After my blown engine was looked at, the first question he asked me was what kind of boost I was running. I didn't know for I never had a gauge. Well, I got one now and want to hook it up before running my new engine. Where do you hook up the hose to?
Thanks
Mark

 

theres a nipple on the upper intake manifold. theres actually two, one for the bov and another one that should have a cap on it. use the one with the cap.

 

I tee'd my gauge into the line on the stock MAP sensor because that's the exact same location the ECU reads boost from. It also keeps the line hidden and out of the way and makes it very easy to route through the large hole in the driver side fender and then behind the fusebox and into the cabin.

 

What's the difference in readings form these two locations? If my MAP sensor boost gauge reads 12 psi, what would the manifold nipple read?

 

I'd think they'd read almost the same, except for slight differences caused by different air flow over the gauge tube inlet, and pressure fluctuations near to the intake port caused by individual intake pulses. The MAP location should be a little more steady.

Another point - the shorter the length of tubing from the manifold to the sensor (electronic gauge) or to the gauge itself, the faster the gauge will respond. The MAP sensor location will probably result in a shorter length.

 

does it matter if the boost is tee'd off before or after that check valve(?)/filter(?) thing leading to the map sensor? do i want to tee between that and the sensor or before it? or does no matter?

 

there is also less room for error. the shorter the distance, the less of a chance there is of the hose getting pinched somewhere.

another thought that i dont think was mentioned...alot of people cant find a break in the firewall to run the boost line. as a last resort, you can always cut a small hole through the steering boot

 

I would do the T before the filter.

 

thanks mahjik, finished the install

 

My boost guage is plummed into the line that goes from manifold to stock bov using a T.

With this install both the PFC and boost guage always read -450mmhg at idle. However in the past week or so my gauge is showing a lesser reading of -350mmhg at idle whereas the PFC still shows -450.

I have looked for obvious leaks but cant find any...does anyone have any ideas where I should be looking for the leak...it could be my imagination but I think I can notice a minor hesitation before she spools up since the drop on the boost guage.

Bye the way PFC is mapped!

Any advice welcome!!

Thanks,
George

 

Any advice on solving this leak issue and the way the guage is installed??

 

Isn't there a capped off vacuum port right on the left side of the UIM that is perfect for a boost gauge?

 

Yeah, but mine came preplumbed between the stock bov and UIM which still leaves one free nipple on the UIM.....I think it is ok for it to be plumbed lik this and until recently the guage always had the same reading as the PFC...but I have been seeing a drop in vac reading on the guage only recently.

The car came from Japan plumbed like this!

 

Just guessing -

Is the boost/vac gauge still reading normally otherwise? Same readings as the PFC for boost values? If it is then there is probably a leak very close to the boost-gauge source, or the line to the gauge is weak, causing it to collapse at -350-mm Hg vacuum.

Dave

 

Hi Dave,

Im not really sure, I would find it hard to compare the readings from the PFC with the Guage without crashing tbh...but I will try to verify same!

Thanks,
George

 

Dave I have been keeping an eye on the PFC and Guage reading for the last few days and have realised that the Guage always has a weaker reading for Vac and Boost!!

Also, I can hear a repetitive hiss,hiss,hiss sound comming from either the turbo/downpipe area or back of UIM (not really sure) but it is definately a leak somewhere and it is effecting how the car runs. UIM is vibrating a little also on idle.......very similar symptoms to when the UIM gasket was blown!!

Could it be related to the exhaust as it sounds a little blowey aswell??
I feel its either part of the turbo assembley not bolted down tight, a leaky hose or an exhaust problem!!

What you guys think??

 

Bump^^

Can anyone offer any help here?

 

You mean, the shorter the length, the better it is???

 

if you suspest a vacuum leak the best way, and im pretty sure everyone would agree, is to spray carb cleaner around the area where you suspect the leak at idle, and listen for a rise in your idle. spray everywhere there is a connection first, and then if nothing spray short bursts along the length of the line, i have found many leaks like this.