34mm flapper...

[Jovan Ceklaj]

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.

I suspect that it's just the nature of the beast.  While they're great turbos, 14bs are rather small.  I don't have a flow map on hand, but I'm sure if you looked you'd see some pretty disappointing numbers

[Martin Raska]

See below for the map.  So the 14b could do about 480cfm at 2.6 pr as its max, but on our engines at 2.6p.r are in excess of 550CFM.

[John Hartman]

I have had it hold boost to 19 psi before, but hey, it DOES flow more now, that might make sense.

[Jovan Ceklaj]

I have had it hold boost to 19 psi before, but hey, it DOES flow more now, that might make sense.

same here.  Mine used to be able to hold 18 psi solid.  Now with a whole bunch more done, I run it at 22 at the track but it only holds that until about 4k rpm.  After that it just dies off to about 15-16 :x

[John Hartman]

hehe, I guess I should feel fortunate then, mine doesn't die off till about 5500 and then it only drops to 17.  Still shitty tho.

thing is before it used to creep to 20 or even 21 if I held it to over 7 grand.

[Trevor Engelsmeier]

i am gonna be starting off with a totally stock turbo off of the JDM motor.  so i can start from scratch.  would it be better for me to try and port it, or send it to someon on here who can port it professionally

trevor

[Wade Carlson]

u can give it a try yourself and save a bunch of money its really not too tough

[Jesse Veitch]

Jovan just a thought but maybe has something to do with the fmic? that's a lot more volume to pressurize every time you spool up than the stocker, more bigger diam piping aswell

[Jordan Gladman]

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.

I only did an hour or 2 of porting, it was mostly removing the casting marks and polishing. Nothing too significant around the flapper port.

[John Hartman]

Jesse, that very well may be the case, at least in my situation.