I live in the sunny south of Europe, hardly ever have the fan on at all, don´t have much lights on either and no sound system fitted.
As such I could do with an ´underdrive´ (i.e. larger) pulley on the alternator.
A smaller pulley on the crank would dictate a smaller waterpump one and has less traction so better not.
Anyone fitted a diferent alternator pulley?
Any EU (UK) source for one?
Yes but. The power required to turn the alternator varies with the load. The bigger the load (served by the battery), the harder the alternator works to keep the battery up. Can't see a massive advantage to a bigger pulley. Not like a supercharger....
Quote from: Carolyn on October 27, 2019, 12:40Yes but. The power required to turn the alternator varies with the load. The bigger the load (served by the battery), the harder the alternator works to keep the battery up. Can't see a massive advantage to a bigger pulley. Not like a supercharger....
Totally true.
Regardless of the load though is the weight of the rotor. The lower the reduction, the lower the power spent on speeding it up.
I have not measured the diameters but it lóóks like the generator turns about 3 times crankshaft speed and it is not a lightweight thing.
Slowing it down basically has a comparable effect to taking some weight off the flywheel.
It would have no effect at constant speed.
p.s. how much does the rotor weigh? 3 kg.?
Although the diameter is small, it doés need to be sped up.
I would quite like to slow it down some 30% at least.
I find it surpring there is so little availeble.
The MWR I would prefer to avoid; tax/shipping plus it is US made.
An Italian tuner offers one for 100€ and that is a bit steep.
Done some rouh calculations and I think it worthwile.
A véry simple modifacation which would not even need a belt change yet ís effective.
The only negative is that it will raise the (engine) revs of max output of the generator.
Asked Boris if he could look into it.
Meanwhile found reasonably priced ones accross the atlantic but with taxes and shipping it becomes silly for a simple pulley.
While Boris thinks about it will ask around locally.
If possible I´d prefer to support the car club source because of the nature of that.
One obeservation:
It is claime that it gives apower gain with evidence by a dyno-bench. Yes that is true BUT no, it does not give more hp. The dyno-bench is an acceleration-bench which then calculated the hp generated. Because the engine needs to accelrate less mass it will thus ´measure´a power gain. If it were a bráked bench it would not give any gains.
So no, it does not increase output but it will make the engine more lively AS IF it has 3, 4 hp more.. Again, like a lighter flywheel but without the negative in the way the engine runs or the stall chacteristcs.
Considering how difficult it is to squeeze extra hp from the n.a. 1zz I am going for it.
If the pulley was 3 foot across then yes i could see it,or if the engine was only 50cc, but something so small on a 1.8 i just cannot see that either the car or driver would notice any difference.
Quote from: 105e on October 28, 2019, 11:49If the pulley was 3 foot across then yes i could see it,or if the engine was only 50cc, but something so small on a 1.8 i just cannot see that either the car or driver would notice any difference.
I agree. And i haven't weighed it, but no way is the alternator pulley 3kg. 300g maybe. I'd put a tenner on it :)
Alternator pulley is so small that you cant care less for it. 5cm diameter tops. Id guess it weights nothing. If you want to do such mod you can replace 1zz water pump with 2zz water pump. It does the same you explained, needs to be driven less times to deliver the same performance.
It's not the weight of the pulley that Petrus is concerned about. It's about maki ng it easier to move the inertial mass of the alternator rotor, (which is a chunky bit of kit).
However. The idea that reducing the inertia of the overall engine package is not the same as lightening the flywheel, doesn't hang together for me. Anything that makes the engine spin up quicker, also makes it spin down quicker.
I know you are one for 'marginal gains', Petrus, but I think I'd find this margin hard to justify in terms of expense and work vs a very marginal return.
Each to their own though.
Quote from: Carolyn on October 28, 2019, 13:29It's not the weight of the pulley that Petrus is concerned about. It's about maki ng it easier to move the inertial mass of the alternator rotor, (which is a chunky bit of kit).
Yes buy you can spin it up with your fingers pretty easily and as he says very little electrical load to make it harder.
