Piers Boost Bolt, where to install?

[Stiffler]

Hi all, I'll be installing my gauges in a few days and a photo of where to install the Piers Boost Bolt would be a big help. The photo of the Boost Bolt installed on the Piers website shows a different engine than mine. If anyone has a photo of the boost bolt installed on a 03 H. O. I'd greatly appreciate it.



If anyone with a H. O. , who doesn't have the boost bolt installed but knows where it goes, a pic with an arrow would help.



Also, what wire is the best to tap into do allow my gauges to dim with the insturment panel? I've been wearing out the Search button but have been unable to come up with a definitive answer. I did find that the dark brown wire with the pink tracer behind the emergency brake is the key on hot wire.



Any and all help for me and my 03 HO would be greatly appreciated!!!



Thanks in advance!

 

[David Muench]

I don't have a picture, but there is a plate running the length of the engine to the driver's side of the valve cover. It has bolts running down the sides of it. I replaced the far forward inboard bolt with the boost bolt. I unplugged the front injector electrical connection for some room to put it in.



For the light dimming, I tapped into the wiring coming out of the headlight switch. The headlight switch panel and surrounding trim just pulls out if you remove the lower kick panel, and it was the orange with white tracer wire.

 

[Stiffler]

Thanks for the info David! It'll come in handy real soon.

 

[rbattelle]

David,



Is one of the bolts you replaced in this picture?

 

[Stiffler]

I'll go one step further here. I assume that the bolts marked in this pic are acceptable to replace with the boost bolt. ( 03, H. O. )

 

[rbattelle]

Why not put it further forward? That first inboard (engine-side) bolt is super-easy to access.

 

[Stiffler]

Originally posted by rbattelle

Why not put it further forward? That first inboard (engine-side) bolt is super-easy to access.

I'm just trying to make sure I have the right bolts ID'd to replace with the boost bolt. I'll assume by your post that these are the right bolts, and your right there are easier ones to access.

 

[rbattelle]

To be honest, I have no idea which ones are the "right" ones. I suspect any of the bolts along the manifold would work fine. I'm waiting for David Muench to reply with which bolt he used.

 

[rbattelle]

What about this one?

 

[Greg Boardman-RIP]

Originally posted by Stiffler

I'll go one step further here. I assume that the bolts marked in this pic are acceptable to replace with the boost bolt. ( 03, H. O. )

I used one of the farther back bolts.

 

[Stiffler]

Originally posted by Greg Boardman

I used one of the farther back bolts.

Thanks Greg, that's what I was thinking to make the install look cleaner. Just wanted to make sure I was eyeing up the right bolts.

 

[Greg Boardman-RIP]

I had to try a couple to get it right. If you hook it up and no boost, Grab the next bolt over.

 

[d90boy]

You can't use the one on the intake horn it's a long bolt. Any of the ones on the inside of the manifold will work. Yes the front one is easy to access but I want to use a back one so the boost line isn't running up in the front part of the engine compartment.

 

[David Muench]

Here's the one I used. Other than that, d90boy summed it up. I just didn't want to be fishing around down in the injector lines.

 

[rbattelle]

I'm getting ready to install my boost bolt tomorrow, but I noticed as I was preparing the things I'll need that the Piers bolt uses a 1/8 inch NPT STRAIGHT thread. The compression fitting that came with my ISSPRO tubing kit is 1/8 NPT TAPERED thread.



Was this the case for you guys? If so, was there any problem with leaks?

 

[rbattelle]

Well, I installed the gauge yesterday. It all went pretty smooth, except the last step (of course). When I tightened the fitting for the pressure tube at the engine-end I managed to mangle the ferrule.



I think it's holding pressure (for the most part) and will be OK until I can get a new fitting later this week.

 

[rbattelle]

How I did it

For the benefit of others who might attempt installation of a boost gauge, here's a short description of how exactly I did it.



First, I removed the center bezel. This is quite simple; there's 1 screw and a series of clips that pull out. Just tug gently but firmly on the edges of the bezel... it'll free up without breaking.



Then, I spliced into the heater control circuitry to obtain a dash light signal (so the gauge will be backlit at night). Specifically, I spliced into the orange/yellow wire in the smaller of the 2 heater control connectors (connector C1, page 8W-80-6 of the service manual). For the ground, I spliced into the big 10-gauge black/dark blue wire on the larger heater control connector (connected C2, page 8W-80-6). I'm ashamed at how crude these splices were. I just twisted the wiring together... at some point I need to go back and solder them in place.



Next, I poked a small hole in a rubber boot just below the clutch pedal that didn't seem to be used for anything at all and fed my tubing through there.



Last step was to remove the intake manifold bolt (the one David Muench used) and replace with the Piers' bolt. Service manual states 18 ft-lbs torque, which is 218 in-lbs. I torqued to 205 in-lbs and called it a day.



Note: take care when you connect the tubing to the compression fitting at both the gauge and the engine-side! The ferrule is small and easy to mangle (like I did).

 

[Badunit]

I tapped into the orange/white wire at the headlight switch for the lights. The dash panel pulls off easily there (no screws, just pull) and it's easy to get to.



I tapped into the red wire going to the cigar lighter for the 12V switched power. I reached under the dash to get to it but it was a bear to reach.



For ground, I used one of the bolts (screws) that holds the bottom edge of the dash on. I crimped and soldered my ground wires to an eye and slipped it under the bolt (i. e. , sandwiched between the plastic dash and the metal) with a star washer for good measure.



Geno's highly recommends not exceeding 12 ft lbs on their hollow bolt and to be careful tightening up the fitting (i. e. , use two wrenches) so you don't inadvertently tighten up the bolt more.



I dropped my ferrule on the engine accidently. Luckily it fell somewhere where I could reach it with tweezers.



I used the front bolt for the boost fitting for ease of access. It was about the farthest the tube would go, though, while still leaving some slack.

 

[rbattelle]

I went to 17 ft-lbs and had no trouble. It's not very much torque at all, really. . and it seemed like the Piers bolt was very sturdy.

 

[Blakers]

Here's mine...



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I used one of the screws back further on the air intake cover, about straight down from the cowelling where I ran the tubing and pyro wires in the square enclosure.



Blake