what boost do stock evo VIII's run? just a question.

 

19 psi up to 5000 or 5500(can't remember), after which it drops to about 16.5 psi.

 

Ummmm, I could swear that with the stock boost controller boost spikes at 19psi @ 3200 RPM and then tapers to 14/15 psi till redline.

Thats why you need a MBC or for the cash get an EBC

 

It should hold 19.5psi until around ~6000 rpms at which point it will drop off to around 16-17psi. MBC will NOT make it hold 19.5 psi until redline although it helps a lot.

 

so with a EBC, will it stay at 19 psi till red line or close

 

search psi

 

can it or not

 

It will be pretty damn close as the rpm's climb the turbo is going to loose breath and start to taper out pretty fast.

 

what do you mean taper down pretty fast, will it creat turbo lag

 

Ok so your confused at the terms then.

Taper is the point when a turbo can not create any more boost because the demands of the engine are higher than the output of the turbo. As the RPM's climb the engine requires more and more air (volume) which eventually outruns the stock turbo and the boost begins to decline , taper.

Turbo lag is the time is takes for the turbo to start creating boost from some starting RPM to a RPM where it does begin to make boost. As RPM climbs the engine consumes more air and more exhaust is produced allowing even large turbos to spool at the price of requiring higher RPM's to begin spooling, creating boost.

AS you can probably read turbo lag is not caused by boost.

 

oh ok thanks man, so with an EBC. my psi could stay at 19 psi almost until red line, then it will go down to what psi untill red line? and will it hurt my motor or turbo

 

The PSI the turbo eventually drops to by redline is variable on many things. Also while i'm at this unless you do something really stupid keeping boost at 19psi will not hurt your engine. And by stupid i mean like reving the **** out of it when its just warming up or any other such nonsense.

1) Atmospheric pressure, the higher you are elevation wise the less the turbo will be able to flow

2) Temperature, hey cold air is more dense and means the turbo can make more boost.

2) Engine efficiency, how efficient your engine is at consuming air from any source. Obvious as this may seem the more efficient you make your engine breathe the less able the turbo is able to keep up. Things that improve this are simple to start with like exhaust, intake, etc..

So there you have my answer, non answer, to your question. For real data your going to have to try it for yourself.

 

k thanks man

 

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When I got mine it would spike at like 25 and then drop to about 20-ish then on down to around 16 close to redline. I'm still waiting for a mbc...