Legitimate coilovers
#1
03-03-2009, 12:38 PM
Legitimate coilovers
Anybody here have any input on what coilovers are legitimate for track and autocross where adjustment of car balance is very important, and also being able to adjust for street use?
Frankly, all the threads on coilovers are comparing how low they go, but I'm not interested in that. I need for it to handle well at the limits of adhesion and able to be adjusted for better balance in transitions and maybe further in the future revalved for different spring rates.
Frankly, all the threads on coilovers are comparing how low they go, but I'm not interested in that. I need for it to handle well at the limits of adhesion and able to be adjusted for better balance in transitions and maybe further in the future revalved for different spring rates.
#3
03-03-2009, 06:52 PM
Car balance is done with spring rates not with adjusting damping levels, It impossible to have the best of both world, but you can compromise on one side for the other.
Think of it like in the old video games. You get 100pts to use. And can add them to either side. So you can have 100 DD and 0 track or 0 DD and 100 track or 50 dd and 50 track.
I have never been a fan of skunks products but many people on here like them, but keep in mind like you stated most people here are into having their car "slammed"
T1R has little to no damping range and it valved for super stiff springs 10k+ is my estimate. So if you want a track setup go with them, though i wasnt impressed with the particular set I had.
A couple of companys Spoon J's Mugen all offer Showa made non adjustable "performance" dampers for the Fit/Jazz. Im not quite sure if the valving is the same, but i would have to guess they are similar being made from the same company.
This option IMO is the best one, until Koni makes a damper for us. They are actual quality track/street tested dampers that will last, and will give you the best grip in both situations. I run the Mugen Sport suspension with custom spring setup.
Many of the "full coilovers" as they call them will wear out fast, because they are not valved for the springs or for the road conditions.
Also you mentioned you wanted to tune the balance. This is a common misconception that this is done with the fancy knobbers on "full coilovers". The adjustment knobs are meant to adjust the valving to your specific spring rate that is being run on that shock. Therefore there should only be one setting you should run on one set of springs. And then only change them if you change rates. To change the balance of a car, you change the spring rates front to rear or change roll bar settings of Dia.
To understand damping and setting up your suspension, this is a good read....
DGs Autocross Secrets aka Autocross to Win - Shocks
Think of it like in the old video games. You get 100pts to use. And can add them to either side. So you can have 100 DD and 0 track or 0 DD and 100 track or 50 dd and 50 track.
I have never been a fan of skunks products but many people on here like them, but keep in mind like you stated most people here are into having their car "slammed"
T1R has little to no damping range and it valved for super stiff springs 10k+ is my estimate. So if you want a track setup go with them, though i wasnt impressed with the particular set I had.
A couple of companys Spoon J's Mugen all offer Showa made non adjustable "performance" dampers for the Fit/Jazz. Im not quite sure if the valving is the same, but i would have to guess they are similar being made from the same company.
This option IMO is the best one, until Koni makes a damper for us. They are actual quality track/street tested dampers that will last, and will give you the best grip in both situations. I run the Mugen Sport suspension with custom spring setup.
Many of the "full coilovers" as they call them will wear out fast, because they are not valved for the springs or for the road conditions.
Also you mentioned you wanted to tune the balance. This is a common misconception that this is done with the fancy knobbers on "full coilovers". The adjustment knobs are meant to adjust the valving to your specific spring rate that is being run on that shock. Therefore there should only be one setting you should run on one set of springs. And then only change them if you change rates. To change the balance of a car, you change the spring rates front to rear or change roll bar settings of Dia.
To understand damping and setting up your suspension, this is a good read....
