´Racing´ alternator

Started by Petrus, May 12, 2022, 21:08

0 Members and 1 Guest are viewing this topic.

Petrus

Anyone fitted a lightweight alternator?

A Denso/Kubota 40 amps one is only 2,8 kg. , has the same electrical schematic and almost identical fixing points.
Q&D reckoning results that the rotor should be some 1,5 kg. lighter.
Thus 2,5 lighter car and 1,5 kg less engine rotating mass.
Seems worthwhile no?!

Nvy

Quote from: Petrus on May 12, 2022, 21:08Anyone fitted a lightweight alternator?

A Denso/Kubota 40 amps one is only 2,8 kg. , has the same electrical schematic and almost identical fixing points.
Q&D reckoning results that the rotor should be some 1,5 kg. lighter.
Thus 2,5 lighter car and 1,5 kg less engine rotating mass.
Seems worthwhile no?!

Ours is 160 amps, no? I am all in for the lightness, went with 1.2 kg battery :) It has to be tested of course but if the diff is that big I dont think its going to work.

But again I am in the process of buying 2 tons car with a huge v8 so dont mind me 😂😂

Petrus

Quote from: Nvy on May 13, 2022, 07:54Ours is 160 amps, no? I am all in for the lightness, went with 1.2 kg battery :) It has to be tested of course but if the diff is that big I dont think its going to work.

But again I am in the process of buying 2 tons car with a huge v8 so dont mind me 😂😂

Oh no, depending on which one happened to get out of the parts bin it is 70 -90 amps if I recall correctly. Also that is because of the engine also being fitted in MANY more models as in the MR2 it does not really need such a biggie.
Remember that W = I x V.  Add up some users and divide by 14V.

And Í have just bought a Kei car ´WagonR+´ (with Spyder wheels) so dó mind a LOT  ;D  Mán did we have fun at the coast again yesterday. We hopped to and fro several nice places and parked éverywhere close for free. The tightest space had  lass than two hands on either end; say 3.50 meters long and I got it in  8)  The car being so narrow means it does not get a meterandahalf longer when slightly at an angle. Looking forward, sort of, to filling up 600 kms worth for 60 Euros  ;)


Nvy

We are picking the pony next week but wont have money to fill up :D 95 petrol went to almost 2 euros. Just as I was surfing the used car market today an yaris gr went for sale... I had to wait damn it but on the side note the pony is my wifes dream car so we will own it for a bit :)

Petrus

Quote from: Nvy on May 13, 2022, 11:46note the pony is my wifes dream car so we will own it for a bit :)

Has she reverse parallel parked it yet?  ;)

And the energy prices keep floating upwards  :o  ::)

A lighter alternator should be more economic and with the current litre prices only just a tank full  :))

Nvy

For the moment I have my car for sale, its on the mega expensive side but if anyone wants it they can have it. Ill be test fitting a turbo kit if I find some spare time. With a 5 months old kid is not easy so she will be a garage queen for the time being.

Please do share some info if you try the alternator altho I dont think I can use it coz ill be fitting 2 pumps one for the water to air and one oil cooler for the tranny.

Petrus

Quote from: Nvy on May 13, 2022, 12:36With a 5 months old kid is not easy so she will be a garage queen for the time being.


Do you keep the kid in the garage?? WOW!! :o  :o

 ;)

Petrus

Here a 2,8 kg. Denso alternator with the ´Toyota´ wiring



Petrus

The alternator bought and underway.
Have decided not to fit it myself but have the car electrics specialist in the village do it.
They ALWAYS help me out with odd things and more often than not don´t charge me. This is one I can pay them to do.


Nvy

Quote from: Petrus on May 13, 2022, 19:29The alternator bought and underway.
Have decided not to fit it myself but have the car electrics specialist in the village do it.
They ALWAYS help me out with odd things and more often than not don´t charge me. This is one I can pay them to do.


It's a bitch to replace tbh. I gave it to a shop to replace mine. One of the mounts should come off and then it's all by feel. Pretty happy I didn't do it myself not to shorten my life :D

Petrus

Quote from: Nvy on May 13, 2022, 19:49It's a bitch to replace tbh. I gave it to a shop to replace mine. One of the mounts should come off and then it's all by feel. Pretty happy I didn't do it myself not to shorten my life :D

You can actually see the ´blind´ stuff from below. Not having the nappies fitted helps  ;)
Looked/measured that side up for a possible SC12/14  :-[

Petrus

#11
In transit; eta 25-28/05  ::)  ::)
Pátience...
As observed, not counting the airco delete, that would add up to over 6 kg less rotating engine mass.

The effect of which can be multiplied by the (overall) gear ratio, thus gear you are in. On our MR2s (depending on the gear box) it is roughly between 3 and 12 times. As in the lower gears the practical effect is lower, 3 to 5 times the % of rotational mass of total mass is the most representative. Easier still is taking the car weight as 1000 kg. Obviously, the lighter of heavier the car, the smaller or larger the % thus effect. (much like aero  ;) )

In common English it translates to a rule of thumb for our MR2s to every kg of rotational engine mass reduced having the same nóticeable effect as 3 (to 5) times that off the vehicle.*

Here the explanation; The Effects of Rotational Inertia on Automotive Acceleration (hpwizard.com) . Makes for a very interesting read imo. The parting shot; the last observation under the article, is imo paramount for understanding the issue. There is NÓ hp gain, but the available hp has less mass to shift, less work to do so has more effect.

