Lowering the 75 - Page 4

KWIL · 28th August 2016, 14:38

You obviously think they look better by being lower, but it just means the gaps ahead and behind the black rings look tapered and at odds with the body design as originally conceived.

KRISTLEE · 28th August 2016, 15:24

Quote:

Originally Posted by KWIL

You obviously think they look better by being lower, but it just means the gaps ahead and behind the black rings look tapered and at odds with the body design as originally conceived.

Tapered? The gaps look pretty even to me....whoever came up with the large gap design must have got mixed up and thought they were designing a Land Rover that drives through rivers, streams, uneven/broken surfaces etc...must have been the same designer that came up with the bonnet gap that most folk end up modifying to look like a normally conceived body design.

Supervinnie40 · 25th September 2016, 09:36

Edit: sorry, wrong topic...

Supervinnie40 · 1st October 2016, 08:23

I've spent the last week discussing lowering the 75 with a company in Holland. They can offer several custom build set ups for my car, and we have been discussing in length the possibilities and the pros and cons of all the possibilities.

I thought that this post might contain information that might prove useful for others.

First I started to discuss the biggest problem when lowering a car. Obviously, these are height-differences. Which are most common as speedbumps and drive-in-entrances (not sure what the proper words is lol

).
I have been walking around my town measuring several different speedbumps and drive-in entrances. And these are the most common, smallest ones I've come up with.

Speedbump 1
60cm long with a height difference of 10cm.

Speedbump 2
100cm long with a height difference of 10cm.

Alls the other speedbumps had a lower angle, and would be less of a problem. These would be my first concern and that is why I choose these 2.

My 75 has an uneven clearance from the front wheels to the nose of the car. The lowest part is just in front of the wheels and sits at 13cm. The highest part sits at 18cm.

I made calculations on the basis that I would lower my car 4.5cm all around.
The lowest part would then sit at 8.5cm and the highest part at 13.5cm.

I also made a calculation how far the nose would drop if the rear of the car was 20cm higher then the front (a slope). Bases on the distance from the front-axle to the lowest point, and the front axle to the highest point. And then the ratio with the distance between front-axle and rear-axle.
The difference between the axles is 274.6cm. The difference from the front-axle to the highest and lowest point are 56cm and 28cm.
The ratio calculated that if the rear axle is at +20cm height, the 2 points at the front would drop -2.03 and -4.1 cm.

This would mean that the 2 points at the front would sit at a clearance height of 6.5 and 9.4 cm.

I then calculaten what would happen if the wheels would sit at the beginning of the speedbump, and how much clearance would be left (I had to assume that the incline was linear).
Speedbump 1 would give:
Normal= high point:8cm low point: 8cm
lowered= high point:3.5cm low point: 3.5cm
lowered at a slope= high point:-0.6cm low point: 1.5cm

Speedbump 2 would give:
Normal= high point: 13cm low point: 10.5cm
lowered= high point: 8.5cm low point: 6cm
lowered at a slope= high point: 4.4cm low point: 4cm

I can then conclude that if the car is lowered, and the rear axle would be +20cm heigher in the air then the front axle (which would never happen in NL) I would be 0.6cm to low. And the underside would touch the ground.

However, in any other case then the 20cm height difference, I would have a minimum clearance of 3.5cm. Saying that I would (theoretically) lower the car a good 3cm more then 4.5cm without a problem.

Conclusion, I should be able to lower my car a maximum of 7.9 cm without having any serious problems with speedbumps. If I take the slope into account, I should limit it by roughly 4 cm.

As a sidenote: lowering the car more then 4.5 cm would mean getting an adjustable set, which has a very big impact on ride quality. Lowering with a combination of coilovers and different shockabsorbers give more control over the ride quality. Which means that 4.5 cm is the limit unless you really want to sacrifice the quality ride that matches the 75.

According to the mechanic and my calculations, the wheelarch of the 75 is simply to high. It could've easily been made a little lower, so the car wouldn't need to be lowered in order to get rid of that huge gap. Just a little bit more sheet metal that would made the wheelarch a bit smaller.....

Plezier · 1st October 2016, 09:14

Quote:

According to the mechanic and my calculations, the wheelarch of the 75 is simply to high. It could've easily been made a little lower, so the car wouldn't need to be lowered in order to get rid of that huge gap. Just a little bit more sheet metal that would made the wheelarch a bit smaller.....

Of course your mechanic knows much more than the design team responsible for the 75 and ZT range ........................................ naturally

.

