Electric Power Steering

MGBV8 · July 08, 2019, 10:21:30 AM

Look forward to your hands on observations, James.

b6281t · August 01, 2019, 10:16:08 AM

Over 4 years and 30.000 miles with the Vue power steering unit flipped upside down with no issues.

jjohanski · September 09, 2019, 12:25:16 PM

I just repeated reading of the recent posts. I was looking to see what the Roadmaster has in it for Power Steering. Did Jim Blackwell install a EPAS in the Roadmaster or was that in his own car? Will the Roadmaster be at the V8 GT in Townsend this year? Thanks to all.

MGBV8 · April 05, 2020, 06:24:58 PM

Since James joined us at the GT in Townsend, his questions were answered. For those that were not, yes, the MG Roadmaster now has EPS (EPS column built by Mike Moor & installed by Jim Blackwood). And, no the MG Roadmaster was not there.

Jim has also installed EPS in his own MGB.

MG-Chuck · July 21, 2020, 12:49:20 PM

New member here today. I posted my implementation of a Prius EPS (EPAS) unit in my '69 MG project on The MG Experience. Carl Floyd suggested that I join this site and share it here.

The unit I chose was from a 2009 Toyota Prius. I needed to mate the MG steering column to the Prius. At the front end, I cut off the Prius's outer column and trimmed the inner tube extension to length. I removed the key steering lock sleeve and cut the MG inner to the required length. The 2 fit together well. I plug welded them in 2 places and then ran a bead around the joint for a belts an suspenders repair.

The lower section required a purchased Borgeson adapter that fit rather well. Then the sliding shaft was disassembled cut and welded together to get the required OAL as the MG OEM column. I did lose the collapsible feature in this implementation. I could have kept that function but would only have had an inch or two of collapse. I decided to make it simpler and ended up with a solid shaft.

The MG steering mount bracket needed to be relieved to make room for the drive assembly. That made it a bit flimsy. I added some reinforcement that cleared the drive. I addition I used that reinforcement to become the torque link for the motor. Also changed was the MG outer column mounting tabs.

The Prius unit (and many other Japanese cars) uses a limp-home mode if it's control box cannot communicate via the CAN link. The controller unit is required. The only external wiring necessary are Battery, Ground and ignition on.

To mount the controller, I ground off the original mounting tabs from the EPS control unit. The OEM mount fit 3 different crazy body locations that simply do not exist in the MGB. I was concerned that I may destroy the electronics internally with all the heat and electrical noise of the cutoff wheel on my angle grinder. I figured if it was designed properly, as I expect all major auto manufacturers do, it should be well protected from spurious noise on any unused inputs, so I moved forward with that plan. I fabricated an aluminum case to enclose the box and mount it to the vertical firewall virtually right next to the motor of the EPS unit. Added 4 rivet nuts to the firewall. The box now screws to the firewall with four 10-32 screws.

I tested the system in situ. Lo and behold, it still works as it should. No damage was done during my br@cketectomy procedure.

I won't know for a few years yet how this will work out. I am doing the required mods while I finish up attacking the body repairs and V6/auto installation etc.

I hope this info helps others.
EPS Complete.jpg

BlownMGB-V8 · July 22, 2020, 11:11:35 AM

The collapsible column feature should be retained if possible, MGs have had a collapsible column since the Mark-II I believe.

Jim

MG-Chuck · July 22, 2020, 10:35:07 PM

I agree with you Jim. It should be kept, even if greatly reduced. The drive assembly did take up a lot of the space available for the collapse feature. Like I stated, I could have kept maybe 2 inches of collapse(ability?) had I had enough forward vision to do my cuts accordingly. I made a judgement call that I am OK with. I do not recommend others follow.

