[Dopeskills]

I've been wondering what exactly the difference is between an internal and external wastegate. Does an external wastegate provide less turbo lag?


<hr noshade width=60% size=1 align=left>Cobalt Blue 2K Tib - 5 spd

 

[Stephen_Gsi]

I don't have the answer in my brain right now, I lost it, but I do know where I read about such matters. Sport Compact Car has had a series of articles detailing everything, I mean everything about forced induction. I will look it up tonight at home if you want or if you can find the last few months of Sport Compact Car then you can find it yourself probably


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[alieo]

how can I find those back issues of sport compact car, is it something I can search on the web or do I have to find all the old magazines<img src=/images/forums/snitz/oogle.gif width=15 height=15 border=0>


<hr width=60% noshade size=1 align=left>leave it to you to ruin a wet dream

 

[scoupe91]

an internal wastegate is built in the turbo and they let go of exhaust gases exit up to a certain psi or bar it is set at (ex. 12psi) and when the throttle plate closes it opens so that exhaust energy is let go instead of spinning the turbine wheel and that is where a blow off valve is good because all the air is being pushed by the turbo in the intake tract is let off so it doesn't back pedal back into the turbo and seriously screw up the compressor wheel and in turn frag the turbo. now internal wastegates are used in as i know up to small T3 garrett turbos and some of the T3/04 hybrids have them but as you get bigger housings and turbos are used the external wastegate comes in. also boost can only be taken up in some internal wastegated turbos past 24psi before using a turbo with an external wastegate you can go farther up to or byond 40 psi. i will check some resources.


<hr width=60% noshade size=1 align=left>i give the honest performance facts and if i i don't know it i will tell you because i am not some riceboy*****

 

[Stephen_Gsi]

I checked Sport Compact Car's web site and they don't have those articles archived online, but there must be something somewhere on the internet. I said I forget the facts, I will post what that article says just as much for my benefit in remembering as anything. And Alieo, if you have a good and big library, they may have these articles, but that is a long shot. If you need them bad, SCC will gladly take your money in exchange for back issues. And seeing as I am rambling on, I should add, just to be a real stickler for tecnical stuff, Scoupe91, you need to be careful about your terms, a wastegate is very much different from a blow-off valve.


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[scoupe91]

sorry if i forget to make sh!t clear but a wastegate is used on the exhaust side of the turbo or turbine housing(internal) or just before the turbo on the exhaust manifold(external). and the blowoff valve is located on the pipe coming from the intercooler(if you have one) and if you do'nt it is the pipe coming from the compressor housing of the turbo. i just don't want to confuse anybody here and just helping out. <img src=/images/forums/snitz/smile.gif width=15 height=15 border=0>


<hr width=60% noshade size=1 align=left>i give the honest performance facts and if i i don't know it i will tell you because i am not some riceboy*****

 

[Random]

SCC back issues are available, the number is in the mag. They keep promising to have their articles online, however they still don't have 99% of them.

I wish they would put their "suck, squish, bang, blow" series online at least!


<hr width=60% noshade size=1 align=left>quote from 4DoorGL: "Told you. Random is cool as hell in person, even if he is a dick on the net <img src=/images/forums/snitz/wink.gif width=15 height=15 border=0> (j/k)"

Leave it to Random to Needlessly complicate things.

 

[UFB]

Scoupe,

Let me add to your comments, the internal wastegate you describe is actually not a wastegate. that is the function of the BOV - the BOV releases the backpressure when changing gears to prevent the Turbo from spooling down and also is the cause of the TSSHHHH sound when changing gears.

The wastegate's function on the other hand is as follows:- Whilst the engine is boosting, and the boost level reaches the set maximum governed by the Actuator valve, the wastegate flap (Internal example) will be opened by the actuator valve and in-turn releases all the excess boost OVER the manually set maximum.

The external wastegate basically performs the same function, but is able to flow alot more CFM than an internal version and therefore is more stable at higher boost levels. Th internal version tends to boost creep when "over-worked"

Hope that helps.



<hr width=60% noshade size=1 align=left>Tiburon Turbo 350KW and 700NM AKA Black Monster

 

[Dopeskills]

Great <img src=/images/forums/snitz/thumbup.gif width=25 height=18 border=0>

everything makes sense now. Thanks guys...


<hr width=60% noshade size=1 align=left>Cobalt Blue 2K Tib - 5 spd