4x4 saff running greens etc,boost max's at 25psi but then drops to 19/20
psi,have just fitted a forge racing actuator with a range of 20 to 28psi but still not holding boost pressure or is this normal to lose 5/6psi,please help

 

When it starts to boost , it spikes at 25 and then drops to 19/20.

This is normal.

It holds 19/20 psi.


Dave.

 

yep! your standard turbo wont be able to hold that boost all the way to redline as it will just run out of puff, if you want 26psi all the way then you will need to get a t34 (or bigger)

 

Look's like i'll have to strart saving for a bigger turbo,T4 would be
nice but a t34 is more within my budget,just out of interst though
would a T4 fit a 4x4 manifold or do you have to use a 2wd one?

 

i think it will fit as i was looking for one for mine but i went for a 34 in the end as a t4 on my car would have been the end of me!

all depends on how far you want to go really mate?
a t34 with the .48 housing would see you to around 370ish bhp max or a t34 with the .63 housing is good for around 400bhp.
and a t4 will make it pretty horrid around town cause there laggy as fook!

whatever you fit you would be better getting a 2wd manifold on there as well cause they flow much better! dont know if you need to move anything to fit the 2wd one but im guesing not as lots of the big bhp boys do this.

 

Thanx for the advice mate,had heard before that the 2wd manifold
is better for flow but i used to have a 2wd saff and i had to have
manifold studs drilled out after they had snapped,will stick to my
manifold and go for a t34 as im only after 350/370bhp.

would there be a noticeable difference between 48/63 housing on
a t34? majority of my driving is round town so the less lag the better,
what housing did you go for?

Love the look of your car mate bet she's a bit of an animal

 

t34 will not make 400bhp for long untill it dies, 370/380 MAX

 

i ran 390bhp on my old cossie for 9 months fine and done pods and everything

 

I have just had mine set up, i am using Greens, 3Bar and -34 , We had to remove the amal valve as i was having the same problems with wavering boost and fitted a Bleed Valve set to 21 Psi Held. Came out at 310 BHP !! A runs really well.

Al......

 

pj were did you get this figure from mate?
i have seen this question asked lots of times on here and the general consensus was that a .48 could make 370ish but it gets bloody hot after 350bhp so not really a good idea, and that a t34.63 was happy at 380bhp but could be run up to 400 with no problems.

am i wrong again? lol