I have a HKS ST with 3582r T3 set up and the manifolds and T3 are keeping me at 450RWHP.

I want to have a kit like the twin scroll boosted performance kit that uses OEM location of headers not a cross over design like HKS.

I saw this post that showed the restriction of exhaust gass (back pressure) where the stock 350z (and HKS) headers are 1.64" ID. Where 370z OEM and some aftermarket headers are 2.2" ID
https://my350z.com/forum/forced-indu...ml#post9689002


I brought Fujitsubo headers thinking they are 2.2" ID but they are only 2" ID.
https://www.fujitsubo.co.jp/prods/de...03313/00000748
Am i better off finding another set (RHD) that is 2.2" like the Megan Racing ones (quality not as good as fujitsubo but they are 2.2" ? or has people used 2" ID and got 600-700HP ?

Thanks

p.s fujitsubo drivers side RHD is 6" from bottom of runner mount to top of widest pipe closest to drive shaft. The other side is 7".

Megan is 6.1" for the drive shaft side and 5.9" for passenger side. So they will fit but will they not crack ?

 

Fujitsubo

 

Any after-market header will be more than sufficient for your application and goals. Your turbo however will always be the issue. If you want that kind of power, you must go to a T4 turbo/turbine. The PTE6766 .96 a/r (tangential) or the T4 1.32 a/r (twin scroll) would work very well, although the 6266 will get you over 600whp with the same turbine housings.

 

Thanks for the reply. I am getting 6466 T4 .84 divided. The .84 will flow enough for this?

The 2"ID Fujitsubo pictures above you think will be fine? Its not worth getting megan 2.2" ones or asking a fabricator to cut the collector ends off and make 2.2"

This is for 2003 VQ35DE

 

megan height that goes on the RHD side





megan ID





megan collector





Fujitsubo inner collector

 

Turbine is way to small, you need to step it up to a 1.32 a/r, or at least the 1.15 a/r in a twin scroll configurations. This .84 a/r is good for stock 420whp, and becomes a choking point after that.

Headers are fine.

 

ok great thank that makes it alot easier with headers then

Seems either
1.15 or
132 a/r are the way to go.

Will have to decide which one thou.. ? for 600-700Hp what would you choose