993RS

Do you have the impression that due to the more free flow the low end torque is too low?

TroyN

I have them and didn't notice any change in characteristics except for the sound. I have noticed a nice difference with cat bypasses though, at both the low and high end.

993RS

Thanks. It is interesting, because my mechanic keeps saying he feels the car seems a bit restricted in acceleration at low revs, which is strange considering my short grearing and LWF. Am going to make a test within a week: he will mount some Europipe mufflers and I will try testing them to see if I notice any difference. (To be honest, I do not think I will, but am still curious...)

At any rate, I will have my 60,000 mile service in about a month, and will go over to mechanical valve lifters for more precise high-end reving.

TroyN

If you can, use a dyno before and after, otherwise there's too much subjectivity in it. For me, when a car is louder it feels faster!

993RS

True. I spoke to a very experienced Porsche expert who had a very bad opinion of cargraphic backboxes. "Just noise" said he would never put one on a Porsche. Said that low end loss can be substantial. I will rely on my seat-of-the-pants dyno.