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Discussion Starter · #1 ·
Hey everyone I’m new here so excuse me if this isn’t perfect because I’m not lol. I have a 02 wrx bugeye so far it’s been perfect for me but I snapped the linkage on the wastegate hat goes to the turbo and in haveing trouble deciding what I wanna do. I want to replace the wastegate but I’m not sure what to replace it with. It has a dna racing tdo5 18g turbo on it. Please help or lead me in the right direction. Ps my max boost psi is 24 psi
 

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Hey everyone I’m new here so excuse me if this isn’t perfect because I’m not lol. I have a 02 wrx bugeye so far it’s been perfect for me but I snapped the linkage on the wastegate hat goes to the turbo and in haveing trouble deciding what I wanna do. I want to replace the wastegate but I’m not sure what to replace it with. It has a dna racing tdo5 18g turbo on it. Please help or lead me in the right direction. Ps my max boost psi is 24 psi
You only need one thread friend. Just add a bump to it if you want it back at the top. We have a few fairly knowledgeable members who will be able to better help you than I can you’ve got to give them a bit as they are out doing life stuff.

Personally if all was good I would just replace the wastegate and go. I know a lot of people opt for external wastegates for better boost control and that might be a legitimate option for you especially if you are suffering from boost creep.


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You'll need the same wastegate actuator setup that was on previously, or your boost control tables might be messed up. If you have the ability / knowledge to calibrate them yourself, that isn't as big of a deal, but if you're going to have to pay to have them calibrated, you'll probably want to have something else added (e.g., external wastegate) so that you're not paying a large amount of money for minimal work.

If it was the standard actuator, I would contact DNA Racing and see if they can supply you with a replacement.
 

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Discussion Starter · #4 ·
Sorry man I wasn’t to sure how to work the website yet getting the hang of it now. And I have a guy to do my calibration for me after the install I just wasn’t sure on how the psi differences in the wastegates would affect the car being that I normally push anywhere between 8-24 lbs of boost I wanna make sure I get a new wastegate that will withstand and be capable of pushing that. In fewer words I don’t know how wastegates work since this is my first wrx and turbo car in general I’m learning as i go lol. Any advice will help I’m gonna call dna tomm and see about what they may carry to work with the tdo5
 

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Cherokee_Goon said:
Sorry man I wasn’t to sure how to work the website yet getting the hang of it now. And I have a guy to do my calibration for me after the install I just wasn’t sure on how the psi differences in the wastegates would affect the car being that I normally push anywhere between 8-24 lbs of boost I wanna make sure I get a new wastegate that will withstand and be capable of pushing that. In fewer words I don’t know how wastegates work since this is my first wrx and turbo car in general I’m learning as i go lol. Any advice will help I’m gonna call dna tomm and see about what they may carry to work with the tdo5
Can you take a picture of what is "broken"?

The wastegate is part of the turbo itself, the actuator is an "attachment" to the turbo.



Above is the backside of an OE VF39 turbo (2004-2006 STIs). The "arm" that is in the 2-3 o'clock position as well as the circular piece in the 1 o'clock area is the actuator (notice the bolt that allows for its removal?). Is that what's having an issue?

The "wastegate" itself is that circular part that has the bracket in the 5 o'clock area inside the turbo. The wheel that you see on the back of the turbo is the turbine wheel.

Since you're new to turbos, the wastegate works by bypassing exhaust gas away from the turbine wheel, limiting boost pressure. If your wastegate remains closed, you would just continually build boost pressure uncontrollably.

Here's a front view:


The "1 o'clock" circular piece I referred to earlier is the front part of the actuator (what has the T-d off vacuum line attached); in this picture, it's 10-11 o'clock. I don't have that on my car, because I have an EWG, which replaced the actuator with a bracket that holds the wastegate completely closed. I have a wastegate in the uppipe pre-turbo that manages it, so the factory wastegate is no longer needed.
 

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Discussion Starter · #6 ·
Ok so I’ve did some research and realized I broke the actuator linkage not my wastegate now my question is for my 02 wrx (not sti) with a td05 18g on it I’m not sure which actuator to purchase I can’t seem to find one with a 1.7 bar which has a max psi of 25. My car before it broke pushed 24 psi. I found one for a td05 20g but wasn’t sure if it would work any advice guys?
 

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If you got a wastegate with a 1.7 bar spring then the minimum amount of boost you could run would be 26psi, and the wastegate would be good to hold p to 52psi.. ie., kill your engine boost. The rule of thumb is that you want your wastegate spring pressure to equal roughly half your desired max boost pressure. IIRC when I had a vf22 my wastegate spring pressure was around 8psi, and the turbo couldn't push any more than 24.5psi because at that point the wastegate was being forced open. If you're looking to run 24psi I recommend a 1 bar wastegate MAX. A .8 bar spring should suffice, but personally I would just go with 1 a bar spring.


Just to throw it out there.. if you're bugeye is still on its stock engine you're living on borrowed time. The engine isn't going to last forever at that level. Especially with the age of the car I would set aside funds for a new engine, and/or be prepared to sell the car when the engine fails.
 
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