SRT Intake info. from website- The High Flow Intake system adjusts the air-fuel ratio to optimal settings in conjunction with a high flow Intake system. The stock intake system from Lexus has deficiencies in supplying air needed by the engine. Swift Racing is proud to present the first ever High Flow Air Intake for the Lexus GS400. This system helps the engine breath much better and gives the car quicker acceleration and much crisper throttle response throughout the entire RPM range. It uses 3.5" mandrel bent steel pipes and 5061 aluminum heat shield, enamel coated and uses a 5" conical AFE lifetime air filter. It also includes an ECU that recalibrates the air-fuel ratios for optimal performance and enhanced fuel economy.

I'm sure this has already been discussed, but I don't see how SRT gets these numbers. It seems impossible to get even a 20 HP gain from adding an intake. Have any of you seen results any where close to this?

 

it also includes an ecu.

 

Don't forget the MAF diameter is increased substancially. Generally the MAF is the biggest restriction. Also, as stated, a new ECU is included that provides a more aggressive tune than factory conservative specs. The factory has to include a safety margin as it expects some owners to run regular gas even though premium is specified. Rich is safe as is a slight timing retard. These are the areas that ECU programming can find power.

All the above aside, I have not tested the SRT unit myself. I feel that SRT is honest but I know results can very.

 

I have gotten mine dynoed and yes its a big increase over stock! I dynoed 254hp which was about 18hp more than stock! so It does help! I also raced a STOCK GS4 and started to pull on him at 60 on up. But the true power is the TT set-up.