Running with no PAS

[RIC172]

Instead of doing an EPAS conversion can you just fit a shorter aux belt and bypass PAS altogether?

Has anyone done this, and if so, what's it like? I know the steering will be heavier at parking speeds but surely it can't be too bad?

 

[Rubicon_]

I find it terrible but others find it good.

@Fraser.J. ran none on track etc and had no issues.

 

[JamesBryan]

Trying to turn will be pretty difficult as you're trying to compress the fluid at the same time.

When my PAS pump went i could hardly drive the thing.

 

[Fraser.J.]

I ran no pas, just looped the rack with a dribble of fluid in it.

Was heavy to move as low speeds but fine on track.

5pk847 belt of running cup alt set up with no pas

 

[Kev@KAM]

I dont think its particularly nice with the standard Ackermann on the wheels. Its alright on race cars which dont have Ackermann - that is until you want to get the car in the pit garage. I dont think the gains are worth it on a trackday car where you want to spend as long as possible on track. Maybe you will gain 1 bhp but has anyone on the forum measured?

 

[RIC172]

Cheers guys, mine is a road car so it might not see a track but running without PAS does appeal. I did it to my mk1 mx5 once and it was a good mod. Will definitely consider it.

Or what is the cost of an EPAS conversion if I go down that route?

 

[imprezaworks]

Nah.

 

[RIC172]

Nah.

Why dat? Can’t imagine the steering will be heavy even at parking speeds

 

[imprezaworks]

It is.

I drove a turbo 182 with no pas. Fast in a straight line, nightmare turning, even roundabouts lol.

If your thinking old skool (no idea how old you are) fiesta, pug etc, my experience was nothing like that lol.

For a road car I see no reason why you would want to get rid.

 

[bloke]

Why dat? Can’t imagine the steering will be heavy even at parking speeds

it's fookin' awful!!

 

[RIC172]

It is.

I drove a turbo 182 with no pas. Fast in a straight line, nightmare turning, even roundabouts lol.

If your thinking old skool (no idea how old you are) fiesta, pug etc, my experience was nothing like that lol.

For a road car I see no reason why you would want to get rid.

I was thinking old school and have owned a fiesta and pug so it’s a shame it’s nothing like that.

I found it really improved the steering on the mx5 as it weighted the steering perfectly. Maybe it’s too heavy on a 172 though

 

[Djw John]

See I thought it would just be like an old school car and it would lighten up at speed but even at high speed it stays a bit too heavy for my liking.

Having experienced it I won't be doing it to mine.

 

[Coops Mk1]

i run the track car with a pas rack with everything disconnected and I don't find it too bad, just parking. normal driving including roundabouts etc is fine, heavier than with pas, but fine

I wouldn't however have it on a road car that i'm having to reverse and parallel park all the time, that would be right annoying

 

[PhillipM]

If you're going to do it to a PAS rack you need to weld the shuttle up and take the ram off completely, it'll be a POS otherwise.

 

[mgoode180566]

why do it to yourself. no benefit whatsoever

 

[PhillipM]

Depends what you're building the car for, you'll get a lot more feel and feedback without a PAS rack, so if it's just a fast road/track car, it's great, more fun.

If it's a daily driver for shopping then it'll can get a bit tedious. If it's a race car, keep the power steering, because being easy to drive over long stints is more important than a bit more feel and feedback is.

 

[RIC172]

I ran no pas, just looped the rack with a dribble of fluid in it.

Was heavy to move as low speeds but fine on track.

5pk847 belt of running cup alt set up with no pas

Hi Fraser, I might give this a go.

-Please could you describe how you looped the rack? did you just connect a pipe to both ends to stop the fluid coming out?
-Did you leave the PAS pump in situ and just remove the pulley?
-Does the pulley come off easily or do you need a pulley removal tool?
-I see the standard cup aux belt is a 6pk1147. How come the shorter belt is one rib narrower?

Cheers

 

[PhillipM]

If you do that you'll have slack in it around dead centre all the time, every time you change direction or make small corrections. You need to fix or weld the quill shaft and shuttle solid.

 

[RIC172]

If you do that you'll have slack in it around dead centre all the time, every time you change direction or make small corrections. You need to fix or weld the quill shaft and shuttle solid.

Sorry you lost me there (I am not too technical when it comes to mechanics). Which bit is the quill shaft and which is the shuttle? My intention is just to bypass the pump by fitting a shorter aux belt - so this won't work, or will have issues steering around the dead centre?

 

[PhillipM]

Yes, that's the bit that detects your steering input and applies hydraulic pressure to correct, if you remove the hydraulic pump and fluid then that bit won't function and you'll basically have a load of slop until the input side hits the safety stops.

Any time you're making small inputs or changing direction, etc, you'll basically have a small area where the steering is only connected through a tiny spring. You can imagine what that does to accuracy and feel.
It's not an issue when it's powered because the hydraulics are working with you and the input forces at the wheel are far lower.
You're also better off popping the seals out of the end pistons rather than looping lines, as whilst the friction isn't an issue for the hydraulics, it adds a considerable amount to the handwheel forces without them, and they also damp and reduce feedback and feel.


If people have just been looping lines when trying to de-power a rack that explains why most people think it's been crap, they've done a half-arsed job.

 

[RIC172]

Yes, that's the bit that detects your steering input and applies hydraulic pressure to correct, if you remove the hydraulic pump and fluid then that bit won't function and you'll basically have a load of slop until the input side hits the safety stops.

Any time you're making small inputs or changing direction, etc, you'll basically have a small area where the steering is only connected through a tiny spring. You can imagine what that does to accuracy and feel.
It's not an issue when it's powered because the hydraulics are working with you and the input forces at the wheel are far lower.
You're also better off popping the seals out of the end pistons rather than looping lines, as whilst the friction isn't an issue for the hydraulics, it adds a considerable amount to the handwheel forces without them, and they also damp and reduce feedback and feel.


If people have just been looping lines when trying to de-power a rack that explains why most people think it's been crap, they've done a half-arsed job.

Ah I see thanks for the info! I think I will keep HPAS after all or get it converted to an electro hydraulic system using a pump from a Saxo

 

[PhillipM]

You won't really gain anything if using a Saxo pump, unless you just need the power steering pump out of the way, they're a continously running pump so they're always going full speed and just regulated against the check valve, so it'll still use a chunk of power (and depending on what else you have running - say all the electrics in winter - you might find the battery/alternator load exceeds what you have after a while, they peak at about 50a load) and they're pretty heavy units.

I used to run Saxo/106 pumps on the buggy with a 405 ram and a 306 shuttle welded into the column, and ended up having to go to a 165a alternator to keep up with demand with the pump, lights and cooling fans running, otherwise it'd slowly drain the battery down over the weekend running with the original 105a unit.