uprate my manifold.

[james_19]

what manifold would be best to use in my c20xe??

[jimbob-mcgrew]

im prob not the best person to answer, but ive heard 4 to 1 pipes offer the best flow for high rpm (track car for example). and 4 to 2 to 1 pipes offer better low and mid range flow due to slighly higher back pressure (road car for example). depends what the intended use for the car will be.

friend of mine has the same redtop in his nova tho, and by the looks of it, the standard manifold looks fairly hefty, its a 4 to 1. should stick with that unless your after hefty power.

[dumpycorsa]

The standard xe manifold is a 4-2-1. Depending on your state of tune and what you're using the astra van for. Cosworth reduce the BHP of the original engine to increase torque. They did this by reducing the dia of the headers and altering their length. I'd say to start just go for one with larger dia pipes. Will help to increase the flow and draw more air/fuel into the cylinders

[jimbob-mcgrew]

oh ? maybe his is uprated in that case, thought it was standard.
unless i havent been paying attention and its 4 - 2 - 1