what is the best lowering choice ? 35-50-60 ?
- Thread starter Jager Jon
- Start date
35mm is easy and requires changing the springs only and you ride comfort will be slightly stiffer in the cornors.
50mm is a little harder requiring little moddification but you will have to change the panhard rod and your ride comfort will be bouncy but good in th cornors.
60mm is the same as the 50mm but your ride comfort will decrease a large amount and speed bumps and ruff roads will become an issue.
but its all depends on funds, the look you want and the roads you will be driving on
Guide to k11 lowering
http://www.micra.org.uk/threads/official-msc-k11-lowering-guide-faq.54269/#post-559080
hope this helps
50mm is a little harder requiring little moddification but you will have to change the panhard rod and your ride comfort will be bouncy but good in th cornors.
60mm is the same as the 50mm but your ride comfort will decrease a large amount and speed bumps and ruff roads will become an issue.
but its all depends on funds, the look you want and the roads you will be driving on
Guide to k11 lowering
http://www.micra.org.uk/threads/official-msc-k11-lowering-guide-faq.54269/#post-559080
hope this helps
35mm is easy and requires changing the springs only and you ride comfort will be slightly stiffer in the cornors.
50mm is a little harder requiring little moddification but you will have to change the panhard rod and your ride comfort will be bouncy but good in th cornors.
60mm is the same as the 50mm but your ride comfort will decrease a large amount and speed bumps and ruff roads will become an issue.
but its all depends on funds, the look you want and the roads you will be driving on
Guide to k11 lowering
http://www.micra.org.uk/threads/official-msc-k11-lowering-guide-faq.54269/#post-559080
hope this helps
Agreed with most of this except the ride comfort, this will depend on how you do it, my ride comfort is like stock and I'm lower than 60mm all round
OP
OP
can you still get over spped bump and stuff ?
OP
OP
and i am thinking of going 50 but can i just straight swap springs ?
Haven't come across one I could get over
Past 35mm you're best off getting some proper uprated shocks, these with 50mm springs will make the ride stiffer
I can second everything Karlj said
I run matt humphris 60mm springs with stock shocks and it's like driving stock sometimes. Comfortable for motorway and day to day driving and never ran into any trouble with speedbumps (paired with 15" wheels).
You'll see better results with uprated shocks but your ride will suffer and it's a lot of money for a change if you aren't looking at taking the car to a track regularly.
I run matt humphris 60mm springs with stock shocks and it's like driving stock sometimes. Comfortable for motorway and day to day driving and never ran into any trouble with speedbumps (paired with 15" wheels).
You'll see better results with uprated shocks but your ride will suffer and it's a lot of money for a change if you aren't looking at taking the car to a track regularly.
pollyp
Club Member
I'm no suspension expert but this is what i roughly understand.
There are alot of factors to consider when lowering such as:
Aesthetic - subjective to personal preference. proportion of "tyre to arch" and "chassis to floor" distance.
Ride comfort - how much harshness u and/or passengers are willing to sacrifice over the intended terrain (street, track or offroad)
Handling - amount of pitching/diving under braking and swaying under cornering and stability from altered suspension geometry
Risk of damage - parts of chassis striking the terrain/speedbump, tyres striking the chassis, damper pistons bottoming-out, suspension striking parts of car
Original dampers & bumpstops were configured to prevent the stock 13" wheels and suspension from striking & damaging the chassis/car during sudden intense loads (big high speed bumps or dips).
Removing/repositioning the bumpstop point relative to the hub may increase bump travel but increases the "risk of damage" I listed above.
Adding more -ve camber may allow more bump travel before the tyre hits the arch but excessive amount adds another complication.
The closer the axle/hub rests relative to the chassis (via increased mass, shorter springs, lower springrate) = reduced bump travel = closer it is to hitting the bumpstop (harsh jolt) or striking the chassis if bumpstops were removed (harsh jolt plus other damage)
A coil spring is essentially a spiral torsion beam that "absorbs & stores" the kinetic energy in the elastic material.
The length of steel rod & coil pitch detemines a springs length.
The length & thickness of steel rod & material property determines it spring rate.
Changing the natural length of the spring of the same spring rate alters its static resting point after being depressed by the cars weight. shorter it is = less bump travel = closer to hitting bumpstop/chassis. If the natural spring length if shorter than the damper stroke at full droop, it can unseat.
Spring rate determines how much a spring compresses under the cars weight from its natural length to static resting height, and how much further it compresses/gives when hitting a bump.
higher rate = less give/travel = suspension less likely to suddenly crash into the bumpstop but more proportion of the bump force transferred to the chassis = harsher overall ride but less jolting
softer rate = more give/travel = more proportion of energy absorbed in springs rather than sent to the chassis but more likely to hit bumpstop = soft overall ride but potentially more sudden harsh jolts when braking/turning hard and/or hitting a big bump.
