MTDI boost and tuning question

[avocado]

Hi

I have a Tintin MTDI pump on a 1Z engine.  I have run it for a few hundred miles now, and just put a boost gauge on it the other day.  

I get about 9 PSI boost at full tilt between 2200 and 3500 rpm.  It seems to make good power, with a haze of smoke at fill tilt.  I turned the fuel screw in a half turn and still only about 9 psi boost.  

My question is.....is that boost level right for the motor?  I was expecting to see more boost.....maybe I am wrong?  I was under the assumption that the 1Z, when in a passat, makes at least 15 psi.    

I have one little air line line that comes off of the pressure side of the turbo, that joins the wastegate and then goes to the spaceship-looking-thing on top of the IP.  

I understand there is some sort of adjustment on the wastegate to allow for more boost?  Maybe I need to search for boost leaks?

[96jetta]

the line that goes to the top of the ip is telling the ip haow much boost is coming out of the turbo. this allows the ip to push in more fuel under boost and lest with a ateady throtel. i believe there may be some computer adjusting involved to allow for more boost

[dillenger1]

did you block you WG?theres no electronics on a m-tdi.early tdis got a waste gated turbo correct otr do you have a vnt?

[fairweather]

You most likely have a wastegated turbo that can be adjusted by screwing the actuator in or out. If it is a stock 1Z you have a GT15 which is what I have.

You should have a threaded rod coming out of the diaphragm housing with a fitting on the end that pops over a pin on the wastegate itself. Remove the cir clip and unscrew it 2-3 turns and reattach. IIRC each full 180 gives you about 1 psi or so.

I have found that i don't get much additional response above 13-15 psi.



Is this what you have? Adjustment rod is what is coming out of the gold canister.

[avocado]

I am pretty sure it is a wastegated turbo......It came on a 96 Passat, 1Z engine code.  i was just curious as to what psi level I should be aiming for.  Ill adjust the rod and see where I can get it to go to.  

Pic looks just like what fairweather posted.

Thanks for the input!

[jimfoo]

Depends on how much fuel you are putting in and how much smoke you want out. At least enough boost so that your EGT's aren't too high when it's floored.

[avocado]

Hmmm...I screwed in the wastegate mechanism about 6 turns, and it only makes about 1-2 PSI more.  I don't think I have any boost leaks, I've checked all joints and they seem to be secure.  

Oddly enough, smoke is still the same.  Not too bad, but it is there.  

Maybe I should have bought an EGT gauge too....the nature of this vehicle is such that I cannot keep the pedal down long enough to stir up high EGT's.....the car just goes too fast and feels unsafe.

[fairweather]

the car just goes too fast

I don't understand this statement  :!:

I was able to get mine to max out at 21 psi by adjusting that actuator rod though as I said anything above 14 or so was not effective. I've got an 11mm IP and sprint 520 and don't smoke unless I lug the engine.

[avocado]

Well, the dynamics of the car that surrounds this engine is such that the engine is able to push the car far faster than the car should go.  It is really a trail buggy kinda thing.  Top heavy, flighty, light, etc.  

Still not sure what to think about the boost.....10 psi is it!!  I really do not think I have any boost leaks.  It is a 10mm pump and stock injectors (.184, IIRC).  Maybe bigger injectors would clean up the smoke and give a bit more boost?  More fuel in a shorter injection window?

[jtanguay]

Well, the dynamics of the car that surrounds this engine is such that the engine is able to push the car far faster than the car should go.  It is really a trail buggy kinda thing.  Top heavy, flighty, light, etc.  

Still not sure what to think about the boost.....10 psi is it!!  I really do not think I have any boost leaks.  It is a 10mm pump and stock injectors (.184, IIRC).  Maybe bigger injectors would clean up the smoke and give a bit more boost?  More fuel in a shorter injection window?

the bigger injectors could help...  if you want more than 10 psi, you should plug the line going to the wastegate controller.  15 psi is probably the max you'd want to go without an EGT gauge though.  unless its underfueled or stock fuel.