DGs Autocross Secrets aka Autocross to Win - Shocks
#4
03-03-2009, 07:20 PM
mike,
this is why i was looking for tokico hts shocks, which has a wide range adjustability, but the only springs that fit on these shocks are the stock springs and lowering springs designed to go on the stock shocks(i think).
i'm also tempted to go with b&g rs2 coilovers, which have a limited lifetime warranty, but i don't know what spring rates they have on their coilovers.
you said you were using mugen sport suspension with custom springs, are the shocks revalved for your springs? or are they unchanged? what spring rates are you running? my thought was to put stiffer springs on the rear to get better rotation on an autocross course. the j's racing fit in japan has 13k front and 16k rear, but the spoon endurance fit has 12k front and 10k rear. but i think the j's racing is more of a time attack fit, so it needs to be more agile, and the spoon endurance fit has to be easier to drive and more stable so it can crank out more consistant times instead of one really fast time.
this is why i was looking for tokico hts shocks, which has a wide range adjustability, but the only springs that fit on these shocks are the stock springs and lowering springs designed to go on the stock shocks(i think).
i'm also tempted to go with b&g rs2 coilovers, which have a limited lifetime warranty, but i don't know what spring rates they have on their coilovers.
you said you were using mugen sport suspension with custom springs, are the shocks revalved for your springs? or are they unchanged? what spring rates are you running? my thought was to put stiffer springs on the rear to get better rotation on an autocross course. the j's racing fit in japan has 13k front and 16k rear, but the spoon endurance fit has 12k front and 10k rear. but i think the j's racing is more of a time attack fit, so it needs to be more agile, and the spoon endurance fit has to be easier to drive and more stable so it can crank out more consistant times instead of one really fast time.
#5
03-03-2009, 09:15 PM
I've never heard, of the B&G rs2 coilovers. If they are adjustable, find out what rates they adjust too, and then you can swap to any rates you want within that range.
About the tokico HTS shocks, you are correct, but Ground control has sleeve "coilovers" out for our app, which should fit allowing you to use all of the super popular eibach straight springs of any rate.
The mugen shocks are untouched, but the rates im using are in the useable range so they are fine. im running 180 fronts and 350 rears. (they are progressive, so thats the max rate of each spring) This is a pretty comfy setup, slightly stiffer then stock, yet with good weight transfer stiffen up and really grip well and rolls much less then the stock setup.
The Front or Rear biased setup has always been up for debate. By biased i mean which end is stiffer. Japan generally runs a front biased setup, and in the US people generally run Rear biased. They difference being the use of anti-roll bars. Japanese tuners use huge rear bars. Its all more or less a means to the same end. It also has a lot to do with the particular track your at.
In VERY simplified terms understeer vs oversteer is determined by which end F/R has more or less roll resistance. The end that has the more roll resistance (IN GENERAL) will break free first. But on a bumpy track running stiff springs will make the car hop and skip over bumps and cracks, which is not good for handling. So to keep the roll resistance but be able to absorb the bumps they will run less spring, but stiffer roll bars.
Its all a very complex balance of forces and a lot has to do with the drivers preference.
About the tokico HTS shocks, you are correct, but Ground control has sleeve "coilovers" out for our app, which should fit allowing you to use all of the super popular eibach straight springs of any rate.
The mugen shocks are untouched, but the rates im using are in the useable range so they are fine. im running 180 fronts and 350 rears. (they are progressive, so thats the max rate of each spring) This is a pretty comfy setup, slightly stiffer then stock, yet with good weight transfer stiffen up and really grip well and rolls much less then the stock setup.
The Front or Rear biased setup has always been up for debate. By biased i mean which end is stiffer. Japan generally runs a front biased setup, and in the US people generally run Rear biased. They difference being the use of anti-roll bars. Japanese tuners use huge rear bars. Its all more or less a means to the same end. It also has a lot to do with the particular track your at.
In VERY simplified terms understeer vs oversteer is determined by which end F/R has more or less roll resistance. The end that has the more roll resistance (IN GENERAL) will break free first. But on a bumpy track running stiff springs will make the car hop and skip over bumps and cracks, which is not good for handling. So to keep the roll resistance but be able to absorb the bumps they will run less spring, but stiffer roll bars.
Its all a very complex balance of forces and a lot has to do with the drivers preference.
