vbspec, check this out, per our discussion @ Little Creek...
08-25-2003, 01:06 PM
#1
Registered Loser
Thread Starter
Join Date: May 2003
Posts: 104
Likes: 0
Received 0 Likes
on
0 Posts
vbspec, check this out, per our discussion @ Little Creek...
Engine Harmonics
You may want to read this thread... a lot of it is about pulleys but there is some stuff about the balancer shafts in there and a mention of the QR25.
You may not want to do it even if you're allowed. FWIW.
Andy
You may want to read this thread... a lot of it is about pulleys but there is some stuff about the balancer shafts in there and a mention of the QR25.
You may not want to do it even if you're allowed. FWIW.
Andy
08-25-2003, 05:45 PM
#2
Registered User
Join Date: Dec 2002
Location: Chesapeake, VA
Posts: 306
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm....
Sounds to me you may want to stay away from the crank pulleys and maybe try an accessory pulley kit. My kit is the latter and it underdrives the water pump, power steering pump, and alternator. The crank is left alone so I don't have to worry about any harmonic balancing issues. This is even more important since I also run a lightweight flywheel. For the most part it is a general consensus that a crank pulley + light wt fly is a BAD thing, atleast on my motor it is (an inline 6).
Sounds to me you may want to stay away from the crank pulleys and maybe try an accessory pulley kit. My kit is the latter and it underdrives the water pump, power steering pump, and alternator. The crank is left alone so I don't have to worry about any harmonic balancing issues. This is even more important since I also run a lightweight flywheel. For the most part it is a general consensus that a crank pulley + light wt fly is a BAD thing, atleast on my motor it is (an inline 6).
08-25-2003, 11:14 PM
#4
co driver
Join Date: Nov 2002
Location: chesaintshittodopeake
Posts: 1,373
Likes: 0
Received 0 Likes
on
0 Posts
...same with accords. several ppl (on accord forums) have tried the crank pulley and have had bad results, like the crank bearings wearing out extremely fast.
08-26-2003, 04:52 AM
#5
Registered Loser
Thread Starter
Join Date: May 2003
Posts: 104
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Bandit
thanks for showing me that, as i was about to order a pulley set....
thanks for showing me that, as i was about to order a pulley set....
For instance, I have yet to hear of anyone complain about an underdrive crank pulley for the SR20DE (pre-'02 SE-Rs). And they've been around for 5+ years.
08-26-2003, 12:25 PM
#7
Registered User
Join Date: Nov 2002
Location: Alexandria
Posts: 752
Likes: 0
Received 0 Likes
on
0 Posts
I just checked out what Unorthodox racing had to say, here it is:
"People are getting the pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications that we offer utilize a counterweight as part of the pulley as these engines are internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say that with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.
The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as stroke, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.
Again, there is a lot of internet hearsay about the pulleys. When motor failures occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem. We hope that after reading this you will understand the crank pulleys better."
"People are getting the pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications that we offer utilize a counterweight as part of the pulley as these engines are internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say that with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.
The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as stroke, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.
Again, there is a lot of internet hearsay about the pulleys. When motor failures occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem. We hope that after reading this you will understand the crank pulleys better."
08-26-2003, 01:25 PM
#8
Registered Loser
Thread Starter
Join Date: May 2003
Posts: 104
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by mpg9999
I just checked out what Unorthodox racing had to say, here it is:
I just checked out what Unorthodox racing had to say, here it is:
After all, if we trust the vendors for information, we'd all be sporting cross-drilled rotors.
08-26-2003, 06:39 PM
#9
Yes I race a HONDA!!
Join Date: Dec 2002
Location: Va Beach
Posts: 1,600
Likes: 0
Received 0 Likes
on
0 Posts
Thanx Andy
I think that it depends on the construction of the engine and the rev limit. The SpecV only has a 6200 rev limit so I'm not sure. Dave Coleman at Sports Compact Car mag ralleys a Spec and has had no problem.
I think that it depends on the construction of the engine and the rev limit. The SpecV only has a 6200 rev limit so I'm not sure. Dave Coleman at Sports Compact Car mag ralleys a Spec and has had no problem.
08-27-2003, 04:19 AM
#10
Registered Loser
Thread Starter
Join Date: May 2003
Posts: 104
Likes: 0
Received 0 Likes
on
0 Posts
It *does* depend on engine configuration and the larger the 4-cyl engine is and the longer the stroke it has, the worst the 2nd order vibrations can be.
I'd be interested to see how long SCC's motor lasts. If they drop the crank before every season, then maybe it's not a problem.
*shrug* Anyway, just pointing out something else to think about.
Andy
I'd be interested to see how long SCC's motor lasts. If they drop the crank before every season, then maybe it's not a problem.
*shrug* Anyway, just pointing out something else to think about.
Andy