Boosting 3psi, what else could it be?

[505zoom]

Ok I finally got over this flu and got a chance to get the car the rest of the way back together today. Double checked everything, put the front bumper back on, and took it for it's first spin with the new pipes.

Off boost throttle response is much improved over the old setup. No idle issues or anything weird going on. Car warms up fully, I stomp on it for the first time, hit 3psi. Grabbed some lunch, brought it back home, and just got done eating. Haven't gone out there to look at everything yet, but wanted to throw this up on here to get any other suggestions you guys might have.

Obvious thing I will check for to start is all of the charge pipe couplers. Seems logical. The wastegate flapper was closing fully when I put the turbo back on, so I am pretty sure that isn't it.

Anything else?

 

[Maxx Mazda]

If you changed the pipes I'd go with that first off. Use the hairspray trick, and it seals them REAL well.

Take the coupler off, spray hairspray on the pipe and i nthe coupler. Slide together, and then clamp. It's acts like a slip agent so u can get it together easier, then when it dries it's all "sticky" kinda so it locks everything down. I have had pipes blow off on me before, so I started using hairspray and never since.

But ya, I'd say you have a loose pipe. Remember, check it actually. It may look tight, but under the slightest bit of boost it can open up.

 

[505zoom]

Checked all couplers/clamps, there is one that wasn't super tight, but it wasn't loose enough to cause the issue me thinks. All clamps are now fully tight, checked the comp housing bolts too, took it for a spin and it still has the same problem. The wastegate can and bracket are both tight, and there was slight tension on the arm with the flapper gate closed fully.

Going to try boosting it up with the BC and see what it does.

 

[BOOSTR]

Was your vacuum reading the same both at idle and when you let of the throttle like before your recent work/project?
That is strange that all of a sudden you suffer a 6 psi drop off. Maybe you overlooked something obvious during reassembly. It happens and I've done it few times myself.

 

[505zoom]

Idle and cruising vac is the same as before. No audible leaks, and it didn't sound like the turbo was really pissed off or anything. Not like it would with a huge leak somewhere.

So I gave the MBC a couple turns, right back up to 6 where it was before. Set it at 7 and the car feels great. Pulls really hard for such low boost and such gimped timing (still have the MPI timing retard set where it was for 15psi, I have no laptop to hook up to it and change it, lol). Boost definitely comes on quicker with the new pipes.

So all is well I guess, I am curious as to what is causing the 3psi drop with this new setup, but if the MBC takes care of it with no problem then oh well I guess. I will keep my eyes on it.

 

[BOOSTR]

Good deal then, business as usual. Must of been gremlins that backed it down(dunno)

 

[ND4MSP]

Did you change pipe dia? Shorten the route of the piping? Actually never mind. Both of these would change response, but it wouldn't explain why your only making 3psi.