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Lowering Springs For A Ke


Big G

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Hey Guys getting to the I'm running out of time period of a build coz my daughter is close to getting her licence. I am struggling with organising lowering springs for the front and was wondering has anyone used the Kings KFFL-15sl they are supposed to be a 50 mm drop which is what the boss wants the car to sit at. My dilemma is that the local auto shop guys say yep that is the part required but King Springs say that they don't make them any more. Looking on Ebay they are all over the place for sale however when you put the KE55 details into their fitment search the result is that they don't fit the car.The KFFL-15 are a match but the drop isn't enough only 30 mm and according to my daughter hardly worth the effort. Are there any other brands out there that will do the job. So any advice on the subject would be greatly appreciated.

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50mm drop is significant and has negative effects on steering geometry without the appropriate counter measures. ie. RCA's and camber tops. It flogs the tie rods, pitman and idler arms, controls arm bushes and the front tyres.

30mm springs and 1&1/2" lowering blocks gives a good balance between stability & steering and doesn't attract as much unwanted attention, which is important for learner burners. And I'd still recommend the RCA's with that.

 

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This is not good news. I have trolled through other forums and no one has ever mentioned the geometry issue. I was unaware how detrimental dropping it 50 mm could be. i broke the news to my daughter and she is not impressed. As expected I was told that it was hardly worth the effort. So in what way is the steering and stability effected. I was always under the impression that if the car has a lower centre of gravity it would handle better.

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Lowering the body to the road, lowers the centre of gravity which does increase the cornering ability but the tie rods(steering arms) and the lower control arms end up on funky upward angles where they were once almost square. This places load on the ball joints of these particular parts which they are not designed to sustain. The steering becomes heavy and the parts deteriorate rapidly. This increases sloppiness in the steering and bump steer.

Roll centre adjusters (RCA's) are spacers used between the strut leg and the lower control arm to correct this problem.

 

Next you have the issue of increased negative camber, where the top of the front wheels tend to lean inwards. Generally a positive trait on a track car and for the fan boys who love to chew through tyres, but the tread doesn't run squarely on the road, increasing tyre wear on the inside line and decreasing forward traction & braking capacity. Also increases bump steer. You use adjustable camber tops (strut tops) to counter this issue, although most wouldn't consider it one.

 

Finally you have shock absorbers. Short stroke shocks are required to keep lowered spring trapped inside the strut itself. The standard shock absorbers upward travel is big enough it will allow the lowered spring to fly free of its upper and lower enclosure. These shocks are not generally of the shelf items and extensive part cross referencing is required to find the right shock and then you generally have to modify the strut to fit it.

 

It's generally illegal to do for Provisional licence holders. It is definitely a lot more complicated than most people expect and the detriments out way the style points 9 times out 10 unless you do the job properly.

 

Just do the 30mm springs in the front with 35mm RCA's (available through Techno Toy Tuning or others) with standard shocks and get a wheel alignment. Then use inch and a half blocks in the rear with Nolathane or Super Pro bushings. It will be cool.

 

 

 

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Lowering the body to the road, lowers the centre of gravity which does increase the cornering ability but the tie rods(steering arms) and the lower control arms end up on funky upward angles where they were once almost square. This places load on the ball joints of these particular parts which they are not designed to sustain. The steering becomes heavy and the parts deteriorate rapidly. This increases sloppiness in the steering and bump steer.

Roll centre adjusters (RCA's) are spacers used between the strut leg and the lower control arm to correct this problem.

 

Next you have the issue of increased negative camber, where the top of the front wheels tend to lean inwards. Generally a positive trait on a track car and for the fan boys who love to chew through tyres, but the tread doesn't run squarely on the road, increasing tyre wear on the inside line and decreasing forward traction & braking capacity. Also increases bump steer. You use adjustable camber tops (strut tops) to counter this issue, although most wouldn't consider it one.

 

Finally you have shock absorbers. Short stroke shocks are required to keep lowered spring trapped inside the strut itself. The standard shock absorbers upward travel is big enough it will allow the lowered spring to fly free of its upper and lower enclosure. These shocks are not generally of the shelf items and extensive part cross referencing is required to find the right shock and then you generally have to modify the strut to fit it.

 

It's generally illegal to do for Provisional licence holders. It is definitely a lot more complicated than most people expect and the detriments out way the style points 9 times out 10 unless you do the job properly.

 

Just do the 30mm springs in the front with 35mm RCA's (available through Techno Toy Tuning or others) with standard shocks and get a wheel alignment. Then use inch and a half blocks in the rear with Nolathane or Super Pro bushings. It will be cool.

 

All this sounds fine in theory, except from personal experience - 6 years in a road going KE35 and 9 years in a competition only KE20 - which were lowered 50mm(+) I never had any of the issues mentioned. In fact, the only time I had to replace any front suspension component was when I landed heavily after a jump in the KE20 and I had to replace the strut tops (also cracked the subframe as well......).

 

Never used RCA's, ran cut springs which were not captive, relocated lower control arms in the KE20 and never had an issue with bump steer or undue component/tyre wear. If I was doing it again though, I would source shorter front struts to hold springs captive for peace of mind.

Edited by coln72
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yeah i wouldnt be too concerned woth rcas with a small drop. The beauty is if you use lowering springs they are generally stiffer, this reduces your travel and thus reduces any bump steer effects that may be exadurated.

 

Oem cars have a degree of bump steer built in anyway, probably to promote understeer on the limit for safety.

 

 

The other thing is is that what alot of people describe as bump steer is often issues with scrub radius increase from using wheels that are too wide.

Edited by ke70dave
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50mm drop in a ke30/55 is more than fine. bump steer is negligable. Ran my own ke30 with 50mm+ drop with all new suspension. -3 camber upgraded swaybars.

brand new rear leaves with the lowered amount built in. let me assure you the car embarrassed quite alot of so called 'Sports" cars out in the adelaide hills.

 

As for springs i can't help you. i had mine custom made through industrial springs in adelaide. and as far as i'm aware they are no longer trading.

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Oh my that set the cat amongst the pigeons. There always seems to be so much conjecture around this subject on all the threads I have looked at unfortunately there is no definitive answer. I wont be cutting the springs thats for sure so I was trying to keep it as safe as possible with off the shelf products manufactured to do the job properly. Currently the body of the car sits 100 mm above the top of the tyre so I figured 50 mm wouldn t be an issue with tyre contact and the attention of the police. Its not gonna be a racer as it is mostly stock with an auto and aircon if I can get hold of a system. Its more for the cruise appeal coz its all about the look don't you know.

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Cut springs, home made wide wheels, twin antiroll bars, cut down bump stops, self reset leaf springs, softer rear leaves, re drilled crossmembers, cutting longer threads so we could run more castor ............. back in my day we did all these naughty things, how did we survive??????????

 

Seriously, you need to step back and look at just how much a 50mm drop in ride height is going to make to the suspension angles. There will be bugger all difference.

Edited by coln72
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