stu21t

i am struggling to make boost on my car.
its a cossie with a t34.63
turbo has probably done 2000miles at best and 99% of them at under a bar due to varios reasons. i bought it brand new.
now im trying to up the boost but i cant get more than 1.9bar peak, 1.5ish held.
ive tried re-jetting the amal valve, thats set to fully open all the time, doesnt back off,
i even disconnected the hose to the wastegate and blocked it off and the boost is the same as above.
its a brand new genuine -34 with about 6mm pre-load.
wastegate is in good condition, no cracks and looks to seal properly

can i run more pre-load than that or will it cause more problems?
i dont have any air leaks at the inlet manifold and im confident that i dont have any leaks in the rest of the system but i am about to test this now, have made my own tester that im gunna try in a min.

i dont know if it makes a difference but i have 2 pace charge coolers, no intercooler.

stu21t

scratch that.
i just found a leak on the 1st charge cooler lol, just a dodgy clip/join
i wonder how many more there are, ive got 12 jubilee clips and joins in my system. lol

on a plus note my homemade boost system tester works well. lol

CossieRich

iTrader: (1)

glad someone close to me has a leak tester that works.

YOu could try more preload to see what happens. What pressure are you testing the inlet too with the leak tester?

stu21t

well i found another leak.
i had 2,
1 at the inlet to the 1st charge cooler, 1 at the inlet to the 2nd.
i took the hoses off cleaned the hoses internally,
scratched the outlets of the coolers with some rough sand paper then cleaned them,
re fitted hoses, 1 with a new clip as the old 1 was a bit big.
i can now pump the whole inlet system, throttle open (all valves shut) and it holds 2.5bar pressure, i cant get any more in, thats as much as my compressor will allow. maybe a valve is slightly open.
but i held it at 2.5bar for a good while, longer than i ever will on the road and i now have no air leaks.
with the leaks 1.5bar was the most it would hold before bleeding past the clips
good job done.
rich if you need to borrow it just gimme a shout.it hooks up to a tyre pressure gauge so can pump air in with a compressor, i have these to if you need to use them.

thats if you ever get out there to fix yours. lol

cossie4i+

iTrader: (15)

So what boost does it now hold when driving ?

Steve

stu21t

well ive just been out in it but i restricted the bleed from the amal valve as i didnt want to make too much boost.
it now peaks and holds 1.5bar which shows me that ive fixed it but restricted it too much.
before i had to bleed off more air to hold 1.5 bar
and as it peaked at 1.9 then dropped, it was obviously making more than 1.9 bar but leaking through the 2 boost leaks i had.
tomorow i will open the restrictor a bit untill i get 2 bar held.

CossieRich

iTrader: (1)

Nice one Stu

I will be fixing mine, i just want a break from it all for a while lol