Been thinking of removing the power steering ever since I first tried an MR2 mk3.
Been rallying a 950 kilos car with 550 of that up front, nooooo issues. Ok, that is on 155 wide wubbahs but still. The MR should have near 100 less up front.
Have read the write up on Driftopia and it seems 15 minutes of faffing and just as much to refit if needed.
I need to change the fluid anyway so I will have a go at it.
Nevertheless I would like to hear from anyone who has done it.
Thanks.
Yup, has been done on here before.
@MattPerformance (https://www.mr2roc.org/forum/index.php?action=profile;u=2835) had a manual set up I am sure of it.
It has been done but by using a proper manual rack
Didn't think it was recommended to bypass the pump
A manual rack should than be one adapted from another model. That would probably easier than taking the piston out of the OEM one.
Bypassing the pump by looping the in-out should be without issues. You will be ´pumping´ the fluid from one siide to the other, that is all. The negative is slight resitance but the up is that you keep the same oil lubricating the lot.
I took the ´fuse´ out to do a q&d and did not like it: Way too heavy untill you get to about 20 km/h and even then you feel resistance. Not something I want going through switchbacks over here.
That is however pushing the fluid through the electrical pump which múst give noticeable resistance.
It will also be 4 kg. lighter where it does count but that is insignificant in comparison with the feel in the wheel. That rimes so it´s true ;)
I am giving it a go, hopefully this week.
It is easily reversed and I will let the warning light in till I have decided one way or the other.
Have you tried a smaller steering wheel? Weights up the steering a bit, think mine is 320mm
Quote from: james_ly on February 11, 2019, 11:11
Have you tried a smaller steering wheel? Weights up the steering a bit, think mine is 320mm
Petrus I believe is all about weight reduction ;)
Quote from: Joesson on February 11, 2019, 11:57
Quote from: james_ly on February 11, 2019, 11:11
Have you tried a smaller steering wheel? Weights up the steering a bit, think mine is 320mm
Petrus I believe is all about weight reduction ;)
Good one!
I will stick with the OEM steering wheel.
By deleting the ps I hope to increase feel and eliminate overanxious assistance. As strange as it seems, ps masks the feedback from the rear as much as from the front and less of thát is what I try achieve. Not at the price of Schwarzenegger steering though.
The week is filling up a bit rapidly with dates and the girl comes before the car ;)
Hope to have a look this afternoon or it will be Thursday at the earliest.
Done it.
See Belle´s thread.
Would be interesting to know which bit weighs what... where the best gains are as there isn't really much to strip out of MR2s!
Have a look at Petrus's thread, his added a lot of lightness.
Quote from: Joesson on February 11, 2019, 16:39
Have a look at Petrus's thread, his added a lot of lightness.
The verdict is out now too: Give it a try!
I have looped the lines sometime in 2008. The PS pump weighed in at 13lbs. Looping the lines is much better than just disconnecting the pump as its much easier.
The feel is great and better than most manual racks because it has a much shorter ratio so it makes its very responsive and not like a bus with too many turns to lock.
Now for the downsides. There is a possibility of breaking the pinion gear. No one that has done the modification has had this happen yet but it can happen because most PS pinions are not as strong as manual rack pinions. The PS rack is assisted so less force is on the pinion.
On some other vehicles where they have gone manual with a PS rack there are cases where the pinion would fail and the steering would lock up.
Quote from: Dev on February 11, 2019, 21:50
I have looped the lines sometime in 2008. The PS pump weighed in at 13lbs. Looping the lines is much better than just disconnecting the pump as its much easier.
The feel is great and better than most manual racks because it has a much shorter ratio so it makes its very responsive and not like a bus with too many turns to lock.
Now for the downsides. There is a possibility of breaking the pinion gear. No one that has done the modification has had this happen yet but it can happen because most PS pinions are not as strong as manual rack pinions. The PS rack is assisted so less force is on the pinion.
On some other vehicles where they have gone manual with a PS rack there are cases where the pinion would fail and the steering would lock up.
Hence it is the proper way to weld up the pinion.
For those mulling it over: This illustrates how much the assistence takes over/away from your hands. It is thát much easier to control your car as you will know thát much better what is happening: The tyres tell you áll of the story, not a random 10% of it.
Thanks btw for the confirmation that you have done it as well. There is always this confidence thing. You knów it should work out well but... So good to know!
Will put up a photo of the final plumbing when I am done which will be when I come round to the exhaust.
Hey,
I guess you have seen it or you know about it as it seems that you know quite a lot about cars but could be a good read for the others. Here is the link:
http://www.driftopia.com/2008/03/04/mr2-spyder-power-steering-removal-part-1/
The guy has 4 parts where he has his stages of modification. I have interest in doing the mod too but im afraid that it could be too heavy for my linking. You can share your results once everything is done, i assume that it will be much better with catch can and a breather.
