PDA

View Full Version : making a hood scoop functional



ads2357
05-17-2005, 11:53 PM
i have a 98 outback impreza and i was wondering if there is any way i can make my hood scoop functional either with a kit or by building it by myself?

Reason
05-18-2005, 01:52 AM
The hood scoop is for an intercooler. Other than that I think it's pointless, just looks cool. Pwise2326 did it to his Legacy, he ran into issues.

jey
05-18-2005, 10:11 AM
Well you can take off the plastic thing that blocks the flow of air through the hood scoop and get a little extra engine bay cooling :)

Pwise2326
05-18-2005, 12:16 PM
Exactly. Basically you just unscrew the metal plate thats underneath it, you'll probably have to rip a little of the heatshielding (if you haven't gutted it off the bottom of the hood yet), and theres 6 or 8 screws, no biggy. I had mine off for a while, it was nice because all the airflow chilled the heck out of my engine bay, especially the intake plenum box that sits just underneat the opening attached to the throttle body. Butt dyno was telling me that the extra chill on the box was nice made the car feel more torquey, then again it could've just been my mind playing tricks on me as it was my first mod on the car pushing the placebo effect. It most likely dropped intake air temps a little as well (the box was always ice cold even after cruising around for a couple hours whereas with the plate on it would be hot/warmer to the touch). Only problem with doing so is that if it rains the water will drain right onto your block, and if you have any old or exposed electrical connections (knowing subaru, you probably do), expect the worse after a good rainshower. I went to start up my car and it was running awfully rough, the check engine light was on, smoke was coming from all sorts of places, throttle response was irradic, it was crazy. Turns out if you haven't replaced the gas line (as per the service bulletin about smelling gas on cold starts) water may seep into the system, in my case a good amount did, so a bottle of dry gas later I was fine, but I'm lucky it was only that. I had a cylinder misfire and other electrical systems go haywire due to crazy sensor readings, and the smoke - thank god was only steam...but you know how it is when your in a panic and you don't realize your hot engine has a puddle of water hanging out on top of it.

So long story short, if you live in Cali where it rains twice a year, go for it, but in NE it's probably not the best idea. What I did to compromise is I cut the openings in the metal plate considerably larger but left all the parts where water would mainly be drawn away and drain in its original path. Has been working fine. I wouldn't remove it unless you had an intercooler sitting right below it, in which case I would find an L hood, chop it and put a WRX or STI scoop (basically anything larger than stock) to make it more efficient (unless you want the sleeper look and the FMIC - which would leave you with a pointless scoop again.

ooberdoob
05-18-2005, 02:15 PM
^^werd. he nailed every point i could think of.^^

[/thread]

masube81
05-18-2005, 02:25 PM
Ryan you're the man. :smt023

haplesspete
05-18-2005, 06:04 PM
Pwise you should be posting in the DIY section with knowhow like that !

your detail is great.

Pwise2326
05-18-2005, 06:59 PM
I'm one for the free mods, thats all, comes with the territory being a college student. My only big expensive mod nearly wiped all my summer earnings clean and left me with nothing for the school year! I'll add a whole bunch soon.

ads2357
05-18-2005, 10:58 PM
thanks everyone, i also found out one of my friends totaled his wrx sti and maybe i can buy his intercooler from him

fibuz
05-18-2005, 11:08 PM
uhh...hopefully you'll be buying more than just the intercooler...

ads2357
05-18-2005, 11:11 PM
yea when i said intercooler i meant everything with it too :lol:

haplesspete
05-19-2005, 07:14 AM
I have seen plenty of turbos without intrecoolers maybe an intercooler without a turbo is the new craze :smt043

haplesspete
05-19-2005, 07:38 AM
i have a 98 outback impreza and i was wondering if there is any way i can make my hood scoop functional either with a kit or by building it by myself?

Just on the off chance that you dont know ads, the scoop on the hood is there to catch the air as you drive, on a turbo charged engine the air is used from the exaust and forced back in via the turbo the air is realy hot. there for if and an intercooler is used the hot air is pushed through the cooler much like water through a radiator. and the air going through your scoop cools the intercooler. the theory behind it is that the colder the air going in to the engine the better the combustion. That is the case with all engines not just turbos. any car will go better on a cold day. but because turbos use exausted air they use an intercooler. The bigger the better !!

I hope my ramblings help :-D

PETE

ooberdoob
05-19-2005, 11:53 AM
intercooling 101 with professor Petey BH4 - Auckland (like "PHD - Harvard" for those who didn't catch it)

ads2357
05-19-2005, 08:16 PM
how could i do it w/o the intercooler are there any plans, kits, etc.

subieyacht
05-20-2005, 12:44 AM
I know a guy with an gc8 that just pluged the inlet side of the torque box, and cut the top out of the box, and fabed up a plate much like the one on the wrxs that seals around the intercooler. It esentally created a super short ram intake, but then again youd have to take the maf into consideration, because the 2000 imprezas have the maf bulit into the intake manifold. so i guess its up to you. your best bet is to just take the plate off. thats what i did, and i havent had any problems yet. get a cone too.

jey
05-20-2005, 10:48 PM
how could i do it w/o the intercooler are there any plans, kits, etc.

