Stock boost levels on 996TT / GT2 / 997TT - Page 2 - 6SpeedOnline

Jan 16, 2011 | 09:10 AM

#16

E90076

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I have a stock 996TT and my boost levels are generally 0.6 and have only spiked to 0.7 on a couple of occasions. Is that normal or should I be reading 0.7 at all times?

Jan 16, 2011 | 11:01 AM

#17

996ttita

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I own a stock 996tt x50, on the road the maximum I have seen is .9 but during a track day at Mugello I have seen 1.1

Jan 16, 2011 | 12:13 PM

#18

OCTurbo

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Quote:

Originally Posted by E90076

I have a stock 996TT and my boost levels are generally 0.6 and have only spiked to 0.7 on a couple of occasions. Is that normal or should I be reading 0.7 at all times?

That's normal. Get your car flashed and you will be seeing 1 bar!

Jan 16, 2011 | 12:23 PM

#19

earl3

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Quote:

Originally Posted by emadelta86

Mmh, 1.2 bar gauge pressure on k16....

here is the comp map:

Attachment 141505

With 1200 mbar gauge pressure, 981 ambient pressure, you are at 1.22 pressure ratio (more than this actually, because the gauge pressure is measured after piping and IC's, so there would be some additional pressure to add because of the pressure drop).
Assuming a VE of 90%, at 5500rpm the turbos are flowing 360cfm each, which is 0.16 liters/second. This means the turbos are working in the 70% efficiency zone, pumping air at 135°C.....
At 6000 rpm they are flowing 0.175 liters/minute, efficiency is near the 65% zone, with air temp 145°C...
This is with ambient temp of 25°C.
So during winter I would say no problem, but I wouldn't run that much boost during summer on k16's....

Boost gauge could be wrong though..

thanks for posting this. Bugs me when people blanket it with "more than 1 bar and K16s are blowing nothing but hot air". You can go aways on them with a low restriction intake, inlet pipes, good ICs, TB, exhaust, etc vs a stock car. On the other hand, slapping on bigger compressors may get you better initial bang for the buck. One minor correction -> 1.2 bar gauge is around the 2.2 PR (you referenced the right points for efficiency on the 2.2 PR line on the map though)

Altitude affects this as well -when I lived in Albuquerque and density altitude hovered around 8000ft, my K16s were around the 2.5 PR region when they were trying to generate ~2.1bar absolute that the flash called for.

Last edited by earl3; Jan 16, 2011 at 12:31 PM.