#6
03-03-2009, 09:41 PM
oh snap!
that's what i've been looking for. Tokico HTS + ground control...then i can customize however i want. i didn't know ground control had coilover kits for the fit...i looked a few months ago and it wasn't out.
so...tokico's to tune damping, and i can use ground control to use any springs i want. i hope the gc's fit on the hts's...
so when you order ground control kits, do they come with the springs at predetermined spring rates, or do you specify the spring rate when you order them?
this combo will be pretty expensive though...
GC is ~$400, Tokico's are ~$1000, total 1400, but this would be better than any coilovers...
hmm just read on the gc thread that koni will have shocks for us soon...
do the koni threaded spring perch sleeves work?
that's what i've been looking for. Tokico HTS + ground control...then i can customize however i want. i didn't know ground control had coilover kits for the fit...i looked a few months ago and it wasn't out.
so...tokico's to tune damping, and i can use ground control to use any springs i want. i hope the gc's fit on the hts's...
so when you order ground control kits, do they come with the springs at predetermined spring rates, or do you specify the spring rate when you order them?
this combo will be pretty expensive though...
GC is ~$400, Tokico's are ~$1000, total 1400, but this would be better than any coilovers...
hmm just read on the gc thread that koni will have shocks for us soon...
do the koni threaded spring perch sleeves work?
Last edited by sl0wp0k3; 03-03-2009 at 11:33 PM.
#7
03-04-2009, 08:22 AM
GC kits are bought in two ways Over the Counter (OTC) which is there basic recommendation for safe highway/autox use. However you can also chose the rates you wish to buy. So its up to you.
I Have not heard many things about tokico but, If it were me I would wait for the Koni Yellows, cheaper and a PROVEN design.
I Have not heard many things about tokico but, If it were me I would wait for the Koni Yellows, cheaper and a PROVEN design.
#12
03-07-2009, 08:23 PM
Its seems pretty neutral, but I havent taken it to the track or autox yet. I dont care what anyone says, there is no way to really feel out a car on the street unless you are extremely stupid or extremely illegal.... or both.
No im not changing the springs. A FWD need all the rear spring they can get.
No im not changing the springs. A FWD need all the rear spring they can get.
#13
03-07-2009, 08:39 PM
i guess i'm just trying to get a feel for what the balance is with certain spring rates
what if your car is *god forbid* too loose once you install the arb?
are you going to buy the progress one or try to fab one yourself?
i have stock springs and been to one autocross with the progress rear arb, and it feels 100x better than without it. i can just lift to get the car to rotate. i used to have to be very dramatic with the inputs to get the rear end to go anywhere, but now it's not the case. I think I want the car to be a little looser though so I can turn harder while accelerating out of a turn and be on the throttle earlier. the arb already pushed my throttle point a lot earlier which I was really happy about. it also made my lines much smoother
have you had any experience with stiffening up the car after you installed an arb. my thoughts are that if a car is stiffened with the same arb, the effectiveness of the arb will decrease (relatively). cause the difference in displacement of the two wheels will be smaller with stiffer springs which therefore decreases the force of the arb on the wheels. what are your thoughts on this? is there a point where an arb would not be useful anymore since the springs are already so stiff?
i really wish there was a way to test out a setup before buying...
i'm thinking about 7kg/mm front and 9kg/mm rear springs (when i get around to it). i know it will be really stiff on the street(megan streets have stiffer so i think these should be decent), but i'm thinking this will really improve the grip and balance w/ the koni yellows when they come out. i want to test to see at what rear spring rates does my car start three-wheeling and when it starts three-wheeling (braking/coasting/accelerating). once the car starts three wheeling there's no point in stiffening up anymore...right?
what kind of brake pads/fluid do you use?
Last edited by sl0wp0k3; 03-07-2009 at 08:59 PM.
#14
03-07-2009, 09:13 PM
I've had my car on the track at MSR Cresson ( MotorSport Ranch - Performance Car Country Club ) and had ZERO brake fade with the stock setup.
