What's normal boost level on a Stock 996 TT if every thing is all right ?
Some people say 0.8 0.9 Spike , but spike pressure at how many rpm is right that arrive ?
Mine wot before was 0.8 costant with 0.9 spike from 6.100 6.200 RpM until rev limiter from 3rd to 6th gear .
Now in last 2 mounth 0.8 costant but without spike at 0.9.
It seems i lost 0.1 of spike boost.
No error code , tha car has 30K Mls , i think Maf is ok ,i never use oiled air filter .
Must i search for a Leak in hoses or Diverter Valves ?
But if there is a Leak i think boost loss shoul be more than 0.1 Bar only.
I'm allright ?
How boost change from summer to winter ?

 

HI,You did not mention the weather/temperature differences when you are giving those boost numbers.....That has an effect on that...... .8 to .9 is normal....When it is cooler outside and better weather[higher barometer],you will get a slight boost increase over a warm day.....There are many threads on this forum about this subject,,,just do a search....But I do not think you have a major problem.........Good Luck with your search

 

There is no problem, you're fine!

 

How about a flash and exhaust and 1.1 -1.2 bar all the time instead? You'll love the HP and TQ bump !

 

I think stock x50 is 0.8 bar max boost...no tune or any mods...

 

Hey Guys,there are always slight mechanical variations,as weather also,,,,not to mention gage differences..We are only talking .1.......

 

I consistently get .9 bar max even with the altitude.

 

my x50 is completely stock and i get .8 to .9.

 

I have CONSISTENTLY seen a delta of 0.1 between winter (40F) and summer (95F)...even more.

I see a that delta between early morning drives in summer, and afternoon drives.

 

Don't worry, it seems fine.

Boost level is likely to change between +0.1 [0.8bar] -0.1 according to different temperatures, altitude and humidity (know Italy has some very nice mountains).

As you go up in height you loose oxygen and the air gets thinner = engine will be less efficient and the turbos will be less efficient as well. Same principle as having difficulty breathing in high altitudes.

Temperature also plays a big role. In colder temps the engine produces more power. Hot air and you produce less power.

And finally, humidity modestly affects engine performance as well, high levels of humidity will reduce engine power output.

 

Check wastegate springs and adjustments

 

agreed 1/10th boost spike seems normal on stock cars...does the same hold true for a car with a tune...say you have a 1.0 bar tune, can you expect to occasionally see 1.1 or even 1.2 bar spike?

 

Hi,Yes it does....As mentioned above,,,When it gets cooler[around under 50] out you will see your boost go up slightly as compared to when it is hotter[around above 80] out...When you have 1bar springs in the waste gates it might even creep up more when it is really cold out because the factory boost controller can not over come/compensate the waste gates with those springs...Thats why some people also get boost controller for this reason.......There are lots of threads on this if you do a search.....Hope this helps...