ewg recommendations and size

dphair05

dphair05

New member
Hey guys I was wondering what mm the wastegate is on an 05 lgt? I was also wondering what brand I should go with. I wanna go with the external because in the near future I wanna put an ecb on. Ive got a vf46 on it right now and im stage 2 tuned. Thanks

 
44mm would probably be fine for you. The usual guidelines are the lower the boost, the bigger the wastegate, unless you have a giant turbo. 44mm for small, stockish turbos and 38mm for bigger ones.

Which size is right for me? That is a question for your turbo vendor and tuner as sometimes their advice counters the external wastegate sizing theory. The theory is that a larger wastegate (44 mm) should be utilized on turbos using low boost vs. turbos that are running high boost which should run a smaller wastegate (38 mm). Where did this theory come from? Remember…a wastegate limits boost. If you want to run more boost, you don’t have to limit it as much. Running less boost means you have to limit it more. Think this premise through to get a good mental picture of it as this concept is terribly misunderstood.
Click to expand...
 
Last edited by a moderator:
where did you get that info from?

to me, it really depends on the horsepower output. The more horsepower, more exhaust, so you need a larger wastegate to expel the exhaust gases. If you are just going to stay stage 2, get the 38mm. 44mm is for(I would recommend) 500 crank horsepower or more.

 
yeah theres no need for a 44mm gate on a stg 2 car lol

a 38mm tial will work perfect for you

 
NASIOC guide.

http://forums.nasioc....php?t=1190530

Also something to note:

Since a larger wastegate has the capacity to bypass more exhaust gas than smaller wastegates, in a given application, larger valves are actually better suited to less boost and lower HP applications. Saying a larger wastegate is necessary for more power is like saying cars with bigger brakes make more power, when in fact bigger brakes assist in making the car slower, not faster. The highest boost wastegate is no wastegate at all, with out a wastegate a turbocharger would produce its maximum boost capability at all times.
CASE STUDY

One example of wastegate sizing constraints is in our very own 80tq project. In various configurations we were forced to change wastegate sizes to achieve different boost control strategies.

Configuration: GT40R turbo with .95AR, stock 30mm Audi wastegate, free breathing 20v 5-cyl turbo. With this configuration, the lower boost limit was 18psi at 5500rpm, boost would quickly taper to over 30psi by 6500rpm on simply spring pressure with no outside control. The reason for this boost taper increase was that the small 30mm wastegate could not bypass enough exhaust gas to maintain springe pressure boost, causing boost to increase. Counter-intuitively, this very small wastegate was perfectly suited to running 30psi or higher at 600 crank HP and above. The only reason to put a larger wastegate in this application would be to lower boost. By fitting a Tial 44mm wastegate we could maintain a 20psi boost curve all the way to redline, a 60mm wastegate could have been fit to run lower boost curves in the 10psi range, or about 300 crank HP. With such a large turbo and a free flowing motor, large amounts of air go through the motor, thus large amounts must be bypassed to control boost. With a smaller turbo, like a GT3071R for example, the stock Audi wastegate is effective at holding 20psi to redline since overall airflow levels are so much less.
Click to expand...
http://www.034motors...yths-a-128.html

drvsdwz said:
where did you get that info from?

to me, it really depends on the horsepower output. The more horsepower, more exhaust, so you need a larger wastegate to expel the exhaust gases. If you are just going to stay stage 2, get the 38mm. 44mm is for(I would recommend) 500 crank horsepower or more.
Click to expand...
 
Last edited by a moderator:
increased exhaust gasses is a direct correlation to increased hp. You have to remember NASIOC is not the best place for reliable information. And what do larger brakes have anything to do with the analogy quoted?

 
Another site saying the same thing about bigger wastegate=lower boost.

http://carterrace.com/front/index.php?option=com_content&task=category&sectionid=8&id=30&Itemid=55

WASTEGATE MYTHS from TurboSmart
The more powerful the engine, the bigger the wastegate you need.

This is one of the more popular misconceptions. Use this simple guide before setting out to find the biggest wastegate you can afford.

Big Turbo/Low Boost = Bigger Wastegate

Big Turbo/High Boost = Smaller Wastegate

Small Turbo/High Boost = Smaller Wastegate

Small Turbo/Low Boost = Bigger Wastegate
Click to expand...
Another:

http://ststurbo.com/f_a_q_#22

If I want to run higher boost will I need a bigger wastegate?Running higher boost doesn't require a larger wastegate, in fact in most situations running lower boost requires a larger wastegate than high boost applications. The wastegate flows exhaust out to lower the boost level. The lower the boost requirements, the more exhaust has to flow through the wastegate valve. Running higher boost will require a stiffer wastegate spring or the use of a boost controller.
Click to expand...
 
OP, both a 38mm and a 44mm will work fine for you, but I only said mainly to go with 44mm because of the theory behind EWG size and the fact that most, if not all 44mm ewgs are v-band (easier to service/maintain/etc.). Many 38mm EWGs are getting to be v-band now, but not all are yet.

 
yeah im gonna go ahead and trust my experence more then what I read on the internet. I have no issues maintaining 7psi on a 38mm gate with a 7psi spring. most of the time you get boost creep, its due to improper wastegate placement, not improper size. a 44mm gate is much more expensive then a 38mm, and vband is nice, if you are going to be disassembling and re assembling the setup frequently. but for 90% of people, that will install it and probably never remove it, a 2 bolt 38mm Tial is perfect with a up pipe that has wastegate priority flow.

and if smaller wastegate is better for higher boost, why are there so many cars with huge turbos making big power running dual 44mm or bigger wastegates? (not talking about twin scroll setups)

 
what about an internally gated gt3071r tuned at 18psi would this call for a 44mm or 38mm ewg or would a ewg be even necessary

 
You must log in or register to reply here.
Back
Top