Not making enough boost

[Anonymous]

Hi All im having trouble making enough boost and thought maybe i could seal off the entry into the intercooler with some bike tube and a clamp and maybe do the same to the other end before the carb then pressurize with a bike pump to see if it leaks however i wouldve liked to check the carb hat as well has anyone got any better suggestions
The wastegate is set to 10 psi but im only making 7-8 the gauge is new and the wastegate is a new turbonetics so these shouldnt be causing a problem...

 

[wallaka]

Set the wastegate higher? Seems like an easy solution to me. Also, just because the gauge is new doesn't mean that it is correct. Defects happen. Could be that the wastegate is actuating a little too fast, or isn't marked quite right.

 

[Anonymous]

ill put another couple of shims in the wastegate and see what happens

 

[gravelrash]

have you got the boost gauge plumbed to the manifold where it should be?? which is the air pressure the engine is actually seeing.

10psi wastegate spring
7-8psi is what your making atm when the wastegate opens??
obviously you have a 2-3psi pressure drop through the intercooler and carby. thats not bad.
because you have a 2-3psi drop you will want to set the spring to 12-13psi to achieve an opening of 10psi.

cheers Greg

 

[hasa68mustang]

what guage do you have? if its a cheap ebay one I wouldnt trust it, mine was showing 10 psi, but when I hooked up my dad snap-on gauge it was showing 7... I would trust the snap-on one over my cheap ebay one... which will be gone soon.

 

[Anonymous]

Cool I didnt realise there should be any pressure drop ill adjust today and see what happens
The gauge should be qua;ity
Thanks guys gotta rush to work

 

[matt1967]

2-3 PSI drop thru an intercooler is normal, as said.

 

[Anonymous]

I put anthother 4 shims (4 psi) in the wastegate today and its made no difference on the gauge didnt notice a large power increase either maybe a small one Ill try another gauge I guess and see what it reads the wastegate is plumbed to the pressure side just before the carb the pipe that ive used is the stuff that came with the wastegate it is a softish rubber any more ideas???

 

[gravelrash]

ditch that soft hose shit, the hose expands and contracts like a balloon. use some stiff walled hose. it may not be the answer to your problems but that cheap ass soft hose is best left for the bin or ricers.

 

[fast64ranchero]

I must be missing something here XA, you say your wastegate is plumbed to the pressure side of the Carb? the wastegate should be plumbed to the downstream side of the exhaust or left open on the outlet side.

 

[fast64ranchero]

OK I went back and looked at your pics again, sorry bout that you are talking about the vacuum/pressure line, at what RPM do you start making boost? might try a very short drive with that disconnected after you verify your gauge is correct, if you still have low boost might look at your .96 exh housing maybe .69 or .81 would spin it up better

 

[Anonymous]

Hey Fast
Yeah I maight try disconnecting the wastegate and going for a gentle drive
Its making boost at around 2000 rpm
Youre right the smaller a/r will spin up faster but if I feed it the fat through all the gears I get consistent boost , its quite laagy though when youre cruising at around 30mph and nail it, Hopefully a tune will help this
thanks
Shaun