Lightened Pulleys - Printable Version

Lightened Pulleys - Printable Version

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Lightened Pulleys - mech - 04-08-2005

Has anyone tried these on a 968? Whats the weight of the stock crank, atl, and ps pulleys? Does the crank pulley on our cars are act as a harmonic dampener?

Lightened Pulleys - flash - 04-08-2005

i have them - the set is 1.5 lbs lighter than stock - the manufacturer has documented claims of output increased by 7hp - this is in line with results i've seen with other similar setups

the crank pulley is not a dampener on our car - that is handled elsewhere

resultant alternator output is insuffiecient at idle for a commuter car - it is fine for a toy - i do not recommend this setup for anyone who may sit in traffic with the lights, wipers, heater, or any other such accessory on while in that traffic - at 1250 rpm, everything is fine

i love the setup, but my car is strictly a toy

unfortunately, the company that made them is now out of business

Lightened Pulleys - mech - 04-08-2005

awww, such easy hp. Nopi has a unorthodox pulley listed for the 968, but I emailed unorthodox and they say that is not correct. Oh well, I'll keep looking <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />

I wonder if we could get them to develop one for a group buy, they make 2 sets, and underdrive set and a lightened set, its cool to have choices...

Lightened Pulleys - flash - 04-08-2005

i'd like to see a set that didn't reduce the alternator output as much - the problem is belt size and adjustability limits - it would mean less hp gain, but better driveability

Lightened Pulleys - skip - 04-08-2005

[quote name='flash' date='Apr 8 2005, 03:22 PM']i'd like to see a set that didn't reduce the alternator output as much - the problem is belt size and adjustability limits - it would mean less hp gain, but better driveability

[right][post="3034"]<{POST_SNAPBACK}>[/post][/right][/quote]

How about a set that doesn't underdrive but is Alum? Or, is it really the underdrive that you're looking for as well? My personal opinion is that underdriving any of the accessories for any other reason than max power output is not recommended. i.e. this mod should be considered for those very serious about power or strictly race cars (no radio, no fan, minimal PS need, no AC). If weight/mass/looks is the issue, how about OE sized alum pieces?

Lightened Pulleys - flash - 04-08-2005

both the power steering and the alternator reach max output and then stop increasing pressure and current very early - underdriving them is not an issue except for not having as much juice at low rpms as i would like to see - the power steering is not an issue at all - the air conditioning may output a little less, but i haven't noticed any problem there either, and it is a pump as well - it may mean that the pump runs a bit longer to achieve its charge

the horsepower benefits are at low rpms where this engine can use it the most - after that, the drag is maxed out and the gains decrease

stock size aluminum pulleys would be better than steel, and there would be some gain from that, but the real gain is in the reduction of drag from the accessories

i agree that this setup is not for the average driver - there are compromises that i cannot recommend to everybody - for me it works because i seldom drive it in traffic, never in the rain, and it is almost never cold here - i've had the heater on twice since i bought the car

i think a set that didn't change the alternator would be a good compromise - it means a completely different set though, because the pulleys sum a belt length within the range of adjustment (for those of you who were thinking "hey, why not leave the alternator pulley alone?") - small diameter differences result in large belt length changes and quickly get outside the range of the adjusters

ah, choices (who said that?)

Lightened Pulleys - skip - 04-08-2005

[quote name='flash' date='Apr 8 2005, 04:26 PM']ah, choices (who said that?)

