MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: shnazzle on August 22, 2016, 14:15

Title: WOSP Alternator
Post by: shnazzle on August 22, 2016, 14:15
In a bid to extract the most out of the 1zz...

Has anybody perchance looked at the WOSP TPS range alternators?
They seem to be available in the correct size, although ampage is a bit high.

Basically these alternators are geared and linked to your TPS and brake light. So if you're braking or coasting, it engages the gear and generates power. But if you're putting load on, it disengages the gear so you get little to no parasitic losses through the alternator.

Not sure what kind of losses you see through the stock alternator. But, might make a bigger difference than, say, an intake or exhaust as you're actually reducing the amount of work the engine has to do to spin.

Thoughts?
Title: Re: WOSP Alternator
Post by: Jrichards20 on August 22, 2016, 14:21
1-2hp loss I would imagine (1hp - 40A?). not exactly a massive alternator. Wonder what the weight of the new alternator is and whether it would actually be detrimental.
Title: Re: WOSP Alternator
Post by: shnazzle on August 22, 2016, 14:23
Quote from: "Jrichards20"1-2hp loss I would imagine? not exactly a massive alternator. Wonder what the weight of the new alternator is and whether it would actually be detrimental.

It's race-spec and supposed to be lighter.
Alternatively (no pun intended) there are also lightweight "race" alternators but these aren't intended to run radios, subs, heating, etc etc.
Title: Re: WOSP Alternator
Post by: vx220 on August 22, 2016, 16:13
Dave Walker rolling roaded a car without its alternator belt and could barely measure the loss from an alternator.

I think it would need to be an absolute on the limit race car to make it worthwile
Title: Re: WOSP Alternator
Post by: shnazzle on August 22, 2016, 16:49
Cool. Best to save that cash then. That's one stg1 cam hehe

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Title: Re: WOSP Alternator
Post by: Essex2Visuvesi on August 22, 2016, 18:16
Now A/C on the other hand....
Title: Re: WOSP Alternator
Post by: shnazzle on August 22, 2016, 18:17
Yes but I've never found a "race A/C"   s:) :) s:)  

And, the compressor needs to run all the time when you've got the A/C on.


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Title: Re: WOSP Alternator
Post by: Essex2Visuvesi on August 22, 2016, 18:21
Quote from: "shnazzle"Yes but I've never found a "race A/C"   s:) :) s:)  

And, the compressor needs to run all the time when you've got the A/C on.


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What I meant was there is a noticeable difference between cars with and without A/C on the dyno. Not as much as there was 15 years ago but its still a good few HP.  My old S14 gained almost 8Hp simply by removing the AC compressor
Title: Re: WOSP Alternator
Post by: shnazzle on August 22, 2016, 19:39
Really? That's a big difference.
Not that I'd do without AC, but it'd be great if a geared compressor existed.

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Title: Re: WOSP Alternator
Post by: 1979scotte on August 22, 2016, 21:32
I have plans to ditch mine anyway for the weight saving.
This just puts the icing on the cake.
Title: Re: WOSP Alternator
Post by: stupink on August 22, 2016, 23:02
resistance (physical) if I am correct increases with load, so if the battery is charged, and no current drain ie lights/amps etc then the losses will be slim, if the battery is duff and constantly accepting charge, or you have high power demand then you'd be drawing more/loading up more.
Title: Re: WOSP Alternator
Post by: Jrichards20 on August 22, 2016, 23:27
Quote from: "1979scotte"I have plans to ditch mine anyway for the weight saving.
This just puts the icing on the cake.

The alternator?? Are you sure....

Or the A/C?  Not like you ever need the A/C I'm not even sure if your car has a roof!
Title: Re: WOSP Alternator
Post by: shnazzle on August 23, 2016, 06:51
Quote from: "stupink"resistance (physical) if I am correct increases with load, so if the battery is charged, and no current drain ie lights/amps etc then the losses will be slim, if the battery is duff and constantly accepting charge, or you have high power demand then you'd be drawing more/loading up more.
So it's a catch22. If you're running lots of electrical gear, you could benefit from an alternator like this as you're likely to require more constant heavy loads. But at the same time, the alternator wouldn't be producing the charge if you were cruising around so you'd run out of juice quickly.

All in all... Stock alternator unless you're building a race car, in which case you miiiiight benefit from a lighter one.
Title: Re: WOSP Alternator
Post by: stupink on August 23, 2016, 09:51
yeah pretty much I expect its aimed at race cars entirely.. just to keep a charged battery topped up to keep brake lights and the ECU alive.   we have EPAS and stereo's and windows and headlights to worry about...
Title: Re: WOSP Alternator
Post by: 1979scotte on August 23, 2016, 10:25
Quote from: "Jrichards20"
Quote from: "1979scotte"I have plans to ditch mine anyway for the weight saving.
This just puts the icing on the cake.

The alternator?? Are you sure....

Or the A/C?  Not like you ever need the A/C I'm not even sure if your car has a roof!

The AC mate.
The rad is shot anyway so get rid and change the belts few more horses and less weight.
Title: Re: WOSP Alternator
Post by: shnazzle on August 23, 2016, 10:28
Quote from: "1979scotte"
Quote from: "Jrichards20"
Quote from: "1979scotte"I have plans to ditch mine anyway for the weight saving.
This just puts the icing on the cake.

The alternator?? Are you sure....

Or the A/C?  Not like you ever need the A/C I'm not even sure if your car has a roof!

The AC mate.
The rad is shot anyway so get rid and change the belts few more horses and less weight.

Totally different  car but I know the A/C delete on the Leons was a big thing for the stage 2+/3 guys chasing 400hp and over. Losing the A/C gained serious power and reduced some serious weight.