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How do I know if my belt is slipping?
I have a 91 5.0 with Edelbrock RPM heads, Edelbrock RPM II intake and a TFS stage one camshaft. I had the 2.93" pulley on and was only getting 5psi of boost reading on my gauge.
I have recently gone to a 2.75" pulley and see no increase in boost.
Why am I only seeing 5psi even while going to a 11psi pulley?
2.93" to a 2.75" that rpm increase would only be a 1.5psi. You will be replacing the internal belt if you spin it much more. Belt slipping you will see either the pulley looking polished or black dust.
I understand about the pulley size and the maximum bearing rpm speeds. I have a rebuild kit coming soon with ceramic bearings from SKD engineering.
I was not aware that the increase in speed will cause the belt to snap.
I've read that the 2.75" pulley is the smallest you should go.
Why am I not seeing the boost register on my gauge?
With a 10psi pulley I should at least see 8-9psi.
I have a better head, intake and cam combo but I've seen better induction packages making more boost with the same kit.
What could be causing this?
I have tightened the belt as tight as the idler will go on the bracket.
Where should the line from the vac/boost gauge be ran from?
I currently have it running right after the EGR spacer on the upper plenum.
Well the heads and everything else you have done has decreased the boost number you see but does not mean your not building more power. PSI-Boost is a reference of back pressure. And like I said earlier your not going to see a double increase in PSI going down that pulley size. People see 9psi with your 2.93" pulley because the car is stock and have restrictive parts. It is a science not just smaller pulley gives more boost.
Put the 2.93 pulley back on it! You cannot get enough belt wrap with the smaller pulley, it's hard enough with the 2.93. If you want more boost go with a larger crank pulley instead from ASP.
For comparison on my 93 GT with dead stock motor I saw 7psi with the 2.93 pulley. After GT40 heads and Corba intake it stayed the same but I also went to a larger MAF and better inlet piping.
ALSO, my cousin's 93 LX with a 14lb ProCharger kit only saw 8lbs with a 8.5:1331 and free flowing heads/intake.
5lbs seems normal to me, but what do you have for an intake pipe? If you want some more boost get a Powerpipe form AFM or a Boostmaster from UPR. I'd do that over a pulley for sure if you want any life out of the belt. ALSO..make sure you have a bypass! A Powerdyne will NOT take compressor surge very well. Think of it as the stress on a timing belt in a car if you go from 4th gear to 1st gear!!!