BlownMGB-V8 · June 30, 2022, 03:16:07 PM

OK here's a puzzle for you guys. On the last part of the trip back from BritishV8 in my '71 MGB roadster (300 Buick powered and equipped with a Prius/Corolla EPS) I noticed that the steering does not self center as it should. (I can't say how long it has been that way) I'm not saying it doesn't track down the center of the road if you take your hand off the wheel, what I'm saying is that if you take your hand off the wheel coming out of a moderately sharp curve it wants to keep turning instead of straightening out. It also doesn't find center while driving straight, tending to result in a zig-zag path. Now this is quite a surprise in an MGB which is justly famous for snapping back to center especially with wider tires, due to the largish caster angle of about 5 degrees, which causes noticeable suspension jacking when the wheels are turned sharply, and which if you take your hands off the wheel in a drift will very energetically whip back to center and I had the rug burn on my wrist to prove it.

For purposes of comparison I presently have the MGB-Roadmaster here in driveable condition, which is fitted with Mike Moor's EPS conversion that uses the Versa unit. By contrast, it isn't as snappy as the stock MGB but it does return to center nicely.

So far the web searches I've seen indicate that the Versa has more of an issue with return-to-center than the Prius unit does but this sure does not square with my current experience. I put the car up on the lift, checking for anything that might account for this and have yet to find anything. It's the same for both directions. The steering components all seem tight and functioning properly. There doesn't seem to be any binding. With the key off I can grab the tire or brake rotor and push the steering from lock to lock with about the usual resistance, probably just a bit more due to the EPS gearbox.

Anyone have any idea what else I could look at here? I'm sorta drawing a blank. About the only thing I can point to might be wheel offset.

Jim

MGBV8 · June 30, 2022, 05:14:01 PM

Wheel offset? Has that changed much since you installed the EPS?

I have found many instances of complaints very similar to yours on the Toyota/Yaris/Prius EPS. Lots steering & alignments checks a dealers that say everything is fine & normal. Not much resolution.

Except for this one:

"Well I got my steering problem sorted out. The first thing I did was to get the odd thread tire on the front changed so that the tyres had the same profile, I then got the four wheels laser tracked and the report showed that the toe in was out. The result of all this was that the steering was marginally better but not right. My mechanic mate then sourced a second hand steering motor and ECU, he fitted the steering motor at first and recalibrated the steering etc and this also improved the steering vastly but it still wasn't right. He then fitted the ECU and on reclibrating etc solved the problem entirely."

Another observation:

"I think this is simply the difference between Toyota and VW's power steering calibrations that you're seeing - VW's electric power steering systems have a very aggressive return to center (to the point that they'll hold what they think center is, even with things like crowned roads and IIRC even crosswinds), where Toyota's systems tend to be a little "sticky" near center to try to get a similar effect - it'll stay where you put it if you're near the center."

MGBV8 · June 30, 2022, 05:19:52 PM

Another great link I ran across with pics comparing Corolla, Prius, Yaris, Saturn Vue, Nissan Cube & Versa, & Kia Soul EPS.

Prius ECU may work on Saturn Vue (same torque sensor) for fail safe use?

https://www.therangerstation.com/tech/toyota-electric-power-steering-eps-conversion/

BlownMGB-V8 · June 30, 2022, 10:24:48 PM

Are you saying that the VW unit is the same as the Prius except for the programming?

I do not care for that 'sticky' characteristic at all. Probably should look at what the Mazdas are using.

After I re-seal the valve covers on the Roadmaster tomorrow I want to do a back-to-back comparison, that might be helpful. As for the wheel offset, yes I have been playing with that a bit and I also should be able to swap the tires front to rear and see what the effect is. One set has a 24mm offset and I believe the other is 10mm so that should be enough to make a difference. The 10's would be the ones I have on the front now. Apparently the offset of the Jag rims on the RM (Hollander 59689) is 33mm.

Jim

MGBV8 · July 01, 2022, 09:26:19 AM

No. The article in the link shows a pic saying the the torque sensor from Prius is the same as a Saturn Vue. So, a Prius ECU could be used in fail safe mode on a Saturn Vue EPS. Lots of info in that link.

My old OEM 5" wide Rostyles have a 24mm offset, My 6" ARE wheels have a 13mm offset. My tires are not nearly as wide as yours, though. The wide tires may be accentuating a minor issue?

BlownMGB-V8 · July 01, 2022, 11:20:13 AM

I'll get it back on the lift this afternoon, I have an infrequent ugly klunking at the right front that I have to find. (Nothing seems loose so some dissassembly is in order. Bearings maybe.) I might try swapping the tires around to see what that does. Assuming the klunk isn't causing it somehow.

