A Probably dense question about boost setting and boost pressure

paz

Active Member
So, you may know I'm something of a novice when it comes to engine knowledge in general :lol:

But I was wondering today, if I run higher boost, does this mean my turbo may come on boost earlier/lower in the rev range?

I only ask as on 1 bar the turbo seems to stay off boost for longer/ lower down the rev range than at my 1.3 bar boost controller setting. And I've not run standard boost for agees but I also seem to remember it took even longer still when I did.

Is this something my mind has made up, or is there any truth to this?

Cheers

Paz
 

Gaz gtiR

New Member
I dont think it will come on boost any quicker @ 1.3 bar than it would @ 1 bar! your just getting more of a kick when the turbo spools up that maybe just playing tricks on your mind?

What boost controler have you got?
 

PobodY

Moderators
Staff member
There is a certain amount of logic to this (although I think you've got it arse-about). - The boost builds as the speed of the turbo increases; so if you've set it at 1 bar you'll always reach that before you get to 1.3 bar. You haven't moved the boost up or down the rev range, it just takes less time to reach a lower boost setting.

I'd guess what you're experiencing is that a boost controller does a better job of building boost by keeping the wastegate shut until the set point is achieved; something like a bleed valve, or the 1-bar loop, will always build boost slower as you get creep (I don't know if that's the correct term) as the actuator sees some of the boost and starts to open early.
 

MarkTurbo

Well-Known Member
There is a certain amount of logic to this (although I think you've got it arse-about). - The boost builds as the speed of the turbo increases; so if you've set it at 1 bar you'll always reach that before you get to 1.3 bar. You haven't moved the boost up or down the rev range, it just takes less time to reach a lower boost setting.

I'd guess what you're experiencing is that a boost controller does a better job of building boost by keeping the wastegate shut until the set point is achieved; something like a bleed valve, or the 1-bar loop, will always build boost slower as you get creep (I don't know if that's the correct term) as the actuator sees some of the boost and starts to open early.
The simple answer would have been no :lol:
 

paz

Active Member
:lol: hmm interesting, so in theory if you make the attempt to drive off boost and use an safc which I believe has the same map for both settings (may be wrong?) there should be no noticeable difference in fuel consumption.

Gaz- I've got a greddy profec b

Cheers all

Paz
 

Gaz gtiR

New Member
As pobody says your controller my bring boost in at higher rpm? I use a avcr, so not realy played with a profec B!

Id say there wil be a bit of difference in fuel consumption as the car will need more fuel @1.3 bar than it would @ 1bar but nothing you will probably notice! if your safc is set up properly or the car has been mapped to run 1.3 bar you should be ok!
 
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