Quote from: Carolyn on October 28, 2019, 13:29However. The idea that reducing the inertia of the overall engine package is not the same as lightening the flywheel, doesn't hang together for me. Anything that makes the engine spin up quicker, also makes it spin down quicker.
The difference is the ´rubber band´ it is attached to.
Where the flywheel is bolted to the crankshaft and thus equalises small variations caused by the stroke phase and con rod/crank angle, the rotor has a long stretch of rubber attaching it. To put it is other more direct words: The flywheel pushes the pistons through the compression, the rubber band will give.
So the effect on acceleration/decelleration is comparable with a lighter flywheel but the effect on the smoothness of the engine is not.
Thus comparable advantage with a bit less of the downside.
The chunky bit of kit will be spun up to less speed = sapping less energy = making the engine just that bit livelier without lowering the stall speed a lot.
The compromise I was looking for when looking at lighter flywheels.
Again; nothing more or less than reducing the effort to spin up the chunky bit of kit which is the rotor.
Remember that this rotor is spinning at thréé times crank revs! The force needed to accellerate it, to put the kinetic energy in, is to the power of that.
Yes it also deminishes that load on the belt.
Quote from: Carolyn on October 28, 2019, 13:29I know you are one for 'marginal gains', Petrus, but I think I'd find this margin hard to justify in terms of expense and work vs a very marginal return.
It will do more than taking the sound system out and I thought/think that worthwhile too ;-)
Quote from: Carolyn on October 28, 2019, 13:29It's not the weight of the pulley that Petrus is concerned about. It's about maki ng it easier to move the inertial mass of the alternator rotor, (which is a chunky bit of kit).
However. The idea that reducing the inertia of the overall engine package is not the same as lightening the flywheel, doesn't hang together for me. Anything that makes the engine spin up quicker, also makes it spin down quicker.
I know you are one for 'marginal gains', Petrus, but I think I'd find this margin hard to justify in terms of expense and work vs a very marginal return.
Each to their own though.
He did state the rotor weighs 3kg and needs to be spun up!
Although indonalso agree with your objection. :)
Quote from: jonbill on October 28, 2019, 15:47Although indonalso agree with your objection. :)
She does not object. Just differs in opinion about whether it is worth it the effort. That can and will be said by most people, even enthusiast, about a lot of my efforts and it misses an important point: For mé a lot of the fun is in the figuring something out, the tinkering, the modding itself already and if it has ány positive effect, then that is a bonus.
Also; a lot of little things do add up to a big thing: No, taking the seakers out of the doors definitely makes no noticable difference BUT my car is some 150 kilos lighter now and that is just as definitely quite noticable. Worth the effort? That is beside the point; it makes mé smile :-)
Bottom line is that no, no first hand experience here and no, no ´local´ source.
(https://www.monkeywrenchracing.com/wp-content/uploads/2015/02/MWRudpulleydyno1.jpg)
Quote from: Petrus on October 28, 2019, 17:26Quote from: jonbill on October 28, 2019, 15:47Although indonalso agree with your objection. :)
She does not object. Just differs in opinion about whether it is worth it the effort. That can and will be said by most people, even enthusiast, about a lot of my efforts and it misses an important point: For mé a lot of the fun is in the figuring something out, the tinkering, the modding itself already and if it has ány positive effect, then that is a bonus.
Also; a lot of little things do add up to a big thing: No, taking the seakers out of the doors definitely makes no noticable difference BUT my car is some 150 kilos lighter now and that is just as definitely quite noticable. Worth the effort? That is beside the point; it makes mé smile :-)
Bottom line is that no, no first hand experience here and no, no ´local´ source.
(https://www.monkeywrenchracing.com/wp-content/uploads/2015/02/MWRudpulleydyno1.jpg)
Sorry, I meant objection as in argument. I do understand you do this because it pleases you. We all do I think.
Quote from: jonbill on October 28, 2019, 21:39Sorry, I meant objection as in argument. I do understand you do this because it pleases you. We all do I think.
