Lowering a dsm AND having a soft ride, how?

[MysticMarine]

Gentlemen,

I want to lower my uno-G DSM with coilovers but I don't want a stiff ride, is this possible AND who makes the kit?

Thanks,
-A

 

[MysticMarine]

Mr. JTM,

What coilovers would you suggest and what's the price range?

 

[Johng322]

In post #41 he gave you his recommendation. Talk to Robispec about a set of KW Variant 3's. More details in this thread. http://www.dsmtuners.com/forums/vendor-announcements/391836-robispec-kw-variant-3-1g.html

 

[jtmcinder]

Yep. KW Var3s are very digressive in bump and the adjuster only alters rebound, just like a Koni. The new Fortune Auto 510s are also digressive, but they have other issues and I don't even know if they make them for 1Gs. If they do, they'd be cheaper.

 

[Johng322]

For the last freaking time, then. #1: don't run out of travel. #2: make sure the shocks are highly digressive in bump. #3 (and it's a distant #3): run softer springs.

If the KW is out of your price range and you use this as your guide you could have good results running Koni yellows since they are digressive in bump. The 1g Koni rears are hard to find but the 2g rears fit and have easier adjustment than the 1g rear had. I ordered mine through jnztuning. The biggest thing may be how low you go. I believe the lower you set the height the less travel the suspension will have which is #1 on the list.

 

[jtmcinder]

And TrueChoice can shorten any Koni if you're running out of travel on a 1G.

 

[boost97gst]

ive been a sport bike rider for a LONG time and i can tell you that damping makes all the difference in the world. Spring preload, not so much.

 

[94awdcoupe]

what i understand about how a car rides and tips that might be helpful.
tires. not all tires ride the same. sure lower profile tires will naturally ride stiffer. but that equation only applies to tires of exact same make. less side wall rides stiffer. taller side wall flexes more are rides better. I have ridden in 35 series 18s that rode better than 50 series 16 inch tire. sidewall construction dictates ride quality just as much as height. stay away from steel belted side wall tires. best to actually feel the sidewall stiffness with your hand before installing the tire. it tells you right away how stiff the tire will ride. I always choose a fiber reinforced sidewall.

chassis. frame stiffness of car has HUGE affect on how a car rides. stiffer frames force the suspension to absorb energy of bumps. if the frame is flexing your body (you) feels it more. I installed a roll bar (4point) in one of my cars. just driving out of back yard and I was shocked at how well the car absorbed bumps. it was like new shocks were were just installed. two part exoxy foam can be installed in roof rails, frame rails and any other cavity in chassis that can be filled. its like installing eight point cage in car. wonderful mod to do to a car without the extra weight and inconvenience of a roll bar in the car.

springs. spring stiffness is HUGE PART of how a car rides. springs support the vehicle weight and allow the suspension to go up and down, the amount of of resistance the spring has a a HUGE effect on how much is felt in the car. if you have ever driven a car down the road with out shocks you will quickly understand what the shocks real job is. I drove a car with out shocks once. I was naive. The car drove well up to about 35 mph. then the suspension bounced up and down uncontrollably. It was quit fascinating at the time. the shocks main job it to control these osculations. And the speed at which the spring compresses and rebounds. spring quality is very important to ride quality, same as tires. . not all springs are springy. some are poor quality and quite dead. dead springs ride stiffer than springy ones. cutting coils from springs make them ride stiffer. if you have five coils supporting 500lbs and each coil deflects .25 inch you will have 1.25 inches of total deflection. . cutting one coil off and you will now only have 1.00 inch deflection for that same 500lb load. going from stock 7 inch spring to a 3.5 inch coil over spring also makes car ride stiffer for springs supporting same load. the 3.5 inch spring would have to be made thicker to support the same loads as the 7 inch diameter. so it would deflect less. to compensate there would need to be double the number of coils to ride the same. then you have reduced the overall travel length before coil bind.

shocks is perhaps the largest subject of all. there are 30$ struts and 5000$ struts. do we really expect them to all work the same? course not. but to cover subject briefly there are some points that need to be pointed out. there are a few basic shock designs out. for lowered cars you want a shock that is not progressive. a progressive shock starts soft and gets stiffer as travel is increased. using lowered springs with this type of shock leads to stiff ride and short sock life. the shock will be starting in a stiffer part of its travel. oil shocks are generally not progressive. they have same resistance throughout the shocks travel. this is better choice for lowered springs . now you only have to be sure shock does not bottom out.

compression and rebound. these are the shocks two main jobs. the stiffness of each needs to match the stiffness of the spring. mismatching spring rate to shock rates leads to a very poor ride in both handling and ride quality. a stiff spring will always ride stiffer than a softer one if both are properly matched to a shocks valving. a stiff spring can ride better than a softer one when the stiff springs shock is valved properly and the soft one is not.
shock quality. a shock is a shock. NOT. how shocks are valved is pretty much everything. there is good and bad quality and good and bad designs. mix and match and you get the idea. a good shock will control spring motion with both authority and smoothness. to big a subject here really.

vehicle weight, wheel and tire weight. both have affect on shocks performance. more so wheel and tire i think. going from 45 pound wheel and tire to a 35 pound one is like installing stiffer shocks. the shocks job just got much easier. you will feel bumps more with the lighter wheel and tire. lightening the car 300 lbs has same effect but to lesser extent.

