Relentless

It seems that the Unorthodox Racing Ultra SS Pulleys are extremely popular with 350Z owners.

I was looking at the Unorthodox Racing lightened and underdrive pulleys (is it pullies or pulleys? I thought it was pullies...), the SR Motorsports pulleys, and the thread on cortc's lightened pulleys. The UR pulleys are appealing because they are cheaper than the SRs, as well as looking pretty.

I know there is discussion of these in other threads; I just wanted to start anew.

The reservations that most people have on the UR Pulleys is that they are also underdrive as well as lightened. So I did some web searching, as well as some searching of the same topic on a 350Z forum (where I found further discussion on such topics as pulleys, the Tein Flex coilovers with the EDFC that is about to come in the mail, and the Volk Racing SF-Challenge rims that will arrive in another 2 to 3 months).

By most accounts, the underdrive is so marginal that no appreciable difference in the air conditioner was noticed. The difference between the Ultra SS Pulleys for the 350Z and the RX-8 is that the accessory pulleys on the 350Z are lightened, and only the crank pulley is lightened and underdriven. All pulleys in the RX-8 kit are both lightened and underdrive.

The heated discussions on the 350Z forum center around the harmonic balancer (which I don't really understand, but rotary engines don't have one, so I guess it doesn't matter much). The counter point is that the 350Z's VQ engine is internally balanced, so the crank pulley doesn't require one. Beyond that debate, it's apparent that a large number of 350Z owners own the UR pulleys and like them.

Now the last reservation that I have is that the UR pulleys underdrive the crank pulley, which if I understand correctly will rob power when I slap on a supercharger (which is driven by the crank).

Jeff


Check out:

Pulleys on 350Z
http://www.nissanperformancemag.com/august03/350pulley/

Pulleys on Altima
http://www.nissanperformancemag.com/...r02/altima_ur/

Sport Compact Car
http://www.sportcompactcarweb.com/pr...cus/index.html

Jaguar_MBA

Hi, I installed an aluminum underdrive pulley on my 300ZX. I have not had any issues with the AC or the alternator. I even replaced the stock clutch fan with an electric fan. So I am underdriving the alternator, while adding an increase load for the electric cooling fan.....and still no isssues after 1 year. I live in NC so it was very warm this Summer (96F + some days) and still had no issues with the battery.

I felt that this mod was worth it, a guaranteed gain (unlike the exhaust ~ intake issues.....people do not flame me, just go to Racing Beats and read up on their exhaust research of aftermarket systems) Any mod that can take weight off the crank is going to free up horsepower and make your engine more efficient....maybe you would want to do an aluminum Flywheel first?

I too have the same concern of supercharging, but my concern is not focused on the underdrive pulley moving a suprcharger's pulley, but with the MS electric turbo setup. If I am underdriving the alternator, will this decrease the electric turbo's output or allow the turbo to drain my battery faster then the alternator can recharge it?

If I was not concerned about a SC or MS Electric Turbo I would, without a doubt use a light weight underdrive system.

A pic of my Z is in my vgarage with my LY 8.

Relentless

I actually have the Mazdaspeed flywheel, and really my attraction to the pulleys has to do with my newfound obsession with engine response. One solution would be to go with just a lightened pulley set when it becomes available, or go with the UR pulleys and replace them with the stock pulleys when I install the supercharger.

Another interesting fact is that almost all of the gains on the 350Z come from lightening the crank pulley.

Ole Spiff

I've been following Cortc's progress with great interest. I've just about decided to go the weight-reduction path to performance. The cost would be nearly the same as trying to add horsepower through turbo or supercharging. The big plus for me is the reduction of the problems and issues that you get when adding horsepower. The heat, cooling, pressure, and additional strain on the drivetrain that accompanies adding horsepower just doesn't appeal to me. I like the elegance of reducing unsprung, rotational, and overall weight. Gaining performance by this method has none of the undesirable side-effects that adding horsepower does. The pluses are considerable; better handling, reduction of strain on components, better stopping power and control, quicker overall response, better gas mileage, just to name a few.

This isn't to say that slight horsepower increases through intake, exhaust, ecu mod aren't desirable....they certainly are and especially since those mods don't add weight or cause any undue problems of their own. I already have RB's exhaust, and I'll get their intake and ECU mod when they're available.

I'm in the process of gathering all the info and specs I need to map out a plan for serious weight reduction, along with the cost. Kind of like modding a car on the Gran Turismo game, except this is for real.

pressure

A quick note about UR. I'm not advising that you will have a problem with their products, but they do take shortcuts sometimes. I was a part of a group of Eclipse and Civic owners that had problems not only with their pulleys but with the company itself. In my (and about thirty others') case, they pulled the Galant pulley they had off of their shelf and sold it as an Eclipse part without testing it once, by their own admission. An immediate check engine light resulted and they refused to refund the product. I still have mine four years later. Not only that but the president of the company then went on an Eclipse smear campaign, inventing the myth that their product didn't work because the platform was unreliable. Should all still be at Club3g if anyone would like to know more.
Long story short - if you have a problem with an Unorthodox product, don't expect any help from them on it.

rotarygod

A lightened pulley set isn't going to have the same effect as a lightened flywheel. The weight of the pulley's is almost irrelevant. Their weight is spread over such a small diameter that lightening them won't do a whole lot. They aren't a whole lot lighter than stock. You won't notice a gain based soley on the fact of their weight. Underdrive pulleys (pullies? damn it now you've got me doing it!) will give you a benefit solely on the fact they have more leverage on what they are turning. Yes the alternator, a/c compressor, water pump turn a little slower but they aren't that bad. You don't really notice any bad side effects. If you have a good charging system with good wiring (on a new car this shouldn't be an issue) the alternator won't seem any different. At such a low rpm you are really only affecting where it starts making power by only a couple of hundred rpm's. The water pump is turning slower. This isn't necessarily a bad thing. On the RX-7's, you had to underdrive the water pump as it would cavitate before you got to redline. The underdrive pulley would change this by over a thousand rpms. Expect a few usable horsepower gain from new pulleys.

If you are using a supercharger, I wouldn't suggest using underdrive pulleys. If you are then you need to adjust the supercharger pulley size to accomodate.

s13lover

On some cars the difference can be quite a bit. I have a light weight / underdrive crank pulley on my 240SX. It weighs around 5 lbs less than the stock pulley. But I do have to say that the performance gain wasn't what I expected. I can really only feel a difference at high rpm in 4th and 5th gears. I was expecting the power gain (which i think is suppose to be around 2 hp for every lb removed from the crank) to be throughout the rpm range. But like you said, the roational mass is centered around such a small area with a pulley that the motor really has to be under a large load to feel the effect.