Willys

After market coil springs.....????

12 posts in this topic

OK, folks...it seems the wreck has on it a set of HR 29345 lowering coils springs mounted on it.
They are mounted on brand new struts with brand new shocks on the rear. This is telling me that they haven't seen much use at all.

The question is.....has anyone else used these or know anything about the manufacturer and quality of these, over stock coils??  They are noticeably thicker material which makes me wonder two things....first harshness of the ride and second, better ability to withstand potholes breaking the top coil off them?  

They advertise them to drop the front by 1/2" and the back by up to 1 1/2 ".  

I worry about the front tire rubbing at full lock..?   Also the inter cooler scoop hitting the road if the drop is actually 1 1/2" in the rear  going over bumps etc..?  I have already extended the scoop to grab better air so if so I will trim it back.

 

Thoughts on these coils will be greatly appreciated....thanks.

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1 1/2" drop on the back means you'll be riding on the stops hence a rather uncomfortable ride.

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Posted (edited) · Report post

Standard rear shock absorbers on the Smart ForTwo 450 only have about 3.5" of travel when measured off the car.

 

When the rear shock absorbers are on the car, they have even less than 3.5" of travel due to rubber bump stops. Lets say about 3" of travel.

 

3" is very little travel, which is why the standard coil springs have to be quite hard to prevent the car from regularly bottoming, ie. hitting the bump stops.

 

Eibach rear sport springs are claimed to lower the rear of the car by about 20mm which is about 0.75". In this case, the spring travel is down to about 2.25". However, the weight of the car means that you won't be driving along with 2.25" of remaining travel but with quite a bit less...let's say only about 1.5" of suspension travel left why driving along.

 

This is why people who have fitted rear Eibach sports springs complain about destroyed rear bump stops as they take a real pounding as you drive along. I'm on standard springs.

Edited by Big453
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I'm looking to add some ride height. I think that you can use 451 rear springs to add an inch or so but I don't know about the front. A slightly more compliant ride is all I want.

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42 minutes ago, Getfuzzy said:

I'm looking to add some ride height. I think that you can use 451 rear springs to add an inch or so but I don't know about the front. A slightly more compliant ride is all I want.

Try fitting 451 rear springs on yours and let us know what mods are required to make them fit. 

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Hmmmm....?
I am going to add these next summer just to see what happens to the ride height and ride comfort....OR if someone else wants them I may be open to offers.  They interest me simply because they are basically new and their construction is far thicker than stock when eye balled.

I too enjoy the softer ride and not the bone jarring feel of a sports car as I age.

IF I sell them it'll be just the springs/coils and none of the other new items., Shocks or struts. Those will be installed no matter what.

Thanks for everyone's input.

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1 hour ago, Getfuzzy said:

I'm looking to add some ride height. I think that you can use 451 rear springs to add an inch or so but I don't know about the front. A slightly more compliant ride is all I want.

IMHO, the best way to add ride hieght would be to use spacers between body and sub frame and not to mess with the suspension. Just keep that stock as not to over strain the drive shaft CV joints and seals.   You could add as much as your heart desires if done this way to be able to fit taller tires etc. The front i would do the very same way. Drop the front sub frame and space up the strut mounting points......No you will not gain as much ground clearances but you will retain the stock ride feel besides the higher centre of gravity and the side to side wobble feeling....Similar to the Daystar replica kit I made, then removed. Far easier to lower the sub frame front and rear.    To each their own.

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Posted (edited) · Report post

On 21/08/2020 at 1:10 PM, Getfuzzy said:

I'm looking to add some ride height. I think that you can use 451 rear springs to add an inch or so but I don't know about the front. A slightly more compliant ride is all I want.

 

451 rear springs won't fit the 450 as they are a different shape.

 

The 451 rear springs use a pigtail finish at both ends. The 450 rear springs only use a pigtail finish at the bottom.

 

You can see a photo of both springs on gknautomotive.com

 

450 MK7 (01/2003-01/2007) Rear Springs

https://web.tecalliance.net/gkn/en/parts/1/56806/detail?targetType=cars&targetId=18145&typeNumber=18145&groups=188#@brc/brands:Car;targetType:cars;mandator:gkn/assem:SMART%20FORTWO%20Coupe%20(450)%200.8%20CDI%20(450.300%2C%20450.301%2C%20450.302%2C%20450.303%2C%20450.306);targetType:cars;mandator:gkn;targetId:18145;typeNumber:18145/lnkparts:Coil%20Springs;targetType:cars;mandator:gkn;assemblyGroupId:100113;targetId:18145;typeNumber:18145;groups:188;brands:1;pf:2;page:0/detail:56806;brandId:1;articleNo:56806;mandator:gkn;targetType:cars;targetId:18145;typeNumber:18145;groups:188

 