One of my favourite ways to lower car without affecting ride quality is to lower mounting bracket on shock itself. you will be moving the spring perch closer to tire and the bottom shock closer to CV boot. I have been able to get 3/4 this way with zero negative affect and how the suspension works,

best way to get what you need without trying a hole bunch of things your self is to find feed back from those who have actually tried different combinations. this is very difficult in itself. cause there is no way to really decipher statements. people tell me their car rides good. but after I drive it I cant wait to get out of the car. not everyone's "rides good" can be taken as good advice.

lowering DSM is a bad idea from the start. they have very little suspension travel to start with. getting one to ride well is an uphill battle.

 

[jtmcinder]

Interesting. A bit rambling, but interesting. Only one part calls for comment:

vehicle weight, wheel and tire weight. both have affect on shocks performance. more so wheel and tire i think. going from 45 pound wheel and tire to a 35 pound one is like installing stiffer shocks. the shocks job just got much easier. you will feel bumps more with the lighter wheel and tire. lightening the car 300 lbs has same effect but to lesser extent.

All else being equal, reducing unsprung mass (e.g., switching to lighter wheels) will actually reduce the transmission of bumps to the chassis, because the lower unsprung mass will require less force to move. In loose terms, the wheel will resist moving up and down less, so it will do so, absorbing the bump. Conversely, a car with more sprung weight rides smoother because the same force on the wheel moves the chassis less. This is why really heavy cars ride nicer than lighter cars.

Key point for the OP: lighter brakes and wheels will help.

 

[94awdcoupe]

i should have expanded that more on that point. i always install lighter wheels and tires on every car so I have fiirst hand experience. what you say it true with shock compression. its rebound where the tire returns to pavement quicker and is felt through the car more.

I have two evo 1 in driveway right now. one has adjustable struts of unknown brand. I have had both my wheel/tires on the car.
18 (17lb wheel) 24inch 35 series (18lb)
16 (11.5) 23.5 inch 45 series (17lb tire)
both tires are general UHP with soft sidewall. the 18s ride better. on the car. the 16s are perceived as more harsh.

point being that both compression and rebound need to be matched to setup. its not just compression of shock that make car smooth.

you also got me thinking how much the wheel itself has to do with ride. reminds me the day a bicyclist taught me the beauty of a good riding frame. I had just bought a bike to ride across the state. he took for a spin and came back and said the bike rode like crap. I took his bike for a ride and was like holy wow. shocking how much his frame absorbed energy.

 

[jtmcinder]

Good point on lighter wheels being a negative when you hit a divot, instead of a bump. If you really are feeling the difference, I'd say that you don't have enough rebound damping. I'm from the school that goes even farther than the standard 2/3-3/2 rule. I run closer to 5:1 in many situations, in which case, there are no negatives to a lighter wheel.

 

[Mr PopUps]

My .02 from my rear end... if you want to go lower and retain a somewhat stock feel, get H&R race springs and a new set of KYB's. Looks awesome and rides nice.

 

[94awdcoupe]

JT, are there any struts for dsm that are digressive or only coilovers? can you list which ones are digressive and which are not ?

 

[GoCanes777]

war? I don't see any war. I see a lot of nonsense that i won't let stand.

+100000000000

 

[jtmcinder]

JT, are there any struts for dsm that are digressive or only coilovers? can you list which ones are digressive and which are not ?

I've not put too much effort in learning about and keeping track of stuff for 1Gs, but Koni Yellows are digressive and Bilsteins (if they're available) are usually highly digressive. Things like AGXs are not, which is why they ride so poorly. Same goes for all KYBs, which is why Mr PopUps is over-charging us by more than two cents for his advice. Fancier Tokicos have a bit of an elbow, but still not enough. If you'd like an outrageous and hyperbolous rule-of-thumb, you want something from Europe, not Asia.

 

[94awdcoupe]

do you know if koni reds would be digressive?
and do you know anything about the koni FSD? is it really anything special? cause it just sounds like it would be highly digressive

 

[jtmcinder]

I'm sorry, but I don't know enough about either Reds or FSDs to say anything useful. I can tell you that a Koni Yellow drops about in half when the shims open. If you find some plots, post them up.

