RB25 Stainless V StockExhaust Manifolds

[Boosted Zed]

Note in this case it is not conclusive with flow figures and real results as with factory log style manifolds one runner feeds into another and although firing order is well apart at high rpm contamination from one can effect another. Although same deal applies as in cast iron does not crack or radiate heat as much as stainless and cannot be HPC coated. Although top mount staino has big bling factor.

As tested on flow bench test showing CFM at 25 inches of water.

Stainlo high mnt.. Stainlo low mount.. Stock.. Stock Extrude honed

1. 150.4 .............. 159.7 ................. 175.1 ................ 175.3

2. 234.9 ..............162.4 ................ 164.2 ................. 172.7

3 .169.2 ..............160.7 ................175.8 ............... .. 179.7

4. 176.6 ............... 50.1 .................140.3 ................. 164.2

5. 160.1 ............... 149.9 ................143.6 .................. 155.8

6. 180.4 ............ ..173.3 ............... .145.7 ..................180.3

Max variation

....84.5 ..................23.4 ....................24.5................34.8

Average

....178.6................157.45 ................159.35.............171.33

Pic shows flow bench test machine although pic is of VG30 head.

http://300zx.com.au/ProjectZed/zedexthonemanifold.jpg

[Beer Baron]

haha, johnny is hooked on the goo hone.

interesting that on the stock manifold number 1 flowed the most, but after the goo hone 6 was the highest flowing... don't know what to make of it but it certainly is a big flow imrpovement over stock.

have a V on me john.

[Boosted Zed]

The goo works and seeing is believing as slightly bigger but much smoother.

Also re before and after if high he does not pump that one as much as takes the time and interest to not lonly flow more but try and get more even.

[StockyMcStock]

which manifolds were they? can you throw some pics up of them?

[Boosted Zed]

Not HKS or Greddy some fo these no name brands from OS. Some of the Jap ones may be better although could be worse too. HKS are nice but have seen some yucky Greddy ones although they were for a zed very rough welded and had jagged edges inside.