Discussion
SILICONEKID345HP said:
How difficult is it to remove the diff. Without a lift and what is involved ?
Its a heavy thing. I had the car on a 2 post lift and used a gearbox jack to get it down.Edited by SILICONEKID345HP on Monday 28th March 22:08
Remove exhaust
Remove 4 bolts propshaft to diff (9/16)
Remove the allen bolts to the driveshafts
Cut or unplug the wire to the speedo sensor (original on BTR cars)
Support the diff with a jack or similar
The front diffbushes mount to the diff with bolts that also have nuts on the back. Take off the nuts (19mm) then unscrew the bolts.
Remove the bush brackets
Remove the four allen bolts on the back of the diff
The diff needs to be turned on its side to go down. I had to unbolt one upright (lower) to get the CV away from the diff so I could turn it
ClassiChimi said:
I've been assuming mines a 3.08 as its a 2000 car,,,, but now I'm not so sure,, how do I confirm what mines running, does the dif have markings etc, ?!?
Jack up the rear of the car, rotate the prop by hand, count the number of rotations to get the wheel to turn 1 revolution. If it is a 3.08 diff then the prop will turn 3 and a little bit times to get the wheel to turn once. If it is a 3.45 then it will require 3 and half turns to get the wheel to rotate once.
I'm seriously considering a 3.08 diff in 'Ol Gasbag', Ok so I only have 250hp and 260 ft/lbs but I still think it could work well?
Is it not a case that once you're out of 1st the negative effects would be minimal because you're still changing up when the engine spinning at the same speed as it would be if you are running the standard diff?
The box remains the same so as long as the engine has enough power to pull 1st smoothly from a hill start with the 3.08 diff then because the five ratios and spread between them remains exactly the same you just stay in the lower gear for longer.
Currently my gearing looks roughly like this with a 3.77 diff and 225/50 R16 rear boots:
1st - 7mph per 1,000
2nd - 10mph per 1,000
3rd - 15mph per 1,000
4th - 19mph per 1,000
5th - 24mph per 1,000 (Holds an 80mph cruise at 3280rpm)
With a 3.08 diff it would look more like this:
1st - 8mph per 1,000 (Hardly ant difference, doubt I'll notice a thing)
2nd - 12mph per 1,000 (Half way between 2nd & 3rd with standard diff)
3rd - 18mph per 1,000 (Still a fraction lower geared than 4th with standard diff)
4th - 24mph per 1,000 (Becomes same as 5th with standard diff)
5th - 30mph per 1,000 (Will hold an 80mph cruise at 2700rpm)
As far as I can see there are very few negatives, for situations where I normally drop from 5th to 4th to execute a typical A road overtake on my current 3.77 diff I will already be in 4th at the same A road cruising speed, so will simply drop from 4th to 3rd to access the same the overtaking acceleration.
So looking at it this way during normal driving where firm passing acceleration is called for there will be little or no difference with the 3.08 diff other than the fact you'll always be starting from and dropping to one gear lower than I would be with my current 3.77 diff.
I really don't think it'll take any time at all to recalibrate by driving, indeed I would expect the 3.08 will feel perfectly natural and intuitive.
Most importantly the key benefit of the 3.08 diff being 'Ol Gasbag's' engine will be turning a very useful 580rpm slower at my cruising gate of 80mph.
That's going to translate to better economy and lower cabin noise without any loss of real world overtaking performance at all.
TBH I can only see benefits even for my Chimaera because while I may not be in the big horsepower league 260 ft/lbs of torque in a 1100kg (with gas bottles) car is still a very good torque per tonn figure compared with most cars
Then when you look at how low down in the RPM range 90% of the available torque is accessible it becomes quite clear to me even 'Ol Gasbag' could pull the taller 3.08 diff with zero negatives and the one big benefit described in 5th.
Indeed at 80mph with the engine spinning at just 2700rpm 'Ol Gasbag' is already making 93% of her total available torque so the phrase "Sweet Spot" comes to mind, and possibly worth another 2mpg at least
Is it not a case that once you're out of 1st the negative effects would be minimal because you're still changing up when the engine spinning at the same speed as it would be if you are running the standard diff?
