R5FORD

iTrader: (1)

my cossie will be going to around 400-420bhp..wich is the best actuator to go for??

pete mcrash

iTrader: (1)

no difference on what power/boost they hold,but for a 2wd i'd use a -31 as it's a smoother release of power............

NEIL A

iTrader: (6)

Are you going to be running air injectors ? If you are stick to the -31

R5FORD

iTrader: (1)

no air injectors on the cards at the moment.. but what are the benefit or air injectors??

pete mcrash

iTrader: (1)

.....just ment to be better,more controll over the boost when mapping etc...........

KSA-Cossie

iTrader: (4)

Got a -34 on mine feels no different to the -31 that was on before tbh.

CossieRich

iTrader: (1)

R5FORD

See here

https://passionford.com/forum/viewto...asc&highlight=

Halfway down page 1 is a mini essay by Stu

pete mcrash

iTrader: (1)

.......so what do u conclude from it...........

Stu @ M Developments

iTrader: (12)

May as well post it on here for those who cant read it.


Ok,
Tiny essay, then ive an engine to build....

The -31 has a base lift pressure of approx 8psi
The -34 has a base lift pressure of approx 14psi

The -31 and -34 springs are also linear/progressive rated.

In a scenario where you require 20psi with no form of boost control at all, a -34 is best as the -31 becomes useless after 15psi achieved via spring preload.

EG:
With a base lift of 8psi, to make her lift at 15psi would require you to compress the spring enough to make it lift at 15. A -34 will be in a minimum loading situation at this pressure.

However,
With correct boost control applied, we simply dont send 15psi to the actuator to make it open at 15psi, we BLEED enough air to the can to match its spring load setting.

IE:
We want to run 20.
So we load the -31 to say.. 10, and we bleed 10psi off via amal or bleed control, so the actuator ONLY gets to see 10psi.

Now,
In cases of extreme turbine housing pressure (T34 at 24+psi is a good example) we can hit the scenario where the turbine housing pressure alone is enough to overcome our spring. This is when the -34 comes into it own.

Hope this helps..

pete mcrash

iTrader: (1)

stu............how does this work then..i use a -31 and run 2bar on a t38 and even t4 cars at grove use -31's........

Stu @ M Developments

iTrader: (12)

How does what work pal?

pete mcrash

iTrader: (1)

...my set up on a -31.........howay stu...u know i'm thick.......cos even if i unplug my amal valve i still hold the same boost...........edited... is it the "jets" that bleed off the air

CossieRich

iTrader: (1)

I conclude that i use a -34 with the correct sized jets in my amal valve to achieve my silly boost pressure

pete mcrash

iTrader: (1)

.........but u can use a -31 aswell.........