my mk 3 ibiza tdi

it feels the same speed as before but on the boost gauge it's reading lower boost. Any tips on adjusting this rod, i thought all the boost was adjusted through the map on the ecu? Yeah your right i do lol it doesn't help that i can't spell and my gf wasn't there to check it

VAG TDIs have MAF sensors, right?

If so, it could be perfectly normal and the ECU is regulating airflow, not air pressure. Bigger turbo = more airflow at lower pressure, so where your old turbo ran a certain flow with 1.5 bar, this turbo might be flowing the same flow but at 1 bar. Because its VTG, its simply opening further so it doesnt hit boost cut.

Its just a theory though.

Another theory is:
If the actuator rod is set slack, then it takes less pressure to open the VTG (and therefore regulate boost) so the base pressure (what it runs at with boost pressure fed straight back to the actuator) is lower than it should be.

Now VAG boost control utilizes a high speed solenoid valve that bleeds the actuator pressure off, in amounts determined by the ECU. If the ECU has an open loop boost control setup (which is quite common) then it only bleeds off a set amount, which means that because the base pressure is lower, the controlled pressure is also lower.

Either way, a custom map would increase the ECU airflow demand and the control solenoid duty so that you'd be making the most of the turbo.

Both these theories could be right if the setup is how I think it is, but I'm not a VAG expert so I could be way off....

Anyways, a VAG custom mapper should be able to tell you for sure.

yeh i undrstand what your sayin that was my first thought about the problem that it might be less pressure because of more air flow but the only fault i can pick in this theory is that vag tdis also have MAP sensors to measure the pressure and i think it would regulate it that way but i could be wrong.
i havent heard of ajusting the actuator rod so that might be the thing to try is it just a bolt or tentioner?

got my new turbo back exhuast yesterday sadly the tip i liked looked about small so i jst went for a 6"x4" oval it sound loud and pulls abit better have been told by mitch it sounds abit like a petrol lol and i am now going to adjust the actuator rod and see if this cures it, although i aint really sure what am doing lol

tryed to adjust the actuator rod and this didnt help lol it made lag 1000 rpm more and it booseted so quick it blew pipes off the turbo so i put it back. i think i will let sum1 have a look when i get my stage two map

I have a good contact at darksidedevelopments who could more than likely sort your turbo and a stage 2 remapp at the same time if your interested ?

May I ask do you have a number for midlands turbos ?