Only 8lbs Boost

[93atlsc]

Hey guys! My 93 SC auto is only getting 8lbs of boost. I know this is well below what it should get. It runs well, plugs and wires are good. No vacuum leaks. No CEL. Only upgrades are K&N cone filter, high flow cats and resonator. Any help would be greatly appreciated.

 

[KMT]

Only upgrades are K&N cone filter, high flow cats and resonator.

If those upgrades are recent, and it built proper boost before, it may be a typical case of where reducing back pressure/increasing flow in the exhaust system means seeing a drop in boost. Becuase: boost = back pressure.

Usual remedy in these examples is to build more boost by swapping a pulley or two for something with a different diameter. Example is to change to a 5%~7% supercharger pulley. This will regain observed boost, and up engine performance in the bargain. It can also cause issues that require other mods...

Mods can be a slippery slope, where one or more changes call for one or more other changes. Often a never ending adventure.

If you do change out a pulley (and that's all that's needed in your case), search here on the topic...lots and lots of discussion. I'd advise to do your homework and make a plan to avoid random changes and missteps along the way.

Good luck.

 

[aroot1]

Take a look at the bypass valve to be sure it is fully closed when under boost conditions, may be stuck slightly open, allowing boost to bleed off.

Adam

 

[93atlsc]

Thanks guys.