electro-hydraulic steering

[hoveringuy]

Looks like a good solution, except for the pricetag. Ouch!

A single day at the track is pushing $400. I need to become an instructor ASAP!!

[hoveringuy]

First drive impressions. with the pump turned to full-on the steering is massively overboosted and it feels like a Cadillac. With the boost turned to minimum there is a bit of weight in the steering. I had it at about 15% above minimum and it felt great.

I barely heard the pump in the trunk and it's presently near the seat bulkhead, and I don't have a seat installed. When it's in the battery box it will be completely silent.

Once i had the correct setting it was completely transparent and I couldn't tell that my steering had changed.

To do: Sadly, my rear sway bar end link interferes with where I put the bulkhead AN fittings through the trunk floor. My sway bar was literally pounding on the fitting so I got a tiny leak and need to replace the 90. The interference just didn't occur to me with the car on the jacks, but packaging is tight! In the short term I've removed the rear sway which doesn't do much for me anyway and I'll re-locate where the lines pop-up into the trunk some day in the future.

The pump is on a temporary magnetic base for now and I need to mount it in the battery box. I will do this in conjunction with an AntiGravity LiPo battery.

Finally, I've duplicated the Arduino code that makes the pump variable boost through the CAN commands, I'm going to add a speed-sensitive input tied to Vss that will taper the boost to minimum above 10mph and it will be about perfect!

[Donkeyshins]

I briefly mentioned this in the Mk60 post, but when I ran the independent rear brake lines I also ran the 3/8 AN6 tubing for a trunk mounted pump unit (highlighted red). My motivation is that even though I mostly got the PS temps under control at the track and it feels great, 275F is still pretty warm and it will decrease my rack life and it still likes to vent. Plus, having just the alternator as my only belt-driven accessory is glorious! Also, 2hp! (or 5... depending on who you ask)

The front is literally just two hoses that connect the tubing to the rack. So clean!

Still working on the final configuration for the rear, but the AN6 bulkhead fittings pop-up in the corner of the trunk giving me lot of flexibility. I had though of just mounting the pump in the back of the trunk, and I could, but I think I'll take the opportunity to relocated the battery back there (going to an Optima 35 at the same time to save 8lbs...).

I'll have a combination of hardlines and softlines to put the pump in the battery tray. I'll mount it vertically at first, using the stock battery tray, and eventually make it horizontal so it will sit under a cover. (The Mazda pumps work really good for this because they have remote reservoirs) Pictured is a Volvo pump.

I've already got the speed controller circuitry figured-out and it's just a $20 Arduino board that I will upgrade to also respond to Vss.

All of my old front PS stuff, including Chase Base reservoir, pump and brackets weighed like 12lbs, the pump weighs about 15lbs.

This is all un-doable so if it sucks I'll let you know...

Lookin' good! When it gets all sorted, I'd love to see its final form!

[moatilliatta]

Maybe even quieter mounted with lord mounts.

Glad to hear you got the assist level you’re looking for. Exciting stuff!

[hoveringuy]

I've got a new aluminum tray out for fabrication, may take a few revisions to get it right

Did a much longer freeway drive and it was absolutely fine. (which also gave me the opportunity to hammer the Mk60 ABS and I like it more all the time!)

[hoveringuy]

Maybe one more itiration to go, need to slide the pump 30mm for more hose clearance, tray can be slightly bigger, flanges a little taller because there's a giant hole in the middle...

[cutsham]

Not sure if this would work or not, but in other forums I've seen the electric power steering unit out of a prius used for many projects pretty easily. Can be had fairly cheap, and eliminates all this hydro work.

[hoveringuy]

Not sure if this would work or not, but in other forums I've seen the electric power steering unit out of a prius used for many projects pretty easily. Can be had fairly cheap, and eliminates all this hydro work.

yeah, between Prius and some of the ready-made e30 kits that's an option, this just seems "safer" because there won't be any change in how the hydraulic rack feels.

I would love to see some feedback, particularly from track use, of the pure-electric assist systems. I mean, the Porsche Cup cars use this and they could use any system they want... (but I'm also not Walter Röhrl)