Exhaust Manifolds

[Tazzy]

whats the difference in power gains from the 4-1 outlet manifold to the 4-2-1 outlet manifold? i know something about top end, but dont know what exactly!

cheerz!

[MC]

I've seen tests done, and the difference is negligable. The 4-2-1 is supposed to be best for bhp, and the 4-1 should give more torque, but In the tests the 4-2-1 came out marginally better. The key thing is that the in primary pipe length should be around 30" before the pipes merge.

MC

[Dicko]

when i went for a std sri exhaust with cat to a full stainless magnex with 4-2-1 i noticed that you couldnt pull off sowly by starting to let the clutch out then putting ur foot on acc pedal, you needeed to get a few revs on 1st, and up top end it just went beter the more revs which was opposite to before, but might be due to the cat.
iv seen tests and with a 4-1 you gain more high rpm bhp but loose low/mid torque

[rob.slader]

I fitted a 4-2-1 to my sr, I had the car rolling roaded before and after fitment. I noticed that bottom end torque was slightly lost, but not much at all, peak power was up by 3bhp! Nothing really noticable when driving but did rev out better.

[mikeoxford]

i just got meself a sportex one ill fill u in later in this week what its like