1967 Cougar build (over 500 pictures and videos)
#781
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Only as an observer. But contact SWagon for firsthand feedback.
He just sold his E39 Touring on BAT.
Tipsy
He just sold his E39 Touring on BAT.
Tipsy
#782
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I guess it's time for a meaningful update. I haven't been doing much with the car except from driving it on a fairly regular basis. I rotate between it and my truck as a daily driver.
One of the things that been bugging me since I have built the car is the rather heavy steering effort. In hindsight, I should have gotten a power TCP rack, but there is no going back on that. There is a lot of information floating out there regarding the adaptation of electronic power steering (EPS) from various vehicles to older Ford cars. The popular swap has been to use the EPS from a Saturn Vue, but recently I ran across some information regarding the use of the EPS from a Toyota Prius. Both EPS units are made by Koyo, but it seems that the Toyota control boxes offer a little more flexibility when being adopted to older cars.
The Saturn electronics need an adjustable box to vary the steering effort. While this feature is nice, I don't really need it (although I may opt for speed sensing power assist...more on this later). The Toyota electronics will revert to a "fail safe" mode in the absence of a CAN bus signal. This mode offers a "middle of the road" constant level of assist, which for now is all I need.
I checked various junk yards around me and scored a EPS column from a 2008 Prius for $70, including the control module. In anticipation for doing this swap I also ordered some parts from McMasterCarr. I got this collar that will be used to attache the upper stock column to the EPS unit.
![](http://www.pro-touring.com/~andrewb/cougar/747.jpg)
![](http://www.pro-touring.com/~andrewb/cougar/748.jpg)
Hopefully I will get a start on this over the weekend, and I will post pictures and perhaps a video for the swap.
Andrew
One of the things that been bugging me since I have built the car is the rather heavy steering effort. In hindsight, I should have gotten a power TCP rack, but there is no going back on that. There is a lot of information floating out there regarding the adaptation of electronic power steering (EPS) from various vehicles to older Ford cars. The popular swap has been to use the EPS from a Saturn Vue, but recently I ran across some information regarding the use of the EPS from a Toyota Prius. Both EPS units are made by Koyo, but it seems that the Toyota control boxes offer a little more flexibility when being adopted to older cars.
The Saturn electronics need an adjustable box to vary the steering effort. While this feature is nice, I don't really need it (although I may opt for speed sensing power assist...more on this later). The Toyota electronics will revert to a "fail safe" mode in the absence of a CAN bus signal. This mode offers a "middle of the road" constant level of assist, which for now is all I need.
I checked various junk yards around me and scored a EPS column from a 2008 Prius for $70, including the control module. In anticipation for doing this swap I also ordered some parts from McMasterCarr. I got this collar that will be used to attache the upper stock column to the EPS unit.
![](http://www.pro-touring.com/~andrewb/cougar/747.jpg)
![](http://www.pro-touring.com/~andrewb/cougar/748.jpg)
Hopefully I will get a start on this over the weekend, and I will post pictures and perhaps a video for the swap.
Andrew
#787
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I thought the EPS would be a cool upgrade, but wasnt a fan of the **** you have to turn to change the ammout of assist it has. I'll be interested to see if you can come up with the speed sensing assits, that would make it about perfect. Good luck with it, I'll be watching.
#789
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I wasn't too crazy about the "****" to adjust the level of assist, which is why I was drawn to the Toyota system. All the hardware in the various EPS systems is very similar and mostly made by the same company. However, the electronics are different. Some people with the Saturn systems have reported poor return to center, while the same doesn't seem to be the case for the Toyota system. I suspect the electronics are the difference.
Most Toyota control modules get their speed signal over the CAN bus, however, one controller was designed to have a traditional square wave speedometer signal. If I can get my hands on one of these controllers then I can feed it a speed signal from my Holley Dominator.
For now I am focused on getting the hardware in place and using the controller that I have. It doesn't have the VSS signal option and will function at a fixed level of assist.
Alex, you make an excellent point and I totally agree. I think this is a more elegant solution for LT swaps instead of trying to incorporate a power steering pump into the LT accessory drive system.
Andrew
Most Toyota control modules get their speed signal over the CAN bus, however, one controller was designed to have a traditional square wave speedometer signal. If I can get my hands on one of these controllers then I can feed it a speed signal from my Holley Dominator.
