BritishV8 Forum

Steering feel is personal, and one system will not satisfy everyone. But after getting experience driving the car, I found an improvement in most conditions, not just parking. Especially impressive is the improvement in sharp, medium speed corners such as turning on to a side road or going through tight S turns (very common in the Midwest since secondary roads closely follow farm boundaries) at speeds of 30 to 45 mph. With unassisted steering, the steering becomes very heavy and makes the car feel ponderous. With power assist the car feels like the lightweight performance car it actually is. This alone justifies the EPS in my opinion. Of course, this assumes spirited driving; much faster than I would drive with my dog in the car, but not up to a competition level.

At highway speeds I sometimes get a periodic shimmy between 65 and 80 mph caused by slight tire imbalance. I always get the tires road force balanced, but with wear, rebalancing is sometimes needed due to an imbalance as small as ¼ oz. Currently, the shimmy is starting to return, but it has been completely damped out by the slight drag of the steering motor. The reduced assist at highway speeds is also much appreciated as the car feels just as stable as always. This was a concern because I am using the Moss quick ratio steering rack.

While the constant assist level of the fail-safe mode of the Prius/Yaris steering may be satisfactory for many people (all reviews I have read are positive), the speed sensitive feature is worth experimenting with. Especially since the Bruno box only costs about $100 including shipping (from Portugal) and can be installed in a few minutes.

"I am not sure if I will be going, but it would be great to compare cars if I do go."

What the heck were y'all doing in Monticello?!  I am sure there were, at least a half a dozen conversion with EPS in attendance.  We should have set up a parking lot demo somewhere.


Alan Hendrix of British Wire Wheel in Greensboro, NC maintains that much of the steering wheel shimmy on our LBCs is caused by out of round tires.  He specializes in truing wire wheels & shaves tires every day.

Yes, a parking lot demo,aka autocross, would have been informative.

I did drive some cars with EPS but I was gentle with them since they were not my car. However, a parking lot demo session is much better controlled than driving fast on public roads, and I agree it would be an excellent thing to do. If I had known about the true advantages of an EPS system I would have installed one much earlier.

What is your opinion of the reduced road feel, Larry?

The big improvement with electric power steering ,along with what everyone has mentioned , is the total lack of vibration and harsh steering wheel movement while traveling. I'm much less tired after long trips, similar to current automobiles. This is welcome the older you get.

I have fabricated and installed EPS on my MGB , my MGA and my Fiero and am very pleased with each installation. Thanks to Mike Moor for starting this improvement.

I just removed the caster wedges from the front crossmember and so the caster is back to 6 degrees. The improvement is noticeable in that the steering feels more precise now, with some more feedback. The Moss quick ratio rack I have seems ideal for use with this set up.

That also gives you back your camber gain that you lost.

Of course it should be kept in mind that Larry is running the Hoyle front suspension. Whether his results will cross to a stock king pin suspension or not is an open question.

Also, shameless plug here for Mike Moor's EPS conversion, as it remains the easiest way to do this and works very well.

Jim

Hoyle still uses kingpins.  Not that that matters.  Negative camber gain is the direct result of the amount of positive caster when the suspension is compressed.

Carl is correct; one of my motives to install the power steering was to be able to take advantage of the camber gain with the stock caster angle. The rear suspension grips so well there was always some understeer with the caster wedges, this is now gone as I hoped it would be. I did experiment with negative camber on the front suspension but that has too many compromises.

I also agree that Mike Moors' steering is a fine alternative. A short drive in his car two years ago convinced me that I could be happy with power steering, but I also wanted to try the speed sensitive feature.

This picture shows the relative sizes of the Yaris (left) and Prius (right) EPS units.

I'm a little late to the party but I started to disassemble my dash in prep for adding EPS this afternoon. I was intrigued with the Yaris unit and that's what I got this week. It's a non-ABS unit. The main reason I went this route is because you can add a VSS signal and the unit is supposed to run like factory......less boost at higher speeds. There is a good writeup on this site:

https://mgaguru.com/mgtech/steering/sr302.htm

Based on the above article,  I can confirm that the unit requires VSS pulses to become active. The easiest way for me to test it was temporarily wiring it into my car to get access to a VSS signal. The article says it requires 5 pulses to become active, which is roughly 6' with a GM system. So backing out of a parking space should get you there. I'm anxious to get it installed to see how it performs in the B. One of the things I wasn't aware of was the damping these units apply to the steering when going down the road. The article talks about this in detail. I had considered installing a VW steering damper at one point so I'm looking forward to experiencing this as well.

I hope to be closer by this time next week and I'll update everyone here when I have more to report.

On a related note, my wife has a 2015 Corolla with EPS. It has good self-centering, FYI. I believe it only has about 3 degrees of caster.

QuoteI can confirm that the unit requires VSS pulses to become active. The easiest way for me to test it was temporarily wiring it into my car to get access to a VSS signal. The article says it requires 5 pulses to become active, which is roughly 6' with a GM system. So backing out of a parking space should get you there.

So, if you are parallel parked, you are SOL?  That is when one would need it the most.  

Good question Carl. Are you there Larry?
On a related note, my alignment check showed caster of just barely under 7 degrees after installing the reverse caster wedges. They are about 3/8" tapering to maybe a 32nd or less. With the Prius EPS self centering is pretty much non existent.

Jim

I pulled this off a YARIS yesterday at a local yard.

Dan, is it from an ABS or non-ABS car? Is it a winter project or are you trying to install it before Townsend?

What year, Dan?

2012.  I don't think it was ABS.  What difference does that make?

I have a 81 TR7 parts car out by the barn with briars and crap growing all around it.  I should be able to get the column out of it and then we can see how much difference there is between the MG and TR7.  Hopefully I have a little more room to work with.

Dan, not sure if your unit is the same as the one I have but it sure looks like it is. They say 2006-2011 for the Yaris but that might be what was known at the time the post I looked at was created. If it is the same as mine, non-ABS, you'll need to either give it a VSS signal or put power to pin D31-5 to get it to work. If not, then you'll be running in limp mode. Read the link I posted a couple of posts ago. It has a bunch of information about the Yaris EPS including the wiring.

Quote2012. I don't think it was ABS. What difference does that make?

Tsk, tsk. you haven't been doing your reading assignment, Dan.  

You may be okay.  We will see.  Go back & read (or re-read) Larry Shimp's posts.

Scott wrote: "If it is the same as mine, non-ABS, you'll need to either give it a VSS signal or put power to pin D31-5 to get it to work."

I do have a sensor (magnets attached to the driveshaft) that I installed long ago with the cruise control.  Not using with the cruise, since I am using tach signal for that.  I wonder if it would work with the EPS box.

Hard to say. VSS sensors typically have a considerably higher pulse rate.

Jim

QuoteI do have a sensor (magnets attached to the driveshaft) that I installed long ago with the cruise control. Not using with the cruise, since I am using tach signal for that. I wonder if it would work with the EPS box.

Dan, that's convenient and it should work. In the article I linked to, the guy used a 4 tooth reluctor located on his differential flange to run his unit.

I'm hoping to have mine ready by the end of this week.