Out of curiosity, what made you go with the Mini Mantis kit over SLR's?

 

Few reasons:

• Cheaper... I paid $351 on Black Friday (granted I don't know what the SLR kit cost then). Although the SLR kit does include inner tie rod so that's a little extra value.
• From what I've seen, the SLR Speed kit requires the original toe link arm to be removed. Supposedly it can stay in place with careful grinding, but between a couple videos and at least one person's forum post they all cut the arm off.
  • This makes the SLR kit install non-reversible. The Mini Mantis kit requires only a little grinding under the arm, but it would still be reversible.
• 2 steering angle positions. I suspect the Mini Mantis outer hole might be less aggressive than the SLR, and that's what I want.

 

Agreed on all points. I would be seeking increased steering sensitivity and range, but not so far as a drifter ratio.

 

It's been a little while... managed to complete the steering rack DIY-rebuild a few days ago, and so far in the garage with engine running there haven't been any detectable leaks when steering from lock-to-lock.
It wasn't a quick process considering: 1) nobody else has documented C5 rack disassembly so I went in somewhat blind; 2) I documented the process along the way. But it was still 2+ weeks quicker than if I had waited for any company to rebuild or provide a remanufactured rack.

I just dialed in the passenger-side toe adjustment and verified the driver-side, have the car on the ground, and flashed the latest code (which was from almost 4 weeks ago, and includes the Mini Mantis conversion factor). Just need to GO FOR A DRIVE!!
Needless to say I'm really excited to see what the steering is like.

Later on I'll evaluate if the steering rack will need spacers added to limit travel (due to contact between wheels and lower control arms) and/or material removal.

 

To add to the fun, apparently WiseFab has joined the market for quick steer kits on C5s now. Theh are shilping direct from the manufacturer with a 2 to 3 week delivery time expected.
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Woah that's quite the kit. Little rich for my blood, though! https://usa.wisefab.com/chevrolet-co...t-for-oem-arms

 

After getting a little seat time I have some comments/thoughts:

• Steering is certainly quicker. Because my Z06 was down for a while, I didn't have a quick back-to-back comparison of pre-vs-post angle kit install. BUT one cool thing I realized last night is that I can make right-hand turns comfortably with only one hand! Also because the C5's factory steering is SO slow, the modified steering rate just feels more normal like other cars. That's a good thing
  Steering effort has increased a little as expected, but it's far from excessive IMO.
• Turning radius feels much improved [as expected]. It's odd to say, but I'm still acclimating to this aspect... I was very much in-tune with the crappy stock turning radius.
• There is definitely rubbing between the lower control arm and wheel. Sooner than later I'll have to address this, probably with a small rack spacer and mild grinding of the LCA.
  
• One of the first things I did for a test drive was driving in circles in a parking lot, during which I was paid attention to turning radius and rub. It triggered an AH/SWPS fault code on the DIC. However, I've driven ~17 miles since then (been iteratively adjusting front toe) and so far the DIC hasn't reported any AH faults.
  
• Going back to post #98, I've realized a dumb error on my part. When I set up the data for wheel steering angle vs steering wheel rotation angle, it was ONLY for a single wheel (driver-side). Because I did this, my code outputs a different angle value for turning right vs left... whereas in reality if you turn the steering wheel 90 degrees left, the output wheel angle should be the equal but opposite as when the steering wheel is turned 90 degrees right.
  • So what I think I need to do is take the equations used to generate chart #2 in post 98 and develop "average" equations for right/left for both stock and Mini Mantis.
  • Wondering if this error helped trigger the afore-mentioned AH fault code.
    
• My current code requires the steering wheel to be within ~135 degrees rotation from center when the EBCM turns on / device powers up, otherwise it may mis-detect what center is (and be 360 degrees off).
  • I'm going to start working on some additional code that will "auto detect" a condition where the device has improperly determined center. Should be pretty simple: if it detects SW angle greater than, say, +/- 500 degrees (where ~ +/- 460 degrees is the expected maximum travel), then it will shift the whole SW angle range by 360 degrees... and hopefully become centered with the SW.

