Has anyone tried those cheap manifolds they sell on ebay ?

Whether there is evidence or not, do you want to be the Guinea pig in trying it out?

Made in China stuff like this isn't known to be of quality construction.

Engine out to replace them if they go wrong is a pain in the arse if you can be bothered.

 

Things like

A magnet wouldn't stick to the pipe, but was very strongly attracted to the flanges.

They look really well welded, and they're at least 2mm thick, but they're only partially smoothed and finished inside.

I was a staunch supporter of these. (ten years ago) But with the MSP and AMS cast manifolds so cheap now, it's not worth the potential drama. :zlove:

 

Talk to Craig

Chewy go and talk to Craig at Extreme Engineering in Archerfield. He will be able to point you in the right direction or even supply you what you need.

 

Cant provide input on the z32 specific manifolds however I have used a cheap chinese stainless low mount manifold doing an N/A+T conversion to an RB30E.

not only did the manifold require the stud holes to be drilled larger (no easy task given how hard the steel is) the manifold lasted about 4 weeks before cracking, maybe another 4 weeks until the second crack...

Both cracks along the welds where runners join - this manifold had extra "tabs" welded on to provide support for the flanges as well - didn't stop it from cracking. I got by with exhaust cement and wrap... literally just packed it full of cement and wrapped it all up like an infected wound or something.

its generally accepted that cast manifolds are a far more reliable choice on an RB and they are no effort to change - usually people go stainless just to high-mount the turbo. Imagine changing them on a Z32 one month after fitment... No thank you.

 

Having priced up Inconel and Titanium mandrel bends and plate I

think I'd have to sell the house to pay just for the materials I'll stick with the MSP cast ones I think.