L28 stock exhaust replacement. What is the power gain?

[Stanley]

8DC: that looks horrible. 240Z downpipe has long secondary pipes to a nicer "Y" that might bolt on; they look cool and may have a scavenging effect. Should be plenty around from people who changed to headers. The local muffler shop can cut it at the Y and put a bigger pipe and muffler - as an alternative to headers.

[8DC]

8DC: that looks horrible. 240Z downpipe has long secondary pipes to a nicer "Y" that might bolt on; they look cool and may have a scavenging effect. Should be plenty around from people who changed to headers. The local muffler shop can cut it at the Y and put a bigger pipe and muffler - as an alternative to headers.

Yeah, I'm looking at having some secondary pipes similar to the 240z's fabbed up. I can't begin to imagine how much power I am down due to that pinched collector. Is there anywhere that I can get a new exhaust flange for where it bolts up to the manifold or am I going to need to cut out my old one and reweld it to the new pipes?

Trying to make a custom exhaust similar to Arne's with a magnaflow and vertical slash tips.

Apologies to ozconnection for the thread derailment.

Edited July 11, 2012 by 8DC

[63ronin]

Interesting post. I never checked power output of my '78"projects" 280Z before I started changing things. One thing I have heard over the years is that different dynos will produce different numbers for the same car. So as others have said, the importnat part of the test results provided is in the relative performance gains. Not the final hp numbers.

Other aspect not discussed is weight. Stock cast iron exhaust manifold weighs a ton. Less weight means faster accel for a given hp... well, generally speaking.

I've removed the stock heavy front bumper. (MSA front), pulled all the FI and fit Holley. Added headers and exhast. Quite a bit of weight pulled off. Front sits high now. Looks funny.