Quote:
Originally Posted by Kodename47
Not at all, after a decent in depth chat with Cosworth's head engineer last week he informed me that a lot of the manufacturers that were "DI only" are now reverting back to dual systems as the PI has it's benefits.
I certainly hope that you're not running 100% DI for most of the time as it's common knowledge that running DI only will mean that the valves etc end up with a build up of deposits over time.
|
A great comment and first understanding why the intake valves have carbon build is important. Usually a carbon build up on back side of the intake valves is due to a couple things, first and foremost the engine breathers return oil and exhaust fumes through the intake track to the back side of the intake valves. The other scenario is when the exhaust and intake valves overlap a small amount of exhaust gases will find there way to the back side of the intake valves.
With that in mind once manufacturers find a cheap and economical way to clean the air from the engine breathers to the intake track (while being legal to various governing boards) this will take care of most of the problem of carbon build up on the intake valves. Porsche's have incorporated their own air/oil separator into their higher end vehicles to combat this problem. They have a lot fewer problems with carbon build up compared to say Audi which has a lot more carbon build up problems.
Now adding in port direction is definitely a great way of cleaning up the back side of the intake valves in the mean time but pretty sure manufacturers are looking for cheaper ways of producing their vehicles (the reason they used DI only). I assume it will just be a matter of time before it happens. Who know what it will take for it to happen though.
Now with respect to our tunes we do use DI heavily in our tunes but we also use quite a bit of PI, which will of course combat the carbon build up issue. Looking at a log from one of our tunes will show as much.
Cheers,
William Knose
Delicious Tuning