Extrude Honed OEM Turbo Manifold vs. Aftermarket Tube-Style?

[codyace]

Just wondering if anyone would have an opinion on Extrude Honing their factory Turbo manifold vs. purchasing a Tubular manifold (such as JIC or Silkroad)??

I know extrude honing GTi-R manifolds from FWD sr20 applications nets great results with the reliability of the factory cast manifold.

Basicaly, would extrude honing the factory RWD manifold net similar results, or would I be better off purchasing a tubular style??

[krustindumm]

That seems like a very good option. I suppose it depends on how restricted the stock manifolds are, and how well the runners are designed.

[Jeff240sx]

Honing is just that.. smoothing out the castings of the runners. If the manifold is a poor design, honing won't do much for that.
-Jeff

[Blues13]

IIRC, someone did a dyno test between the stock manifold and a tubular style and gained about 10-15hp on a mildly setup SR. I doubt just honing it would produce those results.

[sepulchral]

Originally Posted by Blues13

IIRC, someone did a dyno test between the stock manifold and a tubular style and gained about 10-15hp on a mildly setup SR. I doubt just honing it would produce those results.

really where did u hear this?

[codyace]

/\ /\ /\ I'd also love to see those results....I guess this will give me somethign to search for...

15 hp isn't a bad deal for just a tubular manifold either...but guys with FWD applications aren't ness. seeing larger HP gains, but are seeing much quicker response/less lag from the extrude honed cast manifold...

Personally, turbo response>horsepower ... at least in my opinion...and as always you can't fault the strength of a cast OEM manifold vs a tubular one...

heres pics from my buddy Ray's setup...he's yet to install it yet...

BEFORE:


AFTER:

[Blues13]

^ That honed manifold looks really nice!

Haha.. ok, I found the thread that I was looking for and it's a bit different from what I stated in that it's not the stock manifold, but It should be of similar value..

It was a comparison between a JGS tools log manifold vs. Fullrace tubular manifold on the same car. The result was a 60hp (300 vs 360) gain over the log manifold design!

Here's the thread:

http://forums.freshalloy.com/ubbthre...e#Post67875679

[Jeff240sx]

That's not bullshit. I saw the car get dyno'd.
Anyway, horsepower arises because of responsiveness when you do a port job on anything.
However, that manifold pic. I'd love to know where he got it done, and the cost. It's beautiful.
-Jeff

[codyace]

Jeff: The manifold was welded by a friend of his. Quite a few SE-R guys got them constructed around october of last year...They are all GTi-R Pulsar manifolds that have been adapted to accept a tial 38 or 40 mm external wastegate.

The extrude hone was done by 'Extrude Hone' in Irwin California. I believe they have costs listed on their website...

I'll be sending an email to Ray to verify this...again I was at mobilization station at the time it was all said/done...