I bought a peugeot 205 GTI aftermarket manifold for my 405 sri (1989) and it doesen't run very well, It doesn't accelerate properly and feels like it is restricting the flow and the car hesitates and stays at a Set rpm for a second or two. I had to modify it quite a bit to get it to fit because of clearance issues, the diamiter of the branches got a bit smaller because It had to be hammered, cut and welded. The manifold was meant for 1.6 and 1.9 engines, the Pipe after the collector appeared to Be smaller than the stock one, not shure should that effect the performance too mutch. Just wondering did My modifying really effect the performance that mutch or could the manifold be unsuitable for my car.
