I was curious what my entirely stock 2005 NBFL 1.8 Sport (which allegedly left the factory with 146bhp at the crank) was currently producing before I put on a few small engine mods (to see if the difference could be picked up on a rolling road).
The results, however, were pretty disappointing! The rolling road recorded around 100bhp at the wheels and estimated 125bhp +/- 5bhp at the crank (the machine apparently deducted around 5bhp as it was a cold day to make all readings comparable at different temperatures). I know crank readings are an estimate, but I find it hard to believe that you would lose a third of the power through the running gear alone on a car like the MX-5!
The car is on about 87k miles, but it’s lived a pretty easy life (the overwhelming number of engine miles have been at a steady, sensible, cruise on the motorway; no track day work at all) and it recently had a full service with new plugs and leads, etc. I’ve had it since around 46k miles and hadn’t noticed a drop off in power over that time… assuming it left the factory with the claimed bhp and 146bhp wasn’t just the reading of an optimised press demonstrator with a blueprinted engine and some cylinder head work, that’s a drop of around 20bhp!
I’ll find a way to convert the pdfs of the power charts to jpg to post them up here.
I just wondered if anyone else had tested theirs and whether this was normal or not (or whether I might be having a problem with my SVT mechanism, for example - I noticed that in recent weeks my car can now take a over 5 seconds on the starter to start from cold whereas it was always a quick starter before, the starter turns the engine over well though, so I don’t suspect battery - is this a sign of anything untoward?)…
If this is a genuine loss and not just what is to be expected, has anyone got any tips for reclaiming some bhp?
Any comments welcome!
Many thanks all!