| Home > RX-7 > Tech/Mods > Modifications > Turbo NA Guide > Startup, Driving Impressions, Future Plans | 
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| Home > RX-7 > Tech/Mods > Modifications > Turbo NA Guide > Startup, Driving Impressions, Future Plans |
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The day after the install was complete, the car was started. The first thing I did was to walk around the engine bay a few times to look for anything obviously wrong. Finding nothing, I then filled the engine with oil and coolant while checking for leaks. Somewhat surprisingly, there were none. After that it was another check, and the battery was installed.
Before the car was started, the S-AFC needed to be set up. Turning the key to "run" allowed the S-AFC to operate without first starting the engine. I set up the air-flow meter type, TPS settings, NE (fuel/RPM correction points), throttle point, etc. in about 5 minutes. There were no initial corrections set for the first startup, so the car would be running extremely rich on 4 TII injectors and an FD fuel pump.
Because the oil had been drained completely from the block, I removed the EGI (fuel injection) fuse and cranked the engine until it registered some oil pressure. I was not too worried about the rotor chambers since I had very generously fogged the engine with a heavy fogging oil prior to storage.
It was now time to prime the fuel system. The yellow "test" jumper on the passenger shock tower was jumpered, and the ignition key turned to "run". This forces the fuel pump to run until the key is removed. It allows testing for leaks and priming of the fuel system. Speaking of leaks, I momentarily panicked when I heard a loud hissing coming from the engine compartment. With the fuel pump still running, I looked over the engine but could find no evidence of leaks. It seems that the sound was simply the air being bled through the system. The key was then removed, and the jumper disconnected to allow normal operation.
The moment of truth arrived, and I turned the key. After a few seconds, the engine came to life and promptly spewed an enormous cloud of black and blue smoke due to the fogging oil used. The car was then immediately shut off to check for leaks. Once I was satisfied there weren't any, I started it up again and let it run longer and begin to warm up. It was a little rough because of the rich fuel mixture, but otherwise ran fine. After a few minutes of running, when no leaks were found, the car was again turned off. At that point I left it, not willing to push my luck for the day. However, the next day I drove it to work and started entering corrections into the S-AFC for some rough tuning.
There are three videos of the initial startup posted to the RX-7 forum. You will need the Real Player to view them. Most computers already have this installed, but if you do not, just click on the link and download the free player.
Most of this is pretty subjective, since I don't yet have any dyno results or other numbers.
After driving around for a few days, carefully checking the engine for leaks and entering corrections in the S-AFC, I began to boost the car. Up until 3 PSI there was no addition of fuel required (according to an Autometer Air/Fuel gauge) but after that I began adding fuel after 3000 RPM. To show you the corrections I am using on the S-AFC would be pretty useless, but I will say that I needed to lean it out below 3K, lean at 3.5K, then start getting progressively richer at 4K. This is of course under the "high" throttle map. Under the "low" throttle map, everything is as lean as possible up until 4K, at which point I add a few percent fuel for a safety margin. Eventually I plan to get to a dyno to properly tune the car.
The car is quite fast. I have run 10+ PSI, which (unofficially) puts the car comfortably into the 12s in the 1/4 mile. Normal boost is around 8 PSI, and the engine showed no signs of being stressed. There were a few moments where tuning mistakes on my part caused detonation, but no damage was caused. As of 2002, the car was still running stock timing, but that will change (see below). I can say that I am very happy with the results of this project, and the car was a blast to drive. As expected, I did not blow the engine as the nay sayers would have liked, and frankly, had very few problems related to the turbo system.
As for the drivetrain, it held up fine. I killed two transmissions, but that was due to lack of oil and not because they were too weak to handle the power (as many would lead you to believe).
As of Dec, 2003, the car has been living in my garage. I decided that I wanted a little bit more in the way of power, so over the winter I pulled the engine with the idea to rebuild and port it firmly in my head. Since then, the project has ballooned into much more. The engine will be reassembled after being bridgeported, and put into a freshly painted engine bay. A Microtech LT-8 EMS system will run it, and a full 3" exhaust will provide the airflow necessary for the upgraded turbo. Currently, I have not decided on exactly which turbo to run, but I am leaning heavily towards the hybridizing it into a T3/T4.
In addition to the engine work, the interior is being restored, engine bay painted, transmission rebuilt. Basically, every system in the car is being looked over and serviced as necessary.