Aftermarket wastegate vs Internal

[DrBrown]

OK gents I have a car with a stock internal wastegate (housing and actuator assembly) and Im wondering what kind of whp gains if any could be had just by using an external wg? Some people have told me that it can really make a difference but I really dont understand that UNLESS the external wg is venting to atmosphere because that would in turn let it free up the exhaust almost like having a 4" downpipe. So just for guesstimation if a car has 200hp then upgrades from a internal actuator setup into an aftermarket wg that recirculates back down the downpipe (doesnt vent to atmosphere) what kind of power gains would be seen? All comments are welcome because I have NO IDEA if it makes any difference. Thanks!

Dan

 

[out there]

external wastegates are generally just better at holding xxpsi than internal, they don't improve your power (unless perhaps the venting thing).

 

[DSMJim]

Originally posted by out there
external wastegates are generally just better at holding xxpsi than internal, they don't improve your power (unless perhaps the venting thing).

I could consider that a pretty good answer.

I have an external gate, however I routed it back in so I didn't have to listen to it when I drive, just my preference.

Most of the time people change to a new turbo with a gate so it's hard to get an answer on this type of thing, however a wastegate doesn't produce HP. It only improves the chances of holding a particular amount of boost. The bigger the turbo and more HP you make the larger your wastgate has to be to let exhaust by.

I considered cutting my gate out and flanging it so I could switch between internal routing and external routing but I have pretty well decided to just leave it internal cause it's quiet. I'm not really big on noise at all.

 

[BrnOutKing]

larger waist gates are only needed when trying to run lower boost.

again only way I can see it being a power gain is dumping to atmostphere. but then again you can do that with an internally gated turbo anyways so really dumping to atmosphere isn't what you were asking. There are no power gains for going external. Only that you'll have better control over your boost. Oh ever even that is based on your set up. Creap is also caused by to small of an 02 housing as well.

-brian

 

[DrBrown]

Great responses gents. I agree with what you all said for hte most part. I am only running 7 psi off and on. Its a T3/T4 garrett and its been just fine for me so far. The only bad thing is most wastegate actuators are set for like 7.5 psi or higher since most stock OEM turbocharged cars have tiny turbos that run mid to high boost. So if I want to run 3 or 5 psi its not really possible since mbc's only let you make the wg open later and run more boost.

So the bad part is I am putting in a high compression engine and I am only going to be able to boost 6 psi MAX so I need to make my intercooler and piping more restrcitive so the 7 psi actuator only boosts me 6 hehe. Anyhoo thanks for the responses guys. I kinda knew the answer but I wanted to verify you all had the same answers that I came up with. Thanks!

Dan

 

[out there]

put in a weaker wastegate spring, i'm sure you can either find one at a hardware store (just guessing on that), or maybe order on from turbonetics or roadrace (roadrace usually has just about anything you could need)

 

[DrBrown]

I dont have an external one, I cant just change the spring. I would have to change the whole actuator assembly or something.