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pulleys


milu

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Hi Mate

 

I presume thats gregs old car

 

UR pulleys

 

Quote from manufacturer

 

Unorthodox Racing Ultra Street (Ultra S) lightened under drive crank pulley. Made of lightweight Premium U.S. made 6061-T6 billet aluminum to ensure consistency of the material's strength and balance. Every pulley is inspected multiple times from machining to anodizing to stocking and finally at shipping time. If at any point a pulley does not pass inspection it is pulled from production.

 

An average of 5 to 12 HP and 4 to 8 lbs.-ft. on normally aspirated engines and 8 to 16 HP and 8 to 18 lbs.-ft. on forced induction engines. Higher gains are possible. For example, a Nissan 300ZX twin-turbo saw gains as high as 37 HP and 45 lbs.-ft. on the dyno just buy replacing the stock crank pulley with the Ultra S lighted underdrive crank pulley. Power gains are obtained in two ways. First, and most important, is the weight loss. An average of 2.7 HP is gained from every pound lost off the crank shaft. 85% of our gains are from weight loss. The rest of the gains are from underdriving, which accounts for about 15% of the total gains. Underdriving is not pushed for two main reasons. The main reason is to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving. Second, not much horsepower is gained from extreme underdriving. In most applications all of the underdriving is done with the crank pulley, not the accessory pulleys. This is done so maximize weight loss can be achieved at the crank where most of the horsepower gains are found. Many Ultra S pulley applications are available in the Ultra Street Sets (Ultra SS) which in most cases include all the accessory pulleys except for the A/C compressor. You can always upgrade to an Ultra SS kit with the purchase of the Ultra A pulleys. Actual product may vary slightly from image.

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God, thats interesting reading...... not bad HP increases for just pulley replacements? ;)

 

Take with a pinch of salt :)

 

also I think as with all mods you'd need to sort the ecu to stop it correcting the error of your ways :teeth:

 

they do look very nice though B)

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God, thats interesting reading...... not bad HP increases for just pulley replacements? ;)

 

Take with a pinch of salt :)

 

also I think as with all mods you'd need to sort the ecu to stop it correcting the error of your ways :teeth:

 

they do look very nice though B)

 

Yeah I was wondering with regards to the ECU, whether it could correct around it. I mean, if you have lightened the pulleys etc, then what would it do to compensate for it? :blush:

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IIRC along with a plenum change they do improve mid range, and smooth off the top end of the rev range.

 

Knowing this car though the ecu probably re calibrates the fuel tank to read empty when half full to compensate for the change in weight :D

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cheers for that,yes Gregs old car.

 

i was worried about any possible bad side effects as claimed by some on another forum.

 

mike.

 

Think it's to do with something other than the pullies :) IMO just someone clutching at straws to avoid warranty claims.

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As with all mods you take your chances,

 

Nissans stance has always been if the failure can be attributed to the modification then warranty is void,

 

but this is down to interpretation by your individual dealer and then by Nissan, so at the end of the day it depends on how friendly your dealer is.

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As with all mods you take your chances,

 

Nissans stance has always been if the failure can be attributed to the modification then warranty is void,

 

but this is down to interpretation by your individual dealer and then by Nissan, so at the end of the day it depends on how friendly your dealer is.

 

But like insurances companies, if theres a teeny weeny chance of not paying, they will.

 

Personally, I'd take them off :blush:

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I had a set, tried to fit them, first by myself and the crank pulley would NOT shift, at all. The engine was turning, but it would not move. then joe's mechanic failed too, and he said to take off the radiator in order to put an impact wrench in there. Too much hassle for something that basically has minimal or no effect at all.

 

I sold them on

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