VQ37VHR Harmonic Balance
#1
VQ37VHR Harmonic Balance
I apologize if this topic has been covered before. Creating a thread to see if anyone can tell me how balancing works in our particular engines. I understand (vaguely) how harmonic balancing works in a general sense, but I'd love some insight into whether or not this is true for our VQHR motors.
Being internally balanced means... for pulleys, correct? I know most view pulleys as being a waste of money, but from personal experience, I feel that it really does help (revs quicker); could be in my head, but either way...me likey! Thoughts? Is there a threshold to how much the computer can tweak balancing the engine? Quite a few Z's seem to running pulleys...no issues? Thanks in advance!
Can balancing being off throw off a transmission? Coincidentally, on my previous car (2005 Acura TL, fully bolted) the transmission went out following a UR OE size, light weight pulley install. Then again, car was driven rather aggressively (motor mounts putting more stress on the transmission probably didn't help either). Ttthhhaaannnkkksss
Being internally balanced means... for pulleys, correct? I know most view pulleys as being a waste of money, but from personal experience, I feel that it really does help (revs quicker); could be in my head, but either way...me likey! Thoughts? Is there a threshold to how much the computer can tweak balancing the engine? Quite a few Z's seem to running pulleys...no issues? Thanks in advance!
Can balancing being off throw off a transmission? Coincidentally, on my previous car (2005 Acura TL, fully bolted) the transmission went out following a UR OE size, light weight pulley install. Then again, car was driven rather aggressively (motor mounts putting more stress on the transmission probably didn't help either). Ttthhhaaannnkkksss
#4
Registered User
Join Date: Jan 2011
Location: San Jose, CA
Posts: 368
Likes: 0
Received 0 Likes
on
0 Posts
All V6 engines have counterweights since the only commonly used engine configurations that are perfectly balanced are I6 and V12. Pulleys don't deal with engine balance and are used to increase power, right?
#6
Registered User
Join Date: Jan 2011
Location: San Jose, CA
Posts: 368
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, I'd have to admit that I didn't even know about using pulleys, but from what I've been reading, it increases power by decreasing the rotational speed going to the A/C compressor and the alternator and such. This is supposed to allow the engine to spin more freely and deliver more power to the wheels. I don't think it has anything to do with the fact that it's lighter. Again, this is just from some quick research I just did.
Trending Topics
#9
Registered User
Join Date: Jan 2011
Location: San Jose, CA
Posts: 368
Likes: 0
Received 0 Likes
on
0 Posts
Yeah I'm inclined to agree with you that pulleys would probably add zero real gain to power. And it probably isn't a good idea to reduce speed to your alternator.
#11
Premier Member
iTrader: (17)
Get the stock diameter pulley. It shaves about 7.5lbs off of the stock crank pulley, but keeps the diameter the same so your accessories are not altered or under-driven. It does not throw off the balancing of our engines. Do a search on here for either stillen pulley or unorthodox pulley, they are actually the same. This topic has been debated, explained, and dynoed before.
UR states :
"100% of the power gains from the stock diameter pulleys comes only from weight reduction versus the factory crank pulley. The reduced weight allows for more power transfer to the drive wheels. Weight reduction is how we are able to increase Horsepower. Each pound of weight removed from the crankshaft is worth approximately 2.7HP and the gains jump even more dramatically with forced induction, nitrous and variable valve timing."
So basically, it's my understanding that the pulley does nothing to add HP, but what it does do is remove weight from the crank pulley making it easier to spin. The lighter crank pulley allows for the extra HP that it usually takes to spin the heavy oem pulley to flow down the driveline to the wheels. It basically makes it more efficient.
UR states :
"100% of the power gains from the stock diameter pulleys comes only from weight reduction versus the factory crank pulley. The reduced weight allows for more power transfer to the drive wheels. Weight reduction is how we are able to increase Horsepower. Each pound of weight removed from the crankshaft is worth approximately 2.7HP and the gains jump even more dramatically with forced induction, nitrous and variable valve timing."
So basically, it's my understanding that the pulley does nothing to add HP, but what it does do is remove weight from the crank pulley making it easier to spin. The lighter crank pulley allows for the extra HP that it usually takes to spin the heavy oem pulley to flow down the driveline to the wheels. It basically makes it more efficient.
#13
Premier Member
iTrader: (17)
with stock diameter lightweight pulleys the alternator is not effected. There are different opinions on HP gains vs. efficiency claims. I personally had the UR crank on my 2008 coupe and felt like the engine rev'd quicker with the lighter pulley. I saw a small increase in HP on my dyno after the install, like 4-5 hp, but was not certain if it was the pulley itself, or the fact my car was still breaking in and the fact my baseline dyno was performed weeks earlier than with the pulley.