996 Turbo Boost
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Discussion

kkerr3

Original Poster:

87 posts

178 months

Friday 29th March 2013
quotequote all
I recently bought a 996 Turbo.

I did a few runs on a dual carriageway today. Cruising along at 40 then I bury the accelerator. I am getting a constant 0.9 Bar for 5-6 seconds before I run out of road.

The car is the 420BHP (not X50).

What is standard boost for an modified turbo?

The cars runs on V-Power and as far as I know is standard?

Would this boost reading suggest it has been tweaked?

TTX50

52 posts

174 months

Friday 29th March 2013
quotequote all
Mine's an unmodified X50 - so may not be the same. I get 0.8 and very occasional 0.9 - so yours could well be standard? 0.8 seems to be the standard quoted on here and elsewhere.

the other me

614 posts

182 months

Friday 29th March 2013
quotequote all
If I recall correctly x50 ( can't remember exactly as mine was chipped soon after I got it) is around 0.8-0.9. For a non x50 car I would suggest "chipped" hehe but I am led to believe various faults including sticky wastegate can also leave you with this amount of boost, and of course it varies day by day with atmospheric conditions, was it particularly cold ? (Iask, as I am 1500km further South)

yajeed

5,057 posts

283 months

Friday 29th March 2013
quotequote all
the other me said:
If I recall correctly x50 ( can't remember exactly as mine was chipped soon after I got it) is around 0.8-0.9. For a non x50 car I would suggest "chipped" hehe but I am led to believe various faults including sticky wastegate can also leave you with this amount of boost, and of course it varies day by day with atmospheric conditions, was it particularly cold ? (Iask, as I am 1500km further South)
From what I understand, standard is 0.7 with possibility of 0.8 for brief periods.
On another thread it was said that .6 was full boost with .7 on occasion, so I'm not entirely sure.

I think mine peaks at .7 on standard unleaded but I've not really had the space to test that yet as other cars get in the way.


kkerr3

Original Poster:

87 posts

178 months

Friday 29th March 2013
quotequote all
Temperature was about 6C.

The boost would spike at 1.0 Bar occasionally but was holding 0.9.

yajeed

5,057 posts

283 months

Friday 29th March 2013
quotequote all
kkerr3 said:
Temperature was about 6C.

The boost would spike at 1.0 Bar occasionally but was holding 0.9.
Chipped or sticky actuator IMHO. Standard exhaust?

Rockster

1,515 posts

189 months

Friday 29th March 2013
quotequote all
kkerr3 said:
I recently bought a 996 Turbo.

I did a few runs on a dual carriageway today. Cruising along at 40 then I bury the accelerator. I am getting a constant 0.9 Bar for 5-6 seconds before I run out of road.

The car is the 420BHP (not X50).

What is standard boost for an modified turbo?

The cars runs on V-Power and as far as I know is standard?

Would this boost reading suggest it has been tweaked?
If by "an modified turbo" you mean an unmodified Turbo, and non-S model, the standard boost can vary. Nominal boost is 0.7 bar.

The way it was explained to me is the Ecu attempts to meet the torque demanded by the driver (signaled by the e-Gas pedal).

If the Ecu can do this with 0.6 bar of boost that's all the boost you see. If it takes 0.7 bar of boost you'll see 0.7 bar of boost.

However, in some situations (more on this below) boost can rise and not due to an anomalous spike to 0.8 bar even 0.9 bar.

Where I live and drive the most boost I see with my stock 03 Turbo (not an S) is 0.7 bar.

However, I have been in the mountains of various western USA states driving at much higher elevations than where I live and spend most of my time driving.

A few examples are at around 7700 feet (I-40 at the continental divide just outside of Flagstaff AZ) and at over 8000 feet (I-80 at several places in Wyoming) and when I subjected the car to under hard acceleration (pedal to the metal hard acceleration!) I have managed to see 0.8 bar and even 0.9 bar boost with my stock 03 Turbo.

Some drivers have reported seeing the same levels of boost at lower elevations (in the 4K feet range).

The times I've have observed 0.8 and 0.9 bar boost the reading remained present long enough to convince me it was not a spike.

I do not know if the Ecu in the S model also allows for a boost level over "nominal".

dank

1,160 posts

281 months

Friday 29th March 2013
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Myn has 0.7bar boost, standard, not seen 0.8, then again i havent had it long and not driven it that hard!

LeighB

3,858 posts

254 months

Friday 29th March 2013
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0.7/0.8 is fairly normal for a standard setup.

Anything more could be down to very nice cold air or a duff diverter valve, boost leak, sticky actuator etc.

I would suspect, as happened to mine, something faulty would show in how it boosts, any hesitation in how it accelerates would be a clue that there's a fault with something. Mine would spike at 1.3bar when one of the DV's was knackered.

NBTBRV8

2,066 posts

237 months

Saturday 30th March 2013
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My non X50 mapped car use to sit on 0.9. 0.7 is standard.

nick996tt

45 posts

203 months

Saturday 30th March 2013
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I had a 2001 tt with a high quality Manthey remap. IIRC it hit 1.1 to 1.2 bar at max. Unbelievable acceleration. Torque was off the scale. And oddly, the mpg was around 26 over the long term (and i NEVER drove it any way other than "enthusiastically"), which is better than stock i think. Amazing car and 100% reliable - should never have sold it!


Angelus

2,209 posts

193 months

Saturday 30th March 2013
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nick996tt said:
I had a 2001 tt with a high quality Manthey remap. IIRC it hit 1.1 to 1.2 bar at max. Unbelievable acceleration. Torque was off the scale. And oddly, the mpg was around 26 over the long term (and i NEVER drove it any way other than "enthusiastically"), which is better than stock i think. Amazing car and 100% reliable - should never have sold it!
I've got a 2003 one, same numbers as you got. Car is epic and I love every minute. Got Alcons and 6 pots on the front though, with that power it needs to stop too. smile

nick996tt

45 posts

203 months

Tuesday 2nd April 2013
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Angelus said:
I've got a 2003 one, same numbers as you got. Car is epic and I love every minute. Got Alcons and 6 pots on the front though, with that power it needs to stop too. smile
Yep, agree - i put gt3 brakes on the front.

stubbsy996

785 posts

242 months

Tuesday 2nd April 2013
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On my 2003 (non X50)maximum boost was normally 0.7, although I seem to recall hitting 0.8 once or twice.
Since re-map now hitting 1.0/1.1.
Think the above figures are normal for standard/re-mapped turbo.

StuB

6,695 posts

268 months

Thursday 4th April 2013
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Sticky actuators/waste gate will possibly give higher boost readings. Mine (X50 with mods) used to read 1.2 bar regularly.

Fantomx

85 posts

155 months

Tuesday 13th May 2014
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My mapped X50 with a nuvolari exhaust shows 1.2bar average with monster torque!

Fantomx

85 posts

155 months

Tuesday 13th May 2014
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My mapped X50 with a nuvolari exhaust shows 1.2bar average with monster torque!

Crimp a Length!

5,697 posts

252 months

Tuesday 13th May 2014
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Mine is boosting at 1.3, occasionally i see 1.4.
Car has been DMS tuned uprated turbo's 997 GT2 inter-cooler and non standard DMS exhaust.
Goes like st off a shovel.

My previous standard 996 Turbo's were all boosting around 0.8