PLease help with this WTF issue

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Nov 18, 2013 | 01:59 PM

#11

Random User

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Quote:

Originally Posted by Byrdman11

Get a new belt away. I have seen old belt do this alot.

Swapped on a new Gates Micro V last night but didn't feel like getting out and testing it.

Nov 18, 2013 | 02:03 PM

#12

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Quote:

Originally Posted by REDCYCLE13

Your boost gauge should be reading from the manifold after the throttle body, or from the brake booster. The spike is from the throttle body slamming shut and creating a quick jump on the gauge before the blowoff opens. You may be making more boost than you think. I also think 5800 rpm is a low reference point. Centrifugal superchargers make more power with rpm. Calculate your impeller speed, and you should be able to get an idea how much CFM your moving.

I understand where the spike is coming from.
I also bumped up the shift points to 6000 last night when I swapped the belt. I may take it out tonight and see what it's doing. I can swap in my vac/boost gauge that reads from the brake booster line and see if I get a different reading too but in 20+ years of owning turbo or otherwise boosted engines I've never gotten a false reading from the intake tract.

Nov 19, 2013 | 09:23 AM

#13

damianldaigle

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From: Jennings LA

Quote:

Originally Posted by Random User

The valve sensing point should be plumbed between the TB and valve, Not the boost gauge though? Why subject it to the the extra abuse of spikes. Yes, Under full throttle you will get an accurate reading but at any other time your not, There will be a pressure drop across the butterfly.

Nov 19, 2013 | 03:27 PM

#14

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The valve opens via a vacuum signal when the TB closes. The boost gauge doesn't care where it gets a feed from...in every other vehicle I've ever built anyway. I'll put the vac/boost gauge back in this weekend and see if I note a difference...anything is possible.