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Discussion Starter · #1 ·
I have a 77' 280z, and I got 3 to 2 headers from motorsports auto, and a 2.5 inch pipe system with a turbo muffler, and I don't feel much more power at all. I was thinking that maybe the engine isn't getting enought air to even make it effective, so if anybody knows would a new throttle body help, or even a new cam shaft? If anyone has any suggestions please respond. Thanks
 

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Re: I added headers, yet didn't feel much differen

> I have a 77' 280z, and I got 3 to 2 headers
> from motorsports auto, and a 2.5 inch pipe
> system with a turbo muffler, and I don't
> feel much more power at all. I was thinking
> that maybe the engine isn't getting enought
> air to even make it effective, so if anybody
> knows would a new throttle body help, or
> even a new cam shaft? If anyone has any
> suggestions please respond. Thanks
i would try an airfilter setup first. arizona z car makes a cheap one you can try for $30. it is a foam element and lead pipe that attaches directly to your air flow meter boot and eliminates your entire filter box and assembly. also, if your motor has a fair amount of miles on it, you will realize less of a gain with headers and an exhaust because you will have less pressure in the cylinders from things like rings being worn in and therefore your engine doesn't have as great of a capacity to breath better because it is not moving a much air volume under as much pressure as a tight engine.
hope this helps
andy
[email protected]
 

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What most people recommend

Most people would say a mod to one area cannot be truly taken advantage of unless you make a mod to something else. When I first had my 240z, I purchased the 6-1 header and the 2.5 exhaust, very similar to what you have. I felt some difference, but comparitively I gained more in the mpg are than in the hp area. Well, I was wanting more, so I purchased a cam. .495 290 duration and man, that car woke up something fierce. Also, the bigger TB is said to take .5 seconds off your 0-60 time with no other mod. To make a long story short some mods require you to make others in order to feel the full benefit. I would suggest the TB and a performance K&N filter. You will be suprised from your results. If that is not enough, then get the cam, you will definetely gain some horsies.
 

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Re: I added headers, yet didn't feel much differen

> I have a 77' 280z, and I got 3 to 2 headers
> from motorsports auto, and a 2.5 inch pipe
> system with a turbo muffler, and I don't
> feel much more power at all. I was thinking
> that maybe the engine isn't getting enought
> air to even make it effective, so if anybody
> knows would a new throttle body help, or
> even a new cam shaft? If anyone has any
> suggestions please respond. Thanks

You may have a clogged up cataletic converter, or you might not be getting enough intake to offset the change in exhaust. Ever think about a K&N air filter assembly?
I didn't see a notable difference with my 81' 280zx when I put on a Sebring muffler, headers, and a 2.5 exhaust.
 

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Re: I added headers, yet didn't feel much differen

> I have a 77' 280z, and I got 3 to 2 headers
> from motorsports auto, and a 2.5 inch pipe
> system with a turbo muffler, and I don't
> feel much more power at all. I was thinking
> that maybe the engine isn't getting enought
> air to even make it effective, so if anybody
> knows would a new throttle body help, or
> even a new cam shaft? If anyone has any
> suggestions please respond. Thanks

Well, I've prob. posted 10 or more times to stay away from Motorsports 3-2 header, it's not a tuned header and it's basicly as eff. as the stock manifold at best. You should have went to nissan and got their header, or motorsports 6 to 1 header or that Arizona Z's 6 to 1 which is basicly the same as the motorsports 6 to 1 unit. The Monza 6 into 2 header offered by Victoria British isn't all that bad either but it's still not as good as Nissan's headers. The main thing or the magic word in headers is TUNED, equal length but even still the overall lenght of the primary's makes a difference in how it works overall with what intake your running and the diam. of the primary pipes also makes a difference. This is one of the main strenghts of Nissan's offerings, they offer 2 differnt sizes and for a most stock it's better to stay with the smaller diam. primary's to keep the power in the lower end where it's more usefull for street cars. And these ones arn't a weekend throw togeather set like the motorsports 6 into 2. If you can get your money back do it. Or to make the most out of what you have take them in to someplace that will coat them or wrap them up, this will make them at least better than the stock manifold and will show some results plus it's best to not even stop there but wrap it as far back as you can. You will at least show better gas mileage and a snapier throttle responce even if you don't see much HP gain it's the overall eff. of a header that is why it's good to use. You should also try to run a better air filter and run outside cool air into the intake, this really makes a overall better package when adding a header, with a tuned unit it sets up a good scavaging effect that clears out the burnt fuel much better than a untuned and is where you get the most benifit. I did a switch of those motorsports 6-2 to a nissan and the difference is very real, so is the price I'm sad to say and I got these used even but if you want to stay in a affordable range go get the Arizona 6 into 1 setup, it's only 149.00 and a decient header. I guess I should have put more posts about that darn motorsport 6 into 2 one but I hate to keep nagging about a single header, makes me sound fanatic but I hate to see others find out what I did at the cost I spent learning the same thing. So at least wrap it up and that will help, it will make it last longer also and won't overheat your intake runners also where you will hurt performance also, I heard it kind of upsets the resonance of them unless they are all heated the same amount which you'll never get with the heat off of the header. This is second hand info. but to me it makes sence, resonance is super important for a eff. fuel delivery and if the intakes get different heat they get different expansion rates causing turbulance so I'm told. I had a funky running Mikuni setup after the car got warm till I wraped my header and intake and it cleaned it up a lot.
Boy I sure am a yaker ain't I but I hate to leave a stone unturned about a topic so I really rant on.... good luck with it and I hope even a little of what I put here helps...
 

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This is where that FAQ would come in handy!

I can offer you my K&N intake Mod page. If you want to try and free up that restrictive intake without spending a lot more money.

<A HREF=http://www.newtier.com/graber/z-car/Air-Intake-Project/index.html>http://www.newtier.com/graber/z-car/Air-Intake-Project/index.html</A>

Let's see if we can't get that FAQ page going! This is a near perfect example for it!

Steve Graber
 

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Discussion Starter · #7 ·
Thanks every one, but one more question.

thanks for everyones advice, I already have a k&N filter with a pvc pipe to connect, so I think I will try the heat wrap aroud the headers. I want to do the cam yet I am affraid of failing smog, any suggestions. I think I'll check my cylinder compressionalso. anyway thanks.
 

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Mild Set-up

Here's what has been suggested to me and what I'm getting ready to do with my '77.

Install K & N air filter and the Weber big throat throttle body. Install the flat top pistons with the N42 head off a '76. Has stellite valve guides and square exhaust ports. The N42 head with flat top pistons will take the compression ratio up around 10:1. Your stock N47 head will do the same thing but it has inserts that make the exhaust ports round and they occaisiionally fall out on a hot running motor. Oops! Install a new camshaft with about 260-270° duration and .450-.465 lift. Helps with the low end torque and high end breathing. Use stock square port exhaust manifold with 2 1/2 exhaust pipe and reverse flow turbo muffler.
It is possible to put what seems to be all the right stuff in an engine and end up with a dog. The sum of the whole can equal its parts or fall far short if it's not done right.
Phantom
 
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