Cutting out Internal Gate?

[mattasi]

I am currently rebuilding my turbo due to metal shavings from a spun rod bearing. On my turbo the internal gate arm is welded to the body of the turbo to keep it closed because I have an external gate. My question is; is it a good/bad idea to cutout the internal gate altogether to let more exhaust flow threw? Or would it create to much turbulance? As you can see in the picture below the smaller tube on the exhaust is a different color than the other big tube because no exhaust is going threw it. Should I cut the gate out or is there a good reason to keep the gate? besides leaving it incase I sell the turbo. Looking forward to what you guys think.

 

[mike96]

You are using an external waist gate off the manifold and open dump I presume? iIf so you need to either leave the waist gate set up the way it is or completely remove the gate and have the hole that the internal gate flapper cover welded shut. If you remove the internal waist gate all together and don't do anything to plug the hole in the housing then your external waist gate will be useless and your turbo wont boost at all. I would leave it as is. Gives it a better re-sale value.

 

[mattasi]

Yea, external wastegate off the stock manifold and open dump. I will just leave it the way it is then. I don't understand though, how come the external gate wouldn't work if I cut out the internal gate. Seems like cutting it out would just be more exhaust flow. I'm not saying your wrong or anything I just don't understand fully.

 

[turboglenn]

just think of the situation without the external gate in the picture, the internal gate stays closed to let the turbo spool and opens once the boost is at the pressure determined by the internal gate's spring and the boost controller.

If you remove the internal gate it will be like you had a stuck open internal gate on a regular setup. the exhaust flowing out of that hole is bypassing the turbine wheel and not being used to spin it up. when that hole opens it lets air pass the turbine and regulates boost, if it's just wide open all together the thing will barely even start to make 1-2psi.

 

[mattasi]

Ah ok, this makes perfect sense. I feel dumb for asking this now, but thats what I needed. If I cut out the internal gate leaving a hole then a lot of the exhaust doesn't get to see the turbo wheel and create boost. Ok thanks guys I will for sure just leave the gate alone.

 

[turboglenn]

Now you're understanding it. And as far as a dumb question, well like the old saying goes, there is no such thing, only dumb answers. I don't think any of on here were born with the knowledge we have today but rather through the process of trial & error, fail & repeat we eliminate the wrong ways to do things and learn not only the right way and gain a better understanding of the surrounding elements of the job at hand, most times many more than we originally intended to learn while doing the things that we enjoy doing to improve our cars or whatever else we venture into.