Difference between revisions of "Electronics"

Revision as of 19:29, 28 December 2011

Battery

Currently a stockish battery.

Bought a Mueller MotorWerks EVO2 12-cell battery (2.5 lbs) and charger. Eliminate the battery cable and run it in the engine bay.

What does the current battery weigh?

Likely choice:

• Braille B106: AGM, 6.9 lb, 10 Amp/Hr, 210 CCA, 527 PCA, http://www.amazon.com/Braille-Battery-B106-Lightweight-Racing/dp/B004DDI12O 140$+FS]
• B106 Mount: Aluminum, 55$+FS

Others:

• Mueller MotorWerks EVO2: Lithium, 3 lb, 28 Ah, 550CCA, 269$ -- Looks like potentially a really good option. How is it so cheap for so effective a LiIon battery? Something has to be fishy. Try to read up more on it...
• GRRReen 20Ah: Lithium, 7.25 lb, 20Ah, 330CCA, 289$

Ridiculously expensive but awesome:

• Braille ML9C: Li-Ion, 3.7 lb, 36 Amp/Hr, 612 PCA, 950$
• Braille ML14C: Li-Ion, 4.5 lb, 42 Amp/Hr, 773 PCA / 548 CA, 1250$
• Voltphreaks VPH300: Lithium, 2.75 lbs, 340 CA, 140 CCA, 7Ah, 789$
• Voltphreaks VPH450: Lithium, 3.75 lbs, 500 CA, 200 CCA, 9Ah, 929$
• Voltphreaks VPH750: Lithium, 5.5 lbs, 650 CA, 260 CCA, 16Ah, 1300$

NASIOC Battery Post with a bunch of other misc batteries.

Need to buy a trickle charger too.

Does it make sense to weigh the battery cable that runs along the PPF? With a tiny lightweight battery like this, it might make more weight sense to put the battery up nearer/in the engine bay and drop the 10 feet of thick copper cable. ST and SP both allow free relocation of the battery.

There's a rumor that the Deka ETX9 is the same battery as the Braille B106 (that the Braille is a rebadged Deka). The cranking specs are quite a bit different, but the ETX9 is ~55$ and the weight is the same. Some people on Miata.net have run them successfully, but I'm skeptical. Maybe start with the B106 and if it dies too quickly just get Dekas to replace them?

Engine Management

Originally I bought a MegasquirtPnP. It only supports batch fire injection and wasted spark ignition, and I'd eventually need to buy a KnockSenseMS board for knock control with it.

I then realized that I really wanted to control it with the crank angle sensor, and wanted sequential spark and fuel, and useful knock control. In the end, it made sense to upgrade to the AEM. So, I took the plunge.

There's a good SAE paper on the K series engines that describes the crank/cam angle sensor issue.

Traction Control/Launch Control

Picked up the Race Logic RLTC6AL from PDM Motorsports for 1100$ CAD. It will integrate with the existing electronics in minutes using Kyle's patch cable to avoid hacking up the main harness. Don's set it up on a bunch of cars so he'll be a good resource too. Apparently Strelniks runs the same system.

Wideband

Bought a Zeitronix Zt-3, the same thing I've been using with pretty good success on the KLiata. The MS3 seems to support it just fine.

DAQ/Instrument Panel

Buying an Evo4 + MyChron3 for now. It can read from the MegasquirtPnP (MS1) via RS232. It supports as much data as we want down the road -- can do 12 tire temp inputs, 4 shock pots @ 1000Hz, and our other analog pressure/temperature inputs.

Tire Temps

Opti-Grip seems like a surprisingly affordable package. Would need to figure out how to integrate it into existing datalogging, but it could be neat...

Wiring Harnesses

Front Harness

The front harness is different for ABS and/or CA injection. So, we're going to have to steal this from the 93 car. The front harness we want is NA37-67-010B (california w/ABS).

Non-engine stuff we can remove:

• Airbag - Totally done, saved 1.76 lbs
• Power mirrors (Weren't offered in 90 - options list)
• Radio/speakers

Has to stay:

• Power windows
• Cruise control

Rear Harness

The rear harness is different for ABS or not. If we get a car without ABS we'll have to swap this.

To Remove:

• Headrest speaker wiring

Dash Harness

Different for ABS or not. The harness we want is NA02-67-030N that has ABS wiring.

To Remove:

• Radio Wiring

Injection Harness

Sequential CA cars use a different injection harness: NA36-67-080. Steal it off the current car.