These are the configurations I've found you can have with the quick steer kit.

1. TCS/AH On: AH activates during normal turning dragging the outside brake.

2. Comp mode, TCS Off, AH On: Same as above.

3. TCS/AH Off: Should work normally but never tried it because I like to keep my "insurance" (TCS) turned on.

4. Unplug SWPS: TCS On, AH Off, CEL On, Magnasteer defaults to full boost. Steering way too sensitive, especially at highway and freeway speeds, with quick steer and full boost Magnasteer.

5. Unplug SWPS and Magnasteer: TCS On, AH Off, CEL On, Magnasteer defaults to medium boost (boost provided at roughly 45 mph). Steering still too sensitive at higher speeds.

I didn't like any of these options so I put the OEM spindles back on. I'll be listing my VetteNuts quick steer spindles in the FS section.

 

The goal of this thread, or at least my personal approach to it, is to overcome your item 1). If that occurred I'd be curious how/if your perception of the VetteNuts quick steer spindles would change.

 

If you could maintain the normal functionality of TCS, AH, and Magnasteer with no CEL I think it would be a good upgrade.

 

You're going to run into the same problem we have on M70 V12 equipped BMWs. These engines like the one in my 1993 850Ci have dual electronic throttle bodies with a few carbon resistor strips on a PCB inside that are used for super fine position control of the butterfly valve. On the M70 the traces wear through and stop feeding back position causing the car to go into limp home mode. New ones are possibly not even available anymore and are (were?) like $1500 each. I paid $600 to have mine goofed with so they would work again which is an incredibly precise and finnicky task.

The long term goal is hopefully someone can find a way to make similarly resistive strips in their garage. I'm an electrical engineer in the off highway equipment world and have been trying a few things myself at home but haven't had any luck yet. There are multiple challenges, coming up with a material that has the correct resistivity, a material that is durable to survive the constant swiping of the metal wiper and that can be deposited permanently on the original substrate. I am still on step 1 myself.

 

For older C5s (up to 2000 I believe) this is currently an issue due to discontinued SWPS. SWPS for '01+ is still available, and is where my posts are coming from since functioning SWPS is a non-issue. However I can envision building a replacement SWPS for the older C5s that doesn't use resistive tracks, and merely emulates that. Probably would primarily use an encoder and a microcontroller. FWIW I am a Mechanical Engineer who has dabbled a bit in Arduino and basic circuit design.

But for the sake of this thread, I'd like to see a solution to complement the existing SWPS on '01+ so that the SWPS doesn't have to be removed/replaced (assuming it's functional). In my mind many/most of quick-steer kits purchased for the C5 will go on a Z06, '01+ where SWPS availability is a non-issue (for now...).

 

Seems like you need to make an electronic converter box. To make an electronic converter it seems like you would need to obtain the steering wheel sensor output voltages vs front wheel angle as you turned the steering wheel from lock to lock. Then do the same with the kit installed and compare the voltages at each steering wheel position angle. You could then devise a micro controller or a circuit if it's linear, to do the steering wheel position conversion and report it to the PCM and EBCM if that's where the signal goes. This would probably take a good bit of instrumentation to accomplish and it would obviously have to be tested. The only caveat is what company would assume the liability for this mod. You would have to build your own.

 

Not sure if you read my prior posts, but that's pretty much exactly what I'm intending to do
Highly doubt the conversion will be linear. The plan is to map out steering angle vs steering wheel position, and correlate those so that the output from the converter device 100% matches what the EBCM expects.

 

Took pictures of '01+ SWPS disassembly last night:


side view showing my crude cut line (didn't know what I was doing when I started making the cut)


view showing the "teeth" and associated components that allow the inner part to grip the steering column shaft. note that in this picture the over-molded plastic had already been trimmed off the copper-colored part.




cap removed after cutting. note that the black sharpie marks were added after initial disassembly. they are there to demonstrate the "zero" position alignment (which would be achieved if the lock pin were installed)




these are the spring-loaded wipers which run along the resistive black carbon tracks






mapping out the circuit to the pins. note that these numbers don't represent connector pin numbers.


Correlating my numbered pins above to actual connector pin numbers: [(1) 1 gray +5V ] , [(2) 2 org/blk ground ] , [(3) 5 green phase A ] , [(4) 6 blue phase B ]

 

I think you'll find that is an encoder. It's been a while since I looked at it, but the actual GM service manuals give some functional info indicating that it the A and B are encoder signals. The earlier model was the same as that for wiring plus a potentiometer signal and there was talk about the voltage level from that potentiometer when the steering wheel was centered.

If you could get them apart easier and if you could make a new disk then that might fix it too.

Too bad its not an optical encoder.

