Changing The Wastegate Actuator

[The NUT]

Hey guys,

Now I must admit I am not the most mechanically gifted or knowledgable individual, but any help would be much appreciated.

I am currently sitting around the 275rwkw area with - a wog cooler, edit and custom tune, modified air box and water/methanol injection ONLY

My goal is to acheive 300rwkw or atleast close to it

With the next stage of my mods I am planning on putting in siemens injectors, will probably need to upgrade the valve springs and also change the waste gate actuator

My question is this - what is the purpose in changing the waste gate actuator? Is it because the standard one is too flimsy?

Cheers again guys

Nut

P.S - to acheive 300rwkw are there any other bleedingly obvious upgrades which you guys would think vital, be it performance or driveline? (I know the cat will need replacing, but watching $$$ at the moment if it can be helped)

[ETM]

the reason you change actuator is due to the fact that you want to run a higher total boost pressure to achieve more power.

when you raise the boost via a bleed valve you can only go so far with it,therefore if you have achieved the maximum total pressure the actuator/bleed valve is capable of its time to upgrade the actuator to a heavier springed unit.

I have found that 16 psi was the maximum I could achieve on the stndard actuator so I upgraded to a 15 psi actuator could run upto 25 psi or so with that one at maximum bleed

[ba_xr6_turbo]

Where is the best place to buy a 15 psi actuator and what do they cost?

Cheers

Nick

[ORSMF6]

a place called gcg sell them .. check there website .. or there a few turbo shops around like rotormaster in camplbellfeild there is a turbo shop within the shop as they fix concrete trucks and stuff like that.. they can do it all just go in ask for the turbo workshop...

[FLASHXR]

A place called MTQ is where I got mine. Or you could go direct to Garrett. Just check the whitepages for outlets. I think retail for the 15psi actuator is around $140.00 - $160.00. Well worth the money...

[iTec]

you should upgrade your fuel pump aswell... I am running pretty much the same mods as you intend to and am making 325 rwkw I am still on the stock fuel pump and I am pretty sure that it is at its limit

[jasper361]

the reason you change actuator is due to the fact that you want to run a higher total boost pressure to achieve more power.

when you raise the boost via a bleed valve you can only go so far with it,therefore if you have achieved the maximum total pressure the actuator/bleed valve is capable of its time to upgrade the actuator to a heavier springed unit.

I have found that 16 psi was the maximum I could achieve on the stndard actuator so I upgraded to a 15 psi actuator could run upto 25 psi or so with that one at maximum bleed

I didn't think you could use a bleed valve to raise boost presure on the XRT due to the PCM going into limp mode?

[The NUT]

Cheers for the feedback guys, do you think that changing the wastegate actuator is a necessary mod for the power I am trying to achieve?

[PDIDDY]

Cheers for the feedback guys, do you think that changing the wastegate actuator is a necessary mod for the power I am trying to achieve?

Not sure, as every car will handle the mod's you do differntly. Mine is going next week to have this mod done, as it likes to dump the boost at 16psi. Am currently at 288rwkw. Nothing more frustrating than giving it half a bootful, and copping a wave of surging instead of frying the tyres. When you put it alongside the other mods you do, you will find this one very cheap for the result you will get (well I can always hope).

[RAP1D]

A high flow cat and removal of the centre muffler or a new lager exhaust will get you to 300 with the planned injectors you have in mind. But you may have to do it on higher boost due to the restrictive intake/intercooler system you have.

I know of a few cars with low 300s doing it safley with just injs, cooler/pipes/intake and exhaust and on 13-14psi.

The idea of the higher psi wastegate is to help maintain a flat boost response/curve.

For example, mine and many others run say, 14psi then at 5000rpm or so it drops down to 12psi. This is due to the spring in the actuator not being strong enough to keep the exhaust pressure from pushing the flapper closed and losing boost.

A 15psi accuator, will let you run a MINUMUM of 15psi, and hold the flapper closed for higher boost., so choose your accuator to suit what boost level you want to run as you can always go higher, but cant go lower.

So, say a car with 300 is running 14psi then its dropping to 12 ( it is infact producing the 300kws on 12psi not 14 ), once you change the acctuator for a 14psi (or 15 ) it will hold boost at 14 all the way to redline and thus now be making its max power on 14psi instead of 12, so gaing you more power in the top end... 300 should now be more like 320 or so once tuned to suit