Jim

BlownMGB-V8 · July 01, 2022, 04:12:47 PM

Well that wasn't it. Swapped tires, steering is still sticky in the middle. I don't much care for it.

(Tightened the shock base bolts, one was moving just a smidge)

Drove the RM again, it's got a little of that sticky too but not as bad. Reports are good on the Mazda 3 steering, maybe we should be taking a look at that one. I think a junkyard trip may be in my future.

Jim

mgb260 · July 02, 2022, 01:10:02 AM

Jim, 2014 and newer Mazda 3 had electric power steering.

https://www.drive.com.au/news/2014-mazda-3-gets-electric-power-steering/

BlownMGB-V8 · July 02, 2022, 08:29:13 AM

6.5 degrees of caster in the MX3. That's even more than the 5 degrees in the MGB. Then they used that to provide the centering. I think we may be onto something here.

Jim

MGBV8 · July 02, 2022, 08:43:55 AM

I have seen the MGB listed as 7 degrees, as well as 5 degrees. I would love to see someone's alignment printout.

'Engineers behind the new 2014 Mazda 3 have tuned the steering setup of the third-generation 3 to the point that it mimics the best parts of a manual steering system for better response and feedback."

Y'all may convert me yet.

MGBV8 · July 02, 2022, 09:13:16 AM

Frontline & Moss Motors both say that the MGB was designed with 6.5 degrees of trailing castor. I have also seen 7 degrees mentioned elsewhere. Either is perfectly fine with me.

BlownMGB-V8 · July 02, 2022, 04:37:55 PM

Should work well with the MX3 EPS. Local Pick-n-pull has nothing newer than 2011 so they are out. Might look around some though. Wider tires will increase the caster effect. Wonder what the MX3 unit does in limp mode?

Jim

MGBV8 · July 03, 2022, 09:14:30 AM

"Wider tires will increase the caster effect"

Taller will, but wider? How so?

Your wide front tires should require less negative camber & a bit more toe-in.

BlownMGB-V8 · July 03, 2022, 11:54:55 AM

I guess it depends on whether or not they are wider inboard or wider outboard. Inboard wouldn't make any difference but outboard would increase the jacking effect.

Jim

MGBV8 · July 03, 2022, 12:18:03 PM

Which is why a bit more toe-in is needed.

BlownMGB-V8 · July 03, 2022, 10:22:27 PM

Um... maybe? I've found wider tires don't need as much toe in and wear fast if they do.

Jim

MGBV8 · July 04, 2022, 08:38:55 AM

As much? I run zero to slightly out.

It's always a balance with toe-in & negative camber. A matter of finding the right combo for one's tires & driving style.

302GT · July 31, 2022, 12:51:14 PM

The stock MGB caster angle is about 6.5 degrees. A large caster angle gives a strong self-centering action and causes beneficial camber gain during cornering but also increases the heaviness of the steering. Most modern cars have power steering as standard and as such have large caster angles in the range of 6 to 8 degrees or more. For years I had a Mercedes 240 diesel and the shop manual specified 8.5 degrees of caster on cars with power steering and about 4 degrees on cars without (only available in Europe). One of the features of the Fast Cars MGB front suspension is a reduced caster angle (nominal 3 degrees, range 2.5 to 5 degrees). This is a main contributor to a lighter steering feel. Mike Moor has a Fast Cars front suspension in his MGB with power steering. I wonder what the caster setting is? I drove his car at the Auburn meet and it had some self-centering action. I would have preferred more centering, but it did work predictably. I have a Hoyle front suspension in my MGB but since it still uses the MGB cross member I am also running caster wedges to reduce the caster to about 3 degrees. I am considering removing the caster wedges and returning to the stock setting. At that point I may seriously consider adding power steering. I also have the Moss fast ratio steering rack which might be beneficial for a more robust self-centering action; (I wonder how that compares to the Fast Cars steering rack?). Still, in looking through this thread I am not sure if some of the centering problems are related to caster settings.