After many hours of reading on this forum, it seems to me that all can agree that the pre-cat and downpipe combination on the Protege is a serious exhaust bottleneck. While there has been much discussion about headers, I was wondering if anyone has just removed the pre-cat and downpipe and replaced it with a custom piece? (Not to be confused with a test pipe that replaces the secondary cat.)
In one thread about making hp/torque gains going n/a, a guy mentioned a custom downpipe made by Wagner Motorsports. I believe this was specifically for turbos -- it had a 2.5" diameter and came with a hi-flow pre-cat. However, I assume someone could make one with 2.25" diameter piping and no pre-cat for n/a applications. I wonder what kind of gains could be made with that? I imagine it would be pretty cheap to fabricate. Why not just eliminate that and save some $$$ instead of buying a header?
Also, if you had this fabricated and combined it with a Magnaflow ss cat-back 2.25" exhaust (list price $444.00 USD), you would be pretty close (ok, maybe a bit over) to the cost of the AWR header. Doing this would pretty much give you a straight 2.25" pipe from exhaust manifold to muffler -- no bottle necks and enough back pressure to maintain torque!
The bonus to me with this system is that to pass inspection (for those who have to), all you would need to do is put the stock pre-cat and downpipe back in place. Of couse you'd have to take care of the CEL when running the custom downpipe, but there is more than enough info on how to do that.
I'd really like to hear some opinions on this setup and what kind of gains to expect -- particularly if someone has actually done it (I'd just be happy to know what the SOP test says, but a dyno chart would be nice). Torque is more important to me than hp becuase I mostly do city driving and only want to be able to zip through traffic. I have also attached a picture of the Wagner downpipe.
Thanks.
In one thread about making hp/torque gains going n/a, a guy mentioned a custom downpipe made by Wagner Motorsports. I believe this was specifically for turbos -- it had a 2.5" diameter and came with a hi-flow pre-cat. However, I assume someone could make one with 2.25" diameter piping and no pre-cat for n/a applications. I wonder what kind of gains could be made with that? I imagine it would be pretty cheap to fabricate. Why not just eliminate that and save some $$$ instead of buying a header?
Also, if you had this fabricated and combined it with a Magnaflow ss cat-back 2.25" exhaust (list price $444.00 USD), you would be pretty close (ok, maybe a bit over) to the cost of the AWR header. Doing this would pretty much give you a straight 2.25" pipe from exhaust manifold to muffler -- no bottle necks and enough back pressure to maintain torque!
The bonus to me with this system is that to pass inspection (for those who have to), all you would need to do is put the stock pre-cat and downpipe back in place. Of couse you'd have to take care of the CEL when running the custom downpipe, but there is more than enough info on how to do that.
I'd really like to hear some opinions on this setup and what kind of gains to expect -- particularly if someone has actually done it (I'd just be happy to know what the SOP test says, but a dyno chart would be nice). Torque is more important to me than hp becuase I mostly do city driving and only want to be able to zip through traffic. I have also attached a picture of the Wagner downpipe.
Thanks.
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