brass fitting for boost gauge?

[new-dieselman]

I need more details on the brass fitting that i'm going to tap into the intake. My Autometer gauge didn't come with this fitting. It only has a tee for tubing. Is the fitting threaded at both ends or can it have threads on one end and a nipple on the other for the tube to connect? Thanks everybody

[DmaxMaverick]

If the gage set came with 1/8" plastic tubing (should have), and/or a 1/8" compression fitting (nut with ferrul)at the back of the gage, you can drill/tap and fit it correctly. You'll need a 1/8" NPT to 1/8" tubing compression fitting. Oftentimes, a 1/4" NPT hole is drilled/tapped, and a 1/4" to 1/8" bushing is used with the above fitting, like a pyro probe. All of the above are very common hardware store items. If you aren't sure what they are, just ask someone at the hardware store and they should be able to locate them easily. You will also need the appropriate size NPT tap and drill bit (sized to the tap).

[rustyk]

I got my 1/4" NPT tap at NAPA. I used a brass 1/4"-1/8" elbow and a compression fitting, all from Lowe's.

[sturgeon-phish]

Here is a picture
http://i126.photobucket.com/albums/p81/sturgeon-phish/Truck/000_0015-5.jpg
http://i126.photobucket.com/albums/p81/sturgeon-phish/Truck/000_0016-4.jpg
Jim

[new-dieselman]

Thanks Jim for the picture. I've seen other picures just not as close up. I aslo got a bit confused when i couldn't find a 1/8th to 1/8th fitting. My local hardware stores only went down to 1/4. The hose on yours looks larger in dia. then mine, i have a white nylon 1/8" dia tube. It seems sort of hard and i might have trouble getting it to straighten out. I finally found the right fitting so i'm putting her in this weekend. Which is a good thing because ever since i broke the vac line from the wastegate solenoid to the vac pump and tried to rig up a new vac line my boost is nearly gone and my egt's are way up. Looks like i'm heading for a Heath chip and Turbo-master? Any thoughts on those?

[Robyn]

You can easily fix the vacuum line with some vacuum hose and a brass adapter barb fitting.

The plastic line set is also available from Ma General if you so desire to repair the factory system.

Truthfully a quick trip under the hood with a tape measure a note pad,pencil and a few mesurements should arm you with enough information to head off to the NAPA store and get the needed stuff to patch up the vacuum system ao it will work well again..

The hard line that comes with most gauge sets is fine and will work well with the proper fittings.


The chip and the TM are a great choice. The TM is a simple little creature and the chip will take care of a buttload of issues and the ECM will not set codes from over boost.

Stay conservative with the boost. 10-12 MAX under a hard pull in top gear unless you add an after cooler/charge cooler.

Good luck

Robyn

[DmaxMaverick]

Thanks Jim for the picture. I've seen other picures just not as close up. I aslo got a bit confused when i couldn't find a 1/8th to 1/8th fitting. My local hardware stores only went down to 1/4. The hose on yours looks larger in dia. then mine, i have a white nylon 1/8" dia tube. It seems sort of hard and i might have trouble getting it to straighten out. I finally found the right fitting so i'm putting her in this weekend. Which is a good thing because ever since i broke the vac line from the wastegate solenoid to the vac pump and tried to rig up a new vac line my boost is nearly gone and my egt's are way up. Looks like i'm heading for a Heath chip and Turbo-master? Any thoughts on those?


Yours will be 1/8" tubing. Don't know why you think yours is smaller than that pictured, but there isn't any smaller (that will be used on any vehicle). Perhaps the color, or the illusion in relation to other components. You need a 1/8" NPT to compression fitting. If your hardware store doesn't stock it, well, they're not very well stocked. Very common item, used for many other things, such as HVAC, plumbing, instrumentation, etc. A mechanical oil pressure gage, fuel gage, vacuum system, and others, will use the same fitting. You may find this at the auto parts store as a replacement mechanical oil pressure fitting. Same animal, different name. Napa will have this, or be able to order it, but normally stocked. It's just 1/2 the cost at a hardware store for the same thing.

[new-dieselman]

Ok i'll try to make this the last dumb question................. for awhile :-). What size drill bit do i use for 1/8th " npt fitting? I think it's .339 or type r , is that correct? I don't have that type of drill bit at home so i'll have to go get one.

[JohnC]

Use 21/64. If you don't have one, use 5/16. In alluminum that'll work OK. Don't run the tap in too deep or you won't be able to get the fitting to tighten up before you run out of thread.

[new-dieselman]

thanks JC. I finally figured out 21/64. It's funny you mention not to run the tap in too deep.I'm having the opposite problem you describe. I ran the tap into the 21/64th " hole until the tap was sticking about an 1/8th or so out the other end, that was hard to do, i thought i was going to crack the intake.. But when i tried threading the fitting it was very tight. No room for any of that thin pipe tape and i was afraid to tighten too much. The fitting does not go in as to be flush with the inside wall of the intake. But after all the gauge seems to be working. Only getting 4- 4.5 lbs boost max. for short period then she falls right off. High egt's as well of course. So i've rigged up a spring that i bought for 2 bucks and hooked it in between the wastegate actuator rod and the canister to keep her closed a little longer and now i can hit 10lbs boost. Maybe this 2 dollar springy can be a permanent boost control with a little tweaking.