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oilmagnet477

Power demands of additional items

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oilmagnet477    344

Hi all,

As my 501 came with nowt added as standard, does  anyone know what sort of impact power steering (if any?) and Air con had on power delivery with 502 and 503 models?

One would assume that there would be some detrimental effect but not sure I've ever seen it spelt out.

Cheers all

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Dunc    323

I not sure how reliable these figures are as every application differs, but it seems you can budget about 10bhp for a/c as alternator.

http://mechanics.stackexchange.com/questions/1536/how-much-power-hp-do-the-components-on-the-engine-belt-generally-use

period road tests did suggest the 520 and 521 were more responsive.

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andydclements    292

What a lot of people forget is that the alternator is rated by its maximum current generation, which it would only achieve on a really flat (discharged) battery, once the battery is re-charged from the start-up it doesn't really matter whether it's 150 amp or 50 amp rating it's just replacing what's used by the engine running.Unlike the PAS pump which generates pressure in the system whether required or not, and when required it actually means the pump isn't under as much load.

 

 

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Escape    332

I agree about the alternator, it's all about the electric power drain at the moment Which is why one some cars the idle dips slightly when a high electrical load is turned on (like a winch or jumper cables).

As for the PAS pump, when there is no steering input the fluid is circulated without much resistance, so the pump doesn't need to build up pressure and needs less power.

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oilmagnet477    344

Thanks chaps, interesting stuff.

Currently bored as am recovering from a damaged cornea. Not allowed to drive and am being kept in the dark (no change there then!) - wouldn't believe something so small could be so painful and debilating, however, things appear to be slowly improving.

Cheers

Ant

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JayEmm    1,163

I think that's one reason people are moving to electric PAS - it only needs power when it's doing work, and doesn't cost your engine BHP... so is an efficiency improvement.

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ian29gte    1,911

Ant - The alternator probably takes no more than about 1.5 HP at full load, depending on its output, which is negligible. And there's nothing you can do about it apart from switch off what you don't need. The A/C pump on my car probably takes about 10 HP at its full load, but it cycles. In that case, you have to decide between a bit more oomph, or staying cool!

Sorry to hear about your eye problem, hope you have a swift recovery.

 

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USAndretti42    80

On the Honda IRL engine pressing the overtake button turned off the alternator.  Gave all of 2hp. It was more of a place o than a performance gain.

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Neil D.    4
On 10/8/2016 at 17:37, oilmagnet477 said:

Hi all,

As my 501 came with nowt added as standard, does  anyone know what sort of impact power steering (if any?) and Air con had on power delivery with 502 and 503 models?

One would assume that there would be some detrimental effect but not sure I've ever seen it spelt out.

Cheers all

 

For the Delco A/C system 8hp, and this is not compensated at idle.

Power steering a lot less for sure, but how much ?

Neil

 

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clivef38    98

The A/C compressor is all cast iron and you almost need a fork lift to lift it. Did away with it all. added lightness.:lol:

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rjwooll    28
On 08/10/2016 at 16:37, oilmagnet477 said:

Hi all,

As my 501 came with nowt added as standard, does  anyone know what sort of impact power steering (if any?) and Air con had on power delivery with 502 and 503 models?

One would assume that there would be some detrimental effect but not sure I've ever seen it spelt out.

Cheers all

It certainly would - and does - have an effect. Hydraulic PAS saps a handful of bhp. This is one reason that electric PAS is used frequently on modern cars - instead of a pump running constantly, power is only used when it is needed. Similarly aircon will, when active, sap bhp, but the compressor (which is the device that takes the power) normally has a clutch fitted so it's only activated when needed.

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