 

Yeah you're right, it's not a potentiometer, but an incremental style of encoder. However, because it's such a simple resistive device, I'm inclined to call it a multi-pole (2 poles I think) 2-phase rotary potentiometer (if you consider that a typical pot is comprised of a round resistive track with a wiper).

Its two phases seem to cycle through 0-5v every 180 degrees of rotation (or something like that, which I got from this thread: https://www.corvetteforum.com/forums...post1554526132 )

I'm curious to see what a plot of phase A & B output voltages vs rotation angle would look like, i.e. sine wave?
Ultimately this data/plot would be one of the primary inputs into the converter device, and the converter would effectively shorten the period of 0-5v cycle. What I don't expect is that the "cycle shortening" will be a linear relationship, but progressive due to non-linearities of changing the toe link mount location while using a quick-steer kit.

And for that same reason, a new resistive-track disc might not be an ideal solution. In my mind a software solution would be preferable especially when considering all of the different quick-steer kits/solutions out there also to include adjustability among those kits (i.e. both the Mini Mantis and SLR Speed kits offer multiple adjustment positions). Using software would make it a quick change to accommodate different kits vs a physical disk which might work for one kit/one adjustment position.

 

Ya, thinking more a disk wouldn't work because it would have to include a little over 1 rotation which means there would be a discontinuity when it ended.

A converter box should be a possibility. I'm thinking digital potentiometers might work for the outputs if a voltage as the output isn't liked by the EBTC module.

 

This may be a stumbling point, no doubt. I don't know how the module senses voltage / interacts with the SWPS output. i.e. high-kOhm pullup or voltage divider resistor? My current thoughts on determining that:

• disconnect SWPS connector, and measure resistance on vehicle harness between phase A & B and ground
  • make an educated guess for how the EBCM senses SWPS output
• measure phase A & B voltages against ground on my car while moving the steering wheel, and compare to voltage readings reported by Tech 2
• feed a variable 0-5v signal to phase A & B and compare that voltage to the voltage reported by the Tech 2
  • with any luck the voltages will match, or have an obvious offset, and then this simple approach can be used as the converter's output

A digital potentiometer looks like a possible solution as well. I'm seeing that most [low cost] digital pots are 8-bit except for a 10-bit 10kOhm I also found (10kOhm is probably too high). However, a cheap 12-bit DAC is easy to come by and they're <$5. Not sure how much sensitivity is required by the EBCM but more is likely better.

I bought a SWPS wire harness to make probing the SWPS less of a hassle. It's kind of expensive but worthwhile for me: https://www.ebay.com/itm/293702998454

EDIT: Here's a proposed schematic of the converter device which uses 2x 12-bit DACs. This of course assumes that the EBCM can be fed voltage signals. https://photos.app.goo.gl/Vf9d6u2aRM9XYqMx9

Currently working on Arduino code to interface the two 12-bit DACs, read SWPS voltage, output voltage to EBCM, and check for fault conditions. Also have some groundwork laid for the signal manipulation that will take place with a quick-steer kit.

While I'm planning to go with a FDF Mini Mantis kit, there's no reason this device can't also accommodate SLR Speed, VetteNuts, etc. kits. It may be an option to have others take angle measurements on their car with a particular kit installed and send me that data.
Here's an example of how FDF measures steering angle:

 

Making some progress. For the converter device I have a breadboard put together and more than 300 lines of Arduino code written. There's lots more to go but it's feeling promising.

I wrote a separate set of Arduino code that will make the converter device a pass-through, enabling me to "sniff" the SWPS signal and feed a simple voltage signal back to the car. This will allow me to correlate steering wheel angle to SWPS output signal, and then also correlate SWPS output signal to wheel angle. As well, I can correlate the device's voltage signal to the EBCM's interpretation of it (via Tech 2).

For Android phones there's a neat app that can measure angle in [any] 2D plane. It should be as easy as centering the steering wheel and taping my phone to it, zeroing out the app, and collecting the data I mentioned above. I'm also envisioning taping my phone to a couple wheel lugs to measure wheel angle. Should be a lot less hassle than the method shown in FDF's video in my prior post.

Lastly, yesterday morning I reached out to Drift HQ and inquired about potential Black Friday pricing on the FDF Mini Mantis angle kit. Supposedly they will get back to me with a quote. Otherwise, they still have the best pricing when you use coupon code MISFIT5 at checkout.
https://www.drifthq.com/products/fdf...40091215659055

 

Some good news, and finally a picture to go with my rambling.

