I am using the Ntc3 factory team dual chamber pipe(with 10mm or so cut off the manifold) with my Jlr, and it had alot of power when my car switched to second gear. I knew that I was not in the powerband at all in first gear with the 21t/27t pinion combo, so I switched to 19t/25t pinions that matches my competitor's gearing... Dynotech Racing built me some more lightweight aluminum parts that got my Ntc3(1659grams) down very close to the minimum weight limit, from the hefty 1721grams it was before..... All in all I am happy with the progress, but I have not tested my new and improved ntc3 yet...