Thank you; I am not as finely tuned to the finesses of synonyms as you native speakers ;-)
Meanwhile found a source for Ralco RZ pulleys in the Netherlands.
Sent them an email. Might give it a go.
I'm using the MWR Underdrive pulley in my 2ZZ:
https://www.monkeywrenchracing.com/product/mwr-underdrive-pulley-lotustoyota-2zz-water-pump/
Quote from: Alex Knight on October 29, 2019, 00:48I'm using the MWR Underdrive pulley in my 2ZZ:
https://www.monkeywrenchracing.com/product/mwr-underdrive-pulley-lotustoyota-2zz-water-pump/
Thank you for responding Alex and for the link.
Do you notice a difference?
I looked at underdrive pulleys on other cars, they work mainly for the waterpump to stop cavitation at higher RPMs, if you live in a very cold place you should be able to get away with town driving and lower RPM driving with an underdrive pulley.
Basically fit one if you are always above 6k rpm or live in a cool enough country that you don't need a huge amount of flow.
Another option would be to simply not run a mechanical water pump and run a Davis Craig pump.
Others will correct me if I'm wrong. (They always do!!)
BUT
I'm pretty sure the 2ZZ water pump does not fit the 1ZZ.
Quote from: m1tch on October 29, 2019, 07:52I looked at underdrive pulleys on other cars, they work mainly for the waterpump to stop cavitation at higher RPMs, if you live in a very cold place you should be able to get away with town driving and lower RPM driving with an underdrive pulley.
Basically fit one if you are always above 6k rpm or live in a cool enough country that you don't need a huge amount of flow.
Another option would be to simply not run a mechanical water pump and run a Davis Craig pump.
That is the waterpump or the crank pulley yes.
A smaller crank pulley would also spin the ac pump (if fitted) less.
Indeed it does not Carolynne. Ditto waterpump pulley; is different. Ditto crank pulley; the 2ZZ has a harmonic balancer and fitting a solid aluminium one is not a good idea. No such issue on the 1ZZ. That being as it is, fitting only the alternator one avoids any problems with either crank or waterpump ;-)
Quote from: Petrus on October 29, 2019, 01:36Quote from: Alex Knight on October 29, 2019, 00:48I'm using the MWR Underdrive pulley in my 2ZZ:
https://www.monkeywrenchracing.com/product/mwr-underdrive-pulley-lotustoyota-2zz-water-pump/
Thank you for responding Alex and for the link.
Do you notice a difference?
Hard to say, as I had the engine out to do a lot of maintenance & upgrades at the same time.
I'd be amazed if anyone could notice the back to back difference though.
I only fitted it to reduce the chance of any potential high RPM cavitation, as I do a lot of track days.
Have ordered the MWR alternator pulley from a Dutch distributor:
https://www.rideround.nl/shop/3-341-929/mr2-multiriem-systeem/mwr-underdrive-dynamo-pulley.html
Slows the alternator down with only 25% so it should not give electrical issues and is probably not noticable but hey, the n.a. 1ZZ has no excess horses so marginal gain it is.
The equivalent of 2 kg. off of the flywheel with less of the stall issue.
Quote from: Petrus on October 29, 2019, 21:38Have ordered the MWR alternator pulley from a Dutch distributor.
Slows the alternator down with only 25% so it should not give electrical issues and is probably not noticable but hey, the n.a. 1ZZ has no excess horses so marginal gain it is.
Won't the 1zz struggle at idle with a 25% underdrive alternator?
Quote from: jonbill on October 29, 2019, 21:54Won't the 1zz struggle at idle with a 25% underdrive alternator?
Struggle with what or in which aspect?
Quote from: Petrus on October 29, 2019, 22:04Quote from: jonbill on October 29, 2019, 21:54Won't the 1zz struggle at idle with a 25% underdrive alternator?
Struggle with what or in which aspect?
I mean not output a higher voltage than the battery, so the car will be running off the the battery not the alternator at idle and the battery light will come on, no?
Quote from: jonbill on October 29, 2019, 22:18I mean not output a higher voltage than the battery, so the car will be running off the the battery not the alternator at idle and the battery light will come on, no?
