I just got my car re-tuned after I added the crawford plenum, btw, i have a vortech sc and i seem to be losing boost at 6500 rpm, what could the reason be for the loss of boost?

 

Is it the newest cast plenum ? Or one of the older versions ?
If its the newest one , I would say you didnt get the gasket on right , or the rubber thing around the oil filler got caught in the plenum .

If its an older version . They have been known to warp when they weld them back together . Two or three gaskets have to be built up to make up for it

Either way....if you havent changed anything else....its a boost leak at the plenum

 

the car is also running lean after 6500...could it still be the plenum?

 

retune it

 

whats your location..............maybe we can refer you to a good shop.......

 

It could be fuel pressure, belt slippage, a leak, or BOV diaphragm that is not good, etc.

What are you tuning on - the SS box or other?

Where are you located?

 

Retune big time and check your compression

 

You havent answered any ones questions . But finding a good shop to have the car checked out , was the best advice . You had it tuned after the install of the plenum . So Im going to take it that something has happened after the last tune . Take it back to the shop . It could be just that its colder out and its leaned out because of the extra air flow when cold .