Saint AAI

I've done some searching, but found different replies. What is the internal diameter of the vacuum hosing for the standard boost control setup? Car is an MY99 GC8, but I have a VF29 fitted and whatever actuator pipework and restrictor that came with it. I've found a split in the current hose which I believe may be the cause of my slight overboost and unstable boost problems so I'm going to replace it all. Also is there any high quality silicon hose anywhere that isn't going to baloon or shall I just use some fuel hose?

Thanks in advance, Shane.

Motion-Mx

iTrader: (2)

I'm using 3m ID silicone...be interesting to see if anybody is using different?

Saint AAI

I read 3mm on one thread, but then 4mm on another. I'm not sure if it matters which you use.

Splitpin

Real Subaru boost control hose is 4mm bore.

There's silicone and there's silicone. Good reinforced stuff designed for use in this situation would be just the job, but the cheap nasty thinner types sold in ye olde chav tuning shoppe will likely, just as you suspect, balloon a bit, causing odd boost control issues if it's bad enough.

If that's all you can get then I'd suggest fuel pipe would be a better bet.

Saint AAI

Thank you very much.

Motion-Mx

iTrader: (2)

would changing from 3m to 4m make my 3-port quieter? i hate the nose when it let's off boost pressure