can anybody tell me wat determines the rev the turbo starts to kick in at??
thanks in advance>evan

 

bump!

 

Air speed, once the turbo, which is a air compressor, supplys a air speed that is higher than that generated by the engines suction on it's own it is said to be boosting, as in amplyfying the air as it is producing more than the engine could command without it purely by the suction created by the pistons moving down.
Small turbo small lag, big turbo big lag, though the advent of roller bearing turbos has addressed this issue of lag to a large extent, so you can now have a big turbo with a lot less lag.
tabetha

 

also size of turbo to engine capacity driving it as the amount of exhaust gases will be greater on a larger capacity engine so will spin up a turbo quicker than the same turbo bolted onto a engine with 500cc less capacity

ie:

std t3 on 1600cc cvh turbo engine about 3.5k revs

std t3 on 2100cc zvh turbo engine about 2.5k revs

this is what i found quite some time ago

 

fuckin hell gav... where you been hiding?

 

so buy porting the exhuast manifold the turbo will come on boost sooner?is this rite or have i got it wrong??thanks for replying>evan

 

by porting the exhaust ports you may get a bit more lag, but more flow at the top of the powerband.
basically if you want it to spool earlier fit a smaller exhaust housing, but you will compromise top end power.
a bigger housing means more lag but more potential power at smaller boosts.
it is always a compromise, even with variable vane turbos and roller bearings, just not as much as a "regular" turbo.

 

alrite i undersand now mate.thanks for the explenation.my turbo works alrite as it is just never understood about dat part!thanks>evan