Looking for tips on my issue.

I installed an SLP 1900 supercharger on my 2014 silverado 6.2L. I thought the stock pulley was a 3.6 and I ordered a 3.2, because the boost doesn't seem very high. Boost does seem to take off above 4,000 RPM.

I have 1 7/8" LT's and no cats. 3.5" exhaust with open muffler. Now that I know the stock pulley is smaller, I am not sure if there may not be another issue. HP tuners show good low and high side fuel pressure at high RPM's. Fuel trims are good. no knock, so I am not sure if the injector size could be a contributor.

 

How are you measuring boost?

With a roots/tvs blower, it should be post rotors or from the bottom of the tub.

Whipple has a fitting on their lower tubs just for this purpose.

 

Right now I am just estimating based off of the manifold pressure readings in HP tuners. I should have my gauge installed this weekend. Looking for a good place for firewall penetration. There is a plug on the inter cooler / intake I will use for the gauge.

 

There is a rubber grommet by the brake booster area for easy access to cab

 

The 5.3L kit comes with an 83mm pulley and everyone I know who runs it is making 9-10 psi of boost. I'm at a steady 9.5psi

Someone on here with a Maggie and a 6.2 has a low boost concern too. could it be a 6.2L thing?

 

I got my gauge installed. I did find a small vacuum leak that was making quite an impact. It gauge does stay in the vacuum side a lot, but that could be the 6.2 and large headers. One thing I have noticed is that it will go up to 5-6 psi when I jump on it, but it backs off boost pretty quick, even with a steady pedal. Wondering if the stock TB is being a restriction. The 2014’s are pretty small.

 

Check your boost bypass valve for restrictions in movement and zip tie all your vacuum lines, I also shortened mine a bit. Boost comes on much faster now and doesn't back off.

 

Me
Where was your vacuum leak?
My boost does the same as you just described. Granted that's mostly in the tune, but when it was tuned to be more linear, it was way too weak.
So you're getting 6psi with an 83mm pulley on your 6.2L and TVS1900, or are you topping out at more? I've been asking what others are getting because I only get 6psi with my 6.2L TVS1900 but I had to move down to a 78mm to get that.