not that it seems bad or anything.....

Posted: Sat Jan 04, 2003 10:48 pm
by entirelyturbo
I am about to do just that. A cone-filter conversion is great... in cold weather. Other than that it does take a lot of hot air from the engine bay, which doesn't help HP and can give idle issues (my problem). I'm gonna get an aluminum sheet from a surplus store soon and fabricate one very soon (this week, probably). I will be sure to post my results...

Posted: Sat Jan 04, 2003 10:58 pm
by vypa
cool i appreciate it :D

Posted: Sun Jan 05, 2003 7:52 am
by Legacy777
YES!!!

You would want a heat shield. Also....the idle issue and other stuff can definitely not be good for the MAF.

IMO.....an ideal setup would have a cone type filter with about 6-12" piece of tubing, then have a velocity stack right before the MAF.......have the MAF, and then tubing to the intake. THAT, would be an ideal setup.

If I could find someone to fab an intake tube for not too expensive, I would. I would probably use the PRM filter filter, route a small 3-5" section in the fender before the filter so I would be sucking air from the fender rather then hot engine bay. Maybe I could do it ;)

Posted: Sun Jan 05, 2003 10:37 pm
by vypa
what i did for the intake tub is just buy an intake for another car. they sell 90 degree elbows and other tipes of black rubber tubing in 3" size that you can use to make it fit. mine cost me about $40 total... that and a good amount of time grinding down the MAF housing...

Posted: Tue Jan 07, 2003 4:44 am
by entirelyturbo
Drum roll please...

The heat shield...Does Help! Not by much, but it does help... Just the tiniest bit more juice, and ever so slightly better throttle response and idle, but my idle is bad for other reasons...

Cost me $2.25 scrap aluminum at a surplus store.

But just for kicks, after I get my coilpack, I'm gonna put the airbox back on momentarily and see if I really need the cone filter...

Posted: Tue Jan 07, 2003 6:48 am
by vypa
to me the sound is worth it :P even if i lose a bit of bottem end... but what are the chances of gettin some pics of ur setup? :D

Posted: Tue Jan 07, 2003 6:04 pm
by entirelyturbo
Update: To test a change I make to my car, I usually use it normally during everyday errands. I think this is a general rule: Don't go drivin around right after you did something looking for a difference, or you won't really notice it. Wait until you use the car like you regularly do, and then you'll notice it...

That said, I feel that the heat shield has made a definite difference, Noticeable power increase at highway speeds, and less hesitation...


What I do to post pics is I take them with a regular disposable camera, order a photo CD, and then just put them where I want to... So once I have a reason to buy a disposable, I will reserve a few spaces for intake pics...

Posted: Sun Jan 12, 2003 12:11 am
by vypa
ok well i finished my heat shield and bypassed the TB.. uploaded pics of the intake and some other random pics of the car here

http://vypa.homestead.com/index.html

Posted: Mon Jan 13, 2003 7:36 pm
by entirelyturbo
Yours looks to definitely shield heat, but does it also restrict airflow? Maybe not, since it's right by your resonator... Did you take that out? The plastic tank thingie in the fender? Whether you did or not, your intake probably can scavenge enough air from there, so forget I said anything :lol: ...

I would recommend someone that needs a good laugh to get only the intake for their car. The look on people's faces, especially the ricer people, is absolutely priceless as a dowdy-looking Legacy, such as mine, flies past them making all that noise :twisted: !

I should have some pics of my setup on here sometime this week...

Posted: Mon Jan 13, 2003 9:41 pm
by vypa
what i was tryin to say earlier is that the resonator/snorkus, and all that are still there... but theyve been modified by putting a scoop in the front bumper right below it that forces air into the engine bay right behind the heat shield..... plus as soon as it warms up a bit im gonna pull the intake and heat shield off and drill holes in that area or remove a piece of the sheet metal

Posted: Mon Jan 13, 2003 9:48 pm
by vypa
drill holes in the car that is not the heat shield... lol

Posted: Mon Jan 13, 2003 10:16 pm
by entirelyturbo
BTW, understand this is kinda off-topic, but I got my whole cone-filter kit from www.imprezars.com, called "Washable Cone Air Filter converion - for MY97-99 Impreza and Legacy", just thought I'd throw that out there, so people know where to get one so they don't hafta make their own...

However, I was not overjoyed with their service, You have to buy the K&N filter extra, otherwise you get a ractive filter, which is okay, but I feel like a ricer :? ... Plus they did not give me the bracket they said is included in the package... Had to make my own...

Posted: Thu Jan 16, 2003 5:34 am
by vypa
well just happened to notice today that my entire intake (its aluminum except for the elbow right at the engine) is colllld... as is the air behind the heat shield... and this is after driving the car reallly hard for about 30-45 minutes.... i imagine thats a good sight... but def. worth the $4 for the sheet metal and the 15 minutes of my time :)

Posted: Thu Jan 16, 2003 6:08 am
by entirelyturbo
Good, you did it right then... Don't know if you really need pics of my setup anymore, but I'll try to get it on here anyway...

BTW, I noticed you rigged a hose to your IAC valve, but that's all I saw. Did I not look at the pic closely, or did you actually skip the PCV stuff?

Posted: Thu Jan 16, 2003 6:10 am
by vypa
skipped it.. i was told there was no harm in that... u think there is?

Posted: Thu Jan 16, 2003 6:18 am
by entirelyturbo
Well, what the PCV system does:

It takes fresh air from the intake, sends in into the crankcase, gathers blow-by from the crankcase that results from incomplete sealing of the piston rings (which is inevitable), and sends it into the intake manifold via the PCV valve to be used up by combustion...

This blow-by supposedly contaminates the oil and slightly worsens emissions, so I guess by skipping it, instead of changing your oil at 3000, maybe 2950 :o , not really a big difference...

Don't worry, you're not damaging your engine or anything...

Posted: Thu Jan 16, 2003 6:20 am
by vypa
haha... good didnt really figure i was... especially since i put breather filters on the hoses anyways... its sad that i work at a shop and most u guys kno more than me :lol:

Posted: Thu Jan 16, 2003 6:33 am
by entirelyturbo
Okay, I'm going over the routing in my head...

It gets fresh air from the intake hoses and sends it through the two valve cover hoses. It goes through the crankcase, and comes out a hose attached to the block, very close to the IAC. There are two hoses attached to it, one gathers vacuum from the intake hose to make the whole thing work, then the other hose sends the blow-by into the PCV valve which sends it into the intake manifold...

So I guess if you put breather filters on your valve covers (which would look silly) everything would function normally, but you are lacking vacuum to pull it through...

If I'm wrong, someone correct me, but this is how it works logically to me...

Posted: Thu Jan 16, 2003 6:39 am
by vypa
hm... think im confusing myself and you here... 2 of the hoses (the ones that are hooked up to the intake) pull air in.. the others push air out.. i think.... because those hoses misted a bit of oil on everything, i put breather filters on them... :?.... muuuch too late for me to be thinkin about this