EDIT: Turns out that this was a tuning issue.

 

What kind of BOV and is it recirculated?

 

He said WOT.

 

i have FP black never had this problem, did on the FP red tho

 

I used to have a 64mm Red and compressor surge with that on my built motor/head was really bad. The Black cleared up most of it, but there is still this lingering little bit that surprises me.

The BOV is a recirculated 1G DSM BOV with a Dejon Tool leak stop kit. When my car was previously dyno tuned on the Red, it held 30 psi to redline.

I also didn't have this issue with my old EBC, but it didn't divert all air around the wastegate actuator at low boost either.

 

.....and, your point is?

 

What is the targeted peak boost setting on this car? Does this Black have a ported turbine housing?

To totally eliminate the possibility that it might be the DV, then you could remove it and plug the holes in the MAF pipe and the UICP and do a run just for test purposes to ascertain definively whether or not the DV is involved? Or, alternately, you might want to try another different DV which you might have from another car. Just to see if the car acts the same with both DV's.

 

I have not had any surge problems

 

I'm just starting to tune it. Right now, I'm limiting to about 25 psi, but ultimately I'll be aiming for a max of around 30 psi. The turbine housing is ported along with the head.

 

Sometimes these stock frame turbo's
have this surge problem at part throttle..Are you getting this wot or part throttle??I had this issue on my red but not the black but then again i only had the black turbo for two weeks..

 

FYI, 1sloassevo,he stated that the problem is during WOT events. Were you running the standard comp housing on your Red, or the surge ported FP housing?

 

The 84 mm surge cover..If he's getting this at wot it might be the way hes getting into the throttle that's why i don;t like these turbo's.

 

O by the way if you wanna keep this turbo alive i wouldn't do wot pulls at that rpm in 4th or 5th gear..

 

I have a theory about what could be happening here. It has to do with the 3-port BCS being forced to overcompensate and pulsating the 25# actuator. This is because the actuator, which is probably set at a very low preload level allowing the WG puck to be forced up off its seat. Then this is combined with the Black's relatively large comp wheel at low boost levels and low shaft speeds and an insuffiently ported turbine housing.

So, too little preload allows the wg puck to be lifted up off its seat at about 20# which brings the BCS into play and be constantly pulsating in an attempt to close the flapper valve. This is all going on at a boost level between 22-26# where the Black's comp wheel is just starting to crossover into its more effective range. So, there is a mismatch between the turbine and compressor's pressure differential at relatively low shaft speeds with the WG off its seat and venting with the BCS pulsating wildly trying to control the flapper valve.

Until I could sort it all out I would ditch the 3-port and install an MBC. Also, I would replace the 25# actuator with the 18# unit preloaded to 22-23#. And I would remove the turbine housing and hog the hell out of it.

Incidentally, what air filter are you running?

 

I have an 18 psi actuator and my turbine housing was ported by Buschur Racing. I actually think that good porting (on all the parts -- exhaust manifold, turbine housing, cylinder head, etc.) might be part of the reason the turbo is spooling fast enough to trigger surge.

There is a decent amount of preload on the actuator. I set it myself.

I'm not going to change boost control, as this problem is easily rectified by lowering the WGDC to slow the spool of the turbo in 4th gear at this RPM range. In fact, I think 3-port control is that much more important to keep this issue in check. I haven't tested it in 5th gear yet, but I'm guessing that I'll really have to reduce the duty cycle in 5th gear between 3000 and 4000 rpm to avoid this issue. It smooths out above 4500 rpm.

This whole thing is really not a "problem" at all, since I can tune the 3-port around it (thank you Tephra!), except that I can't spool the turbo quite as fast as I otherwise could without the surge. I'm just surprised that I have surge at all with the 80mm antisurge housing. I had a lot of surge with the 64mm Red, which felt exactly like this.

I think maybe others haven't felt this as much with the Black because they don't have my combination of parts.