Just finished installing a boost gauge. Tee'd into the intake manifold to fuel pressure vacuum line. All well and good.

Howsomever, my boost/vacuum gauge now reads the signal as vacuum rather than boost. Do I have some sort of monster leak? Any suggestions welcomed.

Helpful suggestions preferred, with humorous suggestions ranking a close second.

Thanks.

 

At what RPM?

 

At idle it should read vac.

What does it read at WOT does it get out of vac and into the boost side? IF not there is something wrong.

 

Push the gas pedal.

 

Ha! and push it hard and often!

I've found the behavior of my boost/vac gauge to be very interesting -- giving me a new perspective on how the SC and the bypass valve actually work. On my car (maybe all), if you don't really lean into the throttle it still appears to be running under vacuum most of the time. If I get on it pretty good, it's obvious when the bypass closes. For some reason, it looks to me like the boost almost comes on in a step-function manner, first hovering around 1-2 PSI, then jumping to about 5 PSI, and if I go WOT, it jumps to 10-12 PSI.

I don't have the "M7 Device" yet, still waiting. I hope it comes soon so I can check out the difference.

 

At all rpms so far it's in vacuum, but I just started it and watched the gauge. I come from the world of air-cooled bikes where an intake leak can fry an engine in seconds, so when it didn't show anything but vacuum I shut it down. I'll try it under load in the morning and see what it does.

Thanks for the suggestions. I'll post the results tomorrow. Especially if it turns out I've done something stupid and/or comical.

 

Spunky

I beleive it needs to be under load to register boost.

PS thanks for the order, I just saw it :smile:
Your shiftknob will ship out tommorow!

You are going to love it!!!!!!

Best regards

Joseph

Blue Fin Tuna Fan Club

 

Went out this morning and tested the gauge under load and it's doing exactly what it's supposed to do, distract me. Nothing wrong with the gauge or the install, just my lack of understanding of how it works. Another case of user error.

Thanks for your help.

And you were right, pressing down on that long skinny pedal on the right makes the gauge work just fine.

 

! I just spit coffee everywhere! "Boost gauge OK, operator sucks"!!! Hilarious. Have fun with your new toy.

 

Did you use a kit, if so which one. Or if not what parts did you use and how did you connect it to the car?

 

I used this kit: http://tinyurl.com/3sh6a
Autometer gauges, all the fittings hoses and wires, complete down to a little jar of grease to lube the o-rings the gauges are held in by and the long q-tips to apply it with. Beefy bracket that looks like an Alta copy with welds that aren't the prettiest I've ever seen but certainly ought to be strong enough.

Picture instructions that could perhaps be a mite clearer but were sufficiently useful that I didn't plumb anything wrong, blow anything up, or set anything on fire. All of which I've done to one thing or another in the past.

Everything fit and the guy shipped it the day I ordered it. I'm not related nor employed by him but just a pleased customer.

The one thing about the kit is that it follows what seems to be the common approach of drilling the oil filter cover to tap it for the oil pressure gauge. I haven't done that because it just doesn't seem to be a reasonable thing to do. I'm exploring other possibilites, such as perhaps installing a 'T' fitting under the factory oil pressure switch instead. There ought to be a place to tap into the oil system to get an accurate pressure signal without tapping into the oil filter cover.

Why put a fitting into something that you have to remove every time you change oil? Cheap, yep it's cheap to do it that way. Easy, yep it is. The right thing to do? I'd say probably not. But obviously I'm swimming upstream since it appears that's the common way to do it.

 

Maybe you should have gotten a Cooper - it doesn't appear that you really need the whole supercharger thing. Also, if you're not driving so you need boost, maybe you didn't really need gauges either! jk