Volkswagen Passat Forum banner

Turbo running out of breath?

1K views 4 replies 3 participants last post by  Steve in Chicago 
#1 ·
1999 5 Speed 1.8T AEB (Stock)

Hi all!

Finally installed a boost gauge and I noticed today in a 2nd gear pull that I ran out of boost (0~1 PSI) around 5K RPMs. Moreover, I don't get above 6PSI period and I don't have any spikes. Is this normal operating conditions?

For vac at idle I get 25! Which I think is a good sign!

Thanks!
 
#3 ·
The AEB is rated at 150 hp and has a simple (no wideband, no boost pressure sensor, no DBW, no variable cam timing) engine management system that goes open loop when you punch it. You'll see 6~8 psi depending on ambient air temp and fuel quality. (try running two tanks of high octane if you normally run is the cheep stuff). Boost and torque will hit strong down low like 2000 rpm because the turbo is purposely sized small enough to shine at that flow rate. As you hit and surpass 5000 the turbo will be too small to keep up with the flow rate and boost will drop off. Dropping to 1 at 5000 seems a bit low. You could have leaks in the charge path, blocked air filter, restricted exhaust, turbo getting tired, leaking diverter valve, leaking waste gate.

Get yourself a performance tune. You'll go from 150 to somewhere in the area of 195 and the difference will be unmistakable. Ian at Reflect Tuning has flash-on (not solder on) performance tunes for the AEB.
 
#5 ·
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top