Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

found out diff weights interesting???

Started by _1QUICK EH_ , Dec 28 2006 11:00 PM

Next

This topic is locked

47 replies to this topic

#1 _1QUICK LJ_

Guests

Posted 28 December 2006 - 11:00 PM

i weighed my 9in and banjo today to compare them as follows: both complete diff assemblys inc, housing, centre, axles and brakes.

banjo 3.08 open centre LJ torana inc brakes 63kg

9in 3.5 lsd, 28 spline axles, HQ drum brakes 84kg

21kg the difference interesting stuff not as much difference as i thought? i guess a BW or sals would be in between somewhere. prob 10kg less than a 9in, not that much in it really?

Edited by 1QUICK LJ, 28 December 2006 - 11:01 PM.

Back to top

#2 TerrA LX

Fulcrum Fixture

Members
14,241 posts

Location:Sid 'n' knee
Joined: 31-May 06

Posted 28 December 2006 - 11:07 PM

try carrying around a 10kg box for 12hrs and then tell me its not much.

Back to top

#3 FastEHHolden

Steptoe

Members
5,114 posts

Location:Central Coast NSW
Joined: 16-November 05

Posted 28 December 2006 - 11:11 PM

I reckon its stuff all in the scheme of things...the weight is very low and shouldn't affect handling that much....certainly it shouldn't affect it less than the 21 kg of Maccas wrappers in my car.

Back to top

#4 dattoman

Do I feel lucky? Well, do ya, punk?

Administrators
16,489 posts

Name:Neil
Location:Perth Western Australia
Car:LX SS , 76 Cadillac , 3 x dattos
Joined: 04-February 07

Posted 28 December 2006 - 11:16 PM

Depends on the application
Unsprung weight is bad

Back to top

#5 _1QUICK LJ_

Guests

Posted 28 December 2006 - 11:17 PM

try carrying around a 10kg box for 12hrs and then tell me its not much.

im not planning on carrying it around beleive me? its meant to go in the car. lol

Back to top

#6 _1QUICK LJ_

Guests

Posted 28 December 2006 - 11:20 PM

21litres of fuel is around 21kg i cant feel any real difference when my tank has 20 litres compared to near empty.

Back to top

#7 _1QUICK LJ_

Guests

Posted 28 December 2006 - 11:22 PM

i reckon it will take a little skippyness out of the rear, as for extra weight im running a 308 it dont matter much to me.

Edited by 1QUICK LJ, 28 December 2006 - 11:23 PM.

Back to top

#8 tinkers

Admin

Administrators
3,799 posts

Name:Kerri
Location:Perth - Gold Coast - Brisbane
Car:LX Hatch & VX Clubsport & VS Ute
Joined: 04-February 07

Posted 28 December 2006 - 11:35 PM

21kgs difference, any wonder the skateboard didnt like it when I moved the 9in around the garage LOL

Back to top

#9 FastEHHolden

Steptoe

Members
5,114 posts

Location:Central Coast NSW
Joined: 16-November 05

Posted 28 December 2006 - 11:46 PM

This is not directed at anyone

people make such a big deal about the effect of a 9 inch on the handling, due to the weight...but then they slot in a TH350...or whack a 350 chev in the front..load the car up with stereo gear, toolboxes..maccas wrappers whatever. There are far worse things you can do to the handling or you Torana..to me 9 inch pluses far outweigh the negatives.

Dammit the General should have copied the design and sent them out the factory door with one in it already. :rockon:

Back to top

#10 tinkers

Admin

Administrators
3,799 posts

Name:Kerri
Location:Perth - Gold Coast - Brisbane
Car:LX Hatch & VX Clubsport & VS Ute
Joined: 04-February 07

Posted 28 December 2006 - 11:47 PM

Glad I got the maccas wrappers out of the car

Back to top

#11 _rorym_

Guests

Posted 28 December 2006 - 11:56 PM

remind me to drop that 20kgs off my arse b4 I get in the car at the next meeting....
R

Back to top

#12 _1QUICK LJ_

Guests

Posted 29 December 2006 - 12:22 AM

thats it, no more maccas for me then.

Back to top

#13 _1QUICK LJ_

Guests

Posted 29 December 2006 - 12:33 AM

This is not directed at anyone

people make such a big deal about the effect of a 9 inch on the handling, due to the weight...but then they slot in a TH350...or whack a 350 chev in the front..load the car up with stereo gear, toolboxes..maccas wrappers whatever. There are far worse things you can do to the handling or you Torana..to me 9 inch pluses far outweigh the negatives.

Dammit the General should have copied the design and sent them out the factory door with one in it already.

i agree totally 100%, i never hear anyone say a 671 blower is going to stuff up handling, ever felt what they weigh? or a fully decked out boot using mdf board,including battery,speakers ,amp,fuel pumps,nos bottle, spare wheel,jack, tool kit and 120litre drop tank full of fuel :tease:

Back to top

#14 TerrA LX

Fulcrum Fixture

Members
14,241 posts

Location:Sid 'n' knee
Joined: 31-May 06

Posted 29 December 2006 - 12:40 AM

Dammit the General should have copied the design and sent them out the factory door with one in it already.

yeah i dont think you would see too many swaping out a 9" for a bango.

