86 Pistons Pics - Would you use them with a supercharger or turbo?

[Matt]

Throw up a link ill-minded... I'm keen to learn more about this kinda stuff

[ill-minded]

I don't have a means of hosting files, but I'm happy to email it to someone with some web space. It's about 5mb. I guess I could throw it up on a file hosting site, but I've got no idea which ones are preferred/better.

[Matt]

There you go fellas...

[Matt]

Linked it up above...

[Sam-Q]

awesome I am going to have a good read of that later. My suggestion for anyone who wants to know more is to read this book:

"Four-Stroke Performance Tuning" by A Graham Bell

[sprinter666]

insane reading cheers guys, man should invite u guys to a bbq, the insane technical discussions i wouldnt understand would blow my mind no doubt.

[Sam-Q]

If it's on a Sunday or weeknight then yes sure. If you want to cop it till your ears bleed ask me about 2 stroke tuning!

[ill-minded]

Some more interesting pictures of an FA20 internals.

[Skylar]

Didn't read that scientific paper on piston shapes. Looks interesting but no time now. Got a few things to add. Haven't read the rest of the thread either so I apologise if I'm repeating stuff.

A combustion chamber with good squish properties can be the cause of knock when turbo'ed with high boost. Due to the increase charge density in the combustion chamber fromn the turbo, the "jets" from the quench pads causes the charge to swirl too quickly and cause a separation of flamefronts which results in detonation. That's my understanding of the subject. Someone correct me if I'm wrong.

Some engines don't like quench pads and swirl. One engine builder went the other (put the piston further down the bore while maintaing comp ratio) and got more power for some reasons he still can't explain. It was only that specific type of engine though. The guy does use quench pads as much as he can on all his engine builds. The CC looks to be pretty open and the piston doesn't have a slanted squish band.

Is there a reason why a GTX2867 was used over a 2871 for that build above. 2871 would have done the job just fine since it isn't running super high boost which I though was the whole point of the GTX series or wheels. It's a little more efficient but I dunno if it's worth the extra cost for non-competitive guys like us.

[Matt]

Found these on the web...

A fa20 engine pulled apart and lots of good pictures.