If you are planning on using the car for intense braking more often then driving on the street, I'd do the Motul Dot 5.1 or similar and some more aggressive pads like the Hawk's, EBC's, etc.
I too have not found the best solution to a good coilover setup that can go from good daily driver to good track car.
If you are planning on using the car for intense braking more often then driving on the street, I'd do the Motul Dot 5.1 or similar and some more aggressive pads like the Hawk's, EBC's, etc.
I too have not found the best solution to a good coilover setup that can go from good daily driver to good track car.
#15
03-07-2009, 10:55 PM
+1 on that...i couldn't tell any difference with the car after i installed the rear anti-sway bar until i brought it to an autocross course...
i guess i'm just trying to get a feel for what the balance is with certain spring rates
what if your car is *god forbid* too loose once you install the arb?
I Highly doubt the car will be too loose. But my plan is if it is, to buy a stiffer front.
are you going to buy the progress one or try to fab one yourself?
for 150 shipped the time it would take me to fab one up just wouldnt be worth it so im buying the progress
i have stock springs and been to one autocross with the progress rear arb, and it feels 100x better than without it. i can just lift to get the car to rotate. i used to have to be very dramatic with the inputs to get the rear end to go anywhere, but now it's not the case. I think I want the car to be a little looser though so I can turn harder while accelerating out of a turn and be on the throttle earlier. the arb already pushed my throttle point a lot earlier which I was really happy about. it also made my lines much smoother
have you had any experience with stiffening up the car after you installed an arb. my thoughts are that if a car is stiffened with the same arb, the effectiveness of the arb will decrease (relatively). cause the difference in displacement of the two wheels will be smaller with stiffer springs which therefore decreases the force of the arb on the wheels. what are your thoughts on this? is there a point where an arb would not be useful anymore since the springs are already so stiff?
Yes, the point of a ARB like i stated earlier was to control side to side weight transfer withOUT affecting load transfer front to back and absorbing bumps. The stiffer you make the springs, the more you increase the roll resistance. If the springs are so stiff that they dont let the car roll much or at all obviously the ARB wont be affective. The same goes for a small ARB. If you install a 3mm ARB chances are you wont feel anything because itll just bend and the springs will stop the roll not the ARB.
i really wish there was a way to test out a setup before buying...
Oh thats the fun of suspension tuning! trial and error, it takes awhile. And once you think you've got it figured out, youll goto a new track and need a new setup lol
i'm thinking about 7kg/mm front and 9kg/mm rear springs (when i get around to it). i know it will be really stiff on the street(megan streets have stiffer so i think these should be decent), but i'm thinking this will really improve the grip and balance w/ the koni yellows when they come out.
This reminds me of another point. What tires will you normally run? Springs must be matched to the tires your running. The stickier the tire the stiffer the spring you need. The reason? More G load. The more grip a tire can give the faster you can carry in a corner, which transfers more load both in cornering side to side, AND in braking and accelerating front to rear. The T1R's (which were horribly over dampened so this is a tough example) had 6k springs front and rear. For your avg summer tire this was fine. But slap on my kumho v710's it was two soft causing too much roll.... visual example....
Old picture
But you can see the tire almost all the way up in the fender well. Granted i was low with this setup but that was way to much roll in the rear for those tires.
IMO i wouldnt go higher the 5kF 7kR. Which btw when buying eibach springs in the US it is much more popular to use the measurments in in/lbs or jjust lbs for short
This would roughly 275 F 400R
For reference what I run, mind you progressive BUT, 180F 350R
You may find it to be too soft, but if you driving it on the street i would start here.
i want to test to see at what rear spring rates does my car start three-wheeling and when it starts three-wheeling (braking/coasting/accelerating). once the car starts three wheeling there's no point in stiffening up anymore...right?
'3 wheeling' is caused may many different things and definitly should not be used as a tuning guide. And if you are on 3 wheels in a FWD during accel you have some serious issues lol
what kind of brake pads/fluid do you use?