The box remains the same so as long as the engine has enough power to pull 1st smoothly from a hill start with the 3.08 diff then because the five ratios and spread between them remains exactly the same you just stay in the lower gear for longer.
Currently my gearing looks roughly like this with a 3.77 diff and 225/50 R16 rear boots:
1st - 7mph per 1,000
2nd - 10mph per 1,000
3rd - 15mph per 1,000
4th - 19mph per 1,000
5th - 24mph per 1,000 (Holds an 80mph cruise at 3280rpm)
With a 3.08 diff it would look more like this:
1st - 8mph per 1,000 (Hardly ant difference, doubt I'll notice a thing)
2nd - 12mph per 1,000 (Half way between 2nd & 3rd with standard diff)
3rd - 18mph per 1,000 (Still a fraction lower geared than 4th with standard diff)
4th - 24mph per 1,000 (Becomes same as 5th with standard diff)
5th - 30mph per 1,000 (Will hold an 80mph cruise at 2700rpm)
As far as I can see there are very few negatives, for situations where I normally drop from 5th to 4th to execute a typical A road overtake on my current 3.77 diff I will already be in 4th at the same A road cruising speed, so will simply drop from 4th to 3rd to access the same the overtaking acceleration.
So looking at it this way during normal driving where firm passing acceleration is called for there will be little or no difference with the 3.08 diff other than the fact you'll always be starting from and dropping to one gear lower than I would be with my current 3.77 diff.
I really don't think it'll take any time at all to recalibrate by driving, indeed I would expect the 3.08 will feel perfectly natural and intuitive.
Most importantly the key benefit of the 3.08 diff being 'Ol Gasbag's' engine will be turning a very useful 580rpm slower at my cruising gate of 80mph.
That's going to translate to better economy and lower cabin noise without any loss of real world overtaking performance at all.
TBH I can only see benefits even for my Chimaera because while I may not be in the big horsepower league 260 ft/lbs of torque in a 1100kg (with gas bottles) car is still a very good torque per tonn figure compared with most cars
Then when you look at how low down in the RPM range 90% of the available torque is accessible it becomes quite clear to me even 'Ol Gasbag' could pull the taller 3.08 diff with zero negatives and the one big benefit described in 5th.
Indeed at 80mph with the engine spinning at just 2700rpm 'Ol Gasbag' is already making 93% of her total available torque so the phrase "Sweet Spot" comes to mind, and possibly worth another 2mpg at least
Edited by ChimpOnGas on Tuesday 29th March 17:24
ChimpOnGas said:
I'm seriously considering a 3.08 diff in 'Ol Gasbag', Ok so I only have 250hp and 260 ft/lbs but I still think it could work well?
Is it not a case that once you're out of 1st the negative effects would be minimal because you're still changing up when the engine spinning at the same speed as it would be if you are running the standard diff?
The box remains the same so as long as the engine has enough power to pull 1st smoothly from a hill start with the 3.08 diff then because the five ratios and spread between them remains exactly the same you just stay in the lower gear for longer.
Currently my gearing looks roughly like this with a 3.77 diff and 225/50 R16 rear boots:
1st - 7mph per 1,000
2nd - 10mph per 1,000
3rd - 15mph per 1,000
4th - 19mph per 1,000
5th - 24mph per 1,000 (Holds an 80mph cruise at 3280rpm)
With a 3.08 diff it would look more like this:
1st - 8mph per 1,000 (Hardly ant difference, doubt I'll notice a thing)
2nd - 12mph per 1,000 (Half way between 2nd & 3rd with standard diff)
3rd - 18mph per 1,000 (Still a fraction lower geared than 4th with standard diff)
4th - 24mph per 1,000 (Becomes same as 5th with standard diff)
5th - 30mph per 1,000 (Will hold an 80mph cruise at 2700rpm)
As far as I can see there are very few negatives, for situations where I normally drop from 5th to 4th to execute a typical A road overtake on my current 3.77 diff I will already be in 4th at the same A road cruising speed, so will simply drop from 4th to 3rd to access the same the overtaking acceleration.
