IS F (2008-2014) :: PPE Equal Length - Long Tube Headers?

PPE Engineering has been getting lot's of inquires from us ISF owners about the feasibility of making an Equal Length Header for the ISF similar to the one they make for the RCF. Since I am a past customer, live nearby, have another vehicle and am a pretty nice guy they called and asked if I might be interested in having my car test fit for Equal Length Headers.

While discussing this with them, I suggested that if modified RCF Headers wouldn't fit, maybe they could accomplish the equal length task by using long tubes. Well, it seems that RCF headers will in fact fit in an ISF, and the headers they built for me were also Long Tube. How sweet is that? But, the EL, LT headers must be used with the PPE Exhaust due to the exit point of the collector.

I went for Dyno testing yesterday, and it appears I lost 7HP at the top end and gained only 1.5 lb ft of torque at the high end. I also gained grunt at the bottom. My Seat of the Pants tells me the car is faster.

I don't know why it ran out of breath at the high end. Nothing else has changed.

PPE Headers

PPE Dual Mode Exhaust - With HiFlow Cats

Takeda Intake

As far as sound goes, in the cabin with the exhaust open, the drone remains in the same area (between 1900 and 2100 RPM) but is much lower in volume. I can now carry on a phone conversion (with bluetooth hands free) with the exhaust in the open position. The volume level does increase, however, when under acceleration through that RPM range.

Now the ISF does not have a lumpy engine by any means, but it idle with the old headers, the sound (both inside and outside the car) had a sort of lumpy growling quality to it. The sound is now very smooth, again inside and outside. The harmonics seemed to have changed.

Edit - My wheels and tires have changed. I'm now running RCF wheels with larger 295 vs 285 rears, so wheel weight is up a bit!