am currently @ 24 psi and the -31 has been on a few years(with no complaint) and having greys fitted shortly and hoping for 30psi so is a -31 good enough or is it time for a -34? on a t34 turbo

 

yes, put a -34 on it

 

why jim? i ran 34 psi on a -31 no probs!

 

i know you did



miss that car

 

reckon my std erst turbo ll put out 34 psi?hmmmm.......

 

LOL


Boost junky

 

ok so a -31 can take 30+psi no probs will hold on from buying a new one for now then BUT do u know when or why peeps would change to a -34.

 

they give different boost characteristics or summit,most peeps i know run 31s on cossies usually rsts on 34s that I know ,but ask stu,he knows!

 

mine runs a -34 @ 35psi and holds 28 but i also have air-air

 

There was an article answered on here by Stu explaining it.

Try a search.

I seem to remember that the -31 has an opening pressure on the diaphragm of around 7psi whereas the -34 is about 14psi.

Obviously if you are aiming for around 30 psi this would mean if you adjusted the
-31 upto around 10psi you would have to bleed 20psi off
What a waste of boost....

whereas with the -34 tweaked to around 18 psi you would only need to bleed off 12 psi.

Think there was more to it as well, something to do with Compressor housing pressures of a T34 being higher than the T3.........

 

putting 30+psi thru a psi rated actuator is pushing it.

-34 is designed to run higher boost, using a -31 is simply a bodge

 

but if it works it works!!!

 

wont hold high boost well, likely drops off at high RPM? also it'll wear out very quickly

theyres 2 points off the top of my head...

 

but who much better would a -34 work ????


think about reducing creep


mines gota -34 , im hold holding 25pis too, but thats 25psi to the limiter

 

a week actuator is a bad idea, hence why ya change em when they get soft

 

mine was 34 psi peak and then about 26 psi held,all the way mate. my -31 actuator mustve been a good un then!

 

yeah but im sure ya would have had some creep on it


or wound up alot

 

ya could run 30psi through a t3 turbo, but would ya do that now theres a t34

 

was set up by harvey gibbs on a t34 (.63) with a sleeved amal valve,worked perfect NEVER got ANY other readings,no creep nothing,34 psi,then quick drop to 26 but it never stopped pulling(cams i reckon, bd 16)
not arguing,just thats EXACTLY what it did and was a -31

 

I've got a -34 on my turbo, running 15psi and its one hell of a kick up the arse when it comes in.... should I be running a -31 instead then?

 

im not gonna argue with ya at all matey


not saying its right or wrong just mentioning that there are now other options now and sometimes there better than the old ways



mine deffo cams btw as mine fooking pulls in all gears at just under 4 grand to the limiter




wes thats the thing about the -34 is stays shut and at a set psi it then opens and thats what ya get, otherwise ya do get a bit of boost creep ( ya wont really notice it due to the setting up of the car, just like ya can set a car up with a boost leak and still get it to hold the psi, ya will be over speeding the turbo to make that though


its a shame ya broke ya cossie as that had a mental engine in it, ya was very unlucky

 

Alvyn, I have a virtually brand new -34 for sale, keep it in mind

 

Jb Fletch Posting :

Easy peeps,

I had the -31 on my old lump (big wigs engine) and peaked @ 3 Bar & held 2 Bar all day long to the limiter. No creep or drop off, when Harvey took the lid off there was no signs of det which Harvey couldn't believe ! But the cams were the bollox !

I changed from -31 tp -34 on my rs turbo and that peaked 22 and held 18 psi. Couldn't work out why they changed it cos the Cossie run double that on a -31. Prob down to the turbo its self ?

Big Wig, you not got the mota no more then ? I'm building another one !

Cheers

Jb

 

FletchCossie,

absolute bollox 3bar THATS 45PSI yeah right

 

Rs Gus, actually its 44.1 psi
mine runs a - 64 peaks at 30 odd holds 29

 

Jb Postin:

Oi bruv, dont even think bout questioning it until you all all the facts yeah ! Prick.

Harvey always said i was mad too !

Ok the guage might not have been completely acurate but when put on my brothers stage 3 Saph, that showed 25psi which was the same as his guage.

Ask anyone who went in the car or who knew me. They'll tell ya what it went like & what pressures was seen on the guage.

Mikey Rainbird always called me a boost junky cos everytime i see him id turned it up a bit more.

Jb

 

no it isnt,, its 43.5psi

 

14.7 psi = 1 bar multipied by 3 = 44.1 psi or is it different in wales ?

 

Lee, send me a pm with how much u want for it m8 and I'll give u an answer

oh and every one calm down IT'S XMAS

 

i think you wanna get your sums right

1 bar = 14.5037738 pounds per square inch

the confusion comes when talking about standard atmoperic pressure
which is 1.013 bar,, which is 14.7 psi

 

what he said is right

 

no its not,, hes doing 3 x 14.7=44.1

but really is 3 x 14.5 (ish) which is 43.5

 

I been out in jbs old saff and i can say what he says is true

 

jb: alright matey,nah,last time you talked to me it had just done a bottom pulley,scc quoted about 3 grand to repair the motor(10 valves,2 pistons etc etc!!!) so i decided i had fook all cash left,and quit while the goin was tough! bugger me was a quick engine,BUT every time i DIDNT drive it hard it blew up on me in one way or another,loved bein thrashed but hated sedate driving! musta loved you! but just wait till my next project hits the streets,gonna be stealth as fook!