Sorry this might take a while to explain!

I'm now a little worried about the VTS. She's done 27,000 miles and was last serviced at 25,500. I took her to Crail on Sunday and met SVX for a drive up and well, um, we made 'good progress' I noticed when we got to Crail and during the day that she seemed to get faster and faster and posted a very quick time only 0.1 off the best time posted by bluenose in his 172. Then tonight I had a run in in a standard MY99 and on the way home in the Saxo it felt like it could have almost kept up!! I'm not joking the thing is flying!! Now I'd imagine half you will be wondering why I'm complaining but the bottom line is the car is needed to get me from A-B more than anything and I'm worried this new found performance is indicating a potential problem. This might be nieve but can an engine suddenly pull really well when something is/has actually going/gone wrong?? Any suggestions or help appreciated.

Before you start I said 'almost' as well as the MY99 - It's quick but not that quick!!

 

Can't think of anything unless for some reason it is running a bit leaner. Seems unlikely though. I couldn't hear any pinking when you were giving it some tonight - sounded fine.

 

What is pinking by the way and what would it sound like?

 

Pinking is the sound you get when the mixture spontaneously ignites in the cylinder before the plug has fired (detonation). It results in a characteristic noise and if present even on a normally aspirated engine for too long can result in damage because of the high temperatures involved and also because the ignition occurs too early putting great stress on the con-rods. On a turbocharged engine it is a terrible thing in particular.

The sound of pinking/detonation depends on where you listen to it and with what. Some say it sounds like a metallic rustling sound when mild up to a frank banging noise when terminal. I only ever heard it on my Dad's old brown Sierra towing a caravan up hill in too high a gear on $hite fuel, and on a Scooby on a rolling road. Yours was running smoothly though. I can't guarantee it is not detting but it really seems unlikely.

To gain maximum power you want to advance the ignition as far as you can before you get pre-ignition/detonation problems. So there is as ever a compromise.

If you hunt with google there are sound clips out there of det on different engines.

If your car was actually detting it would lose not gain power. Perhaps you have just loosened it up a bit with Crail

 

Perhaps the thrashing has done it some good! Think I'll try and take it easy for a few days and see how she goes.

 

Also I run her on SUL so surely it wouldn't be detonating early on an unmodified car?

 

there is nothing like a good thrash to get things moving.