praedet Posted July 10, 2008 Share Posted July 10, 2008 Well, I know that a number of folks w/ LGT wagons or OXTs have brought this up, but I thought I would post up some helpful info, to maybe come up with a fix... The 05+ Wagon (Legacy or Outback) has a pretty bad problem with airflow in the rear. This is evidenced by how quickly the rear end gets dirty, and how often you have to use the rear wiper when the ground is wet. All along, I had assumed that it was the spoiler on top of the window that was to blame. This past weekend I was driving around in wet conditions with a Thule T2 bike rack folded up (non-bike carrying condition) against the rear of the car. I was pretty amazed because I used the rear wiper MAYBE 1/4 as much as usual. SO… I think the fix is engineering a diffuser for the rear that guarantees the air is splitting off low on the bumper instead of recirculating up to the window. In other words, something along the lines of the lip style spoiler that a lot of folks put on their sedans, mounted on the bottom of the bumper in between the 2 exhaust cut-outs. Thoughts? Link to comment Share on other sites More sharing options...
ShagginWagon1657615070 Posted July 10, 2008 Share Posted July 10, 2008 That's a great idea! I figured the encrapification was due to road dust flowing around the sides and getting stick to the back. I don't know if the diffuser would work, but worth a try! Link to comment Share on other sites More sharing options...
praedet Posted July 10, 2008 Author Share Posted July 10, 2008 Yeah, I might play around w/ a fiberglass one to see what would happen... Link to comment Share on other sites More sharing options...
ShagginWagon1657615070 Posted July 10, 2008 Share Posted July 10, 2008 Yeah, I might play around w/ a fiberglass one to see what would happen... Well, it's bound to look cool, at least. I'll look forward to pics! Link to comment Share on other sites More sharing options...
BDII Posted July 10, 2008 Share Posted July 10, 2008 I agree with your observastion. My wagon was realllllllllly low and I think that cut down on a lot of the under car drag. Need forum help? Private Message legGTLT Link to comment Share on other sites More sharing options...
outahere Posted July 10, 2008 Share Posted July 10, 2008 ...........I think the fix is engineering a diffuser for the rear that guarantees the air is splitting off low on the bumper instead of recirculating up to the window............ Maybe half a dozen winglets, like on a F1 car:lol: Link to comment Share on other sites More sharing options...
Mitch Posted July 10, 2008 Share Posted July 10, 2008 I think you're on to something there. Especially because it seems like the dirt on the back window is oily. The wiper smears it as much as cleans it. If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
bluesuby Posted July 10, 2008 Share Posted July 10, 2008 If anyone hears about an aftermarket part which cures the dirt, please post. Just to play devil's advocate, could the dirty air be coming from over the roof? The oil could be in the spray kicked up by traffic ahead of you. The bike rack could be causing a low pressure area below the window which draws the airflow down. Link to comment Share on other sites More sharing options...
Mitch Posted July 10, 2008 Share Posted July 10, 2008 Anyone have access to a wind tunnel? Just for a min. If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
fastwgn286 Posted July 11, 2008 Share Posted July 11, 2008 I have a friend that works at NASA Langley.... :brow: edit: no :brow: on this forum, eh? Link to comment Share on other sites More sharing options...
Mitch Posted July 11, 2008 Share Posted July 11, 2008 That's right across the water from me. Think he'd let us borrow it one weekend? I know, Not likely. Never hurts to ask. If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
DrCloud Posted July 11, 2008 Share Posted July 11, 2008 Although we now have two Legacy-platform Subarus, we previously had run through four Impreza-platform vehicles, two of which were Foresters. Our first Forester had the Subaru "dust deflector", a semi-scoop-like add-on that fit at the top of the tailgate. The second one had the Forester rear spoiler, which had a slot instead of the scoop. The dust deflector did a marvelous job of keeping the window clean -- as we found out to our dismay when we got the second Forester. This doesn't suggest that the dirt on the window comes in over the roof, but the additional airflow from the deflector kept it blown off quite effectively. When we bought the Outback, I was quite disappointed that there was nothing like that deflector available. HPH Link to comment Share on other sites More sharing options...
iyalla Posted July 11, 2008 Share Posted July 11, 2008 http://cgi.ebay.com/ebaymotors/2003-2007-Subaru-Forester-Rear-Window-Dust-Deflector_W0QQcmdZViewItemQQcategoryZ38659QQihZ012QQitemZ220162034027QQrefidZstore Really wish they had it for the Legacy platform. I wonder if it is available in other countries for the Legacy/Outback. Hmmmm. Link to comment Share on other sites More sharing options...
praedet Posted July 11, 2008 Author Share Posted July 11, 2008 A proper fix to the air under the car would do the exact same thing... Link to comment Share on other sites More sharing options...
