Hi Guys,

Now after i know which exhaust to get, I need some opinion for the headers?
at the moment i got some good price for Nismo R tune headers? some review please..
I tried the search engine,but it seems not to many people using Nismo header.so help needed


cheers,
Jerry

 

get strups headers man , man people are happy with them , and the gain is noticable , that's the only header i would get if i were to buy headers . but FI is coming in feburary . good luck

 

Nismo headers are OK. But for the Same money you could get the Best - Crawford.

Lou

 

NISMO makes quality headers. Workmanship and materials are first rate. However, there are haeders of equal quality for less money.

 

You're right, but they don't have a real collector like the Nismo or Crawford. The closest is from BRM, which is a Nismo Clone.

Lou

 

What is a real collector?

 

I'm wondering what that meant too.

 

Guys, will the R tune headers fit in RHD cars?

 

+1

 

OK - A real collector merges the three pipes into a common larger pipe smoothly, rather than stuffing the three pipes into a common can. I'm not picking on DC here, because they are a good low cost header, but look at this link for an example of a poor (inexpensive) collector design:

http://www.mynismo.com/images/?id=5049

On the other hand the Crawford (and Nismo and BRM) use a real collector:

http://crawfordzcar.com/

And my Crawford's:

 

I just don't see the difference. They both merge smoothly, 3-into-1. The only difference is that the merge point is part of the header on the DC, while the Crawford and Nismo have the merge pipe part of the downstream cat section. I am not disputing the conclusion that the Crawford is a better header, that's what I have. However, I don't see your justification. I can believe equal length, smoothness of the bends, quality, but I don't see the collector differentiation.

 

Here are some pics of the collectors of both headers as I've seen them both first hand. I have the DC sport stainless steel headers on my car. I like them but if I had the money at the time, I would have opted for crawford headers. The install of the crawford headers is very challenging for an average mechanic/tech. The DC's are like nismo as they were made to fit easy without having to tip the engine. What I like about the DC headers as compared with some of the other clones as they grind down the inner piping in the collector = better flow/exhaust scavenging.

 

Pics truly are worth 1000 words.

Thanks for the pics. From an engineering standpoint, the headers on the right are going to flow much better with less pressure losses.

The headers on the left have a lip at the outlet to each of the 3 tubes. This lip will create turbulence whereas the headers on the right will keep the flow smooth. The effect, as you mentioned, will help exhaust scavenging.

Great pics, truly appreciated.

 

The ones on the left are the Crawfords. You think the ones on the right will flow better? What happened to the real collector theory? IMO how much hp a header makes has more to do with the sizing, length, and routing of the tubes, and less with the smoothness of the piping at the merge point. Just an opinion though.

 

I remember reading that nismo has a different design for rhd models.

 

Looks to me that the headers on the left would work better. The exit point where the exhaust comes out looks to be almost a straight line.The all go in the same direction. The other one has the exits at 12,4, and 7 o'clock position. The air has to travel more. I would think less bends = less restrictions = better flow. I don't have an engineering backround but it makes sense to me.

 

The only reason why the Crawford outperform Nismo and DC is because they are long tubes. I wanted to get Crawford but instead went with DC because they do offer performance for cheap. However if you want the max. performance, get Crawfords. I felt a huge difference between stockheaders and the DC ones and I am sure there is a bigger difference with the Crawfords. Just dont get any of the cheap ones(strup, topspeed, alphawerks-all copies of DC or Nismo).

 

I am going to keep my headers. The 3 pipes merge into the collector. Thats good enough for me.

 

Most of teh power gained from any intake or exhaust mod comes from the change in diameter. The next biggest gain comes from the length of the piping and the location of the merge, rather than the shape of the merge. The piping acts like a long tube and the pressure waves caused by teh closing intake or exhaust valves cause 'nodes' of 0 pressure at different locations. By optimizing length, you can optimize where you get most of the power. Thats why Crawford headers give more top power than D/C headers. However, the midrange is about the same. Crawford headers would shine really past 7k RPM where length and quality of merge really matter.

 

are you sure you really want headers?