First off, Drift HQ has Black Friday pricing on the FDF Mini Mantis kit. Pretty good sale price: $335 + shipping, no tax. Normally it's $372 + shipping. I was also able to use coupon code KENNYSLIDES for another 5% off. Came to $351 shipped for me. This is the best price I've been able to find anywhere. Also, they ended up upgrading me to the powdercoated "FDF Silver" color for free! (I ordered "Raw" to save $20).



What are we looking at?

• Arduino breadboard with my spare/chopped up '01-'04 SWPS hooked up
• The SWPS is "centered" (same position as if the installation pin was still intact)
• The left display is reading SWPS voltage in 10-bit format:
  • 0=0V, 1023=4.5V (normally would be 5V, but my power source only did 4.5V)
  • At center position, Phase A normally reads ~2.5V, which correlates to 511 in 10-bit format. Phase B reads 0=0V.
• The right [voltmeter] display is showing the Arduino/DAC's output of Phase A.
  • Phase A output should match Phase A input with my current set of code. And guess what - IT DOES! (keeping in mind my source voltage is only 4.5V... 510 / 1023 * 4.5 = 2.243 V)

Preliminary mapping of SWPS voltage and SWPS rotation angle using the bench setup:​​​

It looks like it's just a "saw tooth" linear relationship, with A/B out of phase, which should make manipulating the signal very straightforward. I'll do it more detailed on my car as mentioned previously, but this is a good baseline.

Lastly I took measurements from the car's connector that plugs into SWPS:

• Ignition off:
  • Phase A & B resistance to ground: 200kOhm (each)
  • 5V to GND impedance: 7.32kOhm (this doesn't really mean anything, but I was curious)
• Ignition on:
  • 5V to ground voltage (ignition on): 5.02V
  • 5V to Phase A & B voltage (connector unplugged from sensor): 4.92V (each)
  • Phase A & B voltage to GND (connector unplugged from sensor): 0V (each)

As well, I'm finding that the steering wheel rotates roughly up to 450 degrees in each direction (slightly more). This is how that plot looks theoretically with regards to SWPS voltage:

With an angle kit installed, the effective maximum SWPS rotation angle will be quite a bit more than 450 degrees... the amount is still TBD (until I install the angle kit) but fingers crossed the EBCM will be able to interpret >> 450 degrees. That said, there's a good chance I will add in some steering rack travel limiters as I anticipate the total steering angle / turning radius will be more than I want/need at full lock.

 

This is a really interesting thing that you are doing. It's a little confusing to me as to what you are actually doing with the Ardrino and what the results mean. Can you describe in more detail what your software is doing and how you are converting the pulses to steering wheel angle.

 

In my last post the Arduino isn't doing a whole lot ultimately, it's just measuring voltages of the green and blue wires (phases A & B respectively) from the SWPS. The numbers shown are a representation of voltages, where 0=0% voltage (0v) and 1023=100% voltage (5v). The 510 shown on Phase A = 50% voltage (2.5V). As shown in the graphs, the SWPS output voltages cycle through 0-100% in a sawtooth pattern.

Your last question is a representation of the "hard part" of this project: coming up with a strategy to translate the cyclical sawtooth voltage patterns into a usable steering wheel angle measurement. There are surely many ways to go about this! I don't have a ton of experience in processing similar signals but I did come up with a very functional method yesterday
At this point I'm not ready to share the nitty-gritty details on this strategy. BUT I did take a video of it in action last night.

Some info on what is shown in the video:

• Using the same '01-'04 SWPS shown previously. Initially it is centered.
• On the screen:
  • top left is Phase A voltage (just as before)
  • top right is Phase B voltage
  • bottom shows calculated steering wheel (SW) angle
• It's set up to report up to +/- 540 degrees of rotation. This is plenty to handle the stock steering rack travel of ~+/- 450 degrees.

There's still more work to do, but I believe this is a successful proof-of-concept.

I've also developed a strategy for taking SW angle and outputting that back into Phase A & B voltages as the car expects to see. Still have to write that code but it will be quick. This will tie in to verifying the car will properly read any 0-5v signals I feed it for Phase A/B.

 

You're doing impressive work so far.

 

Keep it up

 

Some people have trouble with the active handling system when they accidentally turn the wheel 360 degrees when they do a balancer replacement. Looking at how the signal just repeates itself, how does the active handling system know if the steering wheel has been rotated 360 degrees. Is there some kind of index signal that you are not showing?

 

The car learns what "straight ahead" looks like every time you start the car. It looks for the wheel speeds to correlate with what going straight looks like aka equal left to right at front and back and checks what the SWPS says and calls that "straight" if you ever started the car then maneuvered around a parking lot or something steering a lot and the car said "ACTIVE HANDLING WARMING UP" thats the car saying the system isnt ready yet because it didnt learn what straight is yet.