Cutting a spring to shorten its length will also increase it spring rate cos there's less elastic material in the reduced length of steel to absorb the energy.
imagine twisting a long rope, feels quite soft n alot of give, then cut it really short n twist it, feels quite stiff with little give.
eg.
A shorter closely-wound spring of the same spring rate lowers the ride height but also reduces the amount of bump travel before hitting the bumpstops.
This would provide the same ride comfort over bumps that are within the dampers bump travel but when travelling over larger bumps beyond the bump travel, it hits the bumpstop at the end of travel n jolts the chassis & occupants.
Reducing the rolling diameter of the wheel requires a shorter spring and lowers the chassis to floor height.
Increasing the rolling diameter may not require such a short spring but can increase the chassis to floor height.
4. Geometry
Lowering a car will change it's suspension geometry.
The rear axle will shift offset (affecting rear alignment & RH tyre could strike the arch before reaching bumpstop) due to the panhard rod, therefore when lowering the height excessively the rods length should be shortened to pull the axle back to centre.
The front lower arm normally rests at an angle below horizontal.
When excessively lowered, they may rest above horizontal and this means that when the suspension is pushed up during cornering, the lower arm pulls the wheel inward and induces +ve camber which may degrade handling and tyre wear.
After any lowering the wheels should be realigned
There are alot of factors to consider when lowering such as:
Aesthetic - subjective to personal preference. proportion of "tyre to arch" and "chassis to floor" distance.
Ride comfort - how much harshness u and/or passengers are willing to sacrifice over the intended terrain (street, track or offroad)
Handling - amount of pitching/diving under braking and swaying under cornering and stability from altered suspension geometry
Risk of damage - parts of chassis striking the terrain/speedbump, tyres striking the chassis, damper pistons bottoming-out, suspension striking parts of car
1. Bumpstops
Original dampers & bumpstops were configured to prevent the stock 13" wheels and suspension from striking & damaging the chassis/car during sudden intense loads (big high speed bumps or dips).
Removing/repositioning the bumpstop point relative to the hub may increase bump travel but increases the "risk of damage" I listed above.
Adding more -ve camber may allow more bump travel before the tyre hits the arch but excessive amount adds another complication.
The closer the axle/hub rests relative to the chassis (via increased mass, shorter springs, lower springrate) = reduced bump travel = closer it is to hitting the bumpstop (harsh jolt) or striking the chassis if bumpstops were removed (harsh jolt plus other damage)
2. Springs
A coil spring is essentially a spiral torsion beam that "absorbs & stores" the kinetic energy in the elastic material.
The length of steel rod & coil pitch detemines a springs length.
The length & thickness of steel rod & material property determines it spring rate.
Changing the natural length of the spring of the same spring rate alters its static resting point after being depressed by the cars weight. shorter it is = less bump travel = closer to hitting bumpstop/chassis. If the natural spring length if shorter than the damper stroke at full droop, it can unseat.
Spring rate determines how much a spring compresses under the cars weight from its natural length to static resting height, and how much further it compresses/gives when hitting a bump.
higher rate = less give/travel = suspension less likely to suddenly crash into the bumpstop but more proportion of the bump force transferred to the chassis = harsher overall ride but less jolting
softer rate = more give/travel = more proportion of energy absorbed in springs rather than sent to the chassis but more likely to hit bumpstop = soft overall ride but potentially more sudden harsh jolts when braking/turning hard and/or hitting a big bump.
Cutting a spring to shorten its length will also increase it spring rate cos there's less elastic material in the reduced length of steel to absorb the energy.
imagine twisting a long rope, feels quite soft n alot of give, then cut it really short n twist it, feels quite stiff with little give.
eg.
A shorter closely-wound spring of the same spring rate lowers the ride height but also reduces the amount of bump travel before hitting the bumpstops.
This would provide the same ride comfort over bumps that are within the dampers bump travel but when travelling over larger bumps beyond the bump travel, it hits the bumpstop at the end of travel n jolts the chassis & occupants.
3. Wheel size
For a given "tyre to arch gap":Reducing the rolling diameter of the wheel requires a shorter spring and lowers the chassis to floor height.
Increasing the rolling diameter may not require such a short spring but can increase the chassis to floor height.
4. Geometry
Lowering a car will change it's suspension geometry.
The rear axle will shift offset (affecting rear alignment & RH tyre could strike the arch before reaching bumpstop) due to the panhard rod, therefore when lowering the height excessively the rods length should be shortened to pull the axle back to centre.
The front lower arm normally rests at an angle below horizontal.
When excessively lowered, they may rest above horizontal and this means that when the suspension is pushed up during cornering, the lower arm pulls the wheel inward and induces +ve camber which may degrade handling and tyre wear.
After any lowering the wheels should be realigned
