twin exhaust for subaru???

[jamesc76]

i fancy getting a twin exhaust made for my 2.2 subaru conversion but the problem i think i might face is that as it would basicly be two seperate exhausts (ie from manifold to silencer and out on each side) would i be able to plumb the lamba sensor in just one side and if so would it run ok and not think its running lean

[HarryMann]

It would run based on those two cylinders which may or may not have equal fuel/air and thus mixture distribution to the other two, but should be exactly the same, the motor and manifold is symmetrical so there shouldn't be a problem there...

However, the problem would be that you are messing around with usual wave tuning of the exhaust, and the basic tuned lengths as well. Depending on the lengths of the exhaust systems you could well end up with a motor that has lost torque in the mid range although might appear better in the upper rev-range.

Personally, I wouldn't do that. When you see cars with twin pipes, they are rarely completely separate systems from manifold to tailpipe, and if they are, they would have much longer systems than you could weave easily on a rear mounted engine installation, or they are turbos, where wave tuning just isn't important in the same way.

The complication of cross pipes and general exhaust pipework on VW and Subaru boxers is there because the engines run better throughout the whole rev-range with it. Its still a compromise, but a good one.

[jamesc76]

well the exhaust i have now is home made and works ok maybe i was just lucky !!! do you have a pic of a decent exhaust set up ??????