34mm flapper...

[Trevor Engelsmeier]

I have a 3" downpipe, and a 3" straight exhaust to a 3" in magnaflow.  to aid in the battle of the evil boost creep, i had the wastegate in my 02 housing dumped externally.  as much fun as it is to scare aNYONE with it, i really miss the turbo spooling sound.  i was wondering if a 34mm flapper in the internal wastgate would be big enough to get rid of the boost creep.

thanx

trevor

[Kimyee Lai]

I found that porting my turbine housing, especially around the entrance to the wastegate, really helped with my boost creep.

[Trevor Engelsmeier]

so porting and a 34 mm (which allows your to port the hole larger) should then take care of my boost creep.  i guess i can always just port the heck out of it, and see how it is and if i need to take out the turbo and get the 34mm.
hey kimyee, when u said that porting really helped with ur boost creep, what was it creeping to b4, and what is it creeping to now??  what type of exhaust do u have?

[Sean Tran]

while you're at it, why not go with a 38mm?  That's what I have, I believe.

[Ritchie Hui]

I believe its around the same price to put in a 34mm as it is to put in a 38mm...

[Trevor Engelsmeier]

well if it is close to the same price, might aswell.  i just wasn't sure how big of a flapper you can go on an internal wastegate.  

so as far as porting, u just open the whole as big as u can without leakage?  making it that big won't make the walls to thin?  adn i guess u can port where the arm goes, so it can open further

trevor

[John Hartman]

one piece of advise I read was that you don't want to go too big with your flapper or even with the porting in the wastegate area because if you go too big, it will not be able to make enough boost up top.

[Sean Tran]

one piece of advise I read was that you don't want to go too big with your flapper or even with the porting in the wastegate area because if you go too big, it will not be able to make enough boost up top.

That's when you get a bigger turbo (I'm beginning to see a trend here)

[Kimyee Lai]

hey kimyee, when u said that porting really helped with ur boost creep, what was it creeping to b4, and what is it creeping to now??  what type of exhaust do u have?

My exhaust is a 1ft long 2.5" pipe after the O2 housing .  I have an exhaust cutout on the first bend of the DP.  It used to creep to 21psi@~5.5k,6k or so.  Now, I can stay down at 17psi all the way through.  Any lower and it'll creep up to 17psi.  Mind you, this is on an EVO16, which is known to creep.  Basically porting + ported Evo O2 housing got rid of all my creep.

A 14B with a well set-up O2 housing really shouldn't creep.  I wouldn't worry too much about the wastegate flapper size yet.  Just port the entrance of the wastegate, also the exit of the wastegate flapper, make sure you've got an O2 housing with a nice big wastegate route and you should be set.

[Jovan Ceklaj]

If you're sticking with a 14b, don't worry about creep because it won't.  In fact, mine is so good at NOT creeping that it just dies off instead :x .  I have a ported 14b/EVO O2/EVO manifold and a 3" turbo back.  No creep to be found and it won't even hold boost to redline.

If you're concerned about getting one that's too big, you could always get an EBC which opens when it hits full boost, unlike an MBC which opens linearly through the rev range

[Kimyee Lai]

Actually, if the wastegate flapper is too big, the actuator is unable to hold it close, regardless of the pressure on the diaphragm.

[Wade Carlson]

If you port the 14b well enough you don't need to even put a bigger flapper on it to keep it from going over 15psi

I've ported a few that had significant boost creep problems that afterwards even with the stock flapper could keep 15 to redline

[Trevor Engelsmeier]

well i guess i can save some money and just do a porting job on it.  i guess the only thing to be carefull of when i port it is to not make the walls to thin.

i had gladman port the exhaust side of the turbo, both inlet, outlet and wastegate, and on the way home from his place even with the 02 dump it creeps to 20+.  also, while i'm driving it seems as if exhaust is leaking past my wastegate cuz u can hear it slightly at any rpm
u can hear it at idle, so my guess was he ported a lil to much??

thanx

trevor

[John Hartman]

Jovan, my completely unported setup dies off too.  Tell me what you find with yours would ya?  I'll do the same if I can find the cause of it.

[Kimyee Lai]

So is the turbine housing already ported?  If so I'll be worried about going much bigger.  Sounds like you have an exhaust leak...probably your turbo-manny or turbo-O2 gaskets.  One other thing, did you check to make sure your actuator arm has a full range of motion?  You really shouldn't be creeping that much on a 14b.