Boost Gauge

through the hole in the firewall its a total b!tch to find, its up and to the right of the pedals. else you could take the fender off to give yourself an easier time of finding it. if you've got a/c removed you can use the holes in the firewall there. easier to get to. sits behind the big black box behind the glove.

It that the spot at the center?:

no way man do you have ac? if not pull your heat exchanger out (4 bolts 10 mm) and gut the internals... then where your ac lines once ran are two gromited perfect holes easy to reach from the engine bay.
then put back the empty box between the blower and duct matrix and wamo your fan works better and you'vr got two awsome fire wall holes in the perfect spot... PS the ac heat exchanger makes a great oil cooler

i've got ac,. I'm wondering if that's the hole to the right and top of the pedals suggested, [where the black rubber donut like thing is seen partially] where the line could pass through?

i believe thats the one, i havent been down underneath my car in ages. take apart a coat hanger and poke it through and see where it ends up

what vaccuum source did you guys use?

yet to do mine but would like to use same source as stock.
btw:
? is the unused connector at fingertip for engine diagnostics?

is that your fuse box, i thought engine thingy was in there on the bottom?

yes thats the consult port. i just t'd into the stock vacuum line for the stock boost sensor. it sits on the passenger side of the engine bay

Yup, the fuse box is right up there; the flash shot is up from the floor & tilted a bit forward where the gas pedal foot's heel could rest.

Here's the other side of the gtir electrical harness's 'donut' hole through to the inner fender area, viewed from about where the top of the right wheel would have been looking backwards. Fender is removed from a parts car.
I guess the vacuum/boost line could then pass into the engine bay via the about 1" hole to the right.
Removing the fender as was said looks necessary to see enough for the vacuum/boost line to bend and fit the tube just right unless hands can fit in there and guide the line thru the other hole going into the engine bay by feel. i'm hoping not to have to revove fender on the installation vehicle; it happened to be off for other work.
That opening where it passes into the engine bay is hard to see too but looks to come through to the back and side of the brake pot.

Here is the firewall with engine gone, ..there is another rubber donut/grommet located beneath the green stained lines on at center left, but with the engine/tranny in it could be difficult.

My plan, as I have a/c, will be to use the wiring harness hole with something like a sleave/conduit/1/4" hoses etc around the boost vacuum line to protect from chaffing when running straight through from the interior via the small hole to the engine bay.
My other thought was to drill a fresh hole through the firewall somewhere safe and fit a rubber grommet from wreckers etc..

i think i might just drill on and put in a grommit lol, im gonna take a look tonight if i dont go fishing

Judging by the photos, the fender grommet is the one i used. I ended up tying a wire to the inside of the body, and running a long piece out to the suspension tower and wrapping it around the strut bar. this way i can tape a piece of hose or wire and pulling it through, then pull the tied wire back through for later use. Hence not needing to search for the hole anymore. Ugly but it works.

Great pics and info for future reference, guys. Well done.