Photography & Motorsports
12A Power to RX8 Renesis Power
January 2, 2010
Here is the progress for the make-over from a bone stock 12A to a 2004 6-port RX8 Renesis power plant. It has been my daily driver for the past few years that I believe made about 85 HP and was getting around 23 MPG in the city when I didn't have my foot in it! As you can see, it has "factory air" which I will retain although I will adapt the RX8 compressor into the system. The RX8 engine came from a wrecked car with considerable damage (the center plate was broken where the left side mount attached and had internal cracks, which I had never seen before) and will be managed be an Electromotive TECgt.
I completely disassembled the engine. I have never seen a rotary engine so gummed up with carbon. I literally spent days cleaning the rotors and intake manifold with all its valves and passages. I elected to replace all the seals and springs, and keep it stock as I believe going from 85 HP to 160 HP should be just fine for this light car. Additionally, I will be changing the front struts and rear end to 1985 GSL-SE for better brakes, wheels and tires.
The plan: The two vacuum operated valves will be activated by their respective solenoid valve enabled/disabled using a output and the 3rd stage electrically operated port will be operated by another output (RPM & TPS/MAP) through a circuit I designed!
The really cool part about this project has been that swapping out the stock RX8 MT flywheel and front counterweight to the AT counterweights I had laying around sine my All Motor days so I could use the smaller size Racing Beat flywheel which in turn allowed me to bolt the engine up the stock 12A transmission. As you can see, I have an ACT Carbon-Kevlar clutch disc and pressure plate, a big jump from the original parts.
The next thing was to fabricate new engine mounts. I had several ways I could have done it but I think I came up with the easiest by fabricating them to use the stock engine mounts in their original location. That meant I didn't have to mess with the cross member and steering. The only thing was; would the hood fit as it is a "taller" engine? I would worry about that later and even thought I could have a Turbo II style hood scoop made. I spaced the oil pan 1/2" above the steering cross shaft and went to work. Here are the left and right hand site mounts.
Then came the rest of the stuff! Exhaust, Wiring harness, Fuel Pump & Regulator, Throttle Body modification, Oil Injection Modification. As for the exhaust, I elected to use a high flow cat and the stock pre- silencer which I connected to the "stock" rear muffler. I will change this later but for the tuning "experience, I wanted to keep it quiet and save time.
Oil Lines connected to the stock oil cooler requires custom fittings be fabricated, Custom Radiator Hoses, Electric Fan in front of the radiator
January 9, 2010: OK guys, progress has been made over the past couple
of weeks and I am please to tell you that I managed to "fire it up" last evening
in my closed shop. (Its freezing here in Texas. This was not as "simple" of a
project as I anticipated but the light is at the end of the tunnel!
January 17, 2010: I have to confess, this has been the most
frustrating engine to "tune" I have ever done. Not knowing anything about how
and when all the injectors and manifold valves operated or are staged in the
factory ECU has been the challenge. I literally have used up over a tank plus of
gasoline just in my shop with the car on the lift.
February 6, 2010: The transplant is almost complete. Working through tuning "issues" I have never done before has kept the pace down to a crawl before the car has been to the dyno. I can't even begin to tell you how sensitive this engine combination has been to tune from scratch. The corrections that have to be programmed are the kickers, battery voltage correction is HUGE, cold start, warm up, manifold air temperature, and acceleration having to use TPS and MAP corrections. Just to illustrate how sensitive, a mere 1/4 percent change in the VE (Fuel Map) table has a huge impact on AFR. Now try doing that for EVERY CELL of the 16 x 16 table?
I initially thought I would have to cut the hood and install a fiberglass Turbo II style hood scoop but fortunately, by cutting out just the internal hood bracing as you can see above, the hood closes with just enough room to clear the throttle body after trimming it as well. The radiator fan had to be installed in front of the radiator and "blow through" because there is not enough room as you can see. I will have to keep an eye on this when it warms up and the air conditioning is on as well. All in all, this has been a fun project and I have to say that after I have tuned the car on the dyno, it's going to be fun to drive. Even without the 3rd stage intake opening, it's a rocket compared to the 12A and it pick up is so much faster.
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