HP+ up front with plans of swaping to a NSX front caliper 11.1" disc up front (still searchng for rear shoes, if i dont find any i may be forced to go with a disc conversion)
For fluid im using wilwood, but I got that for free but no complaints so far but again not really tested. I also now can get motul rbf600 for real cheap so will probably switch to that later on this year. Our race cars use this on stock sized brakes with no issues so with good pads im sure youll be fine.
For autox only the stockers are pretty decent and would perhaps just get a set of HPS or HP+ pads.
i guess i'm just trying to get a feel for what the balance is with certain spring rates
what if your car is *god forbid* too loose once you install the arb?
I Highly doubt the car will be too loose. But my plan is if it is, to buy a stiffer front.
are you going to buy the progress one or try to fab one yourself?
for 150 shipped the time it would take me to fab one up just wouldnt be worth it so im buying the progress
i have stock springs and been to one autocross with the progress rear arb, and it feels 100x better than without it. i can just lift to get the car to rotate. i used to have to be very dramatic with the inputs to get the rear end to go anywhere, but now it's not the case. I think I want the car to be a little looser though so I can turn harder while accelerating out of a turn and be on the throttle earlier. the arb already pushed my throttle point a lot earlier which I was really happy about. it also made my lines much smoother
have you had any experience with stiffening up the car after you installed an arb. my thoughts are that if a car is stiffened with the same arb, the effectiveness of the arb will decrease (relatively). cause the difference in displacement of the two wheels will be smaller with stiffer springs which therefore decreases the force of the arb on the wheels. what are your thoughts on this? is there a point where an arb would not be useful anymore since the springs are already so stiff?
Yes, the point of a ARB like i stated earlier was to control side to side weight transfer withOUT affecting load transfer front to back and absorbing bumps. The stiffer you make the springs, the more you increase the roll resistance. If the springs are so stiff that they dont let the car roll much or at all obviously the ARB wont be affective. The same goes for a small ARB. If you install a 3mm ARB chances are you wont feel anything because itll just bend and the springs will stop the roll not the ARB.
i really wish there was a way to test out a setup before buying...
Oh thats the fun of suspension tuning! trial and error, it takes awhile. And once you think you've got it figured out, youll goto a new track and need a new setup lol
i'm thinking about 7kg/mm front and 9kg/mm rear springs (when i get around to it). i know it will be really stiff on the street(megan streets have stiffer so i think these should be decent), but i'm thinking this will really improve the grip and balance w/ the koni yellows when they come out.
This reminds me of another point. What tires will you normally run? Springs must be matched to the tires your running. The stickier the tire the stiffer the spring you need. The reason? More G load. The more grip a tire can give the faster you can carry in a corner, which transfers more load both in cornering side to side, AND in braking and accelerating front to rear. The T1R's (which were horribly over dampened so this is a tough example) had 6k springs front and rear. For your avg summer tire this was fine. But slap on my kumho v710's it was two soft causing too much roll.... visual example....
Old picture
But you can see the tire almost all the way up in the fender well. Granted i was low with this setup but that was way to much roll in the rear for those tires.
IMO i wouldnt go higher the 5kF 7kR. Which btw when buying eibach springs in the US it is much more popular to use the measurments in in/lbs or jjust lbs for short
This would roughly 275 F 400R
For reference what I run, mind you progressive BUT, 180F 350R
You may find it to be too soft, but if you driving it on the street i would start here.
i want to test to see at what rear spring rates does my car start three-wheeling and when it starts three-wheeling (braking/coasting/accelerating). once the car starts three wheeling there's no point in stiffening up anymore...right?
'3 wheeling' is caused may many different things and definitly should not be used as a tuning guide. And if you are on 3 wheels in a FWD during accel you have some serious issues lol
what kind of brake pads/fluid do you use?
HP+ up front with plans of swaping to a NSX front caliper 11.1" disc up front (still searchng for rear shoes, if i dont find any i may be forced to go with a disc conversion)
For fluid im using wilwood, but I got that for free but no complaints so far but again not really tested. I also now can get motul rbf600 for real cheap so will probably switch to that later on this year. Our race cars use this on stock sized brakes with no issues so with good pads im sure youll be fine.