451 Rear Springs

https://web.tecalliance.net/gkn/en/parts/1/85535/detail?targetType=cars&targetId=22476&typeNumber=22476&groups=188#@brc/brands:Car;targetType:cars;mandator:gkn/assem:SMART%20FORTWO%20Coupe%20(451)%200.8%20CDi%20(451.300);targetType:cars;mandator:gkn;targetId:22476;typeNumber:22476/lnkparts:Coil%20Springs;targetType:cars;mandator:gkn;assemblyGroupId:100113;targetId:22476;typeNumber:22476;groups:188;brands:1;pf:2;page:0/detail:85535;brandId:1;articleNo:85535;mandator:gkn;targetType:cars;targetId:22476;typeNumber:22476;groups:188

 

Even if they did fit (which they don't), they wouldn't raise the ride height as they are both the same length, ie. 245mm.

 

Note that gknautomotive.com have made a mistake in the length they quote for 450 MK7 rear springs. They are 245mm long, not 343mm as shown in their listing.

 

Also note, that the 450 had four different standard rear springs. 450 MK1 (to 04/1999), 450 MK2 (04/1999-11/1999), 450 MK3-MK6 (11/1999-01/2003), 450 MK7 (01/2003-01/2007)

 

Both the 450 MK3-MK6 and 450 MK7 rear springs were 245mm long, the earlier cars used much shorter and harder rear springs. There is a small difference between 450 MK3-MK6 rear springs and 450 MK7 rear springs. The 450 MK7 rear springs have 6 coil turns, whereas the earlier 450 MK3-MK6 rear springs only have 5.75 coil turns. Strangely, Mercedes claim that both have the same compression rate, ie. 25N/mm. However, I suspect that the 450 MK7 rear springs with the extra 0.25 coil turn would be slightly softer, as more coil turns equals a softer spring when all the other variables are equal.

 

You can find all four rear springs and their OEM part numbers on the gknautomotive.com website.

 

Also, even if you could fit 451 rear springs to a 450 (which you can't) they wouldn't make the ride softer. Although 451 rear springs have over 7 coil turns compared to the 450 MK7's 6 coil turns, the coil spring thickness is 10.5mm on the 451 compared to 9.5mm on the 450 MK7. Owners often complain that the ride on the 451 is even worse than the 450.

 

450 MK1 (to 04/1999) Rear Springs (OEM part number 0004860V002)

Spring Design Coil spring with inconstant wire diameter
Fitting Position Rear Axle
Thickness 9,75 mm
Length 204 mm
Outer diameter 100 mm
Weight 0,80 kg

 

https://web.tecalliance.net/gkn/en/parts/1/56808/detail?targetType=cars&targetId=9339&typeNumber=9339&groups=188#@brc/brands:Car;targetType:cars;mandator:gkn/assem:SMART%20CITY-COUPE%20(450)%200.6%20(S1CLA1%2C%20450.341);targetType:cars;mandator:gkn;targetId:9339;typeNumber:9339/lnkparts:Coil%20Springs;targetType:cars;mandator:gkn;assemblyGroupId:100113;targetId:9339;typeNumber:9339;groups:188;brands:1;pf:2;page:0/detail:56808;brandId:1;articleNo:56808;mandator:gkn;targetType:cars;targetId:9339;typeNumber:9339;groups:188

 

450 MK2 (04/1999-11/1999) Rear Springs (OEM part number 0006807V001)

Spring Design Coil spring with inconstant wire diameter
Fitting Position Rear Axle
Thickness 9,50 mm
Length 219 mm
Outer diameter 100 mm
Weight 0,80 kg
   

https://web.tecalliance.net/gkn/en/parts/1/56809/detail?targetType=cars&targetId=9339&typeNumber=9339&groups=188#@brc/brands:Car;targetType:cars;mandator:gkn/assem:SMART%20CITY-COUPE%20(450)%200.6%20(S1CLA1%2C%20450.341);targetType:cars;mandator:gkn;targetId:9339;typeNumber:9339/lnkparts:Coil%20Springs;targetType:cars;mandator:gkn;assemblyGroupId:100113;targetId:9339;typeNumber:9339;groups:188;brands:1;pf:2;page:0/detail:56809;brandId:1;articleNo:56809;mandator:gkn;targetType:cars;targetId:9339;typeNumber:9339;groups:188

 

450 MK3-MK6 (11/1999-01/2003) Rear Springs (OEM part number 0007502V002)

Spring Design Coil spring with inconstant wire diameter
Fitting Position Rear Axle
Thickness 9,50 mm
Length 246 mm
Outer diameter 99 mm
Weight 0,90 kg
   

https://web.tecalliance.net/gkn/en/parts/1/56805/detail?targetType=cars&targetId=9339&typeNumber=9339&groups=188#@brc/brands:Car;targetType:cars;mandator:gkn/assem:SMART%20CITY-COUPE%20(450)%200.6%20(S1CLA1%2C%20450.341);targetType:cars;mandator:gkn;targetId:9339;typeNumber:9339/lnkparts:Coil%20Springs;targetType:cars;mandator:gkn;assemblyGroupId:100113;targetId:9339;typeNumber:9339;groups:188;brands:1;pf:2;page:0/detail:56805;brandId:1;articleNo:56805;mandator:gkn;targetType:cars;targetId:9339;typeNumber:9339;groups:188

