Im interesting in getting the RB collected streetable header for my streetported s4 na, was wondering if u make power above redline (7500rpm or so), or is peak power usually achieved at a lower rpm (6500-7000rpm)? where will the power dropoff ? I know from what i saw the short primary will make more top end power than a long primary (collected system). I was just wondering if anyone had a dyno chart or anything to compare the difference in powerbands between the two.

Mainly the reason i want to get the streetable header is its alot more cost efficient and the system will weigh alot less using one muffler instead of a dual setup.

 

If you have an aftermarket ignition and fuel control setup probably. But with the stock EFI you don't really have much help for good ignition/fuel above redline.

Maybe if you switch over to S5 EFI setup.

 

intake will be the biggest restriction at +6500 RPM, the stock S4 non turbo manifold runs out of steam at 6000.