Wastegate: Truth Or Lies

[BSK]

during a phone conversation today with a local tuning shop i was told i should be using a wastegate to run 1.2bar on my rb20 powered 32. i have had the car for 3 months now and it has been happy to run 1.2bar thru its gt2510 probably half the time i drive it...

is it true i should use gate to run this boost? or is there a sales pitch going on??

im pretty sure 1.2bar is no sweat for this turbo but i though i'd get another opinion from u guys...

[paulr33]

its much better to run boost control via the wastegaste.

if for example you have as 0.50bar wastergate and want to run 1.1bar boost then the controller has to work very hard to maintain the pressure difference, it will likely fail and try its best.

that being said if you move to a 1 bar actuator thats the minimum about of boost you can run, ie you cant have a 1 bar actuator and set your boost controller to run 8psi

[R31Nismoid]

Off the gate is better.

Reason being (at least with external) you get the spring rate that is closest to your target boost.

This ensures you dont have wastegate creep/gate doesnt open prematurely etc.

I ran 15psi straight off my gate and bleed it upto 17psi.

When i had the 7psi spring, i would get gate creep in 5th gear as it was coming onto boost so it would take longer to build 17psi.

And thus under a great load the car became much slower as it took forever to build boost in taller gears

definately not a sales pitch

cheers

[BSK]

sorry my bad..... i meant an external wastegate.

[paulr33]

ash is spot on, sorry i thought u meant internal gate

[Craved]

2510 is internally gated, i wouldn't see why they would get you to run an external gate on that..

maybe upgrade the actuator, but not swap to external

[BSK]

2510 is internally gated, i wouldn't see why they would get you to run an external gate on that..

maybe upgrade the actuator, but not swap to external

funnily enough it has a nissan stamped actuator.... ?

dont know if thats what comes on the gt2510 or an upgrade

[Craved]

well i doubt it would come with the 2510, could be the old rb20 one ..and not the one that came with the turbo from the shop .. hard to say

[R31Nismoid]

so its an int gated turbo?

hardly worth converting it to ext gate, i think in THAT case you have been had

[Craved]

get an upgraded actuator for the reasons that R31nismoid and Paulr33 have said.

[RB power]

Off the gate is better.

Reason being (at least with external) you get the spring rate that is closest to your target boost.

This ensures you dont have wastegate creep/gate doesnt open prematurely etc.

I ran 15psi straight off my gate and bleed it upto 17psi.

When i had the 7psi spring, i would get gate creep in 5th gear as it was coming onto boost so it would take longer to build 17psi.

And thus under a great load the car became much slower as it took forever to build boost in taller gears

definately not a sales pitch

cheers

hi so if im running a 9psi spring in my external and have a ebc set at 16psi will it thake longer to build boost than if i had a 14 psi spring and ebc set at 16?

[BSK]

ok, so i still dont think i need another gate because theres is no gate creep or boost problems that i can notice so there is no problem in my mind but thanks heaps for the tips and info guys.

soo...just for my own curiosity and maybe some future tinkering with...

are upgraded internal gates a brand name aftermarket item?

or

oem/second hand items available off other turbos on the market?

Edited May 3, 2006 by BSK

[R31Nismoid]

Your turbo is internally gated yes?

If so, there is no "shelf upgrade"

The internal Wastegate is a part of the turbine housing of the turbo itself

They can be modified (ie drilled out) and other things, but again, i dont think you need it

cheers

[R31Nismoid]

hi so if im running a 9psi spring in my external and have a ebc set at 16psi will it thake longer to build boost than if i had a 14 psi spring and ebc set at 16?

potentially yes. every car is different, and you might not have a problem.

But its always best to get it close as you can to give you gauranted max performance

In lower gears you might not notice this.

IMO you dont need an EBC on an external gate, i only ever used a bleed valve as you let the wastegate do the work for you.

That is, after all its job... to control boost.

[Craved]

the less work the boost controller has to do the better.. a more stable boost curve will be acheivable with a gate spring that is closer to desired boost level rather than relying on the boost controller to modify the pressure the gate is recieving.

in the example with a 9psi spring, it will make it to 9psi fine but the progression after that can be affected with the delay and duty cycle of the boost controller.

HKS sell adjustable actuators. could use other ones but not many cars run 14psi std .. so aftermarket is where you would have to go.