 

450 MK7 (01/2003-01/2007) Rear Springs (OEM part number 0012187V001)

Spring Design Coil spring with inconstant wire diameter
Fitting Position Rear Axle
Thickness 9,50 mm
Length 245 mm
Outer diameter 98 mm
Weight 0,90 kg

 

https://web.tecalliance.net/gkn/en/parts/1/56806/detail?targetType=cars&targetId=18145&typeNumber=18145&groups=188#@brc/brands:Car;targetType:cars;mandator:gkn/assem:SMART%20FORTWO%20Coupe%20(450)%200.8%20CDI%20(450.300%2C%20450.301%2C%20450.302%2C%20450.303%2C%20450.306);targetType:cars;mandator:gkn;targetId:18145;typeNumber:18145/lnkparts:Coil%20Springs;targetType:cars;mandator:gkn;assemblyGroupId:100113;targetId:18145;typeNumber:18145;groups:188;brands:1;pf:2;page:0/detail:56806;brandId:1;articleNo:56806;mandator:gkn;targetType:cars;targetId:18145;typeNumber:18145;groups:188

 

 

Edited by Big453

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3 hours ago, Getfuzzy said:

I think that you can use 451 rear springs to add an inch or so but I don't know about the front

 

fronts fit just fine ..i used 451 fronts on a few 450's with zero problems

 

but backs (as stated above) are different 

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I wonder can you reshape the coil ending point to make them fit using a torch...?    It wouldn't be the first time someone has reshaped a coil to make it fit a different application....just saying....lol

Re-working a suspension system is what OFF-Roaders do for fun...lol.   And they do not treat their finished product with care....so a re-worked coil on a light weight Smart car shouldn't be an issue.....but....you'll always get the folks who will not bend from the shop dealer handbook....if it says it doesn't fit, they'll never try and make it fit, one way or the other.

It's all up to you and how determined you are to get the end product you desire.

Go spend a few hours in a suspension shop and I'll bet you in that short time you'll see them doing it .

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Posted (edited) · Report post

On 21/08/2020 at 6:06 PM, Willys said:

I wonder can you reshape the coil ending point to make them fit using a torch...?    It wouldn't be the first time someone has reshaped a coil to make it fit a different application....just saying....lol

Re-working a suspension system is what OFF-Roaders do for fun...lol.   And they do not treat their finished product with care....so a re-worked coil on a light weight Smart car shouldn't be an issue.....but....you'll always get the folks who will not bend from the shop dealer handbook....if it says it doesn't fit, they'll never try and make it fit, one way or the other.

It's all up to you and how determined you are to get the end product you desire.

Go spend a few hours in a suspension shop and I'll bet you in that short time you'll see them doing it .

 

The 451 is about 50kg (110lbs) heavier than the 450. So the ride on a 450 will be even harder than a 451 if you could get someone to work some magic and get the 451 rear springs to fit the 450.

 

Most aftermarket standard rear springs sold for the 450 MK7 (01/2003-01/2007) are actually 450 MK6 (11/1999-01/2003) rear springs. These include Lesjofors and Kilen (same company just sold under different brand names). So if you want the 450 MK7 (01/2003-01/2007) rear springs make sure you get rear springs that actually have 6 coil turns, not just 5.75 coil turns. Brand names that sell rear springs that match 450 MK7 (01/2003-01/2007) rear springs include Optimal, Sachs, Spidan, and Suplex.

 

Here are some part numbers for aftermarket rear springs that match the 450 MK7 (01/2003-01/2007) rear springs (OEM part number 0012187V001):

 

Optimal AF-2855

Sachs 996 927

Spidan 56806

Suplex 19272

 

The 450 MK3-MK6 (11/1999-01/2003) rear springs with 5.75 coil turns tend to weigh about 850 grams each, whereas the 450 MK7 (01/2003-01/2007) rear springs with 6 coil turns tend to weigh about 900 grams each.

 

Edited by Big453
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I recommend standard Smart Roadster rear springs for the 450 diesel. 

These are made from slightly thicker round bar hence stronger and if properly

shimmed will give you a comfortable ride. 

 

Use suitable rubber rings made out of conveyor belt or similar to adjust ride height and effective spring travel before hitting the buffer stops. 

 

For those that like counting coils I have added below a photo of KYB RC6390

89C4783B-843D-4F19-9E3F-503C55FD1A37.jpeg

 

 

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