Dumb boost gauge hose question

[turbo ride]

What did you guys use to "T" the white/clear plastic-y tubing that comes with most boost gauges into the car's vacuum lines? (I wish they made them so you could just slide a typical braided hose or fuel line onto a nipple on the gauge). Last time I hooked up an aftermarket gauge I recall wrapping the junk ball tubing with some elec tape to increase its OD - then inserting it into a rubber "T" and using a small hose clamp - but I'm wondering if there is a better (less rig-job) alternative?? Pic of said junk ball hose below:

[cole930]

Brandon:

Pitch that cheap s--- in the trash and go to your local parts store and
buy some 1/8 vacuum line. You'll be much happier.

Cole

[quattrorunner]

Agreed /\ /\ /\

[patina]

Originally Posted by cole930

Brandon:

Pitch that cheap s--- in the trash and go to your local parts store and
buy some 1/8 vacuum line. You'll be much happier.

Cole

Truth!

[turbo ride]

OK yes - totally agree - but dumb question #2 (don't worry many many more to come!) - I don't see how the 1/8th vac line connects to the gauge...? There is no nipple for a 1/8th braided line or fuel hose to slip over - just the brass fitting that the junk ball hose slips into. What am I missing?

Thanks guys-

[quattrorunner]

You can find a barb to fit at the hardware store

[cole930]

I'm assuming you have a male nipple on the back of the gage. There is a mating
female collar that slides on the hose and then the ball is slid on the hose. The hose
goes in the nipple, the ball slides in the nipple and the female collar screws on and
swedges the ball and hose into the nipple.

Take the female collar that screws over the nipple to a hardware store and get a
female npt of the same size to 1/8 hose barb adapter fitting.

Cole

[cole930]

Cole

[JFairman]

A clear picture of the backside of your gauge would help...

1/8" or 5/16" Fuel line for carburated cars works very well and is alot more reliable than unreinforced silicone or rubber vacuum line that can inflate a little and blow off a barbed fitting under boost.

I have no idea where you're hooking this gauge up to, but if you use the brake booster hose up by the brake booster then definately don't use vacuum line. Use fuel line hose with hose clamps instead.
Carburater fuel line is plenty fine for this and I only mention it because it cost quite a bit less than fuel line made for high pressure fuel injection.

[turbo ride]

Ok cool gotcha - will get a barbed fitting. I'm "T'ing" the line from the engine compartment - will try to find a good spot after the throttle plate - but backup plan is the line to the wastegate. Car is a 964 Turbo - which I'm still on the VERY steep part of the learning curve but I don't think the 964 Turbos have a brake booster up front like the 930s...

Thanks guys - had a feeling there was a better solution....

[JFairman]

Using the line to the wastegate will give higher readings than what the engine actually see's because it is before the throttle butterfly. That's is not the place to use.

You want to use the intake manifold which is after the throttle body butterfly to see what the intake ports or anotherwords what boost pressure level the engine is actually getting.

The brake booster hose is already there and goes from the intake manifold to the front trunk and is most convenient to use if you do it right.
Buy an NHS/VDO boost gauge and it comes with a new brake booster check valve for the brake booster hose and it has a barbed 5/16" or 8mm hose fitting on it for the line going to a boost gauge.

edit: There is a boost pressure drop of around 1-2 psi from the intercooler through the stock throttle body to the intake manifold. That's why taking the reading from the intake manifold is more accurate if you want to know what the motor is actually getting.

[BoxsterGT]

I have Polyamid line I use for remote fuel pressure gauges that would work fine for a boost gauge...........





I also have the Metric fittings and Metric to pipe adapters if you need to drill & tap somewhere on the intake to make this a completely leakproof system.



Please email me for details.

Len at Autosportengineering dot com



Edit: This Fuel Pressure tester was intended for test purposes only. For a boost gauge it would be perfectly safe as a permanent installation.

[turbo ride]

I plumbed it in after the throttle body - and ran a small ID rubber to the gauge (with the barb per advice above). Thanks guys. Boost on :-)

[copbait73]

A word of advice, do not plumb raw fuel into the passenger compartment - use electons. A leak can be fatal.
I had a similar situation in a very old airplane and I'm very very fortunate to be here to warn you.

[gsxrken]

So Jim, just a question on this- if a 1 bar waste gate references boost off the intercooler like my stock one does, can I assume the engine (or the boost gauge off the booster) isn't actually seeing 1 bar?
I don't have an aftermarket boost gauge with a telltale, but I have a 1 bar spring and my AFRs are good. Maybe there's a little more power to be had if the engine is really only seeing 12 PSI boost?

Originally Posted by JFairman

Using the line to the wastegate will give higher readings than what the engine actually see's because it is before the throttle butterfly. That's is not the place to use.

You want to use the intake manifold which is after the throttle body butterfly to see what the intake ports or anotherwords what boost pressure level the engine is actually getting.

The brake booster hose is already there and goes from the intake manifold to the front trunk and is most convenient to use if you do it right.
Buy an NHS/VDO boost gauge and it comes with a new brake booster check valve for the brake booster hose and it has a barbed 5/16" or 8mm hose fitting on it for the line going to a boost gauge.

edit: There is a boost pressure drop of around 1-2 psi from the intercooler through the stock throttle body to the intake manifold. That's why taking the reading from the intake manifold is more accurate if you want to know what the motor is actually getting.