The féél effect with SMT is übercool. The electronics cope brilliantly and it ´only´ shifts quicker. A lót. Logically of course.

* my car weighing under 900 kg., the 6 kg times 12 in first is a WOW figure which is totally meaningless as first also involves taking off on the clutch, traction available and very short time. Hence more representative to take the (higher) highest gear(s) only.

Ardent

Quote from: Petrus on May 15, 2022, 09:33The parting shot; the last observation under the article, is imo paramount for understanding the issue. There is NÓ hp gain, but the available hp has less mass to shift, less work to do so has more effect.
Simple as that.

Petrus

Quote from: Ardent on May 15, 2022, 16:06Simple as that.

Take that; the same force having more effect because it has to shift less mass, one step further and the crux of reducing MR2 becomes clear too, with the sideways force of the front tyre resulting from steering input as the available power: Less MR2 makes the car change direction quicker.

fawtytoo

Quote from: Petrus on May 15, 2022, 09:33There is NÓ hp gain, but the available hp has less mass to shift, less work to do so has more effect.
Power to weight ratio. Probably over 150BHP per ton now.
"My name is not important" - Slartibartfast

Petrus

#15
Quote from: fawtytoo on May 15, 2022, 17:06Power to weight ratio. Probably over 150BHP per ton now.

That too, but that is one step earlier on the ´aha´-erlebnis scale ;)

As to the númbers it is a bit of moot pint as the hp is a bit of an unknown*. Point is that we can take it as a báse value again. I mean: that it is what it is. Then reducing weight by 10% becomes a 10% increase in what it can dó. On mine it is say 15%. Well not counting that the wheel weight counts double. Oh peeps, there we go already  ::)

* the engine puts out from the box hów much?
Then we mix say 100k miles of wear, exhaust headers, MAF mod, derestricted filter horn, sportscat/decat, a better flowing damper and ... anyone´s guess is as good as mine. The section where dyno runs are documented speaks for itself in this.

Which is why I´d lóve for Jason to take mine for a spin. His is pretty much a from the box TTE turbo. Say 1200 kg with 180 crank horses.
It is also why I still have a spin with a stock one for sale on the list. Them´s just só thin on the ground here. No Covid restrictions though this summer !!!

jvanzyl

Do you have a link to the alternator that you bought?
01 Silver 1ZZ<br />The Smile Machine: viewtopic.php?f=88&t=59837

Petrus

#17
Quote from: jvanzyl on May 15, 2022, 18:24Do you have a link to the alternator that you bought?

https://www.ebay.de/itm/115378231050

should be cheaper at your end.

jvanzyl

Terrific thank you Petrus.
01 Silver 1ZZ<br />The Smile Machine: viewtopic.php?f=88&t=59837

Petrus

Quote from: jvanzyl on May 15, 2022, 20:22Terrific thank you Petrus.

If you decide to go for it, you can beat me to mounting it by a week with two fingers in the nose  ;)  I´d be lucky to have it spinning by the belt before june  ::)
Have probably corner weighed it before then as the other gf has a level/flat garage floor. Just need to haul the scales and jack.

Ardent

Drifting OT.
@Petrus

Paraphrasing your own words, power makes it fast, lightness makes it quick. Or something like that.

Despite having a few more ponies than stock, I do not use them. Extremely rare I ever call on all of them. I am a torque guy not a power guy. I just love the shove.
Bit like my astrological sign. Taurus. More Bull than gazelle. Me and the 2 are same on that front.
Even without trying yours, I know yours would be quicker. I would be more than happy with a passenger ride one day.

Petrus

Quote from: Ardent on May 15, 2022, 21:27Bit like my astrological sign. Taurus. More Bull than gazelle. Me and the 2 are same on that front.

Nice one that. Me and mine are libra and balance  ;)

Petrus

Shipping has been confirmed.

You´re welcome any day @Ardent.

Looked at the car sales pages and only two in Andalucia. Oddly enough one with turbo and the other with 2ZZ homologated :o  Both with stunning asking prices and mentioning >20K Euros spent. None close by. One at almost two hours, the other at over three.





Petrus

#23
This morning went for a ride top down under sun. Mán what a nice car is that MR2 cabrio.

Looking forward to the lighter alternator as évery rotating engine mass reduction has been so effective. Álmost makes me regret going conservative for the CC Ultralight steel one and not for the Fidanza aluminium. I chickened out because of the potential complications outweighing 0.4 kg.  :-[
It makes the car feel more... spritely. Probably accentuated by the SMT liking it too. Whatevvah it is; actual or perceived, it is enjoyable.

Ardent

Quote from: Petrus on May 17, 2022, 12:53Whatevvah it is; actual or perceived, it is enjoyable.
and that's all that matters.