Back to top

#15 _rorym_

Guests

Posted 29 December 2006 - 07:30 AM

Its all about reciprocating mass....someone here will drop a forumla soon.. but I have raced bikes....I can tell you stopping a 155KG bike at the end of Conrod compared to a 125KG one is HUGE!!! :blink:

Its is night and day. The weight thing depends on your application and if it hinders you or not.
R

Back to top

#16 _Rally hatch_

Guests

Posted 29 December 2006 - 07:51 AM

Not sure if any one is interested but I'll throw my 2 cents in.......
A complete holden 308 with carbie, exhaust etc weighs in at 224 kg and makes around 124kw (vk black motor).... a holden V6 (VN,VP,VR) weighs in at 180kg and makes the same power, approx 126kw......
A T700 four speed auto weighs 80kgs....... and a Borgwarner single rail weighs 51kgs with no bellhousing....
So if you put a V6 with a single rail(Dellow do a bellhousing) in an LJ you would have V8 power..... late modle fuel efficincy with efi and be 75 kgs lighter!!
Not to mention the fact that the weight of the V6 sits further back past the front cross member to bring your center of gravity closer to the middle of the car...
But i could be talking out my ass too...... :tease:

Back to top

#17 Gump

Paisty White

Members
1,146 posts

Name:Russell
Location:Bridgetown WA
Car:LX SL hatch
Joined: 15-November 05

Posted 29 December 2006 - 09:35 AM

would there be much differeence between McDonalds wrappers vs Hungry Jacks (bugger king to everbody else isnt it?)

Back to top

#18 _stinky_

Guests

Posted 29 December 2006 - 09:51 AM

While 20kgs weight difference might not effect much, a more interesting exercise would be a couple of dyno runs, same car, same motor, just changing the diffs.
The arguement I have always heard is that it takes more HP to turn a 9" than a banjo, hence less RWHP when running a 9".

Back to top

#19 _stinky_

Guests

Posted 29 December 2006 - 09:53 AM

would there be much differeence between McDonalds wrappers vs Hungry Jacks (bugger king to everbody else isnt it?)

Yeah, the HJ wrappers are full of pickles :huh:

Back to top

#20 _bodallafella_

Guests

Posted 29 December 2006 - 09:55 AM

people make such a big deal about the effect of a 9 inch on the handling, due to the weight...but then they slot in a TH350...or whack a 350 chev in the front..

True, but it's not quite the same thing. The extra 20kgs from the diff is unsprung weight but a gearbox or engine is sprung weight. Unsprung weight has much more effect on handling because it is extra weight that the spring has to control along with the wheel.

Back to top

#21 _devilsadvocate_

Guests

Posted 29 December 2006 - 10:54 AM

Not sure if any one is interested but I'll throw my 2 cents in.......
A complete holden 308 with carbie, exhaust etc weighs in at 224 kg and makes around 124kw (vk black motor).... a holden V6 (VN,VP,VR) weighs in at 180kg and makes the same power, approx 126kw......
A T700 four speed auto weighs 80kgs....... and a Borgwarner single rail weighs 51kgs with no bellhousing....
So if you put a V6 with a single rail(Dellow do a bellhousing) in an LJ you would have V8 power..... late modle fuel efficincy with efi and be 75 kgs lighter!!
Not to mention the fact that the weight of the V6 sits further back past the front cross member to bring your center of gravity closer to the middle of the car...
But i could be talking out my ass too......

Good to see some good facts thrown in here. Can anyone quote what the mass of a red six, might be?
Small point: 21 liters of fuel wont weigh 21kg. Density of petrol is typically 0.72-0.77kg/litre depending on blend and temperature.
If you dont need a 9inch, hauling around another 20kg is an unnecessary use of energy and production of CO2......as well as the extra friction that is caused bythe 9inch. Yes, maybe 20kg is only ~2% of the weight of the car, but yes it will burn more fuel, you may not be able to notice the performance difference or measure it tank to tank, but it is there, the difference will also be felt by the brake pads. Increasing weight of the vehicle will basically have cause linear increases in rolling resistance and fuel consumption in suburban traffic, of course at higher speeds wind resistance will have a much greater influence on consumption. Certainly put 20kgs on the packrack of a bicycle and pedal it around and notice how much energy is required, then multiply that by the mileage you might do in a year. There are the good arguments: what about the stereo, the blower, the drop tank, the filled drop tank, .......yes they will have their effect as well, doesnt mean that adding 20kgs will have no effect.
Rorym, yes the rotating mass part is significant, particularly for acceleration, though we dont have any figures to compare on the masses of the actual rotating bits in the two different diffs.
Supposedly, the rts suspension on the torries has been finetuned for optimum handling(perhaps Im gullible here), Im sure increasing the unsprung mass by 20% (adding the weight of the wheels into the equation) would change this tuning significantly. Things would need to be 20% stiffer in the rear suspension to have the rear axle react the same way when the wheel moves suddenly up or down like when hitting a bump etc. But even if you did this, the car hasnt increased mass by 20% and 20% stiffer springs/shocks etc would upset the whole apple cart.
Im not sure if my logic is correct, but I never have my tank over half full in suburbia, figure its gotta be using less fuel overall if Im not dragging around on average an extra 20kg of fuel, but then again, need an extra stop at a station which would require energy to stop and go.

