1999 s80 t6 power flattens around 4500 -5000 rpm

ADB · Post by **ADB** » 24 Aug 2011, 12:29

Hi my 99 t6 accelerates very fast off the line and up to 4500-5000rpm, then it seems to flatten out is that normal? I thought the second turbo is supposed to work at higher rpm. I have new plugs and all cylinders are firing fine with no faulty codes.
Any suggestions?

Post by **boosted5cyl** » 24 Aug 2011, 19:05

Both turbos work simultaneously, they are not sequential like a 2JZ or RX7. In the T6 one turbo is on cyls 1-3, the other 4-6. It should pull strong up to 5500 or so from memory. The turbos (TD03) are small and the T6 is more adept to flexibility than top-end power, how severe is the drop off?

You are using "premium" gas right? Was it pulling better previously? With no codes or signs of misfiring think my plan of attack would involve...

Ensuring plugs are gapped to 0.028"
Compression Test
Inspection of all vacuum pipes, especially those that control the wastegates on the turbos.
Check the wastegate actuation pressures, correct if needed.
TCV solenoid service\cleaning.
Turbo plumbing pressure/leak test.

ADB · Post by **ADB** » 24 Aug 2011, 19:53

It pulls good till about 500rpm then it kinda flattens, I never drove another t6 only a s80 and my t6 is a lot faster than a non turbo. I guess I did not know what to expect,
thanks

Post by **boosted5cyl** » 25 Aug 2011, 10:45

I have a wobbly CV joint in mine right now so I cant punch it to compare... Maybe go to a dealer and drive another one ?