kr inlet manifold

[gazareth]

hey all,just wondering why on earth vw would fit such a huge diameter manifold (50mm) to a 139bhp 1.8 engine? was the engine not putting out the same power with the 42mm manifold?

[clipperjay]

The best thing about KR's are that the more fuel and air you throw at it the faster it goes!
 

[gazareth]

yeah I would see the point in a 50mm manifold if you have a flowed head/high lift cams and maybe a four branch thrown in. but in normal driving if a 42mm manifold produces the same peak power as a 50mm one then why suffer the loss of torque lower in the rpm range?

[Gambit]

The very first 16v came with a 40mm inlet, identified by casting mark on inlet tract 1, they then went 50mm, then 42mm for corrado and very late golf 16v

i think it was just evolution. 40mm was strangled at higher rpm, 50mm give better top end performance/bhp but less lower end torque, 42mm was the compromise.

Throughout all they where rated at 139bhp which i think vw just never bothered releasing new figures hence you nearly always get higher than 139bhp in 50mm inlet 16v's unless they are completely knackered

corrado 1.8kr comes with 42mm inlet and is identical bar rear exhaust section but is rated at 136bhp