Porsche 996 Turbo S boost issues. Help and ideas ?
Discussion
stv951 said:
Have bought an immaculate 2005 996 TS with only 20.000 miles. Car looks smells and feels new. Problem is taht it doesnt pass 0,7 bar of boost. Car is 100% stock apart from a Ruf exhaust. Nothing else
Any ideas as to what could be causing the low boost issue ?
MAFS,Any ideas as to what could be causing the low boost issue ?
Actuators,
Boost hoses,
Diverters.
Edited by s3nick on Saturday 26th October 22:43
stv951 said:
The car is a 996 Turbo S so it has the X50 engine. Should go to 0,9 bar from stock and occassionally 1.0 bar as i have seen in others.
Really? I did not know that? I thought X50 was a turbo upgrade, not the engine and the boost levels were the same as normal ( 0.7 to 0.8 briefly ) and the extra power was due to the larger turbos and increased volume of forced induction? I'm sure stock is 0.8 and only a remap will take you higher, at least that's what I was told at OPC when I bought my X50. 
You may not be driving the car in a way that full boost is realized.
The DME attempts to meet the torque demands of the driver which the driver signals to the DME via the e-Gas pedal.
The DME will not every time the pedal is "floored" allow full boost.
If under hard acceleration there is no CEL, no other symptoms of any engine distress, with the engine fully up to temp pick a deserted road with lots of room and floor the gas pedal and I mean floor it in say 4th or 5th gear at just under 3K RPMs.
Keep the pedal floored. As RPMs rise the boost should increase to whatever the DME requires to meet the torque demands.
Note that if the weather is cool the boost level may remain a point or two less than max.
If a fairly high boost level is reaches, as RPMs continue to climb the DME will dial back boost.
Full or max boost may not be reached (or needed) in the lower gears or may be needed only fleetingly. In the lower gears these cars gain speed at an impressive rate.
Oh, be sure you are using a quality gasoline, of the proper octane grade, and you buy from a busy station.
The DME attempts to meet the torque demands of the driver which the driver signals to the DME via the e-Gas pedal.
The DME will not every time the pedal is "floored" allow full boost.
If under hard acceleration there is no CEL, no other symptoms of any engine distress, with the engine fully up to temp pick a deserted road with lots of room and floor the gas pedal and I mean floor it in say 4th or 5th gear at just under 3K RPMs.
Keep the pedal floored. As RPMs rise the boost should increase to whatever the DME requires to meet the torque demands.
Note that if the weather is cool the boost level may remain a point or two less than max.
If a fairly high boost level is reaches, as RPMs continue to climb the DME will dial back boost.
Full or max boost may not be reached (or needed) in the lower gears or may be needed only fleetingly. In the lower gears these cars gain speed at an impressive rate.
Oh, be sure you are using a quality gasoline, of the proper octane grade, and you buy from a busy station.
Take it to Ken at 9e.
My 2005 S had exactly the same behaviour. Turned out I had a load of boost leaks, on both the pressurised and before-turbo side of the intake system, and also a dodgy diverter valve. Once that was sorted it boosts quite happily to 0.9 bar on a mild day, and the pickup and response is much better. I never found it felt slow when only hitting 0.7 bar, but now I realise how "blunt" it felt compared to now.
I was amazed just how complicated the intake system is on the 996 turbo, and you need someone who has the right set of blanks and the experience to pressure test it properly. Ken gets my vote.
Pete
My 2005 S had exactly the same behaviour. Turned out I had a load of boost leaks, on both the pressurised and before-turbo side of the intake system, and also a dodgy diverter valve. Once that was sorted it boosts quite happily to 0.9 bar on a mild day, and the pickup and response is much better. I never found it felt slow when only hitting 0.7 bar, but now I realise how "blunt" it felt compared to now.
I was amazed just how complicated the intake system is on the 996 turbo, and you need someone who has the right set of blanks and the experience to pressure test it properly. Ken gets my vote.
Pete
Gassing Station | Porsche General | Top of Page | What's New | My Stuff