[right][post="3037"]<{POST_SNAPBACK}>[/post][/right][/quote]

Not me! You'll buy what I tell you to - and, like it! <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />

Agreed on the minimal effect - that might be why they're a hard sell, eh. I wouldn't even entertain the idea of mix-n-match pulley sets, but, a complete underdrive set and an all-but-alternator set might be okay. Belts, schmelts - we use rubber bands anyway. Honestly, there's quite an assortment of belts out there - they just won't say porsche on them - *gasp*

Lightened Pulleys - flash - 04-08-2005

and my iced tea is now all over my monitor - thanks

the pulleys are such sizes that, with a .1" change in diameter meaning a .31" change in belt length, and with the adjustment only being an inch or so, and needing a certain amount of that to get any belt on there, it doesn't leave much room for changing pulley size enough to make a difference if you were just trying to adjust the alternator pulley - you really have to do all of them - that makes things complicated - the underdrive set is dramatically different in size to stock - to give you an idea of how different they are:

when i crunched the numbers, i came up with a 14% reduction in air conditioning speed, 33% reduction in power steering speed, and a 47.9% reduction in alternator speed - given the already dramatically chagend size in alternator pulley, i think you can see the problem

Lightened Pulleys - Greimann - 04-08-2005

The only measurable gains from a different pulley set would be from underdriving. A lighter set with the same ratios would not be worth the skinned knuckels to install them. The reduction in rotational inertia would be small, small fractions of a HP.

Lightened Pulleys - mech - 04-09-2005

I have unorthodox sc(not underdriven) pulleys on my Acura, the difference was more noticable than adding an cai. The stock pulleys on the acura were 14 lbs, the lightened ones were 8 lbs. I guess for the 968 that is not an area we can regain lost power.

Lightened Pulleys - skip - 04-09-2005

[quote name='Greimann' date='Apr 8 2005, 05:51 PM']The only measurable gains from a different pulley set would be from underdriving. A lighter set with the same ratios would not be worth the skinned knuckels to install them. The reduction in rotational inertia would be small, small fractions of a HP.

[right][post="3049"]<{POST_SNAPBACK}>[/post][/right][/quote]

I think you're forgetting about the BLING, baby. <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />

Lightened Pulleys - flash - 04-09-2005

on the bling note - i haven't polled too many, but so far, oddly enough, everybody wanted black ones, which mine happen to be

Lightened Pulleys - skip - 04-09-2005

[quote name='flash' date='Apr 9 2005, 07:20 AM']on the bling note - i haven't polled too many, but so far, oddly enough, everybody wanted black ones, which mine happen to be

[right][post="3060"]<{POST_SNAPBACK}>[/post][/right][/quote]

pink anodize is what I am hoping for - should match my nails. <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />

Lightened Pulleys - flash - 04-10-2005

and there went my coffee - i just got the tea cleaned up - thanks - on a hangover that was just too much

Lightened Pulleys - Jason Judd - 04-11-2005

Why do it that way...just remove the H/V/AC system completely, the wipers and we're on our way.

Now if a manual steering rack conversion wasn't so darned expensive, I'd be all over that, too.

Jason

Lightened Pulleys - flash - 04-11-2005

the rack is something i want to look into myself too - too many turns lock to lock - going to see what other racks fit in there

Lightened Pulleys - NeedPorscheSpeed - 04-17-2005

[quote name='skip' date='Apr 8 2005, 06:42 PM']Not me! You'll buy what I tell you to - and, like it! <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />[right][post="3040"]<{POST_SNAPBACK}>[/post][/right][/quote]

<img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/biggrin.gif" class="smilie" alt="" />

Skip,

I got a big laugh out of this snippet and others on this thread. It's good to see you here. <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />

Lightened Pulleys - mech - 04-18-2005

heres a followup

this is my email

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Is there anyway to get you guys to develop a set for the 944/968 series porsches? Perhaps if a group buy was made to cover the development costs?

this is the email i got from unorthodox,

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Sorry for the slow reply. Your request is doable. We used to offer a two piece crank pulley kit for the 944 but unfortunately sales were fairly weak. Your cost would run approx. $200 per kit if it was based off the two piece crank pulley we used to sell.

Thanks for your question,

Shawn Baumgartner

Distributor, Export & Private Label Sales

Unorthodox Racing Inc.

Phone: 631-586-9525 x.16

Fax: 631-586-2599

www.unorthodoxracing.com

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