Originally Posted by roms33
If you could find an intake manifold with taller runners the crossfire would get some needed torque. That would maximize all the other mods and make the crossfire a contender off the line. Salvaged it may not be too expensive for the power to $ gain. Good luck. By the way does hollowing the cats cause a loss of low end torque on this car?
the magnesium manifold on the xf is active ... meaning 12 runners ... 6 extremely long for low end torque and 6 extremely short for high end hp ... a set of solenoid actuated flaps switches between them at the point the torque curves cross from both respective manifold lengths.
there is a great post about it somewhere on the forum ... it turns out it is the longest set of runners in the industry according to that article.
These photos i found on some random for sale forum should give an idea ... i wish i could give credit to the photographer but i have no idea who it was. Either way i am thankful for them ...
