As above my cars currently running T34 / 48 housing with a -31 ive noticed the boost dropping right back and roughly holds 17 psi sometimes 16psi when its hitting around 23 psi im going to invest in a new actuator to correct this and wondered wht i should go for ? -31 or -34 ? going to need it holding 24 psi at least all the way or round about

 

Nothing wrong with a -31.


But how do you know it is the actuator?


Could be any of the below:

Amal Valve

Dump Valve

Vaccuum hoses (even a leak int he pipe going to your boost gauge)

Actuator

Boost hoses (check in good order, no rips/tears, clips tight ect)

Inlet manifold gasket to head

Plenum cover gasket to head

Throttle body to inlet manifold gasket

Injector o rings to inlet manifold


However yes it is most likely to be actuator, as it still hits its peak

Just saying don't 100% expect it to cure your problem!


HTH.

 

cheers matey

What do ppl think of bleed valves ?? i take it this does away with the amal

 

In all honesty I hate bleed valves


Keep the amal valve, it is there for a reason.


If you're unsure of it, borrow a mates or something


I have the same problem as you, mine should boost upto 27.5psi, only hits 25ish, I disconnected the vaccuum hose going to my gauges (blocked it off) and as SECS monitor takes reading from the ECU this still shows up, and if there was an air leak going to my gauge then the SECS monitor would have shown full boost then, and I think it did


So I think I have a leak going to my boost gauge so going to replace it and see.


Start with checking all the cheap stuff really

 

will do

 

Also if you replace any small vaccuum hoses, do not use the blue stuff. It expands under boost like a balloon (vaccuum pressure). This would then make your gauge or whatever it is going to inaccurate and is possibly dangerous if going to map sensor ect. (If there's a leak there it will tell the ECU it is using less air than it actually is, so the ECU will put in less fuel, we can see where this is going...)

 

No probs my stuff is red

See the two wires that go onto the amal , what do these do exactly ( if one was`n`t conneced say ) its just that mines liiks as if it broken inside clip that holds it to amal , but dont know for sure if its making good contact its maybe nothing

 

sorry to put this on your post but whats the difference with the -31 and -34

Cheers
Rich

 

If it is the red silicon vaccuum hose it will do exactly the same i'm afraid...


It is worth checking the jetting in the amal valve (little white clips that make the bore of the holes smaller). Some have them, some (well, most) don't, but if yours is just blocked up it could be affecting the flow through the amal valve as if it did have jetting. (Hope that makes sense?)


Here's a diagram of the amal valve:



The one to the air box would be left with no hosing if you have a cone filter.

Just check all the pipes are not obstructed by anything. But if it does have the little white things in the bores (jettings) then they are most probably meant to be there, unless you have put them in.


richard_xr2i1800

Hi Rich, just to let you know that Charlie recieved the refund for the pillar pod, top guy (I am his Son)


A -31 has boost pressures (providing on the length of the rod when attatched to the wastegate,) that go from 0psi to 44psi, and a -34 has the pressures from something like 15 to 44psi


I am no where near sure of those figures, but that is the main difference between the two. So don't get a -34 if you want less than 15psi (or whatever the amount actually is)

 

Some top class info there will double check amal , but everything " looks " in check

 

Nice one cheers for the info mate glad your dad got the money , so would i be better having a -34 im running 25psi

Cheers
Rich

 

I'm not entirely sure mate, ask a tuner or someone that knows more than me, obviously there is a limit to my knowledge


Or just go for a -31 as there is nothing wrong with them what-so-ever

I personally would just stick with a -31

 

Yeah mate stick with the -31 , think woodford garage are doing a special just now for £60 or £65

Does anyone know the exact psi of 1.5 BAR

 

Hey rabmc , 1.5 BAR is 21.762 P.S.I mate

The equation is To convert "bar" into "psi" , multiply by 14.508

ie. 1.5 BAR x 14.508 = 21.762

Hope this helps mate

 

Cheers snow for that , im actually not running that much boost , for greens , low comp , 500 cooler

May up it , need it to hold 22 at least

 

So if you up it to 22psi, will that just go to 22 and hold it? Or go to say 26, then drop and hold 22?


If the latter, I'd just get it live mapped

You have got peace of mind then too, and you could have quite a nice boost spike

 

Well thats the next thing ive been wondering about mate , whats the normal boost drop from say peaking at 25psi is every car different basically would like it to hold 22-23 psi i guess iL maybe just need to just get the actuator and take it from there

 

Every car is different I'm afraid mate


Sort your boost problem out and get it live mapped. You won't look back!

 

i had a -34 fitted when i had the car setup recently, it makes boost so addictive

get one!

nothing wrong with -31 though i don't think, but i think it depends on which turbo you have? a T34 running 25+psi will create problems on a -31 IIRC , summat to do with the turbine housing pressure overcoming the weaker spring rating of the -31.

 

I would ask a pro tuner, Karl, Stu, Mark ect ect


I'd swear I've seen 500bhp cars with a -31 though!!

 

so, what kind of hose do you use ?