While reading of @Petrus (https://www.mr2roc.org/forum/index.php?action=profile;u=25573) 's lightness adding power steering pump removal project and the contribution from @Nvy (https://www.mr2roc.org/forum/index.php?action=profile;u=24835) and the Driftopia article all seeking lightness and/ or drivability improvements it occurs to me that this could have an economic benefit.
I have read on here about the high cost of replacement steering pumps and also the damage caused to pumps with incorrect fluid replacement.
It would seem that if the pump stops working from old age or incorrect fluid then an option could be to remove it completely and manualise it.
Quote from: Nvy on February 12, 2019, 13:39i assume that it will be much better with catch can and a breather.
Think of the rack as two cilinders with two pistons.
The one piston going up when the other goes down.
Both cinders have a hole in the cover throuhj which they breathj.
Ok now two situations.
One: both holes are connected though a short tube to the same container venting to the environment.
Two; connected to eachother through that short tube.
Now fill then with a fluid.
A fluid cannot be compressed and pressure is equal in all directions.
The first situation will see both cilinder having pump losses sucking in and out and the pressure will be atmospheric.
The second situation the sucking of the one piston will pull the other and the push ditto; hydraulics at work.
So; no a buffer with breather is not better but worse. Just connect the two sides of the rack.
Quote from: Dev on February 11, 2019, 21:50
The feel is great and better than most manual racks because it has a much shorter ratio so it makes its very responsive and not like a bus with too many turns to lock.
Just went down to the coast with the rally car.
Dropping off the nurse love at the airport with her suitcases so no MR2...
The rally carhas a manual rack ans has more weight up front and indeed véry much more indirect needing a lót of travel of the steering wheel.
Quote from: Petrus on February 12, 2019, 18:18
Quote from: Nvy on February 12, 2019, 13:39i assume that it will be much better with catch can and a breather.
Think of the rack as two cilinders with two pistons.
The one piston going up when the other goes down.
Both cinders have a hole in the cover throuhj which they breathj.
Ok now two situations.
One: both holes are connected though a short tube to the same container venting to the environment.
Two; connected to eachother through that short tube.
Now fill then with a fluid.
A fluid cannot be compressed and pressure is equal in all directions.
The first situation will see both cilinder having pump losses sucking in and out and the pressure will be atmospheric.
The second situation the sucking of the one piston will pull the other and the push ditto; hydraulics at work.
So; no a buffer with breather is not better but worse. Just connect the two sides of the rack.
Actually its better with a breather because you are not pushing the force of the fluid to the other side.
However I do not recommend the breather filter because it will suck in moisture and contaminants not caught by the filter which would be bad for the rack.
The best way to do so is to cut the hoses, take some fluid from the lines and connect the ends using a plastic hose fitting and some clamps. That bit of air gives it less resistance so its easy to turn.
One advantage with the de-powered rack is a cushioning effect when going over bumps and driving in a straight line is resistant change from uneven roads.
Yes you do feel the road and traction of the tires but it also comes with a downside of losing the quick responsive steering.
Is it possible to reduce pump/speed/pressure to reduce the assistance level but not remove it all together or does it not work like that ? power steering is not something ive ever fiddled with so knowledge is basic at best, i dont mind the steering on my MR2 (its much better the Electronic Power steering on my BMW 130) but a little less assistance would be nice to weight steering a touch more.
Ian
I was playing around with the idea of a bypass valve controlled by solenoid. So, essentially join the two pipes together via two-way valve on a switch.
I found this with some quick googling and kind of thing i was thinking but dont know if it will work on our cars - https://www.heidts.com/part/adjustable-power-steering-valve-ps-101/
When i get a minute im going to try with power steering fuse out to see how it feels un-assisted altough i know i have drag of hydraulics doing it that way but will give me an idea, think ive seen the mr2 race cars run a switch for power steering to have it on when not on track/in paddock etc then switch it off for track use i presume, which is maybe an option but worried about breaking the pinion or something, would be nice to just a drop a little of the assistance to see how it feels.
Don't bother with the fuse thing. It feels horrible and it's not representative of removing the power steering.
You're fighting the pump and the fluid. I tried it. It's REALLY heavy.
Quote from: shnazzle on February 15, 2019, 13:07
Don't bother with the fuse thing. It feels horrible and it's not representative of removing the power steering.
You're fighting the pump and the fluid. I tried it. It's REALLY heavy.
Ok thanks wont bother then :)
Quote from: thetyrant on February 15, 2019, 13:37
Ok thanks wont bother then :)
Why?
Emptying the reservoir with a syringe, detatching the two lines and shoving the one over the other using the OEM clip is 5 minutes work and as easily reversed.
I think he means he won't bother with removing the fuse as a means to try it out. Syringing out some fluid and looping the pipes is definitely a better way to try it and as you say, takes no time to do.