So looking at it this way during normal driving where firm passing acceleration is called for there will be little or no difference with the 3.08 diff other than the fact you'll always be starting from and dropping to one gear lower than I would be with my current 3.77 diff.
I really don't think it'll take any time at all to recalibrate by driving, indeed I would expect the 3.08 will feel perfectly natural and intuitive.
Most importantly the key benefit of the 3.08 diff being 'Ol Gasbag's' engine will be turning a very useful 580rpm slower at my cruising gate of 80mph.
That's going to translate to better economy and lower cabin noise without any loss of real world overtaking performance at all.
TBH I can only see benefits even for my Chimaera because while I may not be in the big horsepower league 260 ft/lbs of torque in a 1100kg (with gas bottles) car is still a very good torque per tonn figure compared with most cars
Then when you look at how low down in the RPM range 90% of the available torque is accessible it becomes quite clear to me even 'Ol Gasbag' could pull the taller 3.08 diff with zero negatives and the one big benefit described in 5th.
Indeed at 80mph with the engine spinning at just 2700rpm 'Ol Gasbag' is already making 93% of her total available torque so the phrase "Sweet Spot" comes to mind, and possibly worth another 2mpg at least
I reckon your car is a 3.45 ,the 3.77 diff is used for the speed six .Is it not a case that once you're out of 1st the negative effects would be minimal because you're still changing up when the engine spinning at the same speed as it would be if you are running the standard diff?
The box remains the same so as long as the engine has enough power to pull 1st smoothly from a hill start with the 3.08 diff then because the five ratios and spread between them remains exactly the same you just stay in the lower gear for longer.
Currently my gearing looks roughly like this with a 3.77 diff and 225/50 R16 rear boots:
1st - 7mph per 1,000
2nd - 10mph per 1,000
3rd - 15mph per 1,000
4th - 19mph per 1,000
5th - 24mph per 1,000 (Holds an 80mph cruise at 3280rpm)
With a 3.08 diff it would look more like this:
1st - 8mph per 1,000 (Hardly ant difference, doubt I'll notice a thing)
2nd - 12mph per 1,000 (Half way between 2nd & 3rd with standard diff)
3rd - 18mph per 1,000 (Still a fraction lower geared than 4th with standard diff)
4th - 24mph per 1,000 (Becomes same as 5th with standard diff)
5th - 30mph per 1,000 (Will hold an 80mph cruise at 2700rpm)
As far as I can see there are very few negatives, for situations where I normally drop from 5th to 4th to execute a typical A road overtake on my current 3.77 diff I will already be in 4th at the same A road cruising speed, so will simply drop from 4th to 3rd to access the same the overtaking acceleration.
So looking at it this way during normal driving where firm passing acceleration is called for there will be little or no difference with the 3.08 diff other than the fact you'll always be starting from and dropping to one gear lower than I would be with my current 3.77 diff.
I really don't think it'll take any time at all to recalibrate by driving, indeed I would expect the 3.08 will feel perfectly natural and intuitive.
Most importantly the key benefit of the 3.08 diff being 'Ol Gasbag's' engine will be turning a very useful 580rpm slower at my cruising gate of 80mph.
That's going to translate to better economy and lower cabin noise without any loss of real world overtaking performance at all.
TBH I can only see benefits even for my Chimaera because while I may not be in the big horsepower league 260 ft/lbs of torque in a 1100kg (with gas bottles) car is still a very good torque per tonn figure compared with most cars
Then when you look at how low down in the RPM range 90% of the available torque is accessible it becomes quite clear to me even 'Ol Gasbag' could pull the taller 3.08 diff with zero negatives and the one big benefit described in 5th.
Indeed at 80mph with the engine spinning at just 2700rpm 'Ol Gasbag' is already making 93% of her total available torque so the phrase "Sweet Spot" comes to mind, and possibly worth another 2mpg at least
Edited by ChimpOnGas on Tuesday 29th March 17:24
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