EWG on a mostly stock STi safe?

khalid6197

New member
I have a 2012 STi with very little mods. I'm currently at stage 1 with a cobb I take and nameless axle back. Ive been seeing some videos on EWGs and they sound amazing! Sooo eargasmic! Lol. So my question is can I put a EWG on my mostly stock sti? If not, what modifications do I need to do before I can install the EWG safely? Thanks.
 

35r

New member
Pointless for stock. EWG's are for BIG turbos. You will gain nothing by putting one on, and quite possibly will run the risk of losing power. Making it functional is going to require thousands of dollars. New Turbo, FMIC(or larger TMIC) and if you do a larger turbo you should do your internals otherwise you will end up breaking something. Which means rods, pistons, possibly built heads (springs/valves/retainers), cams, the list goes on and on. You shouldn't base car mods off of sound unless you are purchasing an exhaust. Otherwise you fall into that "ricer" category and nobody will want to help you. So to answer your question... Yes it is "safe" , but it will make you look kind of like a jackass.
 
I am at a stage 2 and I am about to put an EWG to cure a boost creep issue. All I am being told I need is the up pipe , EWG and bracket to keep the stock IWG closed. Oh and a tune. The only thing I am thinking is since I am going this far I might as well go for an E85 set up which will require a fuel pump and injectors.
 

Bang876

New member
I have a 2012 STi with very little mods. I'm currently at stage 1 with a cobb I take and nameless axle back. Ive been seeing some videos on EWGs and they sound amazing! Sooo eargasmic! Lol. So my question is can I put a EWG on my mostly stock sti? If not, what modifications do I need to do before I can install the EWG safely? Thanks.


My car is dual tune on 92 pump and E85 with a stock turbo and on the E85 map I get boost creep and over boost once in awhile but on pump gas its rarely ever happens My set up is mainly supporting mods to max out the stock turbo:

Mod List:
Turbo XS TBE
COBB Intake w/box
COBB Electronic Boost Control Solenoid
FIC 1100cc Injectors
walbro 460lph fuel pump
Cobb AP
Pro tune for both fuel type

For your current build, no it would be a waste of money to get an EWG because you dont required it and the stock recirculating BOV can easily handle the boost pressure of your set up. Additionally the amount of money would have to ditch out in order to do a proper set up is not worth the gains. Also putting an aftermarket BOV on your ride at that power level is actually counter productive and you'll just end up with problems and a slower car. External Waste gate allows you to control boost pressure and enable a more aggressive tune. But its only worth the expense if you actually required it such as having a larger turbo or in my case maxing out my stock turbo. For me it would be a good choice if I plan on sticking with my stock turbo because I am pushing 22psi which is at the limit for the turbo to operate efficiently. If I did went with an EWG I would see little to no power gains because like I stated it would only help improve my car ability to control boost and boost issues since I am already at the limit of the stock turbo. If I was you focus on getting a turbo back exhaust next since it will help fulfill your lust for sound and still get you good power gains at a much lower cost. Once you have that then it would be a good time to really think where you want to go from there, do you want more power, reliability, looks, handling, a mixture or all of them. These should be your factor regarding how you want to modified your car, not because it sounds cool or looks bad ass. Everything should serve a purpose and belong to the category I stated. Good Luck
 

HolyCrapItsFast

Drinks beer!
I am at a stage 2 and I am about to put an EWG to cure a boost creep issue. All I am being told I need is the up pipe , EWG and bracket to keep the stock IWG closed. Oh and a tune. The only thing I am thinking is since I am going this far I might as well go for an E85 set up which will require a fuel pump and injectors.

Assuming it is boost creep an external waste gate is one way to solve it but a better way would be to port the internal waste gate. If you do decide to go with an external though you need to get the larger 44mm if using the stock turbo. The smaller 38mm is suited for larger turbos according to rule of thumb.
 
I looked into porting the waste gate but I figure I am not done looking for power so going EWG now will be good for down the road. 44mm is what I will go with. I thought the larger the waste gate the better it can control boost especially on higher boost application but I am still a newb so I look to you Suby Masters for the knowledge
 

HolyCrapItsFast

Drinks beer!
Waste gate size is more related to the physical size of the turbo and not necessarily the boost level. On a small turbo application you are diverting significant amounts of exhaust to control the speed of the turbine so the waste gate must be able to flow a significant rate. Large turbos require more exhaust gasses pass through the turbine so less exhaust is diverted. The waste gate need not be so large in this case.

If I was to suggest a waste gate for a particular application I would say 44mm for 20G turbo or less and 38mm for Dom 3 or larger. That is not tested though and is just my best educated guess.

Also for your consideration, waste gates have a range of efficiency meaning large waste gates do not control boost well if the diverted exhaust flow and pressure past the valve is low. The ability for the gate to perform well in that situation is diminished and may actually result is erratic boost control. Subsequently the smaller waste gate will have the better boost control but, in some turbo applications, may allow boost creep if the flow exceeds its efficiency range. Most applications will fair well with a 38mm waste gate regardless of the turbo size which is why many tuners will always start out with a 38mm gate. If they experience boost creep then they move to a 44mm gate but if not then they stay with the 38mm.
 
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