Electronic power steering (can't be too hard to do)

[Shane]

What a good idea with the handbrake. I think I'll give that a go.

How do you find the steering with the pump.

 

Well bear in mind the car I have done it on is a front wheel drive Tigra with an engine and box in that is 50% heavier than the one that came out, it feels fine to me. I have to be honest, I never drove the car more than a few miles with its own engine and conventional PAS in, but to me it feels how I remembered it felt. Its a little unnerveing when you very first test it as there is no drain on engine power or tickover speed when turning through to full lock and of course you have pas as soon as you turn the ignition on without starting the engine, but its fine and imo a great way of retaining PAS on modified cars. I have no cooler on mine, other than passing the flow hose across the front of the rad but the fluid is still cherry red after a year and around 20k miles.

 

There are of course two types of EPAS and what I think Gaz was reffering to in terms of Porsche was the newer type which has two motors on worm and bevel gears attached to the steering column. Fiat I believe was the first to try this on a production car with the later Puntos and they were notorious for problems, but in the meantime, all the other car makers seem to be going down this road now.

[hodge]

I have a punto myself, it's a 2003 model and the PAS is utter crap. I've had loads of problems with the rack and it's failed on my a few times too. I need to turn off the ignition and back on again and it sorts itself out.

[Gaz6002]

I'm not talking about problems with EPAS. I'm talking about losing any kind of meaningful feedback through the wheel.

[Shane]

I'm not talking about problems with EPAS. I'm talking about losing any kind of meaningful feedback through the wheel.

 

I realised that yeah. The reason I believe the later method provides limited feedback is because its not hydraulic and the rack is in fact a solid rack. The assistance is applied to the steering column via motors controlled by a complex ecu that knows which way the driver is turning the wheels and by how much and the motor is powered up accordingly.

Edited April 6, 2012 by Shane
i used to be dyslexic bit I'm butter now (see edit history)

[hodge]

I'm not talking about problems with EPAS. I'm talking about losing any kind of meaningful feedback through the wheel.

 

But Gaz I operates the same as a conventional pump (pump and resevior) and the ECU controls the speed assist via the rack so that won't change either.

Don't get me wrong mate it could be utter crud but then again it could be a very good upgrade, it just needs someone to give it a go. If I do find it to be a good piece of kit on more than happy to let you have a drive of it (without any boost of course) so you can make up your mind first hand. I can't say fairer than that mate.

[Gaz6002]

I realised that yeah. The reason I believe the later method provides limited feedback is because its not Pneumatic and the rack is in fact a solid rack. The assistance is applied to the steering column via motors controlled by a complex ecu that knows which way the driver is turning the wheels and by how much and the motor is powered up accordingly.

 

Steering feedback is one of the most important things about Porsche cars and the firm focused very specifically on trying to recreate the traditional system in electrical format to boost efficiency. It worked on the latter aspect, but the feel has evaporated as a result. If Porsche can't get it right...

 

I see this is a totally backwards step in the name of aesthetics, but that all depends on what you're looking for I suppose.

[Shane]

Steering feedback is one of the most important things about Porsche cars and the firm focused very specifically on trying to recreate the traditional system in electrical format to boost efficiency. It worked on the latter aspect, but the feel has evaporated as a result. If Porsche can't get it right...

 

 

 

I see this is a totally backwards step in the name of aesthetics, but that all depends on what you're looking for I suppose.

I do hear what you are saying and am sure that the second method will indeed not provide hardly any, if any at all, feedback to the driver via the wheel. But John is going to maintain a fluid rack and pump system so feedback should be exactly the same as it is with the stock engine driven pump on.

[Polo]

There are pics of the 350z pump fitted in my project thread. For elec systems iv done, the pumps have all had pressure releaf built in.

 

I think if your doing it for power gains your pissing in the wind, not only does an elec pump draw more current probs about the same as a belt driven pump but also any elec pumps iv ever seen are over double the weight.

 

If you want to save power, fit a bigger pulley to the pump, this will slow it down a tad and the effort needed to turn it is less. This is great for track driving as the fluid does not get as hot, the pressure is still regulated by the releaf valve, any thing over about 2krpm the releaf valve is working, so waisted energy above that rpm.