Mitch Posted July 11, 2008 Share Posted July 11, 2008 Tommykaira REAR UNDER SPOILER http://www.japanparts.com/images/ImageFromDB.php?base=1&no=530 Zero Sports REAR WAIST SPOILER http://www.japanparts.com/images/ImageFromDB.php?base=1&no=2352 This might help http://www.japanparts.com/images/ImageFromDB.php?base=1&no=12354 or this? DAMD REAR UNDER SPOILER http://www.japanparts.com/images/ImageFromDB.php?base=1&no=11821 Maybe That's what this is for? Subaru 06 BP WAIST SPOILER SET http://www.japanparts.com/images/ImageFromDB.php?base=1&no=1566 SYMS REAR HALF SPOILER http://www.japanparts.com/images/ImageFromDB.php?base=1&no=14495 SYMS REAR GARNISH WING http://www.japanparts.com/images/ImageFromDB.php?base=1&no=14497 Prova REAR ROOF SPOILER http://www.japanparts.com/images/ImageFromDB.php?base=1&no=5430 Too much? K2 Gear Reiz DEFLECT WING http://www.japanparts.com/images/ImageFromDB.php?base=1&no=1969 ROOF SIDE SPOILER for BP(wagon) http://www.japanparts.com/images/ImageFromDB.php?base=1&no=13747 Hippo Sleek CARBON ROOF SIDE SPOILER in black for wagon http://www.japanparts.com/images/ImageFromDB.php?base=1&no=13754 Gialla vortex generator http://www.japanparts.com/images/ImageFromDB.php?base=1&no=499 Balsarini rear garnish http://www.japanparts.com/images/ImageFromDB.php?base=1&no=14187 Mature REAR BUMPER SPOILER http://www.japanparts.com/images/ImageFromDB.php?base=1&no=1083 If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
praedet Posted July 11, 2008 Author Share Posted July 11, 2008 1. Possibly 2. No 3. Possibly 4. No 5. Possibly 6. No Link to comment Share on other sites More sharing options...
squishyface Posted July 11, 2008 Share Posted July 11, 2008 http://www.hkc-speed.com/index.php?act=viewProd&productId=137 I'm waiting for more from HKC. Link to comment Share on other sites More sharing options...
Mitch Posted July 11, 2008 Share Posted July 11, 2008 Praedet, Are you sure? or just your opinion? I've added some more too. Squishy, You're keeping Jimmy and Co. in business yourself. aren't you? I've spent way too much of my share there too. If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
squishyface Posted July 11, 2008 Share Posted July 11, 2008 Damn those guys at HKC....but I love em! Link to comment Share on other sites More sharing options...
praedet Posted July 11, 2008 Author Share Posted July 11, 2008 Praedet, Are you sure? or just your opinion? I've added some more too.Pretty sure. At least based on the Aero happening behind your typical car... I do have access to a few wind-tunnels, but I need a model of the car to do anything of value... The HKC piece will ONLY change things if the step from the stock piece to the CF cover is large. Other than that, it is the same as stock, but CF. It is not designed to change the fudamental aerodynamic flow underneath the car for sure... Link to comment Share on other sites More sharing options...
Mitch Posted July 11, 2008 Share Posted July 11, 2008 How big is the wind tunnel? If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
praedet Posted July 11, 2008 Author Share Posted July 11, 2008 Different sizes, the one that will be the best to use is the water tunnel. For that, I need a scale Legacy that is about 18" long. The water would allow me to inject dye so that I could watch what is happening as the air goes around the car. At the low speeds a car travels, the density would be pretty close to constant, so water is a VERY good analog, and allows flow visualization... Link to comment Share on other sites More sharing options...
Mitch Posted July 11, 2008 Share Posted July 11, 2008 Well if you do find anything out, keep us informed. I'll wait and see what Fastwgn286 finds out. That's less than a half hour away and will hold a full size car or jet or spaceship. If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
fastwgn286 Posted July 12, 2008 Share Posted July 12, 2008 don't hold your breath. I haven't talked to her in years, and those NASA folks don't like visitors. Had to get on site for some field testing last summer, and it took an hour just to get the visitors pass. Odd, you actually have to declare your citizenship on the form. go figure. Link to comment Share on other sites More sharing options...
Mitch Posted July 12, 2008 Share Posted July 12, 2008 Yeah I didn't really think you'd get access. Just wishful thinking I suppose. If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
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