uh huh 33.gif

 

the same effect comes from you holding the gas pedal at the correct spot. i know it is used to build boost from a launch.

 

^ unless the turbo is really small, you can't build boost at idle by just holding the pedal and keeping it at a constant rpm

 

no load, no spool smile.gif

 

^ Uhh Wat? Your saying you CANT make boost by reving at idle?

The turbo spools by exhaust.. what does the load have to do with it?

Im a noob at turbos, but im pretty sure the bov sill goes pssssh when you rev the car at idle.

Fill me in....

 

Nuetral revving produces very little exhaust gas for spinning the turbo. There is a ton more pressure when the car is actually trying to do something.

 

ok ill do the best i can to describe it for you. If you have an auto you can "power brake " to create boost on the line or in a still position. You do this by holding the brake down and gas pedal to the floor with the car in drive the turbo will start to spool and that is because you are creating a load on the engine, In this case the car is trying to move hence it being in drive but it cant because of the brakes being applied . That's the load. Also the load to the engine basically makes the engine create more vacuum and thus starts to pull more air enough air to start to spool the turbo. Its same kind of load you get when putting a manny trans in high gear at low speed, in low rpms under wot. the turbo will spool faster at a lower rpm in each gear the higher the gear gets. Example: " 1st spool at 3500,2nd 3300 3rd 3000 4th 2800 and 5th 2600. In a manual trans, neutral has no way of loading the engine to spool the turbo. free revving wont do it unless you hit the gas pedal hard and hold it to red line in the upper rpms the engine will for a split second show boost but its really unusable that high in the rpm range and its there and gone just as fast. So us manny guys have to use a 2 step or also known as a stutter box "dsm lingo". This feature allows you to set a preset rpm to basically temp. redline at ex: mine is set to 3800 and at that rpm while it is activated it will retard the ignition to -10 which ignites the fuel at a time that the exhaust valve is open. That power transfer goes through the turbo which basically jump starts the spool process by , in a sense , controlled backfiring . With this setup i can boost 10 psi at a stand still in nuetrel or gear with clutch disengaged

 

<div class='quotetop'>QUOTE (BlueRD2 @ Sep 25 2009, 12:14 PM) <{POST_SNAPBACK}></div><div class='quotemain'>^ Uhh Wat? Your saying you CANT make boost by reving at idle?</div>

That is what im saying cool.gif

 

What koreancorvette just described is anti-lag and will destroy you manifold and possibly exhaust piping. It basically causes the ignition to happen in the exhaust mani to spool the turbo.

 

Yah know about the 2steps...I have some sti friends...

2 step supra breaks windshield

Good info tho, I learned something today, thanks for explaining it.