choosing a header for my Z and how much whp I can get
 

Hi I need help to choose headers for my Z...Right now I have the k&n intake and the invidia gemini catback...So please guys help me....how much whp I could get when I install a header and the flash the car?

Way too many variables to give any kind of firm answer. Which headers? Who does the tune. &c, &c, &c. Some of the other members may be able to give you an approximate range.

IMO skip the headers and just do a HFC at this point. This will give you most of the gains of going with a header, both weight and power wise, while being drastically easier to install.

DR_ is pretty much correct. HFC's are much cheaper and easier to install. They create a little bit of a raspy sound though so keep that in mind.

I have fast intentions long tube headers which delete the cats and I love them. They sound amazing. By themselves they give you about 19hp, but I have full bolt ons so you have to remember the law of diminishing returns when using more than one mod. Cats vary but you could expect 10-15hp from high flow cats.

My only complaint was that my headers were insanely difficult to install (I did it myself), but that was partly because half the bolts in my engine bay were stripped, and one of my O2 sensors was cross threaded from the factory. Major PITA.

You can check out my build thread (project mistress) for videos of the headers and sound clips of what you can expect :) hope that helps, and welcome to premium!


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Agree in PITA install. Also have to plan on buying O2 sensors as they are difficult extract and not break them. I think Nissan employs the Hulk to tighten their bolts. 20whp gains are what are expected for the most part. I gained 30 untuned but had an exhaust installed as well (with HFC). The stock headers are actually quite good, most vehicle have crappy log manifolds, the Z comes with equal length headers right from the box.

Can you guys give me a link of the HFC to see it?

I was looking on ebay and the invidia line have an HFC under $500 any of you know if its a good option?

Berk and Stillen HFC are both high quality.

If I buy a short header I can put a HFC too?

The HFC will give me more or equal whp than a header?

Back in The Good Old Days of big blocks, dual quads, &c, it was a pretty safe bet that the bigger your exhaust pipes, the better the performance. Not quite that simple, but it's my post.

Nowadays engines, especially hipo engines like the VQ, are high-strung, sensitive, intricate works of high-precision engineering, that don't always do better with bigger. You have to reach a balance between intake, engine, and exhaust.
You can't just throw the best parts together and expect to get the best system. You need parts that play well together.

That said, keep asking questions. The more you know, the better your decisions will be.

HFCs won't breathe as well as a no-cat design, but the loss in hp will be minimal. They are just a little more restrictive than headers.


Sent from my iPizzle using magic and new-fangled science stuff

Here is an excerpt from a thread about ART pipes and LTH's. Will give you an idea of how they work

ART Pipe with an aftermarket shorty header vs LTH's. Longer primaries improve scavenging and merge the exhaust together in pulses. Longer primaries generally improve torque over shorter ones. 1 3/4" diameter tubing generally improves torque over 1 7/8ths" Stepped headers use a combination of the two different sizes to improve low end torque and keep top end power. A tuned header means tuning the length of the primaries to the powerband of the engine. LTH's improve scavenging and assists in pulling old exhaust gasses out of the combustion chamber. The higher the rpm, the less critical this is, but is VERY important for making power and torque down low and below 4k rpm. Both the PPE LTH's and the F.I LTH exit at 2.5" and has the benefit of not being restricted to 2 1/4" when connecting to the stock header.

Shorty headers attempt to do the same in a smaller package. Primary length is limited, they will not be stepped, and can only improve flow to a certain degree. Attaching an ART pipe will improve performance... over the stock cats or maybe a standard test pipe, but it's still just a pipe that can't possibly do the same job as having LTH's doing. The only shorty/test pipe combo that came close to LTH's were the momentum headers and TP. But there is no direct comparison as gains made included VVEL tuning.

:iagree: and they sounds awesome.... sad its my last year running mine because for some reason a cast iron long tube header just doesn't make sense for a turbo track car :ughdance: