Just Dyno'd my 98 2.5 986 with supercharger

[Gary in BR]

I hear of detonation alot but what is it exactly??


Thanks
Gary

[insite]

Originally Posted by Gary in BR

I hear of detonation alot but what is it exactly??

cars are designed to combust fuel. this means that a controlled burn of the air / fuel mixture occurs. the expansion of this reaction pushes the pistons down. this all occurs in a controlled fashion at controlled timing.

detonation occurs if the fuel ignites too early in the cycle. in some cases, pressure and heat ignite the air / fuel mixture before the spark plug fires. if the piston is far enough before top dead center, there is not enough pressure to control the burn and an explosion (detonation) occurs. this can also occur because the spark plug ignites too early due to poor tuning. this detonation is NOT controlled; it is violent, uneven and rapid. it can destroy a valvetrain or break pistons.

higher octane fuel helps to prevent this because it is less volitile and not as likely to prematurely ignite (higher flash point).

[Gary Gaukler]

http://en.wikipedia.org/wiki/Detonation_internal_combustion_engine

Note the difference between detonation and pre-ignition.

[Aus986]

pic of my car

Looks great, but 3 complaints.
1. OMG you need clear headlights major bad. Seriously.
2. carbon fiber hood looks good, a little too contrasting though, maybe if your car was black, but it stands out a little too much. Ive been looking for a good deal on a CF hood myself.
3. That lip spoiler is way way too much. Without it, the car would look so perfectly balanced and not front heavy.

[Aus986]

how good are the speedster humps
they make the car

[aussieboxy]

Like the speedster humps. They look hot.

[Cloudsurfer]

From what I've seen, 7.5 pounds on a non-intercooled high compression motor like the Boxster and you are sure to blow the motor. As has been discussed, heat and cylinder pressure are you enemy, and I'm sure you have too much of both right now.

The "starving for oxygen" you describe could likely be detonation, which will likely throw a rod or put a hole in a piston or break a ring land.

If I were you I would turn down the boost on your kit before you find yourself buying a new motor.

Patrick