External Waste Gate Size

[gucio]

Hi all

I have a 180sx (Sr20) that has a Garrett disco potate (2540), now i have been told that i need a external wastegate so that i can increase the boost pressure because the internal one isnt good enough!

Now I am not sure size of wastegate i should get!

Thanks

[Busky2k]

The Discopototo is the GT28RS, and its internally wastegated. Anyways.. 38mm should do the job!

[gucio]

Thanks Busky2k

Now iam not 100% sure on how this works, but when you want to increase boost do you just put in a new spring or is there an adjustment?

[lwboosted]

new spring.. some wastegates come with different sized springs to change the boost

[R31Nismoid]

gucio, i highly doubt you need an external wastegate

[BezerkR32]

Agree 100% whos telling you you need to put an external gate to run higher boost pressure?

gucio, i highly doubt you need an external wastegate

[2BNVS]

the disco potatos are good internally gated turbos, i also cant see why u would have to change

ben...

[gucio]

well the car is running about 14psi which is fine for about 300Hp@wheels, but hyperdrive has told us that to increase the boost and to hold it at a steady rate that we will need a external wastegate! So that way we can aim at for about 350HP@wheels!

[R31Nismoid]

Tell them they are wrong.

get onto nissansilvia.com and see the sheer amount of people running much more than 14psi with the internal wastegate setup.

[slida]

isnt the lowest boost u can run on a gt28rs is 1 bar my mate has one sr and has about 250 kw and it is fine didnt have too change anything

[gucio]

oh ok

i will check it out thanks

but dosent the boost become unsteady when you go over 14psi on a internal wastegate as its to small to pass enough exhaust gas through

[BezerkR32]

Boost controller would be more your issue rather than gate size. you are right in what you are saying but it relates more to bigger turbo setups. here is an example of a modified Z18 engine running a Gt25/40 internal gated, makes over 350rwhp on 19psi. This car is at the stage wher it wants a turbo and wastegate upgrade. If you decide to go external gate a 38mm Turbosmart ultragate will be ample.

oh ok

i will check it out thanks

but dosent the boost become unsteady when you go over 14psi on a internal wastegate as its to small to pass enough exhaust gas through

[croat]

gucio external wastegate is usually a better option on high output turbos. i dont see it as thatr much of an issue in ur application, especially not at 14psi. i ran 21psi with an internally gated turbo and when setup well there are no problems. usually just playing around with ur boost controller.

[gucio]

Cheers guys

BezerkR32: when you said its a boost controller problem we have a greddy electronic boost controller, could that be the problem. I Thought that an electronic one could modify the boost so that the boost curve even.

But would the wastegate give you more control over the boost (eg smoother boost curve etc)