Confusion!

[samsplums]

Have read (I think) all available threads on mbc's and safe boost levels.

Am running 1995 855 T5, just fittwed boost gauge and mbc.

With mbc fully shut off boost gauge idles at -10 psi but boost upto well over 15psi (little scared to push it any further than 15).

Is safe boost stated in threads, safe boost displayed on gauge or some kind of reading taken directly from the engine..?

A little help..?

Thanks.

[BlackBeast]

Some say with an MBC you can run 15psi safely on a standard ecu. Not sure if thats 15psi overboost or 15psi throughout the rev range.

[siamblue]

I don't want to be the bearer of bad news, but -10 psi isn't much at all,
my S70 used to sit at -22 on the boost gauge,

[BlackBeast]

I don't want to be the bearer of bad news, but -10 psi isn't much at all,
my S70 used to sit at -22 on the boost gauge,

Thats true, youve got a boost leak there somwhere or worn piston rings.

[samsplums]

Boost leak.
Vacuum pipes..?

Ides at -10 but full boost goes 12psi(?)

[mike 850]

Thats true, youve got a boost leak there somwhere or worn piston rings.

are you definatley sure about that? tbh i dont know if im right but i got a aftermarket boost gauge goes to 1bar, but if it idled at -22psi itll be right off the scale the other way?? also my dash boost gauge is exactly 1bar too(it mirrors my tim boost gauge) but im sure it shouldnt go off the scale on the dash one too? please correct me if im wrong, if i am then i got problems too
cheers

[Baj]

Mine also sits at -22PSI at idle but only goes up to +10PSI on full welly

[mike 850]

i really dont understand that unless the 850 is different?it would be off the scale at -22, mine boosts at 1bar(rica) and it idles fine at around 850rpm
im confused now lol

[samsplums]

??????

To confirm:
1995 855 T5
(just removed MBC so running completly stock)

Ignition on +5psi
Engine on idle -10psi
Full boost kicks to approx +15psi then dropps to +12psi

Anyone running a (psi) boost gauge on stock 850 that can shed some light on the matter?

[mike 850]

right mines a 1995 and has when stock and is now running -0.7bar which i believe is just over 10psi, my dads 95 t5 is the same on idle

[samsplums]

Is that 10 above or below 0 when on idle?

[zanelli15]

I to have a stock 855 T5 with a tim boost gauge mine is connected to the pipe that feeds the dash guage under the dash board.

Mine reads :-
-10 at idle,
directly vertical with engine not running,
and i get 17psi full boost under hard accelerating.

And the above is on a 228000 mile engine. and still going strong no oil buring etc.