 

Some continuing updates:

Based on the picture of SLR Speed's rack limiter spacers, I designed my own and 3D printed them out of a polycarbonate material (has great strength/toughness and heat resistance). I measured the size of the rack spacer to be 24mm I.D. (steering rack rod diameter) x ~38.5-39mm O.D. (approx diameter of inner tie rod). They snap over/onto the steering rack rod just like the SLR Speed ones. I plan to upload the design to Thingiverse so that others can also print them.

And now with a 5mm thick spacer + mild grinding to the LCA, there's no contact. Obviously I lost a little steering angle but the turning radius is still about 8% tighter than stock.

After more driving, it's been going great and no issues to report as far as the EBCM is concerned.
Also I thought it was neat that the car handled a tight drive-through yesterday, which prior to the angle kit I would have sweated making it without a multi-point turn.

Made some good progress on this part of the code. It went just as described. Also managed to incorporate an error detection section of code into this, where an error code will be thrown if an excessive SWPS angle is detected after this centering happens.

 

How does the altered radius affect wheel fitment and tire width vs contact or rub with any surface with your current backspacing?

This adds a whole new dimension to tire selection.

Oddly, I run larger tires off season with C5Z 18s up front sporting 285/35r18 vs my CCWs which run 275/35r19 to match their 305/30r19 rear sidewall widths. I am against the GM techs deciding to put larger sidewalls on the front end of the car vs the rear, lol.

 

I think the quick answer is: it depends on many things including wheels/size/offset, tires/size, specific angle kit used, and how much angle you want to achieve. For reference my 2001 Z06 has stock Alcoa wheels, currently running 255/40/17 up front.

Some ideas/example:

• Guys who run wider tires on their C5s actually have to limit stock steering angle because otherwise their tires will contact the front brake cooling ducts. Of course they can instead remove those... https://www.corvetteforum.com/forums...ers-stops.html
• Lower control arms are a contact point for stock 17s because of the boss for the sway bar mount.
• Upper control arms could be the next wheel/tire contact point.
• As you've pointed out, other companies make different control arms with more clearance to overcome those obstacles.

 

I finally got around to comparing install for the slr and mini mantis. Pro to the mantis, you dont murder the knuckle like Beezy had to. Or has slr updated their design to avoid this? Pro to the slr, you don't have to space the hub (and wheels, and calipers) by 5mm and risk sticking them out.

I am trying NOT to spend more money on the car right now, but with the suspension fully removed now is a very easy time to get the work done and only have to spend on the alignment once. So I am tempted by the steering kits. Soooo tempted.

Why does it ring in my head that slr doesn't need the knuckles ground anymore? Is that wrong? Tryong to avoid that since I just put C6 knuckles up front and id like to be able to reverse the mod in the future if I wanted to.
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I'm up to about 220 daily-driven miles on the Mini Mantis kit with my SWPS converter device. So far it's worked exactly as I expected.

And I gotta say, my C5Z really is better to drive right now. Steering rate/speed feels "normal", not slow like stock, and not too fast either. Steering effort is still perfectly acceptable. AND THE DARN THING HAS A REASONABLE TURNING RADIUS! With the kit I've managed to take a point off some of my usual multi-point turns. Also U-turns and general parking lot driving are less panic-inducing because it's less likely I will need to make an unexpected multi-point turn.

Only one issue to report: As mentioned previously I added some lines of code that would attempt to detect a condition where the steering wheel is beyond 180 degrees off-center at the start of a drive cycle, and then correct it by shifting the whole range SWPS range by 360deg. The initial trial kind of didn't work well and it ended up triggering an Active Handling fault on the DIC, but since then I revised my code so it should work... though I haven't gotten a chance to test it.

Also, I'm still gradually plugging away on the custom ash tray design, currently building up the circuit board. Perhaps some pictures will be in order soon.

Lastly, I'm going to take the torque tube out again, see if I maybe messed something up when I had everything apart 2 years ago (clutch/FW, TT rebuild, trans rebuild, LSD rebuild, etc.). This may slow my progress on the ash tray design... but in the mean time I'd like to solicit you guys to find out who all might be interested in a "test" unit of my SWPS converter device.

