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MG MGF Technical - Potential Death Trap


Last night I nearly dinged My F -reversing straight out of the garage/drive into the street realised the steering was very heavy and not responding -narrowly missing a few parked cars! - Ok I should of maybe noticed the EAS light was on! What is concerning is that it just happened no warnings - could this happen at speed the difference between having EAS and not, is immense. IS this a caommon problem - loose connections?

Thanks Simon
Simon

Here in Dr Evils lair, This tank of sharks is apotential deeeth trap!

Yes it's a common fault, and no yuo wouldn't notice it at speed because the EPAS slowly cuts out untill it no longer active above 30mph. Most probebly a problem with the torque sensor connections.

The mode you are talking about is 'fail safe' that is the EPAs cuts out and disengauges from the coloumn, leaving you with what non EPAS people will recognise as normal.
Will Munns

I've seen this before too.. But more strange.
When I changed my fan-belt, I had no Power Steering..
After three minutes or so, the streering came back... So possibly linked to that?
Neil H

Unlightly. The EPAS takes a few signals
Ignition on
Engine speed
Road speed
torque left/right

It uses these to turn a motor left/right and to operate a clutch on the motor/coloumn.
The EPAS will not switch on without both the ignition on and the engine running. If the engine is run at over a specified RPM for a specified amount of time* it figures that the drive connection from the speedo is duff and switchs off (to prevent high speed assistance). If it receives conflicting or (what it thinks is) erronous data from the torque sensors it also switches off so you don't get it 'driving' for you.

*If this occurs (due for instance to an MOT check) then the unit resets itself after a few speed indications.
Will Munns

SF = Non-EPAS and a TF steering rack. No probs (just a bit heavy).
Scarlet Fever

thanks for the reassurance, I can now enjoy the drive home tonight.

Thanks
Simon

Oh and enjoy the extra feedback you get ;-)

Will (pioneer of the EPAS Bypass switch)
Will Munns

<<Yes it's a common fault, and no yuo wouldn't notice it at speed because the EPAS slowly cuts out untill it no longer active above 30mph>>

when my alternator failed heading down the motorway, the EPAS kicked out, and you do notice it immediately.

although I'd personally say it wasn't a potential death trap, as the car suddenly feels a lot more solid.

paul weatherill

Paul, The EPAS might not be assisting, but it seems to damp the feedback from the road even at speed, so you feel the bumps thru the stearing wheel, I guess that the cluch does not disengauge and it's the extra inertia of the motor which gives the extra damping.
Will Munns

Interestingly, i have a pet theory regarding EPAS and high speed instability.

As i mentioned before, Scarlet is a non-EPAS F, also i have *NEVER* had a problem with high speed instability, and you know i've done a fair bit of high speed driving (mainly on the Nurburgring!) ;-)

I have always thought that this might be down to not having EPAS, but could never prove it, given that EPAS is suppsoed to switch off above 30mph. I recently fitted a Trophy splitter (for stylistic / aesthetic reasons) and was told i'd notice the difference immediately. To date, i have noticed no change whatsoever, and can only assume that the car was performing perfectly well before hand.

Some of this can be down to the fact that the car is lowered, some of it can be down to the fact that Scarlet has stiffer shocks, some can be attributed to the equal sized tyres front and rear, some can be down to the fact that my TSW blades have a larger offset than standard. But, considering that all of these items were done after i bought the car and i've never had a problem with high speed instability (even before i started modding), i'm sure that EPAS is a big contributory factor, masking some of the inputs from the wheel and damping your responses slightly.

So where does this leave us? The truth is i have done too much to Scarlet to be able to conclusively proove this one way or another, but it is interesting given the recent (lack of?) experiences with a splitter fitted.

Comments?

SF
Scarlet Fever

Totally off-topic, but I agree with you Andy.

I strongly beleive that the EPAS can hide a multitude of problems.

As far as the splitter is concerned, I think the effect of them on a standard 4x4 setup is phenominal.

On a lowered F with correct setup and shock, I don't think the splitter makes any difference at all.

The difference I really would like to see is the difference between a non-EPAS F, and a EPAS F with the fuse pulled.

I have tried my car with the fuse out, and yes it does feel more stable etc, but it does seem you are fighting against more resistance than just the steering. (ie reisistance from the EPAS)

Or maybe I just need to work out in the gym more.

For now the EPAS fuse is staying in.

paul weatherill


EPAS is not too bad. Wouldn't say 'good' though.
Have the fuse in most of the time on the road.
Have the fuse out *instantly* I want to do some real driving on a track.

It really does hide so much of what's happening with the front wheels.

Not sure EPAS affects the high speed problems. I still htink they are setup problems that a splitter will contribute to fixing.

Also worth remembering that there are now three types of rack available. In increasing speed:
- non-PAS rack.
- old with-PAS rack.
- TF rack.

P.
Paul Nothard

I recently fitted a Trophy-style splitter. The difference was immediately obvious.

The steering now reacts instantaneously and is very precise right up to 200 km/h.

Before that at already 90 km/h the steering would start to feel imprecise, and the feeling would increase with speed.

I have the ride height set around 330 mm and the front wheels are set at 5min toe-in each. Standard suspension and bushes.

So to me it's made a big difference and I'm surprised it didn't make any on Scarlet Fever.

However:
I was parked next to a Porsche Boxster the other day. It doesn't have a splitter. Having driven one I know they're very stable at speed.

So now I'm wondering ...
Anthony Braham

This thread was discussed between 11/09/2003 and 15/09/2003

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