Edited by devilsadvocate, 29 December 2006 - 11:02 AM.

Back to top

#22 Litre8

Thrillseeker

Administrators
2,399 posts

Name:Howard
Location:Melbourne, Victoria
Car:1976 LX SLR8000
Joined: 05-February 07

Posted 29 December 2006 - 11:21 AM

Agree with Rory, the reciprocating mass increase of the 9" probably becomes significant when you are driving it with ,say, a six cylinder engine, especially down the quarter mile.

Back to top

#23 dattoman

Do I feel lucky? Well, do ya, punk?

Administrators
16,489 posts

Name:Neil
Location:Perth Western Australia
Car:LX SS , 76 Cadillac , 3 x dattos
Joined: 04-February 07

Posted 29 December 2006 - 11:23 AM

Whats yours weigh Howard with the alloy centre...... or more to the point.... do you know how much lighter the centre is ?

Back to top

#24 _rorym_

Guests

Posted 29 December 2006 - 11:32 AM

I knew Devil would have the answer! :spoton:

We are all missing the point..Small car..big HP = Faster car..pretty simple actually..been working for years..hence why I opted for the B/W at the back of the new car and not the Flaud diff.
R

Back to top

#25 _1QUICK LJ_

Guests

Posted 29 December 2006 - 11:48 AM

Not sure if any one is interested but I'll throw my 2 cents in.......
A complete holden 308 with carbie, exhaust etc weighs in at 224 kg and makes around 124kw (vk black motor).... a holden V6 (VN,VP,VR) weighs in at 180kg and makes the same power, approx 126kw......
A T700 four speed auto weighs 80kgs....... and a Borgwarner single rail weighs 51kgs with no bellhousing....
So if you put a V6 with a single rail(Dellow do a bellhousing) in an LJ you would have V8 power..... late modle fuel efficincy with efi and be 75 kgs lighter!!
Not to mention the fact that the weight of the V6 sits further back past the front cross member to bring your center of gravity closer to the middle of the car...
But i could be talking out my ass too......
Good to see some good facts thrown in here. Can anyone quote what the mass of a red six, might be?
Small point: 21 liters of fuel wont weigh 21kg. Density of petrol is typically 0.72-0.77kg/litre depending on blend and temperature.
If you dont need a 9inch, hauling around another 20kg is an unnecessary use of energy and production of CO2......as well as the extra friction that is caused bythe 9inch. Yes, maybe 20kg is only ~2% of the weight of the car, but yes it will burn more fuel, you may not be able to notice the performance difference or measure it tank to tank, but it is there, the difference will also be felt by the brake pads. Increasing weight of the vehicle will basically have cause linear increases in rolling resistance and fuel consumption in suburban traffic, of course at higher speeds wind resistance will have a much greater influence on consumption. Certainly put 20kgs on the packrack of a bicycle and pedal it around and notice how much energy is required, then multiply that by the mileage you might do in a year. There are the good arguments: what about the stereo, the blower, the drop tank, the filled drop tank, .......yes they will have their effect as well, doesnt mean that adding 20kgs will have no effect.
Rorym, yes the rotating mass part is significant, particularly for acceleration, though we dont have any figures to compare on the masses of the actual rotating bits in the two different diffs.
Supposedly, the rts suspension on the torries has been finetuned for optimum handling(perhaps Im gullible here), Im sure increasing the unsprung mass by 20% (adding the weight of the wheels into the equation) would change this tuning significantly. Things would need to be 20% stiffer in the rear suspension to have the rear axle react the same way when the wheel moves suddenly up or down like when hitting a bump etc. But even if you did this, the car hasnt increased mass by 20% and 20% stiffer springs/shocks etc would upset the whole apple cart.
Im not sure if my logic is correct, but I never have my tank over half full in suburbia, figure its gotta be using less fuel overall if Im not dragging around on average an extra 20kg of fuel, but then again, need an extra stop at a station which would require energy to stop and go.

far out no need to go overboard :blink:

, i wont be calculating if i have enough fuel to get the moon or not, 21 kg is 21 kg, with a performance car i couldn't care less about fuel economy, but i care if I'm stuck at the drags or side of the road with a busted diff :cry:

, and if you run a B/W the difference is even less compared to a 9in i doubt you could even feel it. if you take steel wheels off and put light ally weld wheels on as in my case the difference is even less.

if you busted 2 diffs a year and it cost $95 each tow total $190+repair cost each time, would you save that in fuel a year with a diff that weighs 20kg less i dont think so, your working on a false economy devils :fool: