External Wastegate question.

[dubinprogress]

Ok so I am rebuilding my turbo motor and I have only in the past ever ran an internal wastegate, however I want to upgrade to external various reasons. I was wondering if I can run my external wastegate from the hole that the flapper door used to cover with my internal? In theory I dont see why it wouldnt work. It is located before the turbo. I was wondering so I thought Id just ask. Thank you

[V-dubbulyuh]

I was wondering if I can run my external wastegate from the hole that the flapper door used to cover with my internal?

I don't understand that question... but you can definitely run an external wastegate on your setup. I did this on a car just two days ago. Assuming that your manifold has provisions for an external wastegate then you can:

- Weld the internal flapper shut (and obviouslt remove the wastegate actuator, seems you have done so already). Popular mod with Holsets etc.

- Use a 5-bolt turbo flange which will act as a blockoff plate for the flapper outlet. Make sure that your flange is sealing well or you will induce an exhaust leak and not make full boost.

[dubinprogress]

Since I was running my setup with an internal my manifold is not currently setup for and external. So I have a few options.
First would be Buy a new manifold
Second would be use my 5 bolt block plate and tap into the manifold I already have
Third was ask the question above.

Let me be more specific. I have a 5 bolt block off plate and was thinking of tapping into my manifold to run the external. Could I get the same effectiveness if I instead say used the existing hole by running my wastegate from there instead of the manifold. I will make a 2nd grade paint photo to show whats in my head for you..



Sorry done in 10 seconds on my laptop with no mouse..

I would run an independent tube from my blockoff plate to the wastegate then dump into my exhaust..

Thank you

[V-dubbulyuh]

Could I get the same effectiveness if I instead say used the existing hole by running my wastegate from there instead of the manifold.

I would run an independent tube from my blockoff plate to the wastegate then dump into my exhaust..

Thank you

Quick answer is no. You are looking for trouble. That hole associated with the internal waste is going to be very restrictive for your external wastegate inlet port. The flow is not the same. Let's assume that you want to use a 38mm wastegate, you are feeding it through perhaps a 15-20mm port which will cause the wastegate to open very late/if at all (high pressure - low volume).

I would strongly suggest tapping into your manifold by the runner collectors and welding your 38mm flange there or you will have issues (spiking). The other alternative being purchasing a new manifold but I say if you have the fab skills that is not needed.

I have had numerous wastegate problems in the past due to incorrect sizing of the flange that was feeding the wastegate.

[dubinprogress]

Thank you very much for your info

[scramblingvw]

copy paste this internal external wasegate in search
spelled wastegate wrong never could fix it ,i got 16,000 miles on setup going on 3rd summer
good size turbo 63.ar daily driver 12psi boost ,for me the wastegate open to soon, all boost going thru port opens early,not late 3 to 4 psi was opening up wastegate, grim speed boost controller took care of it ,
no boost creep, full boost about around 4400rpm in 4 gear .i have stage 1 chip,this workes great 4 me

[groundupjetta]

^^well done! I was going to do something like this on my setup but I found a good deal on a external wg manifold and didnt need to do it anymore

You could also port the internal wastegate port a bit to match your wastegate/piping inlet

[GTijoejoe]

The answer to your question is yes...
Its best to make the opening large enough and not route the WG far away.

[dubinprogress]

Cool its good to hear both sides of this. I will have to see what kind of space I have when all said and done. That will be my final decision maker.