4agze still not boosting properly

[akmehd]

ok after tightening my sc belt, and removing the abv, and plating it off to find it works perfectly, its still only boosting 6 psi with a 165mm pulley. it used 2 boost between 10-12psi. I have also checked for obvious boost leaks. the car drives 100% normal and holds 6psi right through the rev, its not like it starts boosting 10psi then looses boost. i have checked all vaccum lines and nothing is off. Where the hell can can 6psi of boost go randomly. i have also cleaned out my ARC top mount, which made jack difference the charger also has fresh oil and isn't makinig any weird noises sounds exactly the same and normal as it used 2.

Can someone throw me some ideas at wat to look at next as i am still scratching my head. Is it possible for a sc12 to boost less if it is stuffed, even though the half cutt has only done bit over 100ks now.

thnks

[Cuzzo]

Is it feeling considerably slower or the same? If the same could it be your guage is stuffed? Or the vaccum line to it is blocked/crimped?

[akmehd]

its hard to say as i just got it back from being tuned and hadnt driven it in a while before. never even tholught of something that simple ay. thnks mate. still keep ideas coming if that isnt it

[old_mr2]

Id be checking for a vacuum tube that has popped off or a big ass leak somewhere.

[c2888]

Id be checking for a vacuum tube that has popped off or a big ass leak somewhere.

I had this happen to my car.

Driving along and it had a bit of a stumble in the idle, and didn't feel 'right' when cruising along.
looking at the gauge i lost a fair bit of vacuum, and it wasn't boosting as much as it used to, but it drove fine at WOT
Turned out i had a crack in the tee piece i had used to run the boost gauge.
So i stole the tee piece from the windscreen washer hoses.
All fixed

Dan

[Ben Wilson]

Check the bolts holding the pipes to the 'charger, I know that one missing one is worth 2psi...

[terryo]

as they wear, the boost falls. leaks kill it completly. many aftermarket boost gauges are unreliable. we have a $200 gauge and regulator at work to check real pressures and set blow-off valves

[akmehd]

but could wear cause it do it so suddenly? its only like 110k old motor

[old_mr2]

no. something has popped off. What sort of air filter are you running? My pod filter came loose and fell off once, I couldnt get more that 7-8 PSI.

I put the pod back on and got back to 11-12 PSI instantly.

A good induction setup is a good way to see all the boost.

[akmehd]

yeh its a pod filter

[Jevon]

Did you change the crank pully too? Most of those kits (nevo for example) come with two pulleys, one for the supercharger, and one for the crank.
Also I have seen them lose boost when there is low compression in the cylinders themselves. Damn 4agze engines and their many mishaps

[Ghetto-Spec .:bayka:.]

Hey man. Just some thoughts

Boost Guage : probably not because it didn't change before and after tune, so its still reading right.

vacuum leak : probable because things may have been fiddled with during the tune.I agree on checking all T-pieces etc. You should be able to find this sort of leak by tracing the induction system and listening for a hiss (or feeling for air) while the car is running.

supercharger damage : definately will cause boost loss that you describe. I had your same problem when my supercharger lost some portions of the teflon coating on one of the rotors. Even a 10c coin sized hole in your teflon coating will cause a consistent loss in maximum boost production and the supercharger wont sound any different.

Cheers

[akmehd]

i feel really dum. the funny thing i solved it pissed. The boost gauge was plumbed of the two lines coming out the charger instead of of the manifold. At a glance it looked like it was t pieced of the mani but wasn't lol

thnks for suggestions