turbos and high compression??

**WPN.22R** · 20-09-2004 07:44 PM

i pumped 15psi through my motor standard, but had a 2mm gasket on to lower the comp!!

**Type R Positive** · 21-09-2004 02:30 AM

you could fart into a b16a and get over 200kw atw on stock internals.
Great engine.

**Weq** · 21-09-2004 11:52 AM

Originally Posted by WPN.22R

i pumped 15psi through my motor standard, but had a 2mm gasket on to lower the comp!!

so what did that achieve?? more boost, less power per psi. less chance of knock, maybe putting the turbo into itsd efficency range?

**shecomb** · 21-09-2004 05:13 PM

Would just help for reliability and longevity...

2mm gasket lowers the comp so theoretically you can run more boost on a stock engine

Not really any power difference

**Weq** · 21-09-2004 05:25 PM

less comp = less power = less effective compression. u wouldnt pump 15psi through a standard h22 without some balls.

**rev-tech** · 21-09-2004 10:05 PM

why don't turbo's work with hi compression.

it's called a flash point. Where the compression in the engine heats up the air/fuel mixture so much that it ignites by itself without the aid of a spark.

i think the flash point for normal fuel is around 15:1.
and i THINK every 3psi you raise up it up's the CR by 1.

essentially in a boosted engine as you wind up the boost your just increasing compression. When the CR of the engine combined with the boost level get's over the flash point you'll get detonation and i think most people know what happens then.
Thats why you can lower compression to increase boost etc etc.
the main other factor in detonation is heat.....if the air is already hot before it enter's the cylinder then it heats up even more.

**tinkerbell** · 21-09-2004 10:45 PM

Originally Posted by rev-tech

and i THINK every 3psi you raise up it up's the CR by 1.

that is close, but this is a table of compression vs boost:
http://www.team-integra.net/sections...?ArticleID=308
(sorry - you need to register)

Originally Posted by rev-tech

the main other factor in detonation is heat.....if the air is already hot before it enter's the cylinder then it heats up even more.

why efficent intercooling (water to air or air to air) allows you to run more boost safely

**tinkerbell** · 21-09-2004 10:51 PM

ie the table shows that at a static CR of 8:1 a boosted engine will be creating a compression ratio of:

2psi = 9.1cr
4psi = 10.2cr
6psi = 11.3cr
8psi = 12.4cr
10psi = 13.4cr
12psi = 14.5cr
14psi = 15.6cr
16psi = 16.7cr

"The numbers in the chart in bold indicate the safe zone of operation for a non-intercooled, Supercharged or Turboed vehicle running moderate timing with 92 pump octane (USA) gas and Stock Internals."

**rev-tech** · 21-09-2004 10:53 PM

i think i know the table you've talkin about.....i've seen it before in a book on turbo's
VERY useful!

basically running a turbo in (or under) it's efficency boost range. Too much above this range and it will develop a hell of alot of heat! which is just wasted energy

**pornstar** · 22-09-2004 12:57 AM

Originally Posted by tinkerbell

ie the table shows that at a static CR of 8:1 a boosted engine will be creating a compression ratio of:

2psi = 9.1cr
4psi = 10.2cr
6psi = 11.3cr
8psi = 12.4cr
10psi = 13.4cr
12psi = 14.5cr
14psi = 15.6cr
16psi = 16.7cr

"The numbers in the chart in bold indicate the safe zone of operation for a non-intercooled, Supercharged or Turboed vehicle running moderate timing with 92 pump octane (USA) gas and Stock Internals."

i assume on one turbo size on one particular ambient temp for one particular piping length, for one particular type of intake piping metal?