22RE Independent Throttle Body Setup
Why * Design/Building * Finished/Results
Why
I wanted a challenging project and to do some aluminum welding. I conceived this project while the 22RE 2.4L engine was still in the car, and I was planning on adding a turbo and megasquirt afterwords. I knew it would probably hurt power until the turbo is added due to the shorter intake runners,but it would probably sound cool. There isn’t much benefit to be gained doing ITBs on a 8 valve, low RPM, poor flowing engine.
I finished the project to make sure it worked, but had already changed my plans to use a 2RZ 2.4L instead of the 22RE. They were tested and worked, but tuning was needed. Someday I hope to use the ITB intake on another 22RE project, if one comes up.
Building
The ITB’s are based on a chopped up OEM lower intake manifold, 16ga aluminum plenum, aluminum tube, 1998 Suzuki GSXR 750 SRAD ITBs, and throttle trumpets made from plastic speaker ports (as in subwoofer). These throttle bodies were chosen because they are separable and are large for motorcycle throttle bodies.
The lower intake was chopped up and aluminum tube was added. The 22RE lower intake is a pita to design around as coolant flows through it between the head and the radiator. I dont know why they did this but it sure is a dumb setup. The replacement for the 22RE, the 2RZ has this coolant connection and injector bungs directly on the head, making removing the intake a drip free affair.
The 1998 GSXR ITBs had their spacing modified (spread apart), and their injector ports plugged (interference fit aluminum plugs with some sensor safe silicon). The throttle cam hole was enlarged slightly so the stock celica throttle cable would fit. The throttle bodies use a modified ‘84 celica 3 position TPS, and the resistance based GSXR TPS can be put back on.
The 22re fuel rail and injectors are used. The fuel rail has a bolt in the cold start injector port, and the pulsation damper/fuel inlet is replaced by a custom made banjo bolt for clearance reasons.
The plenum attaches to the throttle bodies with modified ford taurus SHO rubber intake clamps and radiator hose from some big ‘ole truck.
Finished
The ITB intake was installed on the car with the stock MAF sensor connected to the plenum, and the distributor vacuum advance was connected to the the bridged vacuum ports on the throttle bodies. Stock computer and no other changes to the car. No PCV connected (and thus sad piston rings).
The car would start up fine with a bit of pedaling (and I could hear the flapper door on the AFM slamming open and closed). Idle was fine.
The car ran fine with a slightly improved high RPM range (probably due to the shorter intake runners). Initial throttle response was improved, but the MAF sensor could clearly not keep up. Zero to full throttle would cause the engine to jump and then bog slightly. Part to full throttle had improved response. At WOT, the engine pulled longer through the rpm range and sounded very cool. An aftermarket computer system with a map sensor setup and proper accel enrichment is needed to really benefit from this setup. A map system would also allow open TBs instead of a plenum setup
