I'm glad this topic has come up again because I was going to post a question about GT-R manifolds in the original thread about extrusion honed manifolds that John posted. Despite having pulled apart the exhaust side of my car all of about 2 months ago, I think I'm going to have to do it again as I think the rear manifold is leaking. Its a shit of a job, so I am looking for an incentive
I'd like to know that too. "Stainless manifold" isn't terribly descriptive John: are you able to clarrify exactly what brand the stainless manifold was?
AFAIK, the main options are:
1) Keep the stockers.
2) Go for the UAS extrusion honed versions.
3) One of many jap. manifolds.
Of the Japanese, the ones I have come across are from Silk Road (~$500 + delivery/charges), HPI (~$1500 + delivery/charges) and Garage Saurus (don't recall the cost): unfortunately none of them have any flow data on their websites.
To those who have replaced/changed their manifolds (with twin lowmounts): what did you use and what benefits did you notice?
Cheers,
Lucien.