All good points. For me the 5mm track width increase (per side) from the Mini Mantis is a non-issue because of using stock C5Z wheels. Also spacing out the wheels 5mm helps a tad with increasing steering angle.

I hadn't heard about any revision to the SLR kit that allows you to keep the steering arm, but in general I haven't really heard anything about the SLR kit lately. Still all the videos/writeups I came across on it show the arm getting cut off. Maybe reach out to SLR?

 

I just placed an order for a mini mantis kit. Between product lead time and shipping it will be a while before I see them.

I'd step in gladly as a guinea pig, but I can't guarantee when this project finishes. And I will also have a ton of new systems and issues to chase down once it starts rolling. But as soon as it is steady on its feet I'll be able and eager to play with a box. Probably have to give it enough line to mount in the dash or glovebox and pull it out when adjustments or inputs are needed. I guarantee it won't fit in an ashtray for me... As I have no ashtray. DD Mods double din dash with trio of gauges across the top and hvac dead bottom.

 

Awesome!
So I've been thinking about your situation, here's my take: it makes sense you would want to flush out your car (when it's drivable again) before adding in another electronical device. But I also get the impression you would intend to install the kit prior to reassembling the car. My recommendation would be to put the Mini Mantis tie rod in the stock location, because otherwise it could trigger an Active Handling fault (which is the reasoning behind this whole thread). Then when you get the car flushed out, you can swap to an inner position on the Mini Mantis kit and install the SWPS converter device. Of course you would also need to get toe aligned again... but this might be cheaper than a full alignment. (or you can do a DIY toe alignment like I did)

 

Was it so difficult to attach the tie rod end?

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The normal way of attaching the tie rod end to the Mini Mantis kit is covered in their videos. However, if you use the full Mini Mantis kit (including tie rod end) and put the tie rod end to the stock position, in one of their videos they talk about the need for a really long bolt, a big thick washer, and a locknut. The bolt needs to be grade 12.9, and it should be long enough to accommodate the tie rod end + knuckle + washer + nut. I don't think their video says what length to use, but they might have mentioned the diameter. Might be a M12. Just to clarify, you can't use a stock tie rod end in the stock location with Mini Mantis kit.

 

OH. I see how you mean it now. Install the kit and run it in the oem setting temporarily.

I don't know that I trust running it that way with the bolt securing down over an open area like that.

I was thinking it would be cool if they sold said tie rod bolt to fit the oem knuckle and have sufficient thread at both ends to positively secure the tie rod.

 

This arrangement is called "single shear" in terms of bolt loading. The normal Mini Mantis method for securing the tie rod end is "double shear" because the bolt is captured in 2 locations. Single shear is definitely inferior, but it might still be okay with a 12.9 bolt. Especially if only temporary.

McMaster-Carr is your friend

 

Yes, if I knew how to specify the dimensions needed for said angled bolt.

I've got the kit sitting on the shelf and just took in some fancy bolts and nord lock washers for the hubs in place of the gm bolts. When the heat wave washes away I'll be sneaking back out there to get more done on the car. I'm trying to get it on the wheels for mid August.

 

Dang, been a while since my last real update. But I've been swamped with other work on my C5Z plus all the other usual life stuff. The SWPS manipulator device hasn't given me any [noticeable] hiccups and it's been 740 miles.

Just want to touch on this...
A month or 2 ago I had nearly finished hand-building a prototype circuit board but lost steam on that.
Recently I discovered I could learn PCB design, and did. So I applied that to a PCB design for the SWPS Manipulator, and now have 5 boards of "v1.0" ordered!
PCB design was very motivating to me (I'm a Mechanical Design Engineer) mostly because it will substantially reduce the amount of time it takes to build up the device. I was really dreading hand-building multiple circuit boards for others who might be interested... not to mention a proper PCB ought to provide improved quality & reliability (very important for a safety-related system).

Here's the v1.0 PCB:



This has also pushed me a bit on continuing the ash tray design. I realize that some like @Tusc aren't able to use a stock ash tray location so I'm contemplating other generic solutions. i.e. the LCD screen isn't really needed once the angle kit is selected and "center" is calibrated, so maybe the LCD can be disconnected and then then circuit board can be secured somewhere behind the center console or dash.