I’ve just had my 2005 N/A cat and exhaust replaced under warranty. The engine now feels to have lost some of its top-end bite. At 6200 the noise changes but the shove doesn’t, at least not like it did before, and it struggles to pull over 120 in fifth. Any ideas?
Hmmm, doesn’t sound right does it?
In my experience you actually get the best performance during the first 10 hours of running on a new cat. After that they appear to get a bit sooty and you lose a pony or two (I was desperate to fudge another HP out of an engine I was have witness tested by the VCA…).
Manufacturing fault in the silence? Its not a stage 2 is it?
What happened to the original ones?
i have to say that in my limited experience the exhaust seems to open up over the first 500 miles, getting louder and freeing up the engine rev range…
Thats usually more psycological though, the rorty noise as it dries out the wadding in the can. When I repacked the can on my Caterham R400 is was really quiet but the midrange acceleration got better
Original cat split and exhaust failed probably because of the fire that broke out following a bout of misfiring after a VERY heavy rainstorm! I’d only had the 2nd hand car a couple of weeks and demanded an emissions test to prove the cat was OK, which it was. The failures occurred some 7000 miles later, and as I say both items were changed under warranty without quibble.
I’ve queried whether the wrong items have been fitted (eg 111S exhaust)but apparently only the supercharged version is different - all others (Elise and Exige N/A) are the same. Engine seems to run fine but is definitely lacklustre at the top end.