For now I am focused on getting the hardware in place and using the controller that I have. It doesn't have the VSS signal option and will function at a fixed level of assist.
Alex, you make an excellent point and I totally agree. I think this is a more elegant solution for LT swaps instead of trying to incorporate a power steering pump into the LT accessory drive system.
Andrew
#791
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So, I like to believe that I do wiring better than 2 standard deviation away from the average car enthusiast. I got to looking very carefully at the connectors and terminals that are on the EPAS ECUs. I have two ECUs actually. One is from a Prius and the other is from a Scion xD (I suspect this car is based on the Yaris). I like to document what I do carefully, so this is just a small update, but first some pictures of the Prius terminals.
![](http://www.pro-touring.com/~andrewb/cougar/749.jpg)
![](http://www.pro-touring.com/~andrewb/cougar/750.jpg)
These things are absolutely enormous. I have some MetriPack 800 series (rated at 60 amps, same blade size as maxi fuses) terminals handy, and those look like toys compared to these. The blades that are in the ECU are 9.5mm wide and the wires for power and ground look to be 8 gauge. This being a Toyota, I figured these are Yazaki connectors and terminals. After an hour of looking through a bunch of tech drawings I found the power connector and terminals for the Prius P7 (main + - feeds) connector on the ECU. The connector is Yazaki PN 7283-3521-40 and the terminals are PN 7116-3098-02. I don't need the connector, but it is always nice to source the terminals instead of making butt splices into heavy gauge wire.
The connector for the Scion ECU is interchangeable with the connector from the Prius, but they are not the same. The blades in the ECU are the same 9.5mm, but the terminals inside the connector is not nearly as massive and looks more like a wider Metripack 800 terminal. Also, the power wires going to the Scion ECU are 10 gauge. I have not looked for the other style connector or terminals, but I wanted to make note of the differences.
Another small bit of tech is that people state that for the output shaft from the Prius EPAS the Burgeson PN 312500 works well. It is a 11/16" x 36 spline to 3/4" smooth bore coupler. The plan is to weld this to my existing lower portion of my steering shaft and have it removable from the Prius EPAS output shaft.
Andrew
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Progress on the electronic steering conversion has been very slow, but I am still collecting parts. I now have 2 Prius steering columns and 3 different steering computers. I also picked up a little box on eBay that is supposed to work with the Toyota steering computers and allow the boost level to be adjusted with a ****.
Before doing all this, I want to make sure that the steering hardware is in good shape and that I am not having any other issues, like bump steer. Having said that, I am pretty sure that I have some bump steer because when one side hits a bump, I can feel the steering wheel jerk to the side. In order to fix this, I plan on taking the car to a local race shop and having them do some bump steer adjustments.
I got a kit from TCP so that the outer tie rods can be raised or lowered as needed, which will allow the bump steer to hopefully be minimized. Here is the kit:
![](http://www.pro-touring.com/~andrewb/cougar/751.jpg)
The kit includes high quality billet adjustment sleeves and US made teflon lined outer rod ends, along with the other needed hardware.
I can hopefully get this done next week and I will post some more updates.
Andrew
Before doing all this, I want to make sure that the steering hardware is in good shape and that I am not having any other issues, like bump steer. Having said that, I am pretty sure that I have some bump steer because when one side hits a bump, I can feel the steering wheel jerk to the side. In order to fix this, I plan on taking the car to a local race shop and having them do some bump steer adjustments.
I got a kit from TCP so that the outer tie rods can be raised or lowered as needed, which will allow the bump steer to hopefully be minimized. Here is the kit:
![](http://www.pro-touring.com/~andrewb/cougar/751.jpg)
The kit includes high quality billet adjustment sleeves and US made teflon lined outer rod ends, along with the other needed hardware.
I can hopefully get this done next week and I will post some more updates.
Andrew
#800
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The shop should be able to help you Andrew -- classicly, bump steer occurs when the suspension moves through it's range of motion (compression or sag) and that movement causes a significant change in toe. If the steering arms are the same length (pivot to pivot) and run at the same angle as the control arms, it shouldn't be a problem. It can be a bit trickier to sort if you're car has, as I suspect, an old school steering box with a 3-link/pittman/idler arrangement.