Why WRX downpipes will not fit the Legacy...

The main problem with using a WRX downpipe is that our cars have less clearance to the firewall. It seems to vary from car to car, but in many cases a WRX downpipe will not clear the firewall. Some people have reported successfully fitting WRX downpipes, but I personally have tried a couple and they all hit my firewall.

The length issues is the easy part, but if since most WRX downpipes will not clear the firewall that kind of kills it right there. If you really want to make it work, you will either have to dimple/dent the downpipe or whack away at the firewall and hope that you can dent it enough to gain some clearance. Given that there isn't very much space to swing a big hammer, it's pretty tough... I've tried.

The main problem with using a WRX downpipe is that our cars have less clearance to the firewall. It seems to vary from car to car, but in many cases a WRX downpipe will not clear the firewall. Some people have reported successfully fitting WRX downpipes, but I personally have tried a couple and they all hit my firewall.

 

The length issues is the easy part, but if since most WRX downpipes will not clear the firewall that kind of kills it right there. If you really want to make it work, you will either have to dimple/dent the downpipe or whack away at the firewall and hope that you can dent it enough to gain some clearance. Given that there isn't very much space to swing a big hammer, it's pretty tough... I've tried.

Wow, I found just the opposite...my TurboXS 4" DP from my WRX fit like a charm...there is plenty of space to the firewall! As for the rest fitting up, no go - as the DP to HFC is 3" and the even though it was the right length, the stock flange wouldn't bolt up...way too small. I have an '06 5MT, so any other config. may vary.

I did have to notch the transmission X-member at the DP to HFC flange just a wee bit, as under load, the flange came into contact. After the Dremel, no contact, no noise.

If you want to use a WRX DP, I'd say this is probably the simplest option although I remember there was something of a fiasco with this company over a DP group buy last year I think.

http://www.rallyperformance.com/Legacyhome.htm

Wow, I found just the opposite...my TurboXS 4" DP from my WRX fit like a charm...there is plenty of space to the firewall! As for the rest fitting up, no go - as the DP to HFC is 3" and the even though it was the right length, the stock flange wouldn't bolt up...way too small. I have an '06 5MT, so any other config. may vary.

 

I did have to notch the transmission X-member at the DP to HFC flange just a wee bit, as under load, the flange came into contact. After the Dremel, no contact, no noise.

I said that some fit. I bought a Invidia WRX downpipe well over a year ago because someone on the forum said they got one to fit their LGT. No go, hit the firewall hard. Same thing with the Megan Racing WRX DP I tried. Like I said before some DP's will fit some LGT's. No guarantees one way or another. If you already have a WRX DP lying around, go ahead and try it out, but I wouldn't go out and buy a WRX downpipe thinking that it's a sure thing that you will be able to easily adapt it.

I said that some fit. I bought a Invidia WRX downpipe well over a year ago because someone on the forum said they got one to fit their LGT. No go, hit the firewall hard. Same thing with the Megan Racing WRX DP I tried. Like I said before some DP's will fit some LGT's. No guarantees one way or another. If you already have a WRX DP lying around, go ahead and try it out, but I wouldn't go out and buy a WRX downpipe thinking that it's a sure thing that you will be able to easily adapt it.

My Bad...I just rechecked my TXS and see that there is only 1/2" clearance between the pipe and the farthest foward point of the firewall. Still, the TXS DP is 4" in dia, and there seems to be a ton more room than on the WRX.

Like BoostJ said, if you have one lying around, might as well try it first!

I'm using a WRX Stromung shorty divorced downpipe. No fit problems, but I did have to go and get a section welded into my cat back to take up the extra length.

I have no fitment problems with the firewall (probably like 2-3 inches clearance.)

Thanks to all for the info. I do not have an extra DP lying around and probably will not go buy one just to see if it will fit.

What bugs me is the lack of choice for catted aftermarket DP's for the Legacy. Cobb's piece is just so pricey compared to most everything out there that I just have trouble bringing myself to buy one.

I really dont get the appeal of the catted downpipe -- catted or catless, they're both illegal for street use and will fail an emmisions test based on a visual inspection...

If i really were worried about it, i would do what Suds suggested and get the crucial shorty downpipe - the best solution.

if you get a high flow metal substrate cat, you get a little bit of backpressure to alleviate most boost surge and spikes, but still have better flow and can pass sniffer checks some of the time.

But ya, still not kosher.

I really dont get the appeal of the catted downpipe -- catted or catless, they're both illegal for street use and will fail an emmisions test based on a visual inspection...

 

If i really were worried about it, i would do what Suds suggested and get the crucial shorty downpipe - the best solution.

I have an HFC after the DP for two reasons: 1) Might pass visual on the street (at night in the rain?), and 2) may cut down on the yellow residue from running catless. My WRX rear lower valance and lower fenders were discolored from running catless.

I really dont get the appeal of the catted downpipe -- catted or catless, they're both illegal for street use and will fail an emmisions test based on a visual inspection...

My rationale;

1. It makes more power than the stock downpipe.

2. It doesn't "stink" like a catless downpipe and still provides some beneficial reduction/conversion of pollutants that catalytic converters provide.

3. Emissions testing in CA is every 6 years for new vehicles. I don't normally keep a car more than 2-3 years.

Yes, it's still illegal... But I also drive over the speed limit (on rare occasions).

-Mike-

 

Yes, it's still illegal... But I also drive under the speed limit (on rare occasions).

 

-Mike-

fixed.

I didn't really get a definitive answer out of theses responses, so to raise a thread from the dead-

what needs to be done to make the older style downpipe work on the LGT? lengthening ?

specifically looking at a turbo xs that I believe is off of the older style cars

wrx DPs are too short. if you want to weld in the section of pipe needed for it to connect with the stock catback, then you can use one.

This is your answer. Although, really it's no big deal to add in some extra pipe to connect to the stock catback.

If you find a great deal on one and are okay paying at most $100 to lengthen your stock catback it should be fine.

The only issue will be come time to remove the downpipe, you will need to also cut the catback back down to fit.

There really isn't any need to do this. Downpipes for the '08~'13 WRX will fit your car and there's a metric shit-ton of those on the market, new and used.[/QU

 

Yea i realize that only reason i ask is because there was a deal on an 07 dp.

Will probably end up going with the correct fitment in any case.

 

However spending $50 and a little time welding is a lot more attractive than spending 400+ for a newer carted downpipe.

 

Seems like most don't have a problem spending ridiculous amounts of money on these cars, and I have as well but i'd like to limit any further spending lol