12 lb weight in the trunk lid?
04-28-2004, 04:08 PM
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I have a track model but haven't pulled the cover to look at the "suspended" weight but I'm sure it's there based on the other posts. However, what caught my attention from the other posts is that the "ballast" is suspended. Why suspend a ballast mass - doesn't make any sense, unless ......
I'm going to throw out a potentially crazy idea on what this maybe for. For any of you mechanical/vibration engineers you'll know what I'm referring to. There's a clever vibration isolation concept called a tuned mass absorber. It works on a coupled mass principal where if you suspend a small mass on a larger vibrating mass and "tune" the small suspended mass to a specific frequency one can detune the larger vibrating mass. I wonder if the rear hatch has a natural frequency that Nissan fixed with this simple TVA. I'm guessing it's tuned to somewhere in the 20 to 50 Hz range based on the 1.5# which is getting into the lower end of the acoustic range. For the you that have removed it listen for any "acoustic" booming that you didn't notice before. I maybe all wet, but maybe not. If they needed ballast why not place it at the hatch edge where there's more leverage.
I'm going to throw out a potentially crazy idea on what this maybe for. For any of you mechanical/vibration engineers you'll know what I'm referring to. There's a clever vibration isolation concept called a tuned mass absorber. It works on a coupled mass principal where if you suspend a small mass on a larger vibrating mass and "tune" the small suspended mass to a specific frequency one can detune the larger vibrating mass. I wonder if the rear hatch has a natural frequency that Nissan fixed with this simple TVA. I'm guessing it's tuned to somewhere in the 20 to 50 Hz range based on the 1.5# which is getting into the lower end of the acoustic range. For the you that have removed it listen for any "acoustic" booming that you didn't notice before. I maybe all wet, but maybe not. If they needed ballast why not place it at the hatch edge where there's more leverage.
04-28-2004, 04:23 PM
#23
Originally posted by boyze
I have a track model but haven't pulled the cover to look at the "suspended" weight but I'm sure it's there based on the other posts. However, what caught my attention from the other posts is that the "ballast" is suspended. Why suspend a ballast mass - doesn't make any sense, unless ......
I'm going to throw out a potentially crazy idea on what this maybe for. For any of you mechanical/vibration engineers you'll know what I'm referring to. There's a clever vibration isolation concept called a tuned mass absorber. It works on a coupled mass principal where if you suspend a small mass on a larger vibrating mass and "tune" the small suspended mass to a specific frequency one can detune the larger vibrating mass. I wonder if the rear hatch has a natural frequency that Nissan fixed with this simple TVA. I'm guessing it's tuned to somewhere in the 20 to 50 Hz range based on the 1.5# which is getting into the lower end of the acoustic range. For the you that have removed it listen for any "acoustic" booming that you didn't notice before. I maybe all wet, but maybe not. If they needed ballast why not place it at the hatch edge where there's more leverage.
I have a track model but haven't pulled the cover to look at the "suspended" weight but I'm sure it's there based on the other posts. However, what caught my attention from the other posts is that the "ballast" is suspended. Why suspend a ballast mass - doesn't make any sense, unless ......
I'm going to throw out a potentially crazy idea on what this maybe for. For any of you mechanical/vibration engineers you'll know what I'm referring to. There's a clever vibration isolation concept called a tuned mass absorber. It works on a coupled mass principal where if you suspend a small mass on a larger vibrating mass and "tune" the small suspended mass to a specific frequency one can detune the larger vibrating mass. I wonder if the rear hatch has a natural frequency that Nissan fixed with this simple TVA. I'm guessing it's tuned to somewhere in the 20 to 50 Hz range based on the 1.5# which is getting into the lower end of the acoustic range. For the you that have removed it listen for any "acoustic" booming that you didn't notice before. I maybe all wet, but maybe not. If they needed ballast why not place it at the hatch edge where there's more leverage.
04-29-2004, 07:49 AM
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Originally posted by Dr Bonz
Yeah, either that or they just tried to make the hatch close easier.
Yeah, either that or they just tried to make the hatch close easier.
just a thought.
WayneTN
04-29-2004, 06:14 PM
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Re: 12 lb weight in the trunk lid?
Originally posted by BoostTed
I did a little research on how to install a wing and from a few people they said to remember to remove the 12lb counter weight from the trunk lid when installing the wing. Its supposed to be under the plastic cover. Well I took my cover off and couldnt find a 12lb counter weight anywhere. Well before I installed the wing it would be hard for me to close the trunk, I really had to slam it hard to close it, if I didnt then it wouldnt shut all the way. I thought that that was how it was. But after I installed the wing the trunk lid is so much easier to close, it seems to close like how it should be closing now. So just a heads up for those who's trunk lid isn't shutting like how it should be.
I did a little research on how to install a wing and from a few people they said to remember to remove the 12lb counter weight from the trunk lid when installing the wing. Its supposed to be under the plastic cover. Well I took my cover off and couldnt find a 12lb counter weight anywhere. Well before I installed the wing it would be hard for me to close the trunk, I really had to slam it hard to close it, if I didnt then it wouldnt shut all the way. I thought that that was how it was. But after I installed the wing the trunk lid is so much easier to close, it seems to close like how it should be closing now. So just a heads up for those who's trunk lid isn't shutting like how it should be.
I recently had a wing put on my Z too... Do the little shocks that hold the hatch in the open position hold your hatch up? Seems like the weight of the wing is too much and the hatch won't stay up on its own.
Anyone know if stronger replacement shocks for the hatch are available? Thanks.
04-29-2004, 07:09 PM
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Re: Re: 12 lb weight in the trunk lid?
Originally posted by NISMO_GUY2003
Hey BoostTed,
I recently had a wing put on my Z too... Do the little shocks that hold the hatch in the open position hold your hatch up? Seems like the weight of the wing is too much and the hatch won't stay up on its own.
Anyone know if stronger replacement shocks for the hatch are available? Thanks.
Hey BoostTed,
I recently had a wing put on my Z too... Do the little shocks that hold the hatch in the open position hold your hatch up? Seems like the weight of the wing is too much and the hatch won't stay up on its own.
Anyone know if stronger replacement shocks for the hatch are available? Thanks.
04-30-2004, 12:44 AM
#28
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man i dunno, that kind of worries me. I had a nismo spoiler i was going to be putting on my car shortly after i took delivery so i went to take off the weight like everyone was saying. I most definately did not have the weight in there though(It was visible where it should have been, like in the pic posted earlier in this thread). I dont have a factory spoiler if that helps. Maybe it was just a fluke in my car, but either way thats kind of odd.
12-14-2007, 04:58 AM
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Originally Posted by ssgohan434
bumped from the dead.... going go attempt this very soon, do you just pop off the hatch panel with a flat head to get to the weight?
12-14-2007, 08:21 AM
#31
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Has anyone else had trouble opening the hatch on cold days? I pop the hatch open lift all the way up and the damn thing nearly came crashing down on my head! It was only on cold days though, normal days it opens up, and stays up, just fine
12-14-2007, 09:22 AM
#32
Originally Posted by IX R3VAN XI
Has anyone else had trouble opening the hatch on cold days? I pop the hatch open lift all the way up and the damn thing nearly came crashing down on my head! It was only on cold days though, normal days it opens up, and stays up, just fine
Ya I've since referred to it as ghost hatching, damn thing klobbered me the one day...
12-17-2007, 12:41 PM
#34
Originally Posted by Steve-O Z33
I never knew about this. I have the blitz wing. No problems. 12 lb weight reduction sounds ok though. 
That's like 1 HP. 
That's like 1 HP. 
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