the flyin' scotsman

My car didn't have 'hotter' running issues when the Motorsport X sans cats was installed; that is from a engine coolant perspective. In fact, the car is considerably cooler from the exhaust system as the OEM cats were cooking hot so much so the when I opened the drivers door after a long hard run I was greeted with a 'waft' of super hot air from under the car.

No such issues now with the X coupled to 'GT' resonators and a RMB then the OEM muffler then a GT muffler all with Quad 4 spark plugs. I replaced the O2 sensor with the X and the MAF is a rebuilt unit from John Speake.

Agree with the performance upgrade comments; the X is a nice piece.

marton

According to the figures from John Speake, the % HP loss due to MAF ageing is 2 to 3 times the % deterioration of the MAF. See the enclosed graph for how this looks.
The hard part is figure out when the MAF should be replaced because the MAF deterioration is caused by duty cycles (switching the engine on and off) not by age or mileage. I have shown an example of typical ageing for a 10 year old 928 MAF on the enclosed graph, this is not a single point on the graph because it varies so much from vehicle to vehicle.