Whats up guys? Gm trucks site sent me here. Need your help. I have a 2014 sierra with 6.2. Mods are 2.9 whipple, tsp 5.3 stage 2 cam .630 .630 218 226 113 lsa, afm delete, 1 7/8 headers, no cats, borla xr-1. Im running a 3.75 pulley and only getting at max 6.5 to 7 lbs. Whipple told me I should see 11 stock so with my mods they say 8 -9 min. I adjusted bypass valve and it seems to work correct. Am I missing something? Does this seem correct? Thank you in advance

 

no cats and that cam will show lower boost

 

So I could see 4lbs loss over stock? Whipple said something was wrong. So idk

 

I know with my Magnuson and my set-up I saw 6# of boost that others were seeing 9-10#. keep in mind when you remove the cats you are removing a restriction so the boost is lower but you are still making power.

 

As @terravast4 said, it’s the cam.

The more overlap you have with a cam, aka, holding both intake/exhaust valves open at the same time, you will bleed off boost.

Where are you getting your reading from? It should be from post-rotors, aka, lower tub.

 

Don't know what pulley is stock but Whipples dyno chart shows ~ 7.5 lbs.

 

on a mustang that 2.9 whipple w/ a 3.75 would make 11#s boost


that sounds like the l83 (5.3L) stage 2 truck cam... not the ones for 6.2(L86)
nor does it sounds like any of the blower cams that i read about


how much power do you have?


another user here w/ same pulley, LT headers, no cats
but stock cam
reported 7#s boost


given what others said about overlap on your cam... seems right.


i wouldnt care what whipple told you... what did your tuner say?

 

he specifically said it IS the 5.3 cam.

 

Texas speed recommends this cam for L86’s with a stock stall. And yes it is the stage 2 5.3 L83 cam.

This is the cam they told me to run in my truck every time I talked to them. I even asked if it would work with a blower later on with my truck. And TSP said they have several customers running boost with it and are very happy.

but I believe it is .635/.635 if that matters that much.

So is it a bad cam for boost? Or is it an alright cam you just need to pulley down more?

 

That cam should work good for that setup.