I'd say with almost certainty that removing the exhaust manifold will yield more power, considerably more on a charged car. I doubt very much that the exhaust is genuinely scavenging more than it is restricting. Certainly removing the laminovas or CC matrix will cause heating issues for > 1 pull, but it will isolate whether they are causing an undue restriction. You could use compressed air from a compressor in the inlet pipe to help keep the charge more cool during the test for example. God luck Graeme, if it were me, I'd just drive it as it is for the summer and then look into this mild issue in the winter. 25 BHP here or there is of little consequence TBH.Out with practical considerations, won't removing the exhaust manifold have a detrimental effect on engine efficiency? Plus, where do you mount any lambda sensors? Removing laminovas would result in the whole thing becoming completely heatsoaked in short order. Those that have run without them only temporarily have reported this.Your torque curve is dropping off due to VE % dropping off. This is most likely due to a flow restriction of either the inlet charge or the exhaust gas. Anything from poorly flowing head, poor swirl, poor scavenging, CC causing turbulence etc etc. Quite hard to pin down most probably, as it could be loads of things. The easier things to eliminate might be to do the follow, do a dyno pull and see if the problem is alleviated: 1. Remove exhaust + manifold. 2. Remove airbox + inlet pipework. 3. Remove the laminovas or whatever CC restriction you have.
Edited by Nev, 08 July 2015 - 11:25 AM.
(Even for a bit wrong timed cams, the standard ZZP/Comp timing is known to deviate a few degrees.)
