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dannobee dannobee is online now
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Join Date: Mar 2019
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Early 911/930 pedal box SCRS style with DBW and G50 clutch

I've been slowly making progress on my 930 update. The ECM/PCM work is nearly all complete, and I wanted to show one way of adapting an early 911/930 pedal box to Drive-by-wire, so that your modern ECM/PCM can give you modern features like traction control, cruise control, launch control, etc. I'm using a Link FuryX, but most modern ECM/PCM's can use the input from the APP Sensor to run an E-Throttle by just clicking a few times in the setup software.

It took quite a bit of perusing and scheming to find an Accelerator Pedal Position sensor that could easily adapt to the stock pedal box. Since I worked at dealerships for quite awhile, I wanted something that could be easily adapted and be at least stock appearing. I figured that since I was upgrading the brakes on my 930 anyway, and would be installing the G50/50, I could incorporate all of the changes in one fell swoop.

I ended up using an APP from a Nissan 350z (circa 03-09). I cut off the extension and enlarged the hole for a rod to connect the factory gas pedal link to the sensor.





I also changed from a single master cylinder to the SCRS style dual master cylinders with a balance bar. Since early 911/930's didn't have power brakes, the pedal always felt "heavy," and I feared the girlfriend wouldn't have enough leg strength to utilize all of the power of the brakes on track days, I changed the pedal ratio from 5.4 to 6.5. We'll see how that works out. "Do the math" on the caliper piston and master cylinder sizes to take it back to near factory brake balance if you choose to copy this setup. The stock brake light switch was reused and the original bracket was trimmed and welded in place. A large flat washer on the master cylinder rod actuates the switch, just like the factory setup.

Since I'm also upgrading the transmission to a G50/50 and a hydraulic clutch setup, another master cylinder was needed, along with finding a place to hang it, along with constructing a new clutch pedal to clear the master cylinder rod. Stock G50 pedal boxes locate the master cylinder right where the SCRS master cyliinders would go, so that option was out. I came up with this setup.







The whole setup fits neatly under the stock floorboard and carpet, and retains the factory pedals. The front to rear brake balance can be adjusted by either adding the dash mounted brake balance cable and knob, or by pulling up the carpet and floor board and manually adjusting the balance.

I've been busy with work, so time has been limited, but I hope to be making quite a bit more progress on my project in the next few months.
Old 04-14-2024, 10:14 AM
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