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Has anyone installed one of the many under drive pulleys available for our turbo DSMs? I am thinking of doing this upgrade but wanted to hear some feedback from people who have already done this mod before I make my decision. I am looking for information regarding performance gains and driveability changes. Thanks..
 

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I heard that the solid metal one tends to break, if you look at the factory crankshaft pully, it has a rubber ring in the mid section to insulate shock.

-Kevin.

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May the BOOST be with you!
 

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i bought mine from summit racing for $100. about 1/2" smaller in diameter then stock and a lot less weight. have about 10,000 miles on it with no trouble. didnt take long at all to install.

i think you gain about 3hp for ever 1lb you lose off the rotating assy of the engine.
dont quote me on the hp gain but its close to that.
so depending if you get all lightened pullys or just the crank, will determine your gains.

[This message has been edited by lee (edited October 25, 2000).]
 

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Which pullies did you have installed? Just the crank or all the accessories too? I'm thinking of doing just the water pump, power steering and alternator pullies. The crankshaft pulley has to be dampened or I've heard or it will destroy your engine sooner or later. About how much extra power did you notice after the install?

Jesse
99 GSX
 

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The Unorthodox racing pulley supposedly gives you another 15 ponies.



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99SpyderGST
 

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Last year Turbo Mag. dynoed a gst with and without the unorthodox crank pulley. They gained 9.5 hp. I have the unorthodox crank and I felt a good increase and have had no problems at all in the past 2 years.

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The ones that brake are the stock ones. Wait till that think busts loose and walks through your T belt costing you over $2K !!!

bout the damping thing. No this isn't a V8 :D this is only a pulley it is weighted but not a effect on the motor. the FW is what off sets the weight not the pulley.

About it messing up the lower end. that is TOTAL line of BS. one vendor who I will not name started this just as his $250+ pulley was coming out. Sounds kind of fishy to me.

The Unorthodox (sp?) crank pulley is CNC cut and the balanced so no problem with that.

All in all a lot of hype. That Turbo mag thing is also a load of BS. The person in the test was a RRE customer and I have meet him when I was back in CA. He didn't report that gain with just the crank pulley. Maybe with a race underdrive you would get that gain but not the street brand that you will get. They don't sell the larger % underdrive to anybody unless they know. it slows the Ault down to much and causes charging problems and if you have a amp hitting that for power at idle it WILL stall out the car. this is why you don't see it.

I have installed them for the past 2-3 years and not 1 time have I had a motor come down with bearing failure b/c of the pulley

Bill Marino
Hole Shot Performance
 

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The harmonic dampener is there for a reason. As with all mechanical things, the crank as a natural frequency. At this frequency the crank has a tendency to close some of the oil clearance on the main bearing caps. Exceedingly tight oil clearances, oil contamination, and a vibrating crank are not good to have in combination as it can result in spun bearings or bearing damage. Please realize this damage takes time to accumulate to any appreciable (or even visible to the naked eye) wear.

Any claims from Unorthodox that this engine, or any engine for that matter, do not require a torsional harmonic dampener should be scrutinized. I have not seen any data published by Unorthodox that would support their position, I have not heard of any engine manufacturer in the world who does NOT include a harmonic dampener on their engine that would support Unorthodox, and I have yet to hear of a racer that uses this product that does not rebuild the engines each season.

Trust me guys, if you use this car for anything other than a true race car, skip this pulley and find the extra power elsewhere.
 

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David Buschur sells an underdrive crank pulley that has a harmonic dampener that he designed. Its 350.00 bucks. Has anyone ever used this?
 

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i use the buschur pulley and so do alot of my customers. it dosent give you 10hp but about 2-3 hp. i have seen the unorthodox pulley ruin the main bearings especially on 2 gen. if you drive the car alot and want it to last keep the factory pulley or the buschur one. i wont even sell the unorthodox pulleys in shop.its only good for a paper wieght.
tony
 

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Hmm 2-3 horsepower doesn't sound like much. Especially for $350.00. What I was thinking about doing was buying pulleys for all my accesories and just leaving the crank pulley as is. The cost to performance ratio of pulley's in general seems to be alittle weak.
Oh well I guess I'll shop around some.
 

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I've got some new info on under drive pulleys. Eighty-five percent of the hp gains seen with pulleys are from weight reduction and the rest from underdriving. Unorthodox Racing's accessory pulley's are not underdriven, thus there would be no loss in driveability if you left the crank pulley stock. I think you'd see at least a 10 hp increase since apporx 2.7 HP is released with every 1 lb reduction in the weight of each pulley. Its not just hp though, its throttle response..and I think it would match my lightened flywheel nicely! Rebuttles anyone? :)

Jesse
99GSX




[This message has been edited by DiamondsR4EVR (edited October 26, 2000).]
 

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i wouldnt see a problem with that. just leave the crank alone.
i took off my unorthodox crankpulley and put on a buschur one. i noticed a difference in throttle response. only did it to save my bearings.
tony
 

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A balanced crank and rotating assembly has nothing to do with the purpose the torsional harmonic "balancer" is doing for you. It really should be called a harmonic dampener instead of a balancer as it does nothing for the balance, cancel out imbalances, or any other type of balance disfunction. :)

Basically, think of your crank as a really long rod. This rod is being placed into a severe loading scenario when opposing forces are being placed against the rod bearing system. So in essence, the crank is trying to be twisted and that puts significant stress against the main bearings that support the crank. The higher the compression ratio (or boost pressure in our case) the worse off the crank is. The harmonic dampener reduces the stress on the main bearing caps by creating a capacitive system (unless you've had mechanical systems as a mechanical engineer I've probably lost you here, hopefully the explanation helps) that stores energy and disipates it into the elastomer isolator. Basically, this spares the lower end from a jack hammer effect against the main bearings, especially the thrust bearing in an early 1G, and reduces the wear.

In essence, don't use an undampened pulley unless you have enough money to rebuild between seasons. Buschur's crank pulley is nice, but unless you've really set your sights on beating Mr. Rau, its not a huge advantage. There are easier and cheaper systems to tinker with first.
 

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I been using my unorthodox pulley for 4+ yrs. and I have no problem with it last year I blew up my engine for running to lean ( I don't have EGT at that time =( ) and when my mechanic opens my engine I told him to inspect my bearing for some abnormal wear and after he inspect at measure it he told me that everything still in spec and there is no abnormal wear on it. For 4 years that I am using this pulley it proves me that theres nothing wrong (I guess) using an underdrive pulley without a a dampener. Just my $.02. ;)
 

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I say the same!

I have been running the Unorthodox Pulley Kit for a long time now and have had only one problem with it. It causes the alternator belt and power stearing to slip sometimes during start up and when it's cold....but some belt spray fixed the problem.
I have felt a big difference too, especially with my lightened flywheel. I rip quicker through the RPM range and also have noticed a great difference in throttle responce!
I give the undampered pulleys a thumbs up as well! Just my 2cents! :)
 
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