I think AVO has a turbo kit without an intercooler. I wouldn't advise it though - an intercooler also lowers intake temperatures, preventing detonation, so it's a more reliable setup. If you've got a Subaru and are spending the time/money to turbo it, I think you might as well get the intercooler.

haplesspete
05-21-2005, 12:39 AM
I think he means he still wants to put the scoop on and not get his engine wet ??

Pwise2326
05-21-2005, 03:03 AM
Like everyone said, if you want to turbo it, get an intercooler, but in all honesty, getting a kit like the AVO and turboing an N/A powerplant isn't the most cost effective option. The kit itself (depending on what you get) can cost up to 5 grand for everything you need. To make things worse, being an N/A block, it wasn't designed for high boost pressures, so to keep your engine from blowing, you can only run 7-9psi, which won't get you much power for the money you are spending. Your best bet is going to a junkyard, finding a WRX, oldschool Legacy turbo, etc etc with a block and wiring in good shape, gut it out, find the other parts you need that may have gotten damaged elsewhere (radiator, etc), take the block apart, clean it out, build it back up, spend the extra cash left over (you should still have a couple grand to play with figuring you have 5000 instead of getting the turbo kit) on a better turbo, engine management, fuel management, put it all in, wire it up, and for the same amount of money you now have a car that can play with the big boys.

As far as doing that plenum box intake mod, only way you could do it would be to find the RS manifold that has the MAF built into it, that would be a pretty sweet setup but a bigger hoodscoop would probably be more effective and you'd need to make a pretty decent splitter to seal it to your box and filter, otherwise you're just going to be sucking in all the hot air under the hood and it will be no better than an open cone filter. Just don't use that setup during rain...talk about hydrolock! Thats like pouring water down your engines throat compared to it sucking it up through a straw.

Basically what this mod comes down to is making the plate accessible to either remove and reinstall as the weather changes, or to mod the plate to allow more air flow while allowing a path for water to drain away from the top of your engine. Anything more or less is beyond this mod, and should probably be discussed in another thread as far as turbo options and the like. If weather permits this weekend I'll snap some shots of my plate and write up a DIY guide to either hack the plate or just simply remove it. It won't do anything N/A-wise by removing it, but it will keep things a little cooler.

ads2357
05-21-2005, 08:09 PM
can anyone give me a link for the turbo from AVO

Pwise2326
05-21-2005, 11:17 PM
Go to www.rallitek.com (http://www.rallitek.com) , click on Legacy performance parts and the kit should be one of the first things listed...kinda pricey thought, but if thats what you want to do. It may be cheaper to bolt up a WRX exhaust manifold and turbo to your EJ25 (or 22...forgot which you have), and run low boost with a SAFC or piggyback ECU to correct the fuel and timing. Only other thing you'd probably want is a WRX fuel pump and some slightly larger injectors and you'd be set. You could probably find those parts at the salvage yard for cheap.

subieyacht
05-23-2005, 01:30 PM
AVO makes good stuff but its realy realy expensive, Its almost easier to get a turbo legacy block and build your own kit, i know a guy who did that on his OBS and he runs 19 lbs of boost, those blocks are invinsable. another option is to swap in an sti block, and use your stock heads, (thats my dream set up) but that requires oodles of cash.

ads2357
06-06-2005, 02:08 PM
i was lookingat an injen cold air intake but it says it is only for a 2.5L engine. Will it work with my 2.2L? And if it wont work any suggestions?

Pwise2326
06-06-2005, 11:14 PM
Ads, you should post this up either as a new thread or in another intake forum -- just a friendly reminder. You should be able to, the design is the same, but I'd check with the vendor you are going to buy it from first just to make sure, just send them an email and they will happily answer any questions you can conjure up.

Svenerachi1
07-19-2005, 02:06 AM
something about what you guys said earlier concerning getting a larger, "more effective" hoodscoop like an STI or WRX scoop.

I may be mistaken, but on another forum i read that the legacy scoop was the most aerodynamic and drew the most air in compared to the other scoops due to the way the air flows over the hood. the STI scoop was rushed and Subaru wasn't ever fully satisfied with it.

A guy in another forum had the same idea and they flamed him hardcore

just my .02, like i said, I could be mistaken

gator gt
07-29-2005, 12:01 AM
I have also heard from a person in Japan, who says the BD/BG scoop is very efficient.

I'm not too sure about Subaru not liking the STi scoop...haven't heard that one.

But, supposedly the Legacy scoop draws in the air after riding the longer gentler slope of the Legacy hood, rather than the shorter more turbulent Impreza hood, thus the need for a taller scoop.

I dunno. If the rest of the world had turbo'd BD/BG's then the scoop must have worked just fine.

I'm not worried about it.

GGT