Ok, I understand now.
Because I have a silly light mini battery that is sensitive to overcharging, I fitted a Volt-meter:
(https://myalbum.com/photo/yQj4UduV3WP6/1k0.jpg)
As such I have had an eye on the voltage for the best part of a year.
Even immediately after starting, with the revs at normal idle it is at 14.2 Volt without any users and with main lights on 13.9 - 14.0.
Lowering/raising the windows with the light on does not drop it under 13.8 at idle.
The thing is that it needs only charge very little and the regulator can simply put more current through the stator.
I don´t expect any issue and íf I would be at a traffic light in the dark with blower on, or what; too much drain from electrical users, I can simply raise ´idle´ with the right foot.
But.... we will see soon enough ;-)
The pulley is in.
Will do it at the garage as an air tool will make light work of what manually can be herculean, so next week.
Quote from: Petrus on October 29, 2019, 22:33Quote from: jonbill on October 29, 2019, 22:18I mean not output a higher voltage than the battery, so the car will be running off the the battery not the alternator at idle and the battery light will come on, no?
Ok, I understand now.
Because I have a silly light mini battery that is sensitive to overcharging, I fitted a Volt-meter:
(https://myalbum.com/photo/yQj4UduV3WP6/1k0.jpg)
As such I have had an eye on the voltage for the best part of a year.
Even immediately after starting, with the revs at normal idle it is at 14.2 Volt without any users and with main lights on 13.9 - 14.0.
Lowering/raising the windows with the light on does not drop it under 13.8 at idle.
The thing is that it needs only charge very little and the regulator can simply put more current through the stator.
I don´t expect any issue and íf I would be at a traffic light in the dark with blower on, or what; too much drain from electrical users, I can simply raise ´idle´ with the right foot.
But.... we will see soon enough ;-)
I can tell you what REALLY pulls power; a subwoofer :)
It's hilarious watching my volt meter in my clock and then playing a song that has random bassy moments. I can get it to drop as low as 9v with high bass and volume. If I turn on my seat heating on both seats, all lights, fan on full, and activate windows while playing loud bass music, I managed to get the battery light to come on hahaha.
Good times.
Quote from: shnazzle on November 7, 2019, 13:44It's hilarious watching my volt meter in my clock and then playing a song that has random bassy moments. I can get it to drop as low as 9v with high bass and volume. If I turn on my seat heating on both seats, all lights, fan on full, and activate windows while playing loud bass music, I managed to get the battery light to come on hahaha.
Good times.
Seen mý head unit?
(https://myalbum.com/photo/3GXPafgf8itD/1k0.jpg)
and no woofers nor yeppers in the doors either (got four running around) :-)
Fitted. Sofar no difference seen on the Volt meter.
Idle; fan on, lights on, window up/down; no effect, stable as a rock.
(https://myalbum.com/photo/wDwtP3oWWARd/1k0.jpg)
So, conclusion?
Something we should do or not?
Guess it puts less strain on the alternator if yoy rev it a lot (i.e. Me)
Quote from: shnazzle on November 13, 2019, 18:11So, conclusion?
Something we should do or not?
Guess it puts less strain on the alternator if yoy rev it a lot (i.e. Me)
Í have done it and would do it again.
Depends entirely on whether you nééd the maximum output. If not, go for it.
If you rev it a lot, it is a no brainer imo as above 3K the alternator is spinning more than it needs as max output is reached on the standard pulley.
Changing is a job not worth that name íf, big IF, you use an air tool.
And you need a 5cm longer belt.
Quote from: Petrus on November 13, 2019, 18:23Quote from: shnazzle on November 13, 2019, 18:11So, conclusion?
Something we should do or not?
Guess it puts less strain on the alternator if yoy rev it a lot (i.e. Me)
Í have done it and would do it again.
Depends entirely on whether you nééd the maximum output. If not, go for it.
If you rev it a lot, it is a no brainer imo as above 3K the alternator is spinning more than it needs as max output is reached on the standard pulley.
