Boost Gauge Install

[TaKz]

ok i got some shitty ebay boost gauge, i know it might not be accurate but i'm going to have a go at installing it.

through reading other topics i know the vacuum hose for the stock boost gauge is the safest place for the T piece to be put in.

what i wanted to know before i go cutting the vacuum hose is there any danger to the engine if this vacuum hose falls off other than the stock boost gauge not working from what i read it would suck air on idle i.e. negative vacuum?

also if later down the track when i purchase a better name brand boost gauge could i just remove the vacuum hose on my ebay boost gauge and plug it straight into the brand name boost gauge for it to be working?

thanks for any help, haha i know i'm a noob with cars but just dont want to destroy my baby

[nitestalkr]

yeah it sucks air when it falls off, but its not going to cause crazy engine damage quickly.. Just limit the driving you have to do when it falls off before repair. The other option (which i used when mine was stuffed for a bit) is to put something over the end of the pipe (i used cling wrap) and lacky band the shit out of it.. all your trying to do is stop shit getting sucked in there.

As for using hose on new boost gauge you will be fine providing the hose size is the same on both..

Another tip would be to go and get fresh vacuum hose before you start (cheap cheap from super cheap). Fresh hose wont break, whereas if you just cut and use the old hose on a different size nipple it will end up splitting sooner or later.

Cheers

[TaKz]

okok thanks for that!

just to confirm the right vaccuum hose to purchase is 4mm vaccuum hose? do they sell T pieces to suit?

[nitestalkr]

yeah the matching of t-pieces and hose is the tricky bit.. From memory the T-piece i got with my autometer gauge was WAY to big for the stock hose..

So i actually went down the path of getting a custom copper T-piece from a hose supply place in 2.5/3mm i think (closest to stock). you will struggle to find anything aftermarket in the same size as the stock hose.

Then i bought the new hose in the size to match (then again cant really get hose thinner than 2.5mm).

If you increase the size of t-pieces and hoses slightly, dont stress too much.. All you will lose is a few ms of response time from the gauge but the reading should remain accurate as long as there are no leaks. If you want to get really technical and keep the same response time with a fatter hose, just make the hose shorter, as its the internal volume that makes this difference..

R33 may have a larger hose from stock tho, which would be helpful and much less stuffing around..

hope that makes sense..

[TaKz]

yep yep makes sense

last time at repco they had 3mm hose and T piece i think, might go down there tmr and get the them

and have a go installing it

[**RB2530**]

If it falls off, engine will run a little bit lean off boost and a little bit rich on boost...

Btw negative vacuum is actually positive pressure in a literal sense..but I knew what you meant...

PS...You can always get away with using T-pieces that are one size too big by putting the end of the tubing in very hot water to soften the tubing before you push it onto the fitting...(this is probably the most useful part of my post actually....)

[mosquitocoils]

If it falls off, engine will run a little bit lean off boost and a little bit rich on boost...

Btw negative vacuum is actually positive pressure in a literal sense..but I knew what you meant...

PS...You can always get away with using T-pieces that are one size too big by putting the end of the tubing in very hot water to soften the tubing before you push it onto the fitting...(this is probably the most useful part of my post actually....)

I agree with this tip, very handy. I have 4mm brass t-piece going into 4mm vacuum hose at the moment, the fitting was a bit tight but the heat on the hose did the trick.

Edited April 25, 2009 by mosquitocoils

[Taso84]

Why waste ur time getting a custom t-piece made up when u can get one from repco for like $1 and run the boost gauge to the hose running off the inlet manifold. It wont break and its the same size as normal vaccum hose that is compatible with all gauges ive seen.

Dont use the stock boost gauge hose, its small, flimsy and breaks too easily.