I've been trying to figure out why I was only getting 7-8psi on my secondary for a while, and now I know why.. That 7-8 is now 5 and the car moo's a bit. It sounds like standard turbo sounds, but much lower. I'm assuming a shaft is wiggling in there, and its most likely on the secondary. I can hold 10psi firm on the primary so I doubt the problem is there.

So, what are my options? I'm not interested in going single (too expensive at this stage -- I also still have the original motor), I like power low down. Can I just swap out the impeller, or is it going to require more work?

I have a T25 sitting in my garage in a plastic bag, can I use that as my secondary?

What do you guys think? I'm not looking to invest very much in the turbos at this point, I have no other mods to help there. Opinions?

Thanks in advance guys,

 

I think that you are cold on your problem. There are several threads regarding poor turbo performance and crappy secondary transition which will push you more to the warm zone. As for the mooing, yes, boost leak could cause some strange noises, but if you are running your air pump to an open filter, you may be hearing it moo. Just search "moo" and I believe you will find a few threads covering it.

 

My only mods are the pettit AST and reinforced intercooler hoses..

It was communicated to me by a local mechanic (shop has a good rep) that if I was getting a boost leak, it would be seen on the primary too.. I'll see what I can find, I did a quick look but didn't find anyone saying the same thing..

Its hard to judge with the complexity of the system, it could be almost anything..

 

Rule of thumb; if it's low boost after 4500 RPM it's in the turbo control actuator system, if it's low boost before 4500 RPM it could be almost anything.
Is your mooing really a moo, or is it a wooshing sound?

 

ie. my spaghetti is loose?

 

Mine must be 'cause I don't get it. I do like the way our colors clash. Orange and green. Nice looking thread.

 

haha Spaghetti = unmanageable array of tubular objects under the hood..

I haven't had my vac lines replaced as of yet, I think I'll have the shop do it for me..

 

Good start. I remember reading an old turbo or import tuner where they picked up 20hp from doing the hose job. If you still have issues after that, then come back here and search using keywords like "low boost" and "turbo control actuator"

 

Took the car over to a local shop and had the problem fixed.. Heres my math equasion.

Let
x = moo
y = low boost
a = clogged catalytic converter
b = broken air pump hose

x+y=a+b

so,

let
h = better boost response
i = wicked top end
j = smoother shifting

1/(a+b) = h+i+j


Now that the car doesnt hiccup as much, the shifting is smoother and the 3krpm hesitation is much reduced.

I'm in love.

 

Are there any other symptoms of a clogged cat? I'm getting a boost pattern of 10-8-5 psi.

 

I'm not sure, my car sounded muted after the secondary kicked in. Obviously a lack of power.. I took my car over to the aforementioned local shop and he looked it over for free. Have someone check it out, it's cheap..

Have it looked into as soon as you have a chance.. it could be anything from a stuck wastegate, to a dieing turbo, etc.. My solution was inexpensive, and well worth just doing it..

 

Last night I was driving my FD , and when I floored it I heard a huge POP sound, kinda like a car with straight exhaust sounds when shifting and the flames shootthat started in front and went to the back of the car. "oh ****!!" i shouted. suddenly my power was cut in half and I could hear the turbos make a very low hum. my boost was near zero. I took it into the secondary range and still no boost. I was basically running the power an NA 13b. I couldn't accellerate in 5th! when I got home I looked under the hood, pulled the throttle cable to rev and heard that same low growl. and there stood the hose from the intercooler to the turbo disconnected. I reatatched and problem solved. thank god... I wasn't ready to spend $5k for the single yet. I just hope you are as fortunate.

 

As you can see, he can make 10lbs on the primary, so its not the same problem

I've popped my IC hose before too.. Though its because I didn't tighten the ring clamp enough after installing the reinforced IC pipes from Pettit.