Today my new turbo and wastegate came in the mail. Being excited as i am about installing it i decided to hook up my tial wg.
Well before the install i was running the internal wastegate at 5psi just fine up to redline.Well i unhooked the vacuume line from the internal wastegate and hooked it up to the tial side port.The vacume source is fed from the compressor of the turbo.The problem is at about 5k rpm the car stops accelerating, it boggs and feels like its boucing off the rev limiter.
The turbo boosts up to about 6 lbs before the wg opens accelerating smoothly then all of a sudden it slows way down on accelerating (pointless to even stay in that gear any longer)....boggs.If i shift it's fine until about 5k rpm again.
It seems to be less prominent in the higher gears ( i can still feel the bogging) but not as bad as first gear...

any ideas on what would cause this to happen? any and all comments are welcome.
Monday i will be installing the new turbo so that will eliminate the internal wastegate as possibility and tomorrow i will be re routing the vacuume line to else where....
btw boost stays between 5-7psi even when it acts up......thanks


[Modified by b16ahybrid, 11:11 PM 12/21/2002]

 

any idea's

 

Ok, I ran the vacuum line to the charge pipe..same problem happens..
The only way that i can explain it is...it sounds like the wg is cavitating.I hooked the internal wg back up and it runs perfectly fine..faster....anybody have any idea's..

 

Sounds like a possible plumbing problem... that is assuming your fuel is ok and that's not causing the bog.

I tried various plumbing points for the Tial... and found the best (for my setup) to be the side port of the Tial to the manifold after the TB. Top port on the Tial open to atmosphere.

I found the Tial wasn't being controlled properly when i plumbed the side port to the manifold before the TB.

 

Have you block off the internal wastegate port(hole) on the exhaust side of the turbo. It sound to me that you install the external with sealing it off. That might be causing the problem

 

It's sealed off, but by the internal wg flapper. Could it be that the wg flapper is opening even though there is no vacume going to it?

Please somebody that knows what im talking about reply

 

You do have check valves on your map sensor right? Sounds like its going into limp mode?

 

Thats what it feels like, but it's not going into limp mode.
Internal wg works fine......
I will have to wait a few days before i can check again, today we installed my new turbo so as soon as thats broken in...(and i replace a few things) i will be back on the gas, hopefully the problem will be fixed...thanks for the reply's more are welcome.....thanks

 

that's exactly what i thought when i was reading the post...what size spring is it? and you're not spiking at all...nothign that would throw you in limp mode?

 

That's what I am also wondering.... What kind of turbo and downpipe do you have?
Because an internal wastegate , the exhaust flange probably looks similar to this one....

(pic courtesty of http://www.gcg.com.au/)

you may have to reweld a new flange that blocks off the internal wastegate like this one shown from a T3...

(pic courtesy of http://www.roadraceengineering.com)





[Modified by SpoolinSol, 7:34 AM 12/23/2002]

 

If you are running an external gate on an internally gated turbo you either need to weld the flapper shut or run a downpipe that blocks the WG side of the turbo as shown above.

I'm assuming it is not the map sensor due to the lack of check engine lights.

 

hey, its your internal wastegate being blown open... you should weld it shut... or just wait to install the new turbo... but im POSITIVE that would be the problem...

 

ok guys.. thanks for the reply's.....
i was using a t-3 (.42/.48) with internal wg.I just unhooked the vacuum source to the wg and hooked it up to the tial...thats when i ran into the issues....
I installed the new turbo lastnight (.58/.63 ar) with no hole for internal wastegate..so i am now runing the t3t4 with the tial wg.I have not boosted yet so i don't know if the problem is still happening.It's a .45bar spring and it's wasn't spiking above that...thanks for the responses, i guess all i can do is wait until i test it out....