For autox only the stockers are pretty decent and would perhaps just get a set of HPS or HP+ pads.
You had a bunch of questions so I figured it would be easiest to read with my response in bold right underneath.
Last edited by SHG_Mike; 03-07-2009 at 10:58 PM.
#16
03-07-2009, 11:24 PM
i'm on dunlop direzza sport z1 star specs...probably going to change by the time i get a suspension setup. i'm in ST class in autocross, so nothing with treadware under 140. the best tire i can get at the moment are the bridgestone potenza re11. eventually i also plan to get some light wheels.
you said that spring rates are dependent on tire grip. but isn't almost always better to have weight more evenly distributed so you get more grip? i know shifting weight is also important but..but..... any input on this?
i've seen nationals ST civics set up with 450/700lb springs...and those civics are ~2000lbs also on 140 treadware tires. i figure there's gotta be some method to their madness. almost all have 350lb springs or higher.
the fit is so tall, i want to keep the body roll controlled. in the last autocross, i loved that the car would rotate, but its behavior is so wild because of the stock springs and the car was all over the place. i really needed to tone my driving down and make my inputs a lot smoother.
you said that spring rates are dependent on tire grip. but isn't almost always better to have weight more evenly distributed so you get more grip? i know shifting weight is also important but..but..... any input on this?
i've seen nationals ST civics set up with 450/700lb springs...and those civics are ~2000lbs also on 140 treadware tires. i figure there's gotta be some method to their madness. almost all have 350lb springs or higher.
the fit is so tall, i want to keep the body roll controlled. in the last autocross, i loved that the car would rotate, but its behavior is so wild because of the stock springs and the car was all over the place. i really needed to tone my driving down and make my inputs a lot smoother.
Last edited by sl0wp0k3; 03-08-2009 at 12:26 AM.
#17
03-08-2009, 01:25 AM
i'm on dunlop direzza sport z1 star specs...probably going to change by the time i get a suspension setup. i'm in ST class in autocross, so nothing with treadware under 140. the best tire i can get at the moment are the bridgestone potenza re11. eventually i also plan to get some light wheels.
you said that spring rates are dependent on tire grip. but isn't almost always better to have weight more evenly distributed so you get more grip? i know shifting weight is also important but..but..... any input on this?
yes an no this is a hard subject, and you need to understand some physics principles. Mu the coefficient of friction its not the same Static (no moving or when the tire is within its limits gripping) and Kinetic (moving or sliding with a large slip angle) Notice how when pushing a box on the ground its hard to get it going but once moving its not as hard? or when removing a bolt sometimes takes a great force or even a wack to get it to loosen then its easy to turn? This is that principle that the static Mu is almost always more then the kinetic mu.
Street tires dont have as much grip as r comps would. Having a super stiff setup would not allow the tire or suspension time to give to bumps or quick steering movements to absorb them and jolt them into kinetic mu with too much of a slip angle. Like i mentioned earlier, Imagen your trying to loosen a nut or bolt with a wrench, you push evenly and harder more and more (this is the amount of grip you have and G load) and it just doesnt loosen (or give up grip) now instead you push on the wrench but also give it a few wacks and boom, loose it comes ( or sliding) because your suspension cant absorb those "wacks". The principles that make a impact gun work or smacking a wrench work, are the same reasons you dont want to much spring in a car.
i've seen nationals ST civics set up with 450/700lb springs...and those civics are ~2000lbs also on 140 treadware tires. i figure there's gotta be some method to their madness. almost all have 350lb springs or higher.
Yes and I ran 10k F 12k springs in my old civic. The difference is suspension geometry. Again physics at work, this time being simple machines. Where on the suspension arm the spring/shock combo is, greatly effects how much force it takes to move the shock spring and the resulting arm up and down. Another example. Which would be harder to lift?...