Don.Hasi · 18th June 2018, 14:11

Quote:

Originally Posted by BLMC

My car was fitted with German-made lowering springs when i bought it,

do you remember, which brand was it exactly?

25th September 2016, 09:36	#33
Supervinnie40 I really should get out more....... Rover 75 1.8 Club Join Date: Dec 2013 Location: Tilburg (Netherland) Posts: 2,615 Thanks: 572 Thanked 336 Times in 247 Posts	Edit: sorry, wrong topic... __________________ Proud owner of the Dutch "Golden 75". A much loved Gold White Metallic Rover 75 1.8 na from 2000. Last edited by Supervinnie40; 25th September 2016 at 09:38..

1st October 2016, 08:23	#34
Supervinnie40 I really should get out more....... Rover 75 1.8 Club Join Date: Dec 2013 Location: Tilburg (Netherland) Posts: 2,615 Thanks: 572 Thanked 336 Times in 247 Posts	I've spent the last week discussing lowering the 75 with a company in Holland. They can offer several custom build set ups for my car, and we have been discussing in length the possibilities and the pros and cons of all the possibilities. I thought that this post might contain information that might prove useful for others. First I started to discuss the biggest problem when lowering a car. Obviously, these are height-differences. Which are most common as speedbumps and drive-in-entrances (not sure what the proper words is lol ). I have been walking around my town measuring several different speedbumps and drive-in entrances. And these are the most common, smallest ones I've come up with. Speedbump 1 60cm long with a height difference of 10cm. Speedbump 2 100cm long with a height difference of 10cm. Alls the other speedbumps had a lower angle, and would be less of a problem. These would be my first concern and that is why I choose these 2. My 75 has an uneven clearance from the front wheels to the nose of the car. The lowest part is just in front of the wheels and sits at 13cm. The highest part sits at 18cm. I made calculations on the basis that I would lower my car 4.5cm all around. The lowest part would then sit at 8.5cm and the highest part at 13.5cm. I also made a calculation how far the nose would drop if the rear of the car was 20cm higher then the front (a slope). Bases on the distance from the front-axle to the lowest point, and the front axle to the highest point. And then the ratio with the distance between front-axle and rear-axle. The difference between the axles is 274.6cm. The difference from the front-axle to the highest and lowest point are 56cm and 28cm. The ratio calculated that if the rear axle is at +20cm height, the 2 points at the front would drop -2.03 and -4.1 cm. This would mean that the 2 points at the front would sit at a clearance height of 6.5 and 9.4 cm. I then calculaten what would happen if the wheels would sit at the beginning of the speedbump, and how much clearance would be left (I had to assume that the incline was linear). Speedbump 1 would give: Normal= high point:8cm low point: 8cm lowered= high point:3.5cm low point: 3.5cm lowered at a slope= high point:-0.6cm low point: 1.5cm Speedbump 2 would give: Normal= high point: 13cm low point: 10.5cm lowered= high point: 8.5cm low point: 6cm lowered at a slope= high point: 4.4cm low point: 4cm I can then conclude that if the car is lowered, and the rear axle would be +20cm heigher in the air then the front axle (which would never happen in NL) I would be 0.6cm to low. And the underside would touch the ground. However, in any other case then the 20cm height difference, I would have a minimum clearance of 3.5cm. Saying that I would (theoretically) lower the car a good 3cm more then 4.5cm without a problem. Conclusion, I should be able to lower my car a maximum of 7.9 cm without having any serious problems with speedbumps. If I take the slope into account, I should limit it by roughly 4 cm. As a sidenote: lowering the car more then 4.5 cm would mean getting an adjustable set, which has a very big impact on ride quality. Lowering with a combination of coilovers and different shockabsorbers give more control over the ride quality. Which means that 4.5 cm is the limit unless you really want to sacrifice the quality ride that matches the 75. According to the mechanic and my calculations, the wheelarch of the 75 is simply to high. It could've easily been made a little lower, so the car wouldn't need to be lowered in order to get rid of that huge gap. Just a little bit more sheet metal that would made the wheelarch a bit smaller..... __________________ Proud owner of the Dutch "Golden 75". A much loved Gold White Metallic Rover 75 1.8 na from 2000.

28th August 2016, 14:38	#31
KWIL Precise Rover 75 Tourer 2.5KV6 Connoisseur SE Join Date: Mar 2013 Location: Fleet Posts: 2,966 Thanks: 630 Thanked 617 Times in 480 Posts	You obviously think they look better by being lower, but it just means the gaps ahead and behind the black rings look tapered and at odds with the body design as originally conceived.