Who has removed/disabled their PS?

[m1tch]

Hi all,

I noticed a guide (linked below) on how to disable/remove/vent the power steering on the car to give a better road feel, just wondering how many people have done this mod already, I can see the benefit of doing it, especially with a vented system as there wouldn't be any pressure of fluid stopping the rack from moving. I can see that there might also be a slight weight reduction, although there wouldn't be a reduction in engine load as its not belt driven.

 m http://www.driftopia.com/2008/03/04/mr2 ... al-part-1/ m

Just wondering about peoples thoughts on the matter.

[shnazzle]

That mod is new to me but is definitely interesting.
Maybe one for the track guys to try? Tommyzoom?

[m1tch]

I think the good think about the mod as its got electric power steering is to simply pull the fuse for it which will give some idea of the effect it has, makes sense as the car is as light as some of the older hatchbacks in the 80s and 90s that didn't have power steering. The low weight combined with less weight over the fronts means that the removal of the system might work quite well, will try it out on mine when I get it this weekend to see what the effect is.

[1979scotte]

Surley it will be really heavy if you just pull the fuse.
I would think you need to remove the ps system.
Pretty sure matt performance had modified racks for that purpose.

[shnazzle]

That's what the text suggests. That it's an approximation of the feeling of actually removing the pump.

It's a very good write up actually.

I can definitely confirm that it is FAR too heavy for daily use with just the fuse pulled.

We had this in Helen's car when it stalled and I started the engine while driving. The power steering didn't start (as per design) and it was damn near impossible to drive. That was on crappy 17s though

[m1tch]

I know on other cars there is sometimes a manual non power steering rack on one of the base model cars, I know that its not ideal if the system is still in place as you are also pulling against the fluid as well which is why I can see the 'vented' mod would make sense as the rack gets the fluid it needs but doesn't get in the way of movement.

Usually when people go with a manual rack its usually a 'quick rack' which has fewer lock to lock turns as well, I guess there wasn't really a 'base model' of the MR2 but it might be interesting to see if any other OEM manual racks might fit from Toyota from a different model.

[davew]

my old mk1 mx5 had a depowered rack and i loved it a bit heavy when parking but great otherwise. i would have thought the mr2 would be lighter on the front end so should work ok although it does depend on how high the rack is geared.

[GFB]

I pulled the plug on mine just to try it.
Heavy but manageable at parking speeds, only very slightly heavier than standard above 10 mph.
On my race BMW e30 I basically just joined the two pipes together - I've done many racing miles since without a problem.

[shnazzle]

Tried mine as well. No good for daily.
It was very heavy even at 40-50mph around big roundabouts.
So I'd have to do the full removal and venting to make it feasible, too much hassle

[m1tch]

Tried mine as well. No good for daily.
It was very heavy even at 40-50mph around big roundabouts.
So I'd have to do the full removal and venting to make it feasible, too much hassle

Hmm worth an ask I guess, might try it out on mine when I get it to see what its like, if the OEM power steering is indeed a bit overactive then perhaps there is a way to reduce the assistance of the pump? Perhaps having a variable resistor for the pump power so that it runs at a slower speed and pressure?

[shnazzle]

Don't get me wrong, I felt everything as mentioned. The response and feel from the wheel was amazing. But too much for a daily. I was going around a sweeping bend and I was getting all the judders and bumps through the wheel, which wasn't really something I want on a daily basis.

I'd love to give a removed PS a try

[ChrisGB]

Consider that running without power steering will put extra strain on the steering column joints, so will need to keep a close eye on them for wear.

[shnazzle]

Consider that running without power steering will put extra strain on the steering column joints, so will need to keep a close eye on them for wear.

That was actually one of my main thoughts. It felt like it was straining the system more than it should.
I won't be doing it again that's for sure. To be honest it felt unsafe.

[m1tch]

Might research more into seeing if Toyota ever did a manual rack for a different car of around the same age - not really high on my priorities but a manual rack would be best for road feel etc.

[Tomo70]

Each to their own but why re invent what toyota did, they spent millions in research and development, testing them against Lotus and VX220. The mk1 didnt have powersteering from my recollection so maybe thats a starting point.

[m1tch]

Each to their own but why re invent what toyota did, they spent millions in research and development, testing them against Lotus and VX220. The mk1 didnt have powersteering from my recollection so maybe thats a starting point.

