Originally posted by Ace
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Happy Motoring!
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Underdrive pulleys reduce friction HP because they cause the water pump and alternator to rotate more slowly at a given rpm, thus absorbing less IHP. Strictly speaking, they do not add HP on their own but since IHP-FHP = BHP, the result is a small increase in HP at the crank. On engines operating at high temperatures, such as occur during prolonged racing events, it might not be a good idea to slow down the water pump for obvious reasons.
Happy Motoring!02 DX Millenium Red - The Penultimate Driving Machine
MP3 Strut Tower Bar kit; Cusco Front Lower Arm Tie Bar
MSP Springs, Struts, Stabilizer Bars, Trailing Links, #3 Engine Mount
Kartboy Stabilizer Bar Bushings; Nyloil Shifter Bushings; Red Line MT-90 Gear Oil
MP3 Shifter, Knob and Aluminum Pedal Set
Suvlights HD Wiring Harness; Osram Night Breaker H4 Bulbs; Exide Edge AGM Battery
Summer: 5Zigen FN01R-C 16 x 7" Wheels; Yoko S.drive 205/45-16s
Winter: Enkei OR52 16 x 7" Wheels; Falken Ziex ZE-912 205/45-16s
Modified OEM Air Intake; Racing Beat Exhaust System; Techna-Fit SS Clutch Line
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Cyberdyne Digital Gauges: Tach; Ambient Air Temp; Voltmeter -
^^^ The opposite could be true as well.
The Stock Water pump is only truly effective from 2500 - 3500. Over that and the pump begins cavitation.
If the car is meant for prolonged duty high in the RPM range, the under drive could actually improve the performance of the cooling syste, but then once the car is idling in traffic, you are going to miss that extra 300 RPM of water pump..Comment
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^^^
Interesting point. I hadn't thought of that.
Happy Motoring!02 DX Millenium Red - The Penultimate Driving Machine
MP3 Strut Tower Bar kit; Cusco Front Lower Arm Tie Bar
MSP Springs, Struts, Stabilizer Bars, Trailing Links, #3 Engine Mount
Kartboy Stabilizer Bar Bushings; Nyloil Shifter Bushings; Red Line MT-90 Gear Oil
MP3 Shifter, Knob and Aluminum Pedal Set
Suvlights HD Wiring Harness; Osram Night Breaker H4 Bulbs; Exide Edge AGM Battery
Summer: 5Zigen FN01R-C 16 x 7" Wheels; Yoko S.drive 205/45-16s
Winter: Enkei OR52 16 x 7" Wheels; Falken Ziex ZE-912 205/45-16s
Modified OEM Air Intake; Racing Beat Exhaust System; Techna-Fit SS Clutch Line
Denso SKJ16CR-L11 Extended Tip Spark Plugs; Magnecor Wires
Power Slot Front Brake Rotors; Techna-Fit SS Brake Lines; Hawk HPS Pads
Red Line Synthetic Engine Oil; C/S Aluminum Oil Cap
Cyberdyne Digital Gauges: Tach; Ambient Air Temp; VoltmeterComment
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I ran under drive pulleys on my tiburon for years without any issue... and I know many others that have never had an issue... Tiburon pulley has the same type rubber separation as the mazdas... you will be fine...
just like all the bs people talk about how fidanza flywheels are bad... when I have had nothing but amazing results... Just run it.. you will be fine
1992 MX-3 GS - KLZE
1997 Probe GT
Its not a BP05.... Its a BPOS... BIG PIECE OF ****Comment
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I have seen two threads on here and one on ff.com about people blowing their oil pump gears with under drive pulleys on boosted applications.2011 BMW 128i 6 Speed Manual -- dd
1990 Protege 4WD 5 SpeedComment
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his car isnt boosted. And ive seen cars without underdrive pulleys that are boosted and na break oil pump gears... whats your point?
1992 MX-3 GS - KLZE
1997 Probe GT
Its not a BP05.... Its a BPOS... BIG PIECE OF ****Comment
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I'm not going to risk it guys. I decided to just take it easy and make the engine last until I can afford to rebuild my motor. I decided to stick with the bp for now... FE3 is a little to pricey for me with my college student budget....My family has lots of bg's!
2003 Ford Escort ZX2: Project car/future daily driver. Built Ford Tough (With Mazda Stuff)
1999 Escort ZX2: Daily driver/beater. Going to be replaced by the '03 next summer.
2000 Escort ZX2 S/R: bought wrecked, going to use as parts car
1992 Protege LX: My old race car. Just a wrecked shell right now. Waiting for scrap to go up so that I can get rid of it.
1992 Mazda 323: Race car
1992 Escort Gt: My grandpa's old race car
1994 Escort GT: My grandpa's new race car.
Parts cars; 1993 Escort Gt, 1995 Escort lxComment
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True that! A balanced crankshaft with a light weight pulley should be a problem.Originally posted by The Pile View PostComment
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its not the balance that causes most vibrations... believe me I design crank dampers all day long... its the engine firing and the crankshaft twist caused by the firing that causes the vibrations. Anyway... the original purpose of the thread has been settled I think.2011 BMW 128i 6 Speed Manual -- dd
1990 Protege 4WD 5 SpeedComment
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YupOriginally posted by nerd racing View PostMy family has lots of bg's!
2003 Ford Escort ZX2: Project car/future daily driver. Built Ford Tough (With Mazda Stuff)
1999 Escort ZX2: Daily driver/beater. Going to be replaced by the '03 next summer.
2000 Escort ZX2 S/R: bought wrecked, going to use as parts car
1992 Protege LX: My old race car. Just a wrecked shell right now. Waiting for scrap to go up so that I can get rid of it.
1992 Mazda 323: Race car
1992 Escort Gt: My grandpa's old race car
1994 Escort GT: My grandpa's new race car.
Parts cars; 1993 Escort Gt, 1995 Escort lxComment
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