Underdrive Crank pulley question
Originally posted by Z1 Performance
I have logged nearly 50 hours on my car with the pulley on and off...no change in timing whatsoever
I have witnessed Z's with very few mods (fewest was intake and exhaust, period), run mid 13's at the strip...insanely quick compared to what most NA modded cars (ecu, test pipes, etc) run. Different cars, different build dates, etc - sometimes people just get exceptionally strong runners!
The sensors on most cars are very sensitive, which is how they should be for a street driven car on pump gas. If the car is tuned properly, there is absolutely NO reason that the knock sensor should be picking anything up other than actual knock.
I have logged nearly 50 hours on my car with the pulley on and off...no change in timing whatsoever
I have witnessed Z's with very few mods (fewest was intake and exhaust, period), run mid 13's at the strip...insanely quick compared to what most NA modded cars (ecu, test pipes, etc) run. Different cars, different build dates, etc - sometimes people just get exceptionally strong runners!
The sensors on most cars are very sensitive, which is how they should be for a street driven car on pump gas. If the car is tuned properly, there is absolutely NO reason that the knock sensor should be picking anything up other than actual knock.
What's the cheapest data logger that'll do what I need it to? Workin' on a budget here.
Last edited by MustGoFastR; Nov 20, 2004 at 08:37 PM.
Thread Starter
Registered User
iTrader: (1)
Joined: Jun 2004
Posts: 448
Likes: 0
From: Massachusetts
I have a dent on my pulley from taking off so many times. This could not harm anything can it? I dented it by binding the pulley up so i could get it off.
Im not sure what the hells causing the knock sensor to go off. I have way to many upgrades now that i got myself in a hole.
Thanks Glen
Im not sure what the hells causing the knock sensor to go off. I have way to many upgrades now that i got myself in a hole.
Thanks Glen
Originally posted by Zmego1985
I would put the factory pulley on and test it out again.
Thanks Glen
I would put the factory pulley on and test it out again.
Thanks Glen
Still thnk I'll try to get my tech to make a few runs with me and watch it on the ConsultII. Not sure what it'll tell him, though. Will it or any data logger say if knock is being detected, or does it just display what the timing is at any given time? Wouldn't you need to know, then, what the timing curve SHOULD look like to be able to tell if anything's amiss? Anybody have that info? I have no idea what the timing curve should look like.
Thread Starter
Registered User
iTrader: (1)
Joined: Jun 2004
Posts: 448
Likes: 0
From: Massachusetts
I have my rev limiter highered and i have the unorthordox pulley on. Im nervous now that it caused crank bearing problems and thats why i have a timing loss because the knock sensor feels the vibrations. Look up old threads on pulley problems one person had timing issues.
I noticed the higher i reved my car the more timing was being pulled on the dyno. If that pulley does vibrate it sure would vibrate the most at high rpms. I think im going to go back to stock for my own thoughts.
I noticed the higher i reved my car the more timing was being pulled on the dyno. If that pulley does vibrate it sure would vibrate the most at high rpms. I think im going to go back to stock for my own thoughts.
I'm not referring to vibration from the pulley. I have Blackstone labs oil reports showing I have no abnormal wear that would be caused by an unbalanced pulley. I'm referring to noise that is otherwise dampened by the rubber ring (not a harmonic balancer) in the stock pulley. I do not lose power at all in 1st or second, but only under load as rpms rise in 3rd. I'm thinking that there may be noise from the pulley that is at just the right frequency at that time to be picked up by the knock sensors.
IF that's the case, still unsure if it's worth going back to stock b/c I never drive under those conditions on the street and the pulley DOES have it's gains.
IF that's the case, still unsure if it's worth going back to stock b/c I never drive under those conditions on the street and the pulley DOES have it's gains.
Originally posted by Zmego1985
Look up old threads on pulley problems one person had timing issues.
Look up old threads on pulley problems one person had timing issues.
Originally posted by MustGoFastR
I'm not referring to vibration from the pulley. I have Blackstone labs oil reports showing I have no abnormal wear that would be caused by an unbalanced pulley. I'm referring to noise that is otherwise dampened by the rubber ring (not a harmonic balancer) in the stock pulley. I do not lose power at all in 1st or second, but only under load as rpms rise in 3rd. I'm thinking that there may be noise from the pulley that is at just the right frequency at that time to be picked up by the knock sensors.
IF that's the case, still unsure if it's worth going back to stock b/c I never drive under those conditions on the street and the pulley DOES have it's gains.
I'm not referring to vibration from the pulley. I have Blackstone labs oil reports showing I have no abnormal wear that would be caused by an unbalanced pulley. I'm referring to noise that is otherwise dampened by the rubber ring (not a harmonic balancer) in the stock pulley. I do not lose power at all in 1st or second, but only under load as rpms rise in 3rd. I'm thinking that there may be noise from the pulley that is at just the right frequency at that time to be picked up by the knock sensors.
IF that's the case, still unsure if it's worth going back to stock b/c I never drive under those conditions on the street and the pulley DOES have it's gains.
Thread
Thread Starter
Forum
Replies
Last Post
Colombo
Forced Induction
35
Nov 9, 2020 10:27 AM
