External wastegates Vs std actuators
 

Currently im running a T28 Turbo Technics hybrid with a normal style actuator. its got an adjustable arm which has the arm wound on loadsa turns of preload to give 12psi static opening with another 4psi achieved (16psi total) with a boost solenoid controlled by my ecu.
Is so much preload on the actuator arm accurate enough?
should i:-
A) buy a trick adjustable actuator that is adjustable internally? if so what makes etc
B) go for an external wastegate and lock the internal wastegate flap solid. Fitting one wont be an issue as i have a tubular maifold to go on, but what makes etc. I have seen some on ebay but they generally say 3.8psi or 5.8psi springs or just say adjustable. Has someone got the instructions for one i can have a look at or more info. Ive contacted the sellers on ebay for a few now and no f*cker has even replied!

im looking to run 12psi-14psi min 'static' with up to 20psi via a boost solenoid

actuator is the easiest method as far as i can see, less to go wrong and less weight which is important on my little plastic car;)
Your thoughts please gentlemen.......:D

Main reason to go to an external wastegate is to stop spiking of the boost, where the 'little penny wastegate' can't either open enough or is generally too small to expel the gases.

Problem with tightening up an actuator is that you are also limiting the amount of movement the wastegate opens as well. So although it may increase your boost, it will be more likely to spike.

Horses for courses though to be honest Craig.

I would suggest loosening off the actuator, and increasing the gain on the boost controller, and see how it ends up.

If its a reasonably flat boost curve, then the actuator is doing its job pretty well.

Of course, if you find that when aiming for 20psi that it first spikes higher then that would suggest an external wastegate is better. Have a look at turbosmart wastegates, they are adjustable and you can chose which spring you want. Expensive though

my tial wastegate cost me £215 and i've got to buy another:eek: ,

An actuator that is adjustable by its internals rather than by lengthening/shortening its rod is much better as this stops spiking and boost creep,

A lot of s14 owners with the t28 turbos use hks actuators, there were some on ebay last time i looked

cheers Pukka.
I had a scout for HKS actuators and they seem to be non adjustable internally, anyone used the Forge style of ally actuators with different springs?

http://www.atpturbo.com/Merchant2/me...gory_Code=VSR2
http://www.atpturbo.com/Merchant2/me...gory_Code=VSR2

This might help a little. Link to an Aussie tuners online magazine. He REALLY knows his stuff when it comes to modifying turbo cars.

http://www.autospeed.drive.com.au/cm...7/article.html

http://www.autospeed.drive.com.au/cm...3/article.html

http://www.autospeed.drive.com.au/cm...0/article.html

second link is very interesting although the car in question is basically like a vauxhall omega with a 3L sohc skyline engine.

page 2 doh.

http://www.autospeed.drive.com.au/cm...5/article.html

OK so ive bought an ext wastegate now.
my question is, when the flange is welded to the manifold are there any issues with heatsoak into the wastgate and it sticking/leaking etc?
i was thinking of mounting the flange on a short pipe which would be welded to the manifold (got the idea from s13eaters pics of his double setup).
would this be a better bet? or is direct to the manifold OK?

direct is fine mate, get it as near to the collector as poss, this works the best.