 

[Seamus]

Bilstein TC's and vogtland or h&r springs ride nice. Stick with Germans for suspension if you want a decent ride. I don't know if they still make the TC's for 1g AWD though. I had some years ago with h&r springs and loved them, I tried to buy some for the car I bought 3 months ago and they were unavailable at the time even though they show up in catalogues. Maybe oyu can have better luck. I went with Konis and vogtlands. the vogtlands only drop about an inch in the front and 1.25 in the rear. So they are not too low.

 

[jtmcinder]

Oh, man. If I were Dutch, that post would annoy me, big time.

 

[Seamus]

Oh, man. If I were Dutch, that post would annoy me, big time.

All of those are manufactured in germany.

 

[jtmcinder]

It was your saying that you want German for a good ride that would irk many Dutch. Koni and KW are both Dutch, for example.

 

[TSiAWD666]

KW started in Germany but is Dutch?

 

[jtmcinder]

Maybe I'm wrong on that one. I know that they are based in Fichtenberg now, but I could have sworn that they were Dutch. Well, at least Koni is. That we can be sure of.

 

[94awdcoupe]

My evo 4 has bilstein struts from evo 9. riding on original 4 srings. I was planning on sending them off to have them revlaved softer. The evo 4 is lighter , the wheels and tires are 12 lbs lighter and 1/2inch smaller. the springs are also not as stiff as 8/9s. add all that up and they ride too stiff for my tastes.

You can still get TC bilstein for 1g awd. You can order them for 2000-2004 vovlo s40. The chassis is a mitsubishi charisma. the mounts for brake lines will be different but shocks are otherwise same geometry.

Its my evo 1 that i am struggling with. the 1g front spring perch is higher so they jack front end up too high. very limited with otions for this car. stock shocks are actually pretty nice. they are available from dealer. so i am leaning toward that. but would really like some adjustabity to get it perfect for my tastes.

Bilstein TC's and vogtland or h&r springs ride nice. Stick with Germans for suspension if you want a decent ride. I don't know if they still make the TC's for 1g AWD though. I had some years ago with h&r springs and loved them, I tried to buy some for the car I bought 3 months ago and they were unavailable at the time even though they show up in catalogues. Maybe oyu can have better luck. I went with Konis and vogtlands. the vogtlands only drop about an inch in the front and 1.25 in the rear. So they are not too low.

how do the koni/vogtlands ride comared to bilstein/h&r combo?
do you know if the bilsteinTC are servicable?

 

[Seamus]

It was your saying that you want German for a good ride that would irk many Dutch. Koni and KW are both Dutch, for example.

Ohh Sorry, I wasn't refering to the konis. I meant bilstein, h7r and vogtland. I'm using the yellows, they are a good strut.

I like for my DSM to handle well, but I drive it on the street mainly so i don't want or need some hardcore setup.. Iput good tires on my cars, and reasonable, high quality suspension pieces, regular alignments, and I like the balance in the way they drive. I'm hpde 4,and have always had a dedicated track car till recently, so I don't want street cars to have a "track" capable suspension. The funny thing is, most of these coilover kits are much furthur from track ready in my opinion than some strut and spring combos.


Whoever asked about the bilsteins, and the vogtlands,

I loved the bilsteins with the H&r springs. I really wanted another set for this eclipse, but they were unavailable. I bet they discontinued them for our cars and haven't removed them form their catalouge yet. They probably sell 3 sets a year because they are not heavily marketed as a performance strut. I'll bet they sold a ton to the original owners of these cars though.

This time I bought the koni's cause i couldn't get my first choice. I have no complaints about them. I went with the vogtlands because I am using them on my audi with bilsteins,and I really like them. they only lower the car a bit and basically just make it sit level and get rid of that jacked uplook. I run these with a 15mm spacer on the rear on stock wheels so it doesn't look all sunk in in the rear. it is impossible to compare the ride to stock, as I bought the car as an all stock 22 year old car about 4 months ago. It rode like dogshit. Now it rides very nice. It's been a mi ute since I had an older car, and I forgot that struts are the best modification you can do to an older car. I probably would never drive it if it had the old stock suspension on it. Now it drives almost as nice as a new car, and I actually pass on newer, more powerful, more expensive cars to drive the eclipse.

Whoever asked about the bilsteins/h&r and the koni/vogtland

The

 

[Twilight Slide]

Buzz.

No. It's the shocks and/or running out of travel that ruins the ride. Springs are the least of the problem.

This. Good shocks @ full soft will make a high spring rate more than livable. Good shocks at full hard will have you campaigning for street repavement.