ok, this is semi important since im tuning my car with my boost guage.
i bought an autometer mechanical boost guage cuz i couldnt afford a nice electric on and there are plenty of arguements to go with mechanical anyways. but, it came with silicon tubing that is way too small for the FD's stock nipple. so i put some short larger diameter rubber tubing on the nipple and ran the silocon tube from the boost guage inside that with some silicone tape over it and used 3 zip ties to tighten it very much but not verly so. i get reading but here is my real question. do i have a recipe here for innacurate readings? ive got it tuned to 9 to heir ont he safe side and with my m2 stg 3 and stcok fuel system i should be good to 12-13 for all intents and purposes. do you think that my rubber to silicon with zip ties connection is compromised. if so, predictably?

i rally appreciate all the help fellas
barban

 

pmub

 

I hear ya. I wouldn't want a question like that hanging over my head either.

What about glue in addition to what you've already done?

I would test the whole apparatus with regulated air from your compressor and some windex regardless.

 

I ran into the same issue and did almost exactly what you did minus the tape and zip ties. I just shoved the one tube into the other checked for leaks and test drove it. My boost pattern is exactly what it's supposed to be 10-8-10 so I assume it's fine. I even had a boost problem last summer ( boosting to 6psi according to boost gauge) checked everything found a damaged hose, replaced it and my boost returned to 10psi. I've had the gauge on my car for over a year now. You should be fine.

 

I used a similar setup up, I think thats pretty much the only way to hook it up. Does anyone know if the length of the rubber tubing makes a difference. Shorter the better or longer? I would think the shorter the length of rubber to the uim the better

 

thanks guys, i might look into some epoxy or something for the connection

 

You really should just do it right.

There are 2 ways to do it. First, and best, is to ditch that crappy nylon tubing Autometer gives you. Go to the hardware store and find a brass fitting that will screw into the gauge that has a hose barb on the other end so you can use a regular vacuum line. I have found fittings before back when I had an Autometer gauge that screwed right into the back of the gauge and had the right size hose barb - it was just one fitting, not some goofy contraption of multiple fittings.

If you are gonna use the nylon tubing, most auto parts stores have rubber ends that go on the end of the tubing and adapt it to a nipple - that's how that tubing is supposed to be used. But, that rubber and the nylon tubing WILL get brittle with heat and cause problems down the road. Not to mention the ferrule that goes around the tubing when you screw it into the back of the gauge is only good for one crush - unscrew it from the gauge once, and you need a new ferrule. JUNK.

A basic Greddy 60mm mechanical boost gauge is $94 -
http://www.gruppe-s.com/Greddy/greddymeter.htm

Comes with a good-sized length of proper sized 3.5mm vacuum line - SUPER easy to hook up. Quality wiring connections and quality wiring.

I'm not bagging you for having an Autometer gauge - trust me, I've been there myself, you have to get one to start with then you move up . Good gauges really aren't that expensive, especially Greddy's lineup, and the difference in quality is night and day. Something as important as boost, where a pound or two one way or the other could mean a blown engine, it's worth $94 at least for a decent gauge. Or, get on Ebay - there's deals ALL the time on gauges.

Dale

 

damn, i thought i searched hard for a decently priced greddy too. originally i had their electric but it went on the fritz so i went to an autometer mechanical. now you say i can fix the problem at the guage fitting right? im gonna have to look into this. my car is in a remote location for now but i hope to correct this shortly

 

It should be fine, I would think you would notice pretty easily if it was leaking...

 

I bought my old autometer BG from pettit and it came with a nice rubber adapter. It worked perfectly. I might have it around somewhere, pm me if you want it.

 

no thx moehler im just gonna ger me a new brass fitting and some real vacuum tubing. while this may read slightly slower at least it has all the peace of mind i need.

 

To connect mine, I went to a hardware store and bought an adapter to fit the difference in size from the nipple to the tubing. I know for a fact that Pettit Racing has them in stock. Call them or visit them online. They're an exact fit for the FD.......exact.

www.pettitracing.com