PerformRX-8

I saw the thread "pulley pulley pulley" but it didn't really give me any info on what it does and how it works...I just want to know what the benefits of having the pulley set is, I'm thinking of the unorthodox underdrive pulley set or the Greddy underdriver pulley set... If anyone can help me I would appreciate it!

Nopstnz

I thought that much lighter aftermarket pulleys usually replace the heavier ones from the factory which frees up horsepower. But I don't think this is the condition on the 8 considering its pulleys are already very light.

lurch519

an underdrive pulley serves the purpose of freeing up additional horsepower in the engine.

it can accomplish this in two different ways, either one or the other, or both combined.

first way of freeing up horsepower, and the most common (to my knowlede and how they became known as underdrive pulleys) is to reduce diamater of the pulley. this works just like reducing the size of a drive gear, making it take less effort or force to turn the secondary gear (or in this case, the accessory pulleys).

the second aspect of this type of under drive pulley is where you make the secondary (read accessory) pulleys larger, again having the same effect as making the driven gear in a gear set larger.

the second method is reducing the weight of the pulley, which works just like a lightened flywheel. this reduces rotational mass, so that it takes less effort or force to accelerate the pulley.

now, you can use either one or the other of these methods to design an underdrive pulley or pulley set, or you can combine both methods as well.

if you read through the pulleys pulleys pulleys thread, you can glean lots of information as to what sets do what, and how well in general they perform. i used the info contained in that thread to make my own decision as to which i would go with.

PerformRX-8

hey lurch do any problems occur with having an underdrive pulley kit? like CEL or any weird things, i tried to do a search on problems of pulleys andn othing....

rx8guy86

I have the Unorthodox pulley kit on mine. Driven it now for about 2k miles. Everything has been fine with mine

ddub

Ditto, except 8k miles for me.

rexi

Those with underdrive pulleys have any of the following issues.
1. Aircond not working well.ie must keep engine revs up to work?
2. Any flat batteries as result of decreased idle charging?
3. Engine overheating due to slower water pump operation?
4.Increase in power steering effort ? due to being electric power steering operation?

Your responses would be appreciated. I have a agency power underdrive pulley sitting in the garage and want to alay any concerns before fitting.

Regards
Rexi

ddub

1. No
2. No
3. No
4. No

Using Unorthodox underdrive pulley set (main, alternator, waterpump).

rexi

Thanks dDub.
Regards
Rexi
P.s Anyone with agency pulley with feedback? I would imagine that it wouldnt be much different to the UR pulley!

Brettus

iTrader: (2)

don't have one myself but have read about plenty that have agency power & no reported problems . AC not quite as cold but still works well enough - apparently.

mikeschaefer

I installed the Agency Power pulley a few days before I left and it just happened to be the hottest day in my area at 103 degrees. The A/C worked fine. I don't forsee having any problems with this pulley.

lurch519

to date, no issues that i cant live with (see below) though i do have a cel, which is from the b&b i believe

1. only at idle is the ac kinda blah, we have been having some pretty hot days here, and on long drives, i have actually had to cut the ac back.
2. no, my voltage actually sits right aroudn 14v at idle
3. had an hour long drive in 95-100 temps, no overheat, though the fan ran for a while after stopping
4. no

WantedTwo

iTrader: (4)

the steering is electrically assised so you wont have a change there in teh frist place.

Gambit

That happens in the heat anyway, my car did it and it freaked me out so I checked.

Jaguar_MBA

I have the SR Motorsports pullies on my RX-8. If you must get Pullies, I would suggest UR ones and save yourself a couple of hundred dollars.

On a regular piston car these work just fine because they have a heavy harmonic balancer. The RX-8 does not. Reducing weight on the crank shaft increases HP to the rear wheels...or reduces inefficiencies that reduce HP from the Rear Wheels. A standard harmonic balance on my 1992 300zx must have weighed ~ 20lbs and I replaced that with an aluminum unit that weighed ~ 4 lbs or so. That is where the performance gain is to be had. RX8's underdrive crank pulley must weight ~ 1.25lb stock.

I did not feel any change with them installed.

justjoshin8888

ummm, i got the unorthodox ultra racing pulley set and they work VERY NICE.

website: http://www.modacar.com/products/Mazd...K/pulleys.html

that's where i got my pulleys from.

TeamRX8

iTrader: (25)

the only way to get any real performance from a pulley set is to eliminate the AC all together like the SpeedSource/Mazda Motorsports set

Moostafa29

I experienced the same thing. The AC was never very good, and not its only slightly worse. All in all its well worth it.

PerformRX-8

I want my AC though

PerformRX-8

hey lurch, do you re-use the stock belts for it? also has your dealer given you **** about the pulley set?

Moostafa29

Its really not that big of a difference.

rx8guy86

1. Well, I have noticed that my ac is not near as cold if the car is idle. As soon as I start driving, it picks up fast.
2. No flat batteries for me.
3. nope
4. nope

I would go ahead and throw those suckers on! Installation is a breeze

rx8guy86

I went ahead and changed the belts when I had mine off. I don't even bother going to mazda here in knoxville. They are complete a-holes. They'd probly try to tell me my tint voided my warranty

lurch519

havent had my 8 in for any service work since i got the pulley, but i doubt that would be an issue, as i have it lowered, intake, custom grounding kit, aftermarket flip out, amps, etc and no issues or questions about warranty. my dealer is great.

as to changing the belt, yes you have to change the belt with my pulley as it is smaller in diameter. i got the agency pulley and it comes with the new belts.