Boost Gauge hook up with the M62 Eaton Supercharger?

I know on the M90, you follow the line over the rear valve cover, and tee into that. The line comes from a tee under the M90 supercharger snout. What about the 1995 M62 supercharger?

LARRY70GS wrote:

I know on the M90, you follow the line over the rear valve cover, and tee into that.  The line comes from a tee under the M90 supercharger snout.  What about the 1995 M62 supercharger?

IIRC that tee is just the vacuum port, it goes to the supercharger servo and other places. Basically a vacuum bleed off of the lower intake manifold.

Thanks Albert, but that doesn't answer my question.  Where do you hook a boost gauge up to on the Series 1 M62 supercharger?  I am asking for a member on another Buick Forum.  The M90 on the 96-99 Riviera connects to that line over the rear valve cover.  That is well covered in the Series 2 Forum here, but I can't find a reference in this Series 1 Forum.

LARRY70GS wrote:

Thanks Albert, but that doesn't answer my question.  Where do you hook a boost gauge up to on the Series 1 M62 supercharger?  I am asking for a member on another Buick Forum.  The M90 on the 96-99 Riviera connects to that line over the rear valve cover.  That is well covered in the Series 2 Forum here, but I can't find a reference in this Series 1 Forum.

Got it.

Boost gauge and vac gauge connect to the manifold to read vacuum.  It's just that the sweep differs on the two gauges.  Typically (but not always) the boost gauge sweeps as far for vac as it does for boost.  Don't know what yours shows.

Here is a picture of the Series I vac manifold (courtesy Intense): https://intense-racing.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=IR&Product_Code=GMH-VAC-L32&Category_Code=3800_GH - and next is an entertaining video (I could live without the vulgarity however) about installing a boost gauge. You don't *need* the video but let's just say it's reassurance that you could tee into, for instance, the vac line that goes to the vac-operated bypass solenoid black can w/plunger) on the M62.  Pretty much no matter whose supercharger it is, hookup is typically by 'T-ing' into an existing manifold vac hose or tube. https://www.youtube.com/watch?v=4-r0JSGtH_E

Left to my own devices on the Series I, I'd probably tap in somewhere near that bypass solenoid. That way I can lash it to something if I want so it does not vibrate much and it's easy to see/hear/spray to check for leaks.  A mechanically 'prettier' tap-in would be on the back hidden under the MAP sensor. I think if GM was providing a boost gauge they'd tap the manifold there.   Anyway - Instead of splicing the nylon vac manifold I would probably  replace the vac manifold entirely with tubing from shop supplies to make up the vac runs. That's just personal preference, because I don't think splicing that black plastic tubing is much fun and it's easier for me to test the rubber hose with a Mity-Vac to be sure I got things done right.   But a reliable way to splice the stock vac manifold  is get some common reinforced hose with an ID matching (or just under) the tubing , cut the tubing, and splice in a tee with the hose and fittings from shop supplies.

Cheers

Albertj

Thanks Albert. I'll pass that info along.

LARRY70GS wrote:

Thanks Albert.  I'll pass that info along.

YW. I have a friend who had the Series I SC engine on his RIv, the LIM might have had a different PM but it looked about the same and had the LIM vac nipple in the same under-snout place. There's no magic in tapping the vac line for the gauge, as long as the vac lines are not leaking somewhere or other. I totally get, however, that your correspondent would prefer to hear form someone who'd done this on an M62 (hence the video).

The fun thing is taking the pulley GM used on the M62 and installing it on the M90 on a S II L67. As long as you're burning Premium, it's a cheap HP boost in line with the cheap boost you get from porting the front exhaust manifold.

Albertj