Boost Pressure leak!!!

[996TT_STEVO]

I have a 996TT Tip, my boost reading has always been 0.5 and never above, I never thought anything about it as I have never had the ECU flashed and most Turbo's read between 0.5 & 0.7 anyway.
I have just had the ECU flashed (PSI flash) and it is still not exceeding 0.5, PSI say it should hit between 1.0 & 1.2 (also have a fabspeed system installed) There is an increase in power but that's me just feeling the boost coming on early, which the PSI flash does, but it will not exceed 0.5!

I have replaced DV's and still getting 0.5 although it hit 0.6 once! I have now checked all intercooler connections, given the F-pipe a good inspection, The DV's have been replaced!

What do I look for next?

Someone has mentioned "WASTEGATE"

Could anyone advise me of a specialist that could help out!

[vic cohen]

Lambda sesnsors ...............?????

[roshambo]

I doubt it would hit 1.1 / 1.2 without ECU mods.
Standard cars should hit around 0.7/8, ECU modified cars should hit 0.9/1 bar.
Any more most tuners avoid from a reliability point of view, sure the turbo's are bench tested much higher than this, but the reliability tolerances get reduced & the last thing any tuner needs is a couple going bang to ruin their reputation.
Larger X50 turbos can be fitted to get boost up to 1.2 bar.
Yours sounds very low, almost "limp home mode" slow but that would be picked up on an ECU test.
Porsche's website says 0.8 bar standard for a 996TT, so if yours is well under this then get them to sort it out as the car is not doing what they say it should (did you get it from an OPC?)

Ro.

[agent006]

Is it the speed of the car that concerns you or just the numbers on the dash? Maybe it's a knackered boost pressure sensor? If it was leaking pressure you'd have heard it by now probably. Pressure leaks also tend to destroy fuel economy figures.

[DanH]

agent006 said:

Is it the speed of the car that concerns you or just the numbers on the dash? Maybe it's a knackered boost pressure sensor? If it was leaking pressure you'd have heard it by now probably. Pressure leaks also tend to destroy fuel economy figures.

If it was a faulty sensor now he's had the car overboosted by 0.2-0.3 then I doubt its going to still give exactly the same reading.

Thought garages had a bit of kit to pressurise the intake of turbo cars and measure any losses?

[roshambo]

Go drive another 996TT, see if the performance is the same, if it is then as mentioned its something as simple as a faulty readout.

Ro.

[shadowninja]

Any pipes split? Maybe the split only leaks under pressure? (Get a bucket of washing liquid and start applying.)

[996 turbo]

Put it on the rolling road. A reputable place which is used to Porsches should be able to narrow the problem down a bit. It might even be the gauge / sensor rather than an actual pressure leak. You'll also get a good base line on the actual power it's producing. Most of the ones I've seen on the rollers put out extactly what Porsche said they would give or take a couple of bhp...

Steve, 996TT

[911 habit]

First stop take it to an OPC.
Second take it back to the tuner to help you trouble shoot it.

After I had my TT DMS chipped, I had a problem only happening in top gear between 5-6k rpm (165mph+) & only at full boost, 1.0-1.2 bar, the OPC can't test it at that speed, but the error log on the ECU gave them the direction to go to sort it out.

As it transpired, it was two things, on first visit to the OPC a split pipe on the waste gate (£4 item, not under warranty) after this didn't resolve the fault, the next error indicated a recycle valve sticking. This has been replaced under warranty and bingo! all is well.

Gerry

[996TT_STEVO]

Thanks all for the feedback!

[t urbo]

Steven,
its more likely to be a split/leaky hose, which you will hear under full throttle. (Sounds like an open ended air line). Hope you get it sorted soon so you can give me some feedback on that PSI chip. I went for the Imagineauto stage 2 in the end.....arrives next week so i will let you know how it goes.