Anyone done this. Looking for some feed back or comments on whether it is worth it?

 

Depends on the design - will likely move your spool point 100-500rpm higher up the rev range but pull much stronger through mid to top end.

It's always a compromise, especially if you're not remapping around it (remap can claw back 2-300rpm on the classic shape - not sure on the 7's yet). The owner of the 4-1'ed STi7 I've seen here didn't like the increased lag, so refitted OE manifold...and now doesn't like the loss of power. He's waiting for a remap now

Richard

 

There will be a equal length manifold for the sti & wrx available in the new year it will go from 4 into 2 into 1
Paul

 

Thanks

Paul so in response to Richards comments what will be the benefit of the equal length 4-2-1 as opposed to the 4-1

 

The difference between the 4-2-1 & 4-1 is the latter is more for racing with top end power and the 4-2-1 is for mid range and better alround. Not that there is a huge difference with a pressurized system on the turbo cars.