Good to know, I do find it interesting to look through the various models of certain cars, usually the mk1 is the purest version of the range, take the 'car with the engine in the wrong place' in terms of the weight of the car: Mk1 - 940kg, Mk2 - 1065kg, Mk3 - 1,153kg, Mk4 - 1,058kg. The original is usually the lightest, then it gains weight with leather seats, air con and other driver conveniences such as power steering.

It would seem that the Mk1 MR2 was around the same weight as the Mk3 MR2 so if you are saying that the Mk1 didn't have power steering then it could be worth looking into - this is more of just an interest for me, my MR2 won't be a daily drive but I am just interested in how some OEM parts could be swapped over or subtle mods done to the car.

[lamcote]

The weight of the steering is also considerably affected by the front wheel /suspension geometry. The mk1 will have been designed to have geometry that works with unassisted steering whereas the mk3 was designed to take advantage of having power steering. Things like steering offset and steering axis inclination will probably be different meaning that even though the weight over the front wheels is similar, the weight of the steering may well be much heavier in the mk3 if you remove the power assistance.

[shnazzle]

Agreed. I think the fact that I'm running wider front tyres didn't help matters.
Also, the steering was very hard to get into a corner but snapped back very fast, which on one hand really showed off the qualities of the Yokohama on the other hand showed off how much the stock steering creates a lovely compromise between comfort and handling. Again just showing, as Tom said, that Toyota has not designed the car to be without power steering.

[m1tch]

The weight of the steering is also considerably affected by the front wheel /suspension geometry. The mk1 will have been designed to have geometry that works with unassisted steering whereas the mk3 was designed to take advantage of having power steering. Things like steering offset and steering axis inclination will probably be different meaning that even though the weight over the front wheels is similar, the weight of the steering may well be much heavier in the mk3 if you remove the power assistance.

I see, thanks for the info, still learning various aspects of tuning both engine and suspension - more of interest really.

[davew]

tried mine without power steering today i drove about 20 miles with it disabled , my mx5 had manual steering so im used to having heavy steering ,i did like the feel of it although it does feel heavier than the mx5 but maybe it would be better with the rack vented, what i was concerned about was the extra load it puts on the steering joint.
i do like the idea of ditching the power steering but i like i will be leaving mine alone.

[Dev]

There is a big difference from pulling the fuse vs bypassing the pump.  
I have pioneered this modification on  Spyderchat over 10 years ago and since then there have been several variations from other owners.

When you have the PS pump in the circuit the pump passages are small which restricts the flow of PS fluid. This will make the steering very difficult and not like a manual rack.
What you need to do is cut the rubber tubing just before it meets the PS pump, remove a small amount of fluid and then connect the cut ends by using a plastic fitting and some hose clamps. Now that the hose is looped fluid can move freely and it will be night and day difference from just pulling a fuse.
The car will feel exactly like a manual rack that is easy to turn with all the benefits of increased road feel. The only time you will have any difficulty is when parking from a dead stop but it's exactly the same feeling you get in any manual rack.

  One of the other variations is using a T fitting where it loops and adding a breather filter. Another option that some have done is removing the rack entirely, draining the fluid and greasing the pinion.

 This, of course, requires a commitment to removing the PS pump but another benefit is removing 13lbs of weight.

[keljon]

There is a big difference from pulling the fuse vs bypassing the pump.  
I have pioneered this modification on  Spyderchat over 10 years ago and since then there have been several variations from other owners.

When you have the PS pump in the circuit the pump passages are small which restricts the flow of PS fluid. This will make the steering very difficult and not like a manual rack.
What you need to do is cut the rubber tubing just before it meets the PS pump, remove a small amount of fluid and then connect the cut ends by using a plastic fitting and some hose clamps. Now that the hose is looped fluid can move freely and it will be night and day difference from just pulling a fuse.
The car will feel exactly like a manual rack that is easy to turn with all the benefits of increased road feel. The only time you will have any difficulty is when parking from a dead stop but it's exactly the same feeling you get in any manual rack.

  One of the other variations is using a T fitting where it loops and adding a breather filter. Another option that some have done is removing the rack entirely, draining the fluid and greasing the pinion.

 This, of course, requires a commitment to removing the PS pump but another benefit is removing 13lbs of weight.

what size plastic fitting do i need to do this?

[Dev]

I do not remember. I bought a few plastic barb fittings that are meant to join hose ends.