higher ratio rockers ?
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Joined: Oct 2003
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From: Central, MA
Originally Posted by jz06man
Will the idle quality change going from 1.7 to 1.89 rockers.. I understand that the cam duration does not change, but it will change the duration at the valve, so it might/should affect idle quality- meaning abit more aggresive?
I got my 1.89's in yesterday. I've only had the truck running twice, but it sounds like the idle did change a bit. Only for the better.
Before it was a more of a mellow, muffled note, with either a mildly noticeable lope, or hardly any at all, depending on the day, temp, how I've been driving, etc. etc.
Now it's got a slightly "cleaner" more "pronounced" cadence to it. Like my idle tuning is better or something to that effect. Its slightly louder too. None of this is really anything that someone off the street would notice unless they heard the vehicle before and knew what they were looking for.
It's still the same old 047 at heart.
Launching!
Joined: Sep 2004
Posts: 245
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Sounds very good... Have you noticed any increases in power or torque????
Is'nt the lift more like .589 or is it .583 - 1.82/1.7=1.070 X .551 lift =.589
or did you have 1.79 rockers 1.82/1.72=1.058x .551=.583.
Please post any idle vid's you might have.. I still have you're older video pic..
Thank and enjoy.
Is'nt the lift more like .589 or is it .583 - 1.82/1.7=1.070 X .551 lift =.589
or did you have 1.79 rockers 1.82/1.72=1.058x .551=.583.
Please post any idle vid's you might have.. I still have you're older video pic..
Thank and enjoy.
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Joined: Oct 2003
Posts: 2,620
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From: Central, MA
Yeah, my little lift calculation is approximate... My cam used to yield .531 on the 1.7's... So it could be up around .569" now. I used a straight 1.8 rocker in my little calculation.
Power: I used to talk about how the little cam was a little soft under 1,500 and would really light-up around 1,700 or 1,800 - now the entire bottom-end is very linear, smooth, and torquey. There is a definite increase in power in the midrange (3,500-ish) and top-end. The ~2,000-2,500, maybe up to 2,800 range doesn't seem all that effected, but it was always strong feeling there. Now I guess the whole powerband feels more linear.
The throttle responce from idle is VERY quick now, and I definitely expect my 60' to improve. It caught me off guard when I first dropped it from a dead stop - the stock converter actually snapped my neck back.
I wish I knew how reliable the delivered-torque reading is, at least when used to plot a graph to get an idea of what things look like. It's plotting a big flat torque curve.
I gotta get to a dyno...
Power: I used to talk about how the little cam was a little soft under 1,500 and would really light-up around 1,700 or 1,800 - now the entire bottom-end is very linear, smooth, and torquey. There is a definite increase in power in the midrange (3,500-ish) and top-end. The ~2,000-2,500, maybe up to 2,800 range doesn't seem all that effected, but it was always strong feeling there. Now I guess the whole powerband feels more linear.
The throttle responce from idle is VERY quick now, and I definitely expect my 60' to improve. It caught me off guard when I first dropped it from a dead stop - the stock converter actually snapped my neck back.
I wish I knew how reliable the delivered-torque reading is, at least when used to plot a graph to get an idea of what things look like. It's plotting a big flat torque curve.
I gotta get to a dyno...
Launching!
Joined: Sep 2004
Posts: 245
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Marc,
sounds like it better and more imporant- You like it!
So you went from a VHP 1.72-1.79 rockers to 1.8 rocker or 1.7 rocker to 1.8 rocker with this 047????
I don't know much about automactic torque muliplication numbers, etc, but I belielve once the convert is locked, this is the real number.....
How's the idle?? Any change.. Is it louder, more aggresive or same but deeper??
sounds like it better and more imporant- You like it!
So you went from a VHP 1.72-1.79 rockers to 1.8 rocker or 1.7 rocker to 1.8 rocker with this 047????
I don't know much about automactic torque muliplication numbers, etc, but I belielve once the convert is locked, this is the real number.....
How's the idle?? Any change.. Is it louder, more aggresive or same but deeper??
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Verdad Gallardo TECH Addict
Joined: Oct 2003
Posts: 2,620
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From: Central, MA
I went from the factory 1.7's to the VHP 1.89's -- or what Crane calls their Quick Lift 1.8's. Both the same.
I totally forgot about the torque multiplication thing... but I can definitely say it hits harder from a dead stop.
After almost a week here, the idle really hasn't changed much at all. DEFINITELY not enough for anybody but the owner of the car to notice. I'm not sure abour your cam, but there are times were mine has a little cackle to it - and other times were it could pass as stock. It's still the same way now. It's a bit louder, but not by much. It is "cleaner" sounding, as if I got the idle tuned up better. I can't say for sure if it's any deeper...
I'll get a video online either tonight, or tomorrow evening... I've got an older one from over the summer that you can compare it to, but that was through manifolds.
I totally forgot about the torque multiplication thing... but I can definitely say it hits harder from a dead stop.
After almost a week here, the idle really hasn't changed much at all. DEFINITELY not enough for anybody but the owner of the car to notice. I'm not sure abour your cam, but there are times were mine has a little cackle to it - and other times were it could pass as stock. It's still the same way now. It's a bit louder, but not by much. It is "cleaner" sounding, as if I got the idle tuned up better. I can't say for sure if it's any deeper...
I'll get a video online either tonight, or tomorrow evening... I've got an older one from over the summer that you can compare it to, but that was through manifolds.
