External Wastegate
 

Hi All,

Recently I gave myself a little project which as per the title was to go external wastegate. I know it isnt nessecary with the turbo I have (Greddy T518Z), was just as I like to keep busy haha :D.

Question I have, is it seems like the external wastegate is constantly open a tiny bit, can feel a little bit of air coming out the screamer pipe and it sounds a bit loud and blowy even on idle, if that makes sense.

The wastegate is linked up to the 3 port boost solenoid as per photo below, I am wondering if my current map setup has wastegate duty on it, will this be causing it to open a tiny bit? the vacuum like?

Any info greatly appreciated as I'm supposed to be going for a map tweak Friday for my new turbo and headers etc...

https://www.scoobynet.com/attachment...1&d=1397542816

The issues you are having related to the external gate making a lot of noise on idle is a standard feature on the external wastegate, there is no escaping it. Thats why not so many run one due to the excess noise created giving the car that blowing flexi joint sound.

Oh Really? Thats good news then, I am fine with the noise, I was just paranoid I was having a bit of a leak :)

Ill check my starlet one in a minute, im intrigued now, I cant say I have ever noticed it

can just feel an ever so faint pulse of air coming out the screamer pipe.

What brand wastegate is it?

Im going to the workshop in half an hour or so so ill whip the starlet out for a quick spin and see what is what :)

Its a Tial , Called a MV 38 or something? cheers fella, just dont want to get to mappers Friday and they say sorry mate cant map this its blowing like F*** haha.

Yeah thats okay, I was just worried it was a cheapy ebay one as they have some horror stories of sticking open, or even worse SHUT!

Could you be just feeling a vibration near the screamer pipe? try spraying a mist of water near it to check it is actually blowing!

Just looked on my starlet, and there isnt any form of blowby on idle, a little bit on standing revving.

Its hooked up the same as yours too.

Oh and mine is a SARD racing jobbie

oh, now I'm worried again...

I noticed this with my tial 44mvr, there is a considerable amount of gasses coming through, probably enough to reduce spool up significantly as well, im a little worried about it tbh because i only have 2 litres to spool a gt30r so i need all the spool properties i can get

Hmmmm, What can be done to fix then I guess is our question? Surely it cant just be the norm? is the equivalent of a leaky up pipe right?

Oh, and as per my original question, its nothing to do with wastegate duty then? where it was previously set up for a VF35, I believe I remember the mapper saying something like "the duty is at 55" if that means something to someone?

I am running an electronic boost controller on my EWG on the starlet, and i have to programme it for the EWG as opposed to an internal actuator type.

I am unsure what happens when i do this but In need to go through some dip switches to make it run the EWG.

Could there be something in the map that needs tweaking on the boost control side to set the solenoid up for this?

This is what I am hoping... Hopefully some mapping wizard will be along any minute :D

JGM ?

I have a Greddy Profec B boost controller from one of my old cars sitting here doing nothing, maybe I could try wiring that in and see if changing settings etc stops the blowing?

You could, does it have the EWG/AC dip switch on it?

no idea, never used it before...

Done a bit of googling and it looks like plenty of people use them with external wastegates, I'm just not sure of all the settings :wonder:

Usually underneath or in the back of the unit or something there will be a dipswitch for EWG/AC and you have to select what one you are using.

http://www.supracentral.com/foundati..._ii_manual.pdf

See page 4 for what I mean

Hmmm can't see anything on mine? Here's a photo... Maybe it is a setting electronically with this model?


Attachment 16084



Attachment 16085

It could be, I cant say I have ever played with one of those models before!

After some MORE reading, apparently the wastegate duty should be set at zero for external wastegates... I am hoping this is the reason mine is currently leaking a little as it is at 55 duty at the moment from previous map. I'm hoping the mapper will sort it Friday

Hmm :wonder: if I run at spring pressure and bypass the 3 port solenoid for now then that should close it as no duty? just go straight from compressor housing to bottom valve on wastegate. I'm going to try that this afternoon, will report back incase somebody else reads this int he future haha.

Yep if you just remove the electronic boost control from the mix and go from bottom port of actuator to the turbo :)

Gonna try that, at least if that works I know the wastegate is ok etc and none of my joints are leaking and it can be fixed by map :)
If not then back to square one haha!

I can save you some time, mine is running spring pressure only and still leaks

Im gonna wait till it carbons up a bit around the valve seat and hope it cures as thats how it works with slip joints