Boost problems

[Jamz]

Background:
Bought car with big hole in engine and a dead turbo. Bought and fitted replacement engine and turbo, turned key, car started, hey presto, runs as sweet as and idles perfectly. Car came with an HKS SSQV with purple insert and a bleed valve.

Problem:
Car doesn't seem to boost/dump properly. Boost guage (aftermarket) shows zero when engine is off and minus something when idling. Throttling to 4000 RPM makes the needle move to zero but no further. Upon letting off the throttle (at 4000RPM) the D/V does nothing and I get a bit of chatter.

I'm a bit stumped as to what the problem might be. I didn't get a chance to start taking anything to bits as it started pissing down with rain :evil: .

Any suggestions ?

Cheers

James

 

[Dooie Pop Pop]

Problem:
Car doesn't seem to boost/dump properly. Boost guage (aftermarket) shows zero when engine is off and minus something when idling. Throttling to 4000 RPM makes the needle move to zero but no further. Upon letting off the throttle (at 4000RPM) the D/V does nothing and I get a bit of chatter.

will show minus boost at idle an will only go up to zero when you throttle it in neutral. for posotive boost you need to drive it :roll:

iv been had havent i

 

[ex-gtir]

yeah you cant create pressure without load :roll: unles you have launch control / antilag

 

[Jamz]

I seeeeeeeeeeeeeeeeeeeeeeeeeee!

I presume you do generate some pressure but not much (hence the bit of chatter).

This makes me happy It means I plumbed everything in properly
I was a complete car noob before I bought my pulsar. It's been a fantastic learning experience so far. I might even get a reasonable car out of it when I'm done.

Cheers guys :!:

James

 

[sypher]

does the car run good and boost ok ( you should feel a definate diference in the performance and acceleration ) if so you may have plumbed the D / V in wrongly especially as you said you rebuilt the engine. you need to put the small hose from the DV to a point after the throttle valves. IF IT BOOSTS OK IT SHOULD READ OK ON THE GAUGE UNLESS WRONGLY FITTED OR FAULTY sorry forgot to say idle = neg' ,boost= pos' and engine off = 0

 

[Jamz]

I haven't really driven it at all yet mate (aside from turning it round in my bro's driveway). It's got 4 flat tyres, no front bumper and no front anti-roll bar yet

Oh and the engine wasn't rebuilt, it came from a written off 'R. I didn't have the balls (or knowledge) to rebuild the dead one.

 

[kevgti-r]

yeah you cant create pressure without load :roll: unles you have launch control / antilag

yes you can mine hits over a bar when i rev it :shock: :lol:

 

[Fast Guy]

yeah you cant create pressure without load :roll: unles you have launch control / antilag

yes you can mine hits over a bar when i rev it :shock: :lol:

What have you got fitted on yours? Or is it dodgy electrics?

 

[kevgti-r]

its a rb turbo but still used to make 0.5 with a standard turbo.

 

[Fast Guy]

I'll have to double check mine, but I'm sure I can't make any boost while stood still.
Is your set up standard or any secret sneaky beaky plumbing here and there?

 

[daz]

mine is the same no boost when stood still but 1.2 when moving fairly fast :lol: :lol:

 

[andygtir]

i can make 0.3bar on standstill as shown on the avcr by blipping it quickly.

 

[ex-gtir]

you should rev the t1ts of it at standstill muppets :lol:

 

[LeeSmith]

does the car run good and boost ok ( you should feel a definate diference in the performance and acceleration ) if so you may have plumbed the D / V in wrongly especially as you said you rebuilt the engine. you need to put the small hose from the DV to a point after the throttle valves. IF IT BOOSTS OK IT SHOULD READ OK ON THE GAUGE UNLESS WRONGLY FITTED OR FAULTY sorry forgot to say idle = neg' ,boost= pos' and engine off = 0

this is what a garage did to my car when i had a gearbox rebiuld b4. drove down the road and was feeling really sluggish and jerky - then hks dvalve was making a really quiet chatter. as i turned round to take it back i got a lot of black smoke out the exhuast! turns out dvalve pipe was on wrong way round & something else they did too (cant remember what though) took 5 minutes to sort out.

 

[Fast Guy]

I'll have to double check mine, but I'm sure I can't make any boost while stood still.

Well I did check and I could make about 0.5bar boost if I revved it and kept blipping the throttle at about 5500rpm.
However, since I took my aircon off, I don't seem to be able to make any boost this way anymore :? Surely the aircon pulley couldn't have been putting that much load on the engine?

(sorry for dragging this old thread up)