Are 4-1 Or 4-2-1 Extractors Better For A 5k?

[Twitch]

Hi guys,

I am in the process of trying to buy some extractors, however I have notices that there are two different types.

 

Can anyone tell me whether the 4-2-1 or 4-1 extractors are better for a 5K, and if so why?

 

Cheers,

Twitch

[Felix]

In general 4-2-1's give more torque and 4into1's give more topend.

[snot35]

Considering how many of them are probably anywhere near tuned for a particular motor, probably either. Both will likely be better than a stock manifold.

[philbey]

Considering how many of them are probably anywhere near tuned for a particular motor, probably either. Both will likely be better than a stock manifold.

 

 

Yep, unless you're building a racecar, the gains will be marginal. If you are building a racecar, you'd go through the process of cam spec and then tune your manifold to suit the rev range. +3hp!