Changing is a job not worth that name íf, big IF, you use an air tool.
And you need a 5cm longer belt.
I've already destroyed one alternator, just wondering if I should spare this one a bit.
As for install;
Just a case of belt off, carbon canister out, undo bolt on pulley and replace? I can see how an impact gun would be required here unless you remove the right motor mount which wasn't fun last time I did it
Quote from: Petrus on November 13, 2019, 17:41Fitted. Sofar no difference seen on the Volt meter.
Idle; fan on, lights on, window up/down; no effect, stable as a rock.
(https://myalbum.com/photo/wDwtP3oWWARd/1k0.jpg)
Surprised, but win! Even if its a small one :)
Quote from: shnazzle on November 13, 2019, 19:25I've already destroyed one alternator, just wondering if I should spare this one a bit.
As for install;
Just a case of belt off, carbon canister out, undo bolt on pulley and replace? I can see how an impact gun would be required here unless you remove the right motor mount which wasn't fun last time I did it
It is a véry good idea for making life easier on the alternator indeed.
Yes, correct. As simple as that. In my case even simpler as I have the canister out.
The impact gun also undoes the nut like a treat which by hand may be not even póssible with the alternator mounted.
I
Fitted the 130/90 headlight bulbs.
Started up. Let the idle settle.
Voltmeter reading 14.2V
Switched on lights. Voltage drops to 14.1 and resettles at 14.2.
Switch on mains dipped. Voltage drops to 13.9 and settles at 14.2.
Now large. Voltage to 13.6, settles at 14.1 then 14.2.
I had roughly worked out that it would work, but it still is tense butt till it does.
I mean; 0.8 kg mini battery, high wattage bulbs, underdrive alternator pulley...
Done some night distance with the 100 Watt lights on and there is no issue.
Did notice a difference now. The smt blipping the throttle on the downshift is noatably more brisk.
All in all still a thumbs up!
I feel I should. But... That's a lot of money for a pulley. Too much.
Quote from: shnazzle on November 18, 2019, 21:43I feel I should. But... That's a lot of money for a pulley. Too much.
Well, I agree but... it is not for the pulley; it´s for the effects: Forget about the difference when shifting, just think about the reduction of the load on the alternator.
https://www.ebay.co.uk/itm/VMS-Racing-Light-Weight-Aluminum-Crankshaft-Crank-Pulley-1-8-Corolla-Celica-MR2/292765028911?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D225076%26meid%3D50f99fb17f7a4a61852f86b96bac17d0%26pid%3D100970%26rk%3D6%26rkt%3D15%26mehot%3Dnone%26sd%3D362126773729%26itm%3D292765028911%26pmt%3D0%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100970.m5481&_trkparms=pageci%3A59ce9f1b-53e9-11ea-b263-74dbd180ae39%7Cparentrq%3A62e65b231700a128ed37fa1bffcf15ec%7Ciid%3A1 (https://www.ebay.co.uk/itm/VMS-Racing-Light-Weight-Aluminum-Crankshaft-Crank-Pulley-1-8-Corolla-Celica-MR2/292765028911?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D225076%26meid%3D50f99fb17f7a4a61852f86b96bac17d0%26pid%3D100970%26rk%3D6%26rkt%3D15%26mehot%3Dnone%26sd%3D362126773729%26itm%3D292765028911%26pmt%3D0%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100970.m5481&_trkparms=pageci%3A59ce9f1b-53e9-11ea-b263-74dbd180ae39%7Cparentrq%3A62e65b231700a128ed37fa1bffcf15ec%7Ciid%3A1)
What about this lightweight aluminum crankshaft pulley?
Dangerous territory there.
That's one of those mods where you'll enjoy some quick revving, until the off-balance finally screws things.
The lads at High Performance Academy did a whole seminar on it.
It's one of those things where if you do it you have to do it right. And right = expensive
Quote from: shnazzle on February 21, 2020, 20:43Dangerous territory there.
That's one of those mods where you'll enjoy some quick revving, until the off-balance finally screws things.
The lads at High Performance Academy did a whole seminar on it.
