Custom Light Weight Pullies...
09-10-2004, 12:42 PM
#91
What worked for me when I removed the factory alternator pulley was to tighten the alternator belt up a bit, use the appropriate wrench on the nut, and tap the wrench with a dead-blow hammer. To re-install do the reverse but have someone grab the belt to keep the new pulley from slipping. Then, adjust the belt tension to the proper level.
Charles
Charles
09-30-2004, 04:40 PM
#93
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Ok, this is the final pricing on the pulleys if they go up for sale:
*** Mod edit*** Sorry, can't discuss prices here *** Mod edit***
Pulleys only (Choice of color; red, blue or silver)
Titanium Nut & Bolt Set:
Crank pulley with 10% under drive:
No titanium crank hub yet, will be available later and pricing will be XXXXXX (No hp numbers yet but should be good for 1-2hp in addition to the other numbers...
I have to make 10 sets otherwise the price goes up, will post official results later but so far testing of the pulleys with no under driving yielded 6.2hp/2.4lbs, pulleys and bolts 7.1hp/2.9lbs... Had one crank pulley made with 10% under drive that gave 8.9hp/3.9lbs... Testing was done on a stock RX8 demo with 3700 miles on the odometer...
These are real numbers...
I know some of the other manufactures have claimed 10-12hp and up to 6.9lbs-ft of torque but that was with a 20-25% reduction in under driving (And those numbers may be a little optimistic)… I may do a crank pulley with a 15% reduction I estimate should get me to about mid 9hp and mid 4lbs-ft of torque without the titanium crank hub as I don’t see a 20% reaching 10-12hp and 6+lbs-ft of torque…
Maybe with the titanium crank hub and a 25% reduction crank pulley with no a/c pulley we might see 12hp and 6lbs-ft…
All testing was done with the engine at full operating temp, we ran her stock for about 30 minutes driving around tested let her cool down installed the pulleys ran her for 30 minutes again driving around then tested again…
*** Mod edit*** Sorry, can't discuss prices here *** Mod edit***
Pulleys only (Choice of color; red, blue or silver)
Titanium Nut & Bolt Set:
Crank pulley with 10% under drive:
No titanium crank hub yet, will be available later and pricing will be XXXXXX (No hp numbers yet but should be good for 1-2hp in addition to the other numbers...
I have to make 10 sets otherwise the price goes up, will post official results later but so far testing of the pulleys with no under driving yielded 6.2hp/2.4lbs, pulleys and bolts 7.1hp/2.9lbs... Had one crank pulley made with 10% under drive that gave 8.9hp/3.9lbs... Testing was done on a stock RX8 demo with 3700 miles on the odometer...
These are real numbers...
I know some of the other manufactures have claimed 10-12hp and up to 6.9lbs-ft of torque but that was with a 20-25% reduction in under driving (And those numbers may be a little optimistic)… I may do a crank pulley with a 15% reduction I estimate should get me to about mid 9hp and mid 4lbs-ft of torque without the titanium crank hub as I don’t see a 20% reaching 10-12hp and 6+lbs-ft of torque…
Maybe with the titanium crank hub and a 25% reduction crank pulley with no a/c pulley we might see 12hp and 6lbs-ft…
All testing was done with the engine at full operating temp, we ran her stock for about 30 minutes driving around tested let her cool down installed the pulleys ran her for 30 minutes again driving around then tested again…
Last edited by cortc; 09-30-2004 at 04:42 PM.
09-30-2004, 05:42 PM
#95
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GeorgeH: Will post details on the testing soon including gear used during dyno runs etc... But basically like a flywheel you will see the most benefit in the gears that wind up faster like 1st-2nd-3rd...
The results of light pulleys are very well documented, this really is not some rare mod, and much information is available on the net...
The results of light pulleys are very well documented, this really is not some rare mod, and much information is available on the net...
10-01-2004, 05:33 AM
#99
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Cortc,
is there a chance that you'll produce pulleys exactly the same color as stock, so that the dealers won't understand the change? they are giving us hard time with the warranty here
With the underdrive pulley, what are the effects on the car? handling, drivability?
is there a chance that you'll produce pulleys exactly the same color as stock, so that the dealers won't understand the change? they are giving us hard time with the warranty here
With the underdrive pulley, what are the effects on the car? handling, drivability?
Last edited by RotorManiac; 10-01-2004 at 05:41 AM.
10-07-2004, 03:14 PM
#101
Kaiten Kenbu Rokuren
Cortc, you might want to look at Boostd7's sticky. You've been doing all sorts of crazy stuff and maybe you could get a bigger consumer base by utilizing this free advertisement. I like the products you've made, and I don't see why others wouldn't. Anyway good luck with all of your projects.
10-08-2004, 07:37 PM
#104
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That's great! Then count me in!
cortc you said earlier in this thread "Under driving is good and bad... bad in that it reduces cooling capacity and charging capacity at idle..."
can you please clarify that for me? I'm asking because I'm not sure if underdriven pulleys are worth the risk. Will you put underdriven ones in your car or will you stay with the lightened ones?
Thanks
cortc you said earlier in this thread "Under driving is good and bad... bad in that it reduces cooling capacity and charging capacity at idle..."
can you please clarify that for me? I'm asking because I'm not sure if underdriven pulleys are worth the risk. Will you put underdriven ones in your car or will you stay with the lightened ones?
Thanks
10-08-2004, 08:12 PM
#105
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I would be interested in a set of lightweight pulleys if they looked close to stock. I want the stealth appearance. Are those HP numbers at the wheels or crank?