RangeRovers.net Forum banner

1 - 20 of 36 Posts

·
Registered
Joined
·
133 Posts
Discussion Starter #1
I am trying to custom a quad tip exhaust and found there are 2 free iron weights hanging in the rear bumper, in oder to do the exhaust, its said the weights need to be removed, but I would like to know wut the function of these weights and can these be safely removed? TIA!!
 

·
LIFETIME CONTRIBUTOR
2006-2009 Range Rover Sport
Joined
·
11,014 Posts
pimpn04coupe said:
i thought they served as sensors for tilt and whatnot???
I wish they were that sophisticated... I'm afraid those pendulum weights are there just to reduce resonance (they counteract resonate frequency vibrations coming off the frame of the truck.) They are dead weights alright, but I don't know if removing them would be a good idea. I think a couple of forum members (drevs?) yanked them in the past and reported no ill effects, though.
 

·
Registered
Joined
·
487 Posts
That's what I used to think too. Nope, just vibration dampers. When in doubt, Land Rover usually just adds weight. Thus the 6,000 lbs.[/u]
 

·
LIFETIME CONTRIBUTOR
2006-2009 Range Rover Sport
Joined
·
11,014 Posts
There are some interesting theories out there on what those weights are for, some are just plain silly! Here is a gem from LRW (note that these weights are also mounted on the LR3):

http://www.landroverworld.org/forums/sh ... php?t=1554

But they are indeed there to reduce frame vibrations and improve ride quality. They are pretty chunky pieces of metal, so I'll go with your 50 lbs estimate. :wink:
 

·
Registered
Joined
·
133 Posts
Discussion Starter #7
I got those weight out last friday, its been three days now, have not notice any changes.....fingers cross and hope it stays this way..... :twisted:

BTW, these weights are 100lbs plus....so so so heavy.... :evil:
 

·
Premium Member
Joined
·
1,662 Posts
What the :evil: Did you weigh them? Did you also test drive at highways speeds 60, 65, 70, 75....? If they are 100+ and there are no dynamic problems at speed, they are coming out.
 

·
Registered
Joined
·
643 Posts
It isn't mysterious and they are not to "balance the vehicle."

As umbertob stated earlier in this thread, the weights hanging in front of the rear bumper are to counteract resonate frequency vibrations coming from the integrated body-frame of the truck. Those Land Rover engineers don't just add weight for fun.

You'll see them on the LR3 twin, too.

If you want to discuss harmonics and resonance in vehicle design, it's best to find another forum. :)
 

·
Registered
Joined
·
133 Posts
Discussion Starter #10
So far i test all speed up to 120mph, no issue, cornering seems more responsive, hard breaking feels the same....i am convinced they were there for canceling resonate from the frame but so far i dont hear any noise yet. :p
 

·
Registered
2006-2009 Range Rover Sport
Joined
·
213 Posts
Murdered Out said:
300lbs is not much when you're talking a total weight over 6000lbs. If you find a way to shave a couple thousand, let me know, that may add 3-5 mpg. If I was drag racing it, or need it to be light for real performance reasons I'd contemplate it, however its just a cruising vehicle. I'm not for breaking things that are not broken, especially if no one has a real answer.

I'll keep an eye on this post too, so i can see what happens or when we find out the exact reasons forthe weights. I'm going in to the dealer next week, I'll get some answers from them.
300lbs would be noticeable, and yeah that is a lot of weight. 5200lb curb weight vs 5500 is not different?
 

·
Registered
2006-2009 Range Rover Sport
Joined
·
213 Posts
mambo said:
WhiteE46M3 said:
So far i test all speed up to 120mph, no issue, cornering seems more responsive, hard breaking feels the same....i am convinced they were there for canceling resonate from the frame but so far i dont hear any noise yet. :p
Resonance is not about noise, rather than get into details, look at this.

http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge
The initial topic was acoustic resonance, so yeah it is about noise. Resonance just means it is oscillating in some way.
 

·
Registered
Joined
·
133 Posts
Discussion Starter #14
umbertob said:
How did 50 lbs mushroom to 100 and now 300? Did they hang Oprah down there?
:lol: :lol: initially by visual estimate, they look like about 50lbs, but after actually physically removed them, estimate by my arms, they are like 100lbs plus. I dont know where is the 300 from, maybe if u remove both front and rear mushrooms? :lol: :lol:
 

·
Registered
Joined
·
643 Posts
I don't understand the obsession. What exactly is anyone's goal in removing these from the vehicle? Total distrust of Land Rover engineers?

It's slightly under 90 lbs. total if I remember correctly (from LR3) and in no way is removing it going to improve your gas mileage or performance. 8)

Anyway, if you really want to trim down... put your RRS on a lift, and start removing anything you can't identify as actually useful. In an hour or so, you should exceed 90 lbs. of savings. :lol:
 

·
Registered
2006-2009 Range Rover Sport
Joined
·
213 Posts
Murdered Out said:
WhiteE46M3 said:
umbertob said:
How did 50 lbs mushroom to 100 and now 300? Did they hang Oprah down there?
100lbs plus. I dont know where is the 300 from, maybe if u remove both front and rear mushrooms? :lol: :lol:
nice! even better well i shlt 50lbs. is it worth it now? 100lbs? lol have fun maybe you'll get an extra .0000000000000000001 mpg
Actually in the city, a few hundred pounds would have a positive effect on gas mileage and performance. 3-500 pounds could give you about 1 more mpg average, which doesn't sound like a lot but thats about $5 every fillup. With 2 fillups a month that's $120 a year. Highway driving is more limited by aerodynamic aspects, whereas in the city it's entirely weight.
 

·
Registered
Joined
·
86 Posts
Forumnoob said:
Resonance just means it is oscillating in some way.
Resonance is a tendency to oscillate at maximum amplitude at given frequencies. The point of the dampers is to stop this resonance at these frequencies. Going out for one drive is not good enough to come on here and say that there's no issue - LR testing is slightly more rigorous, and if they realised a need to damp the resonance then they need to be there.
 

·
LIFETIME CONTRIBUTOR
2006-2009 Range Rover Sport
Joined
·
11,014 Posts
I would further add that - in the eye of a LR service department - removing those "useless" weights would probably disqualify you from any warranty claims regarding squeaks, rattles, mechanical failures, Acts of God and related issues that may develop in your car. Sure, you could put the weights back on before going to see the dealer or hire a mathematician to disprove their theory. But for 100 lbs? Doesn't seem worth the hassle and trouble potential to me.
 

·
Registered
Joined
·
232 Posts
Land Rover don't do things for nothing - they are there for a purpose,

keeping the back end on the ground when you go round a tight bend too fast! :wink:
 

·
SUPER MODERATOR
2006-2009 Range Rover Sport
Joined
·
4,466 Posts
Of course, the ultimate irony would be if those quad tips after being welded or screwed on came loose and fell off from the harmonic resonation that occurs from removing the weights to make room for the tips...he he.

:D :D
 
1 - 20 of 36 Posts
Top