{"product_id":"upper-plenum-adapter","title":"Upper Plenum Adapter","description":"The Precision Turbo PEP022-1011 is an upper plenum adapter engineered to resolve airflow distribution issues inherent in the factory plenum of 1986-1987 Buick Turbo Regals and 1989 20th Anniversary Turbo Trans Ams. The stock plenum design can cause uneven airflow, leading to a lean condition in the rear cylinders, especially when power is increased.\n\nConstructed from cast aluminum and finished with CNC machining, this adapter features a 70mm opening and a higher internal volume compared to the stock unit. This increased volume contributes to a larger intake manifold capacity, enabling the turbocharged engine to support greater horsepower potential.\n\nThe PEP022-1011 is a direct bolt-on replacement and is compatible with stock 58mm throttle bodies, ported stock 62mm throttle bodies, and Accufab 65mm or 70mm throttle bodies. The kit includes a new GM upper plenum to intake gasket and all necessary fastener hardware for a straightforward installation.\n\nTesting has shown performance improvements, including a 2-3 tenths reduction in 1\/4 mile ET and an increase of 2-3 MPH in the 1\/4 mile.","brand":"Precision Turbo","offers":[{"title":"Default Title","offer_id":52663335813432,"sku":"PEP022-1011","price":239.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/687074573.jpg?v=1784326053","url":"https:\/\/store.motormia.co\/products\/upper-plenum-adapter","provider":"MOTORMIA","version":"1.0","type":"link"}