Will it steal header hp?
 

I am thinking of purchasing a set of headers for a 77 280z, but they are missing the downpipe. My first question is, will the stock downpipe fit? (probably a no.) My second question is, if I had a custom downpipe made, would it rob power from the headers? I'm talking a 30$ pipe made at a ghetto, (no offense intended,) muffler shop. Thanks a bunch.

Tony

having an exhaust shop make a collector and pipe out the back is fine. You don't need a special one for your headers. I assume you have the six into two headers.
That's basiclly what I had done. My headers came with a "downpipe" that went to a 2" single pipe. I had the shop make one that collected to a 2.5" pipe and ran that size all the way back.

In case you didn't already know, they changed heads in '77. The N42 head has square ports and the N47 head has round ports.

The car actually has an E88 head. Which, if I'm not mistaken had round ports. Correct me if I'm wrong. What I don't know, is what year that came from.

Tony

I just did some homework, the E88 had square. Would it be best for me to switch back to an N47 for performance? (without header.)

Thanks

Tony

That's a good question. Go to www.zhome.com and click on "index to technical articles" about heads. According to them the N47 head seems to be better because it has bigger valves. What some don't know is that there were 3 different E88 heads. Two were used in Calif. cars '72 -'74 and were designed to run hotter combustion chambers- not good. I have a '74 parts car with one of these heads. So beware when you see one for sale, you can't tell them apart. All the heads through 7/77 are square ports.