wastegate and boost controller help

**millsi** · 31-10-2006, 09:12 AM

ok can some one please help me out.
now i know that a wastegates job is to bleed off excess air so the boost doesnt go to high.
i will be turboing my 1uz shortly and already have the gate (45mm pro gate) but what spring should a go for. im only planning on running 7psi, so should i go for a 7psi spring? meaning that when boost gets to 7psi it will vent but how does the electronic boost controller i have (eboost2) control boost as well if the thats what the wastegate is doing? there are also 3, 5, 9, 13 and 21psi springs available.
which one should i go for?
sorry if this sounds confusing.

**TurboRA28** · 31-10-2006, 09:22 AM

I would recommend getting a spring that is rated at whatever the lowest boost pressure is you want to run. So if you want your low boost setting to be 7psi, get a 7psi spring in the wastegate.

Then let the boost controller do its job and bleed off air to the wastegate hence raising the boost levels.

Cheers
Joel

**SilverGhost** · 31-10-2006, 09:26 AM

You can go for a 7 psi spring and run higher boost with the BC if you wish as the BC bleeds pressue away from the wastegate actuator which keeps the gate closed at higher pressures. The spring designates what your minimum boost pressure will be, and your BC designates what your maximum will be.

Hope this helps.

**-==L=a=N=c=E==-** · 31-10-2006, 09:44 AM

another thing to keep in mind, is the smaller wastegate spring can sometime hamper top end boost control. So sometimes you have to go up a spring size to get more boost.

A good example is Sean with his supercrown, he couldn't get more then 23PSI with the current wastegate spring setup, and needs to step up a spring size to go higher.

If that makes any sense.

**millsi** · 31-10-2006, 09:51 AM

awesome thanks guys!
i think i will go for a 5psi spring and let the bc do the rest!

**chris davey** · 31-10-2006, 10:07 AM

I am not sure how it exactly relates to spring pressure in the wastegate but also the pressure in the exhaust manifold can push the wastegate open e.g. have no lines connected to the wastegate at all and it can still open. I "think" mine may be doing this or I have a 15psi spring in it.