Turbo Question

[RB SANDY]

hi guys,

i got the pick of the 2.7 litre jun build up post.

i was just wondering what the small holes are on the turbo inlet are for ?

thanks

[2rismo]

Absolutely nothing if you run a pipe off of it to an air filter

[RB SANDY]

sorry buddy i dont get what youre saying

[2rismo]

Those holes will be covered up the minute you fit an air filter to the front of the turbo.

[RB SANDY]

do these holes have a function are they there for sound.

[datto_boy]

I do believe its called wank factor.

Edited July 12, 2006 by datto_boy

[RB SANDY]

have a look a this link I thinck it mentions something about, The unique ported shroud was designed to minimize compressor surging at the mid-range rpms.

http://www.dragsport.com/issue/2006/0706_tech.shtml

[discopotato03]

RBSandy they are the vent paths for the ported shroud within the inlet boss . 2rismo I'm not sure what you mean by they are covered by the filter or inlet ducting ? So long as the vent paths can vent air from the radial slot in between the main and splitter compressor blades to the atmosphere side of the boss they will work . I have a feeling that HKS do this partly for bling factor (marketing) but I also get the feeling that doing it like this or by having the trumpet mouth insert like say their GT3037's have reduces the shrieking screaming noise that the more common port shroud like say a GT30R (GT3076R) tends to have .

Thanks for the link as well , always wanted to see inside the HKS TO4Z comp cover .

Cheers A .

[paulr33]

the holes on the comp cover are a workaround for compressor surging

it allows air to enter onto the compressor wheel on the outer edge to balance out the some of intake sucking, which is commonly associated with surging. think of it as an anti surging device.

the bulk of the air enters the snout, thanks to the vacuum effect of the compressor wheel sucking in air, but a very small amount enters through the holes also to side step around surge

[RB SANDY]

Thanks guys this is very helpful I can sleep at night now.

[paulr33]

wonder if it would surge with the holes blocked off. logic would say yes.

i guess that was the only comrimise they could come up with to avoid surging. must be a really wacko compressor/housing combo (sounds logical??)

[2rismo]

It's not very hard to picture. How many of you run no filter on your turbo? Do you all have a pipe from the compressor inlet to an air filter? Would the holes be obscured/covered on a T04Z like this?

Tell me what they're for in that situation?!?!?

Adrian

[Amaru]

  2rismo said:

Tell me what they're for in that situation?!?!?

Adrian

It justifys the extra price over exactly the same Garrett item... "My car goes faster cause the HKS one has speed holes"

[discopotato03]

2rismo I can't follow you logic , if you mean "covered" as in out of sight then 99.99% of port shrouded compressor covers the world over are covered . This does not prevent them working as they were designed to . Many Diesel turbos have port shrouding and very rarely are they run without ducting to an air filter . If the manufacturer wanted it not to work the gas ports would exit the cover through the outside of the boss ie the parallel section behind the barb .

[DoughBoy]

Ever seen a T04Z surge anyway? Although holes = lighter= much much faster.

[paulr33]

do you think it would surge with them blocked off ?

[kwazza11]

asmuch as i would like to believe that its just bling factor, HKS have obviously done some R&D into this turbo with a particular housing combo and realised it surges, whether its engine and boost specific or whatever. 2rismo, doesnt matter if thier plumbed back into the induction pipe. thier there to releave flow when its surging.

and if its all bling why wouldnt they do it with all thier other turbos?

[R31Nismoid]

  2rismo said:

It's not very hard to picture. How many of you run no filter on your turbo? Do you all have a pipe from the compressor inlet to an air filter? Would the holes be obscured/covered on a T04Z like this?

Tell me what they're for in that situation?!?!?

Adrian

I dont get what you mean either, the pipe sits OVER the housing, not inside it.

So the holes, no matter if a pipe fed the bellmouth or not, would still flow air as designed

[Roy]

  2rismo said:

It's not very hard to picture. How many of you run no filter on your turbo? Do you all have a pipe from the compressor inlet to an air filter? Would the holes be obscured/covered on a T04Z like this?

Tell me what they're for in that situation?!?!?

Adrian

Im not getting you either

Silicon joiner gets hose clamped to the outside of housing, holes on inside. Why would the holes be obscured?????

[RB SANDY]

Also will this turbo go good on a rb25det or will there be a bit of lag, also what will

be the max efficient boost.

Edited July 13, 2006 by RB SANDY