MrG 3 Posted January 31, 2008 Spotted a Headtune modified inlet (Spec R I think) on ebay, any benefit to say a 1.9 with head and cam mods at all? Share this post Link to post Share on other sites
GLPoomobile 958 Posted January 31, 2008 Like most of these things, any benefit is likely to be so minimal that I really doubt it is worth spending time and money on. IIRC (saw it eBay the other week) all they've done is smooth and port match the ports at the head end, and enlarge the TB end very slightly and smooth it. And without their matching polished TB, which again IIRC is slightly enlarged, the benefit of the larger opening on the manifold is nill. Then you've got all the casting imperfections inside the manifold that they haven't touched (I'm sure when I've stuck my fingers inside a manifold they are quite rough inside). I may be wrong, but I'd say the biggest restriction to airflow is the AFM. Now I'm no expert, but surely improving airflow after the AFM is going to have negligable results unless you can actually force more air through the AFM (i.e. forced induction) Share this post Link to post Share on other sites
Miles 331 1 Cars Posted January 31, 2008 You'd be much better off fiting the later Motronic system on the car, This will sirpass any polished inlet manifold Share this post Link to post Share on other sites