It's one of those things where if you do it you have to do it right. And right = expensive
I just found this thread, but I'm still looking for Yours opinions.
https://www.toyotanation.com/threads/2005-corolla-1zz-fe-light-weight-crankshaft-pulley.1571482/
I'm going to stay with MR2 for a long time.
@edit
Official site:
https://www.vmsracing.com/products/copy-of-subaru-impreza-wrx-sti-light-weight-aluminum-crankshaft-crank-pulley-oem-size
As with an underdrive alternator pulley it does nót increase engine output one bit.
Unlike an underdrive pulley the OEM crank pulley also has a balancing function.
It must however be noted that the word on the more knowledgable fora is that the 1ZZ can be fitted with a lighweight one whereas the 2ZZ can not. Personally I find the ´data´ under the latter conclusion even softer than the pre-cat damage info.
I checked the thing on mine being a harmonic damper or not and it is not much of one. The thin rubber bonding layer is thin and the outer righ rather light. It will do very little if anything at all on the 1ZZ.
Here a clear illustration shamelessly nicked from the interweb
(https://www.rideround.nl/media/Product/241o1bv2e79381e341rpl1hf2i381mjhf.jpg)
Anyway, I have not gone this route, yet. Need more info.
Any pointer to the HP Academy info Patrick?
Just as a footnote: I think lighter/underdrive pulleys rather cool ´tuning´ gadgets by principle.
They do not generate/liberate any more power from the engine. Ok, the water pump impeller going slower meets less water resistance but that is negligeable.
Yet on the Dyno is does register more power.
Same thing on the drag strip.
Both the Dyno and the drag strip are accelero-´meters´ and in that the reduction in rotational mass doés count.
So no they do not do anything to add power, they do however the equivalent by reducing rotational mass. Reducing say 1,5 is that ánd that times engine rev ´delta´ :))
Anyone with more data on the balancer or damper aspect?
Read about several pulleys going wobbly because of the rubber bond layer starting to go. Nothing odd as it is 15 year plus old rubber now.
Both the VMS one in OEM size and Cosmo underdrive version are still availeble.
Still cool ´tuning´.
Meanwhile ordered the VMS pulley.
For explantion see also https://www.mr2roc.org/forum/index.php?topic=69358.0
(https://i.ebayimg.com/images/g/nckAAOxy9X5TZTBT/s-l500.jpg)
For those, or the one, interested in the plus or minus of the harmonic pulley there is another thing to take into account:
There is a whole lot of weight being pushed and pulled around by the pulley by means of a belt. How´s that for a harmonic damper ;-)
Now switch on the a/c and bear in mind the force it takes to drive it.
Ditto a lighter underdrive alternator pulley or a twice as heave decoupling one.
All in all, when we start modding the car, the harmonic argument becomes a moot one.
The lightweight crank pulley looks véry well made and is some 1.2 kg lighter.
Krukaspoelie.jpg
https://youtu.be/J1BGsgIZ_Ek
And the associated blurb.
http://www.atiracing.com/products/dampers/101/index.htm
Now, grain of salt of course because of who wrote this but the reason I knew where to look is because of the sheer amount of random engine builds I've seen online and how many of those use this specific damper.
Funnily enough, they make one for 2zz.
Might be one for the track peeps
Quote from: shnazzle on June 2, 2020, 20:43Funnily enough, they make one for 2zz.
Also informative. The 2ZZ already hás one so they are basically underlining that tuning shifts/cahnges the requirement. The Toyota one is a wide band design so íf it would need replacing than the shift is considerable.
With the 2ZZ though, it is a bit mwah as the engine will not be asked to run at the same revs for long and rushing up/down through the revs does not require such a rev specific damper.
Going down to the coast in a moment. Good comparative trip.
Quote from: Petrus on June 3, 2020, 09:35Going down to the coast in a moment. Good comparative trip.
Just back.
Almost 200 km. Half local mountain roads, half provincials.
Two thumbs up.
1. engine feels ... more dynamic; the whole rear does oddly enough
2. shifts marginally crisper