Power steering state of the art
 

OK long story short I have made my LS swapped, heavily track prepped Miata, legal again for road use. Because Texas.

I am using 275 tires on the street so I want to add back the power steering. Don't try to convince me I do not need to... that topic has been beaten to death.

From what I have seen the preferred setups are either:
1. GM LS Camaro PS pump, lines adapted to a Miata rack, and a PS cooler. Options are an underdrive pulley and/or an adjustable bypass valve to reduce the level of assist as desired.
2. An electric PS conversion as documented here and elsewhere. I would probably DIY this as I have the equipment and skills. I need to do a little more research however.

So, for those racing, autocrossing, whatever l would like to know if you have anything to add to the above or suggest before I get started. The car is not going back to just street duty but may still be used on the track. Basically it's a race car with plates.

Thanks in advance

I haven't added PS back to my car, but when I do it'll be an EPS setup. I've had folks with the setup tell me it's great, so no first hand experience, but for my car that is also a track car I like the idea of not having to deal with the additional belt, fluids, lines, etc. for a hydro setup. Plus PS fluid is super flammable.

+1

I'm working on running a Volvo electric pump with the stock NB rack.
The MaxxECU can control it via CAN, so you can set the assist to whatever you want or add axes (like vs vehicle speed).

https://www.maxxecu.com/webhelp/can_...rsteering.html

From mockup, I think I can fit the pump behind the left headlight and still keep the fender liner. The fill cap will fit up through the stock hole already behind the headlight in the engine bay. It also keeps it mostly out of the engine bay and the lines are still short vs the trunk or somewhere else.

Currently on hold due to cross country move.

I've looked into the EPS conversions, but the feel is pretty lousy. The GM/Prius/whatever column-mounted EPS units were quite numb from the factory, then you remove all the sensors and CAN communication, so the unit is operating in a failsafe mode mostly blind. Even just decreasing the assist, doesn't really add any feedback; just makes it heavier. The only decent feeling EPS setup's I've ever felt were rack mounted.

I did the Camaro pump in my car, although I have the little brother to the LS in mine (V6 LFX). It was a pretty easy install, quick, and relatively speaking cheap. You will definitely want to install a restrictor valve (I'm guessing that is what you mean by adjustable bypass valve although my valve isn't adjustable in any way). I originally installed with the stock camaro valve and the power steering was very over-boosted. Besides burping fluid on the very first track day, (I was a bit over filled) I haven't had any issues with fluid temp (although I am not measuring it, so take that with a grain of salt) and I'm only using the metal line "cooler" that the Miata came with originally. (I do have a proper cooler, I just haven't installed since I haven't had issues and other items have been higher priority.) I'm running 245s 200 tread-ware tires with racing alignment in the middle of summer in Atlanta area like this for the past two years. I'm also using redline power steering fluid (less foaming / handles heat better, etc.)

Link to my PS install: https://www.miataturbo.net/build-thr...9/#post1617949 (nothing exciting here, but incase you wanted to see what I did)
Link to where I bought my restricter valve: https://turnonesteering.com/products...ring-fittings/ (you want to get the smallest flow rate 1.3 GPM) I'm using the cadilac cts-v toyoda one, but you will want to choose for your pump.

I've been very happy with this setup. Good Luck

Good post, thanks. On the valve seems like I had read that one can install an adjustable valve to shunt the high side to the low side to adjust pressure. Works like an adjustable FPR. At any rate your specific resteictor recommendation is helpful thanks.

On the lack of EPS steering feel comment, that is not something I have read yet. I'll have to look into that more.

I have the epowersterring.com setup on my car. I like it. I can dial in the amount of assist that suits me. I was a manual steering guy on my autocross cars until I started running 275 A7’s. I am sensitive to the numb feeling power steering has in the feedback. In brakes also, I run manual brakes. I do not feel the numb feeling with the eps.

Interesting. I had read that feedback was better with hydraulic vs EPS due to the inertia of the electric motor.

RDB138, in your PS installation thread you show the Russel part number that goes on the GM PS pump. What I could not figure out is what the adapter fitting is for the steering rack end of the high pressure line. Could you elaborate?

