GenVibe - Community for Pontiac Vibe Enthusiasts

I just found a set of AEM tru-power pulley kits for the celica GT-S/matrix XRS. They were only $75 compared to the unorthodox racing pulleys for 400. The AEM kits consists of two pulleys and a belt with instructions. They will be at my doorstep tomorrow.

OK, don't tell us where you saw them. Please don't!

quote:OK, don't tell us where you saw them. Please don't!LOL! I was kind of wondering the same thing. Where did you see these at?

http://www.optauto.com is where I purchased them. You can also check out AEM's website for more details! I will installed them on my Vibe GT on Thursday so I will post a response telling all of you how they are and what kind of installation problems, if I have any of them03' Abyss Vibe GTMoon & Tune, 6disk-changer, security system, Injen CAI, TRD muffler, Freedom design strut brace, grafxwerks badging, 20% tint, silentrage See-ya graphics(not installed yet due to winter), interior red neon.

I just though I would let everyone know that Adventon.com has an even better price. They are $60.60 for the kit in red, blue or silver. Take a look: AEM Pulleys from ADVENTON.COM I might have to get a set of these as well!

Ok, what's the tradeoff? Are these pulley's the same size? What gets turned faster / slower?

Let us know how they work for ya.

Looking forward to your good news.What exactly do you get from this type of kit?,

quote:What exactly do you get from this type of kit?, I believe you get the two pulleys, the belt and instructions.

quote:Less weight, means it takes less force for it to turn.First and Sendond Laws of Thermal Dynamics/Energy kinda apply here.I can see more force required to get them moving, but by "conservation of energy", you get it back when you reduce rpm. Also, once you get them spinning, like say you are at highway cruise at constant speed, then you aren't getting any benefit. You may even get a loss, because of those friction from those spokes slicing through the air as opposed to a solid pulley. I'm thinking noticable benefits for use on a daily driver...and I guess i'm asking my usual question of "Does it REALLY make a difference?" I'm new to most of these issues, so just trying learn....

quote:You may even get a loss, because of those friction from those spokes slicing through the air as opposed to a solid pulley.Ah. . . . no. It doesn't work that way. If the spokes were angled like a fan then you would be correct because it would be pushing air but straight spokes don't create any significant parasitic loss.quote:I guess i'm asking my usual question of "Does it REALLY make a difference?"Actually, yes. I have them on my Nova. We're not talking 20-hp but there is an improvement. The weight does help but that's only a small part of it. The main HP increase is because the pulley sizes are different allowing the accessories to slow down in relationship to the engine RPM. It's like shifting a bicycle from 12th gear down to 5th gear. The leverage makes it easier for the engine to spin the accessories (at a slower rpm). The engine now looses less HP to the accessories and can deliver that HP to the wheels.

ok thats make perfect sense, but what if your running a lot of accessories...amps, lighting, etc...is it bad to have these then

I just recieved the kit. It contains just a single pulley (alternator), a belt, stickers, and instructions. I will be installing them on Saturday instead of Thurs. I will let you all know what they do.

to make it easier to understand how underdrive (this is the key) think of how your multi speed bicycle works...... if you pick the smallest front sprocket and the largest rear sprocket it is realy easy ot pedal but you do not go very fast. Under drive pully work the in the same maner. They usually replace the stock crank pully (front sprocket) with a smaller diameter one and then larger ones onto accesories in multi pully kits. (rear sprocket). This makes it easier for the engine to turn the accesories but they spin slower..... As stated this is not good if you need alot of electricity for aux lights or high power stereos.....As an added bonus the pullies are usually lighter and therefore are easier to spin up....... they do add HP...... the amount depends on the kit. Have used tehm on my 5.0 and noticed a significant increase but virtually no alternator power at idle.... (i used a 3 pully kit)Hope this helps out.

Now that everyone understands what power pulleys do, allow me to insert an element of confusion: Any slight weight reduction of the pulleys would not have a measurable effect. Basically, they reduce the speed of the driven accessories. At a steady speed (especially up near redline) there will be a modest reduction in the power absorbed by the water pump, and possibly a very slight reduction in power steering pump losses, but the alternator will require the same power to charge the battery even if it is turning a bit slower. (except for a really tiny reduction in windage losses) Additionally, particularly in the lower gears, there will be a little less inertia for the engine to overcome, as all the accessories are now being spun up a bit slower, as if you had a slightly lighter flywheel. Thus any gain would show up best on an inertia chassis dyno, (e.g. Dynojet) running in a lower gear. The downside is that you are betting that Toyota built a lot of insurance into the water pump flow rates, low RPM charging requirements, etc. so that you won't overheat or run down the battery.Hope someone can get us some dyno data for one of these kits...

sorry silverwd26 I was not intentionaly directing my reply to you. i was just trying to post it to the thread...... sorry for any misunderstanding that it caused.

quote:The downside is that you are betting that Toyota built a lot of insurance into the water pump flow rates, low RPM charging requirements, etc. so that you won't overheat or run down the battery.Hope someone can get us some dyno data for one of these kits... Yeah, thats exactly what I'm wondering too. I want the power but not at the expense of overheating, or killing the battery. A dyno would be nice to see on any of these pulley upgrades, be-it AEM or Unorthodox Racing. I just want to know if the trade off is really worth it.

Wow, So many replies since my question!!Now I understand, Thank you all.I am happy to see all the faces.

>The downside is that you are betting that Toyota built a lot of >insurance into the water pump flow rates, low RPM charging >requirements, etc. so that you won't overheat or run down the battery.FYI, the AEM kit only slows down the alternator on the Toyotas. The water pump is unaffected.

quote:I just recieved the kit. It contains just a single pulley (alternator), a belt, stickers, and instructions. I will be installing them on Saturday instead of Thurs. I will let you all know what they do.Just a single pulley?! That kinda stinks. So thats why Unothodox ones cost so much more....

quote:Yes, but I do not think Unorthodox comes with the belt or belts. That is a problem too.Alright...I've check on the pulleys. The AEM pulley is for the alternator only, but has the belts with it. The UR pulley is for the crank (better), but does not come with belts. The site says you have to find them yourself at the auto store. The power I've heard from the UR pulley makes me think the price aint so bad at this time.

No belts? Unless they tell you what size to get, you could end up wasting a lot of time and maybe money too before you get one that works. And what if you can't get one locally and have to special order?

Ptuning sells the Unorthodox underdrive crank pulley. They state that while the belt is not included, the instructions will tell you which belt to purchase from your local parts store.http://www.ptuning.com/html/Item-Desc.c ... lDesc=Vibe

I finally installed the pulley. It took a heck of a long time to install due to an incorrect belt that was included. I had to call around and purchase a few belts to find the correct size for the application. I haven't noticed too much of a difference, but the red anodized finish looks trick.

quote:.... It took a heck of a long time to install due to an incorrect belt that was included. I had to call around and purchase a few belts to find the correct size for the application. .... Wow! I sure nailed that prediction! I always make sure I have a "spare" car available (as in wife has to stay home) whenever I start in on any maintenance in case anything goes wrong and I have to go in town for more parts. LOL Glad to hear everything worked out in the end!