Ok guys and Gals. I'm looking for information and/or opinions. I'm going to have a used Cooper S turbo rebuilt. It's going to be a hybrid rebuild. (It includes the K04 compressor wheel, high flow turbine wheel, HP 360 rebuild and all machining/balancing to perform the upgrade). When I get this done I'm also going to replace the Exhaust Manifold. I have 2 manifolds at my disposal, A used cooper S manifold and a new JCW tuning kit manifold. What I'm wondering is if I get the Cooper S manifold ported and ceramic coated will it be better than the JCW manifold? And is there any advantage to porting the JCW manifold? The reason I ask is I have heard reports a ported Cooper S manifold flow more than the JCW Manifold. But what I don't know is if this comparing 2 ported manifolds or if its just the Cooper S manifold is ported and JCW is not. Also I don't know if the JCW CAN be ported, as in its already maxed out? So what do people think? Ported Cooper S Manifold or JCW Manifold? Here are some pics to show the difference between the two manifolds. Dirty/used manifold = Cooper S manifold, Clean/new manifold = JCW tuning kit manifold.
Contact Jan / RMW about a Big Valve head and use his High flow header. Big ports on a stock manifold will do you no good unless the head has the same port size. (Port matching)
And now that I think about it. The service center that will be doing the porting wanted me to send the Manifold gasket as well. Wouldn't that be as close to port matching as you could get without having the head there as well?
On a past turbo car (not a MINI) I had good success with Extrude Hone being done to the manifold and the turbo. The process improves the flow, volume, and smooths the inside.
Is something like that a replacement service to porting? Or is that something to do in addition with porting?
Porting can achieve 2 things. First making the ports larger. Second matching the manifold port to the head port so there are no sharp transitions. Extrude Honing the manifold will achieve the first and even better it will maximize and smooth the flow through the entire manifold. For the second you would have to have the head bolted on and Extrude Hone them together. This is done and other then the port matching it also maximizes and smooths the intake flow in the head. There are a few OEMs that now Extrude Hone parts on their performance engines. The one thing to consider with any of this, unless the stock parts are really rough, is the improvement is usually only seen on a timed lap on the track. It's used in racing a lot because of regulations where you can't change the manifold, put on a big valve head, swap out a turbo... For street cars there are no regulations like that (except for Cali) so a bigger gain can be had with bolting on parts. It was done to my WRX because of autocross regulations. The turbo spooled up faster because of the smoothed out flow with in it and it handled a bit more air for top end benefits.