Thanks

@ZX-Tex (fyi, if you put the @ sign in front of someone's name they get a notification)

If you go the restrictor route, you may not need the fitting I gave the Russel part number on. (and that part number might not work on your power steering pump, since I think the LS uses a few different pumps.) The fitting goes into the GM restrictor valve

The arrow points to the restrictor valve (BTW, if memory serves, mine required a very large bar and eating my Wheaties that morning to get off)
https://cimg4.ibsrv.net/gimg/www.mia...c166136b9.jpeg

The reduced restrictor valve that takes care of the overboost that I bought has a -6an at the end of it. So the Russel fitting wasn't needed. (sorry picture isn't the best...it's the black piece)
https://cimg4.ibsrv.net/gimg/www.mia...8e4fe907d.jpeg

As far as the connector at the NB Steering Rack, that came with the hose I got from V8R when I bought the Power Steering Kit thinking I needed all of the other hoses and stuff he shows in the picture. All you get is that one hose and the two fittings (and one of those fittings didn't work for me...you can see it in the picture above) So I don't know the exact part numbers.

That said, I'm 99% sure it's a -6an line on the side that connects to the power steering hose and a M14 x 1.5 on the end that connects to the power steering rack. This was the first one that showed up on the Summit website, I'm sure they have cheaper versions. I would use a crush washer on the steering rack side with it.
https://cimg1.ibsrv.net/gimg/www.mia...76a3e9ca1.jpeg

Hope this helps.

@rdb138 Let me see if I can summarize correctly
- For the high pressure side of the NB steering rack you believe that a -6AN to M14 x 1.5 fitting is what is required, along with a, presumably, crush washer like those used on banjo fittings.
- For the high pressure side of the GM pump you used a -6AN 1.3 GPM restrictor fitting you purchased from this company https://turnonesteering.com/products...ring-fittings/. Question, was there a particular reason for using the extended fitting?

On a related note, I saw some discussion on whether or not the NB Miata high pressure inlet fitting was a M14 or a M16. Short answer here is to check the rack before buying the fitting.

A high pressure (hydraulic) line with -6AN fittings on both ends makes the high pressure side connection (pump to rack). For me, no FAFO on this, and a proper hydraulic line and fittings should be used. I'll have this made at a local hydraulic hose shop.

For the low pressure side, which is vented to atmosphere at the pump tank, a good hose setup will do the trick, along with an overkill sized PS fluid cooler, because of wide tires and racing. Incidentally a friend LS swapped an E36 which had power steering. He autocrossed the car and had a hell of a time with overheating PS fluid until he added a substantial finned cooler. So even though it is 'just' the low pressure side, I would use good hydraulic hoses and good connections, mostly for thermal durability.

Yes, this is what worked for me. & Yes a copper crush washer like you would use for banjo fittings. As far as the extended fitting, I don't exactly remember why I choose it. Would guess because it was the only one they offered or was in stock at that time. It looks kind of too long/ funny at first.


Definitely check, but the M16 is for the low pressure side on my rack.

I agree with you. My hose is 10" long and you could easily buy a premade one from Summit / Jegs vs going to hydraulic hose shop if easier.

I haven't had any issues running six 20-25 minute sessions in the summer here in Atlanta on 200 treadware 245's, but I also planned / purchased items to put a proper cooler in. I was just going to use rubber hose for the low pressure side of this, but you can easily use -6an here too, although I would have to buy a different reservoir since the Chevy one is plastic and "requires" a rubber line. Here are the parts I already researched / bought if any help to you:

https://cimg3.ibsrv.net/gimg/www.mia...2a03852896.jpg
https://cimg6.ibsrv.net/gimg/www.mia...05b0664c60.jpg

Bad picture, but these are needed to connect to the oil cooler. They make different sizes, etc. but this is M22 to -6an
https://cimg9.ibsrv.net/gimg/www.mia...3516f479ab.jpg
https://cimg3.ibsrv.net/gimg/www.mia...4b37eb1a25.jpg

@rdb138 Excellent thanks