Killer Honda Civic Si Build Shies Away from Forced Induction
Retro Civic Si build keeps it real (and naturally-aspirated) right here in the Honda-Tech forums.
These days, turbocharging is all the rage in the Honda scene. And for good reason, obviously. Tossing a huffer or two on your mill is a guaranteed way to add power, oftentimes with unmatched bang for the buck. Regardless, some folks choose to stick with natural-aspiration, for one reason or another. Count Honda-Tech member sh1ntaox among that group. Just don’t count out his Honda Civic Si as one serious performance machine in the making, despite its lack of forced induction.
“I’m a bit stuck on my era correct build. First generation B16A and Y1 transmission to match the chassis. For proper flexibility with tuning and availability of parts, using a Hondata S300 makes sense. I have been accumulating parts and I’m close to it all coming together. The motor has been gone through with the parts below. Porting and polishing of the intake, throttle body, and head have been accomplished as well. Transmission was just rebuilt with new synchros, seals, and bearings. There are a couple items which I am hesitating to acquire.”
Regardless, the OP has questions.
“I’m not sure of the ECU choice. S300 for sure, but should P72 or P28 be the choice? Which would make more sense for this?”
Luckily, as always, the forum has answers. Specially, Full_Tilt.
“P72 would only be beneficial to you if you wanted to retrofit a knock sensor. A P28 or any VTEC converted ECU would work fine. Use an OBD1 distributor and alternator with appropriate adapters or re-pinning.”
“P28 or P72 makes no difference once it’s chipped. With the exception of P28 not offering knock sensor or intake air bypass control (which is never used anyway),” adds Chance EG.
The OP eventually scores a used P06. Which, as 1999 Civic Si, points out, should work just fine in the OP’s Honda Civic Si.
“Should be Hondata S300 V1. I had it on my EM1 up until earlier this year (sold the car). Hondata’s current software had no issues working with it and neither did my tuner. Of course, it doesn’t have as many features as V3 (bluetooth, ethanol content, etc.). But it stills works just fine and I didn’t have to run any additional controllers or sensors, other than a wideband O2. I can’t remember which ECU it was in, I do remember it didn’t have a board for the knock sensor, but we just turned that off in the tune.”
Thus, the OP’s build is off to a solid start. But it’s just beginning, of course. So head over here and stay tuned as this sweet little N/A Civic Si comes together!