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-   -   boost/spool/guage/turbo/ Please look,turbo owners (https://volvoforums.com/forum/volvo-850-16/boost-spool-guage-turbo-please-look-turbo-owners-8229/)

dannydoo 10-17-2006 02:08 AM

boost/spool/guage/turbo/ Please look,turbo owners
 
I have a couple questions about the guage for the turbo.

When it is in the middle means 0 boost right?

My guage only moves about 1/4 of its total positive boost. if you had to say what the guages line in boost represents what would it be?
in other words...if the needle was at the end on the line,would it be 20psi? 15psi? 30 psi?


My needle moves about 1/2 way into the negative@idle,which would be vacume right?
Im guessin the car has about 15lbs@idle, so IM guessing/guaging mental numbers on that blank stock guage.

The car has tons of power,but it seems the turbo spools up slowly and only and more like when shes floored.

I can drive the car and accelerate verry nicely and still the boost needle will only be a hair or 2 into boost.
When shes floored,she takes a couple seconds,but the needle moves noticibly about 1/4 inch past 0


O YA.. plus it makes absolutly no turbo wizz when its floored...Is that normal ?

RedTurbo850 10-17-2006 03:14 AM

RE: boost/spool/guage/turbo/ Please look,turbo owners
 
^You should hear the turbo w/ your windows down if the wind isn't blowing too hard. You should also feel the turbo kick in as there is some lag.

On the guage, the blank part is N/a while the White is turbo.

Edit: I don't the the guage signifies boost. I've never heard of progressive boost...

dannydoo 10-17-2006 03:23 AM

RE: boost/spool/guage/turbo/ Please look,turbo owners
 
Hmm...


I think boost is always progressive....You dont het 10psi of boost at 1000rpm, when it spools up to the piont where it can blow its max bost,whether its 8,9,10.then is spooled up. I guess around 3000rpms is where the guage gets to its max point"in my car"


Im educating myself on turbos w/this car.IM verry knowlegable about centrifigal superchargers and pushrod motors.
This"turbo ohc" is all new to me and IM going to be getting some twin turbos on a dohc motor, IM done w/pushrods.

I have aboost guage...I should just hook the dang thing up.IM going to post a quest where the easiest point of acess is for a ghuage

but thnx

RedTurbo850 10-17-2006 03:37 AM

RE: boost/spool/guage/turbo/ Please look,turbo owners
 
Oh really? So when people say they are running 20 lbs of boost, does that mean 20 lbs at redline or what?

Edit: Do you have that gear ratio changer? If you use sport mode, I think it shifts a little higher. Not to redline, but higher than economy.

dannydoo 10-17-2006 04:08 AM

RE: boost/spool/guage/turbo/ Please look,turbo owners
 
sure they are.if someones running 20lbs of boost,they better have some serious head gaskets and head studs,and forged pistons/rods and realll cool air,colder plugs, 94 or better octane etc etc....or say goodbye in less than a few thousand miles if u have luck.

see? just a little bit of detonation will blow the pistons apart and bend rods up....thats what kills the motors. and you can go pushing 20lbs of boost in a stock programmed car....they arent made for that timing curve....that fuel curve...etc etc.

Thats why I keep asking what these 850s are safe at...IM comfy with about 12lbs and I can get that from adjusting the rod on the turbo..IM gonna do it tomorrow.


Figure it takes about 3000rpms 3500? to get enough exhaust to push pretty much any turbo to its max boost level.
Once exhaust is spinning the turbo its gonna stay spinning at max boost untill the rpms come down under 3k.

But..................remember..the blow off and wastegate,bleed boost and exhaust so its not ......just that simple.



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