You have a 20 ft wooden plank. One has 100 pounds of concrete right on the very end of the board you need to lift. Another has 100lbs of concrete in the middle of the board you need to lift. The second one is easier due to the mechanical advantage. For levers the general rule is the closer to the fulcrum the weight or object is from the force... the less force you need
Its the mechanical advantage of the suspension geometry. A strut suspension has very little mechanical advantage, so generally with comparable weight vehicles a car with strut type suspension will run less spring. A wishbone or multilink car has a suspension which the shock is in the middle(more or less) of the arm or "plank" which has a higher mechanical advantage, meaning its easier for the wheel or "person" to lift up on the spring or "concrete" Therefore takes more spring to counter act the same force of the wheel movement then on a strut equiped car.
This concept is "wheel rate" or the force it takes to move the wheel up and down, which ultimately what matters. So two different cars may handle bumps or feel as equally "stiff or soft" to one another, but one may run a 6k spring and another run a 10k spring
the fit is so tall, i want to keep the body roll controlled. in the last autocross, i loved that the car would rotate, but its behavior is so wild because of the stock springs and the car was all over the place. i really needed to tone my driving down and make my inputs a lot smoother.
The fit is tall but, its where the stiffness and weight it that matters. Most of the weight is all low, so that thin layer or sheet metal and air up there isnt really affecting how much it rolls.
And your last sentence should be true no matter how solid or well the car handles. To be fast you need to "slow down" and be super smooth. It has nothing to do with the car really. Stiff springs will just mask these driving mistakes with marginally better times from stock, but in reality you need to drive that smooth if not more so to be fast. This is way so many people say learn on a stock car and go from there.
you said that spring rates are dependent on tire grip. but isn't almost always better to have weight more evenly distributed so you get more grip? i know shifting weight is also important but..but..... any input on this?
yes an no this is a hard subject, and you need to understand some physics principles. Mu the coefficient of friction its not the same Static (no moving or when the tire is within its limits gripping) and Kinetic (moving or sliding with a large slip angle) Notice how when pushing a box on the ground its hard to get it going but once moving its not as hard? or when removing a bolt sometimes takes a great force or even a wack to get it to loosen then its easy to turn? This is that principle that the static Mu is almost always more then the kinetic mu.
Street tires dont have as much grip as r comps would. Having a super stiff setup would not allow the tire or suspension time to give to bumps or quick steering movements to absorb them and jolt them into kinetic mu with too much of a slip angle. Like i mentioned earlier, Imagen your trying to loosen a nut or bolt with a wrench, you push evenly and harder more and more (this is the amount of grip you have and G load) and it just doesnt loosen (or give up grip) now instead you push on the wrench but also give it a few wacks and boom, loose it comes ( or sliding) because your suspension cant absorb those "wacks". The principles that make a impact gun work or smacking a wrench work, are the same reasons you dont want to much spring in a car.
i've seen nationals ST civics set up with 450/700lb springs...and those civics are ~2000lbs also on 140 treadware tires. i figure there's gotta be some method to their madness. almost all have 350lb springs or higher.
Yes and I ran 10k F 12k springs in my old civic. The difference is suspension geometry. Again physics at work, this time being simple machines. Where on the suspension arm the spring/shock combo is, greatly effects how much force it takes to move the shock spring and the resulting arm up and down. Another example. Which would be harder to lift?...
You have a 20 ft wooden plank. One has 100 pounds of concrete right on the very end of the board you need to lift. Another has 100lbs of concrete in the middle of the board you need to lift. The second one is easier due to the mechanical advantage. For levers the general rule is the closer to the fulcrum the weight or object is from the force... the less force you need
Its the mechanical advantage of the suspension geometry. A strut suspension has very little mechanical advantage, so generally with comparable weight vehicles a car with strut type suspension will run less spring. A wishbone or multilink car has a suspension which the shock is in the middle(more or less) of the arm or "plank" which has a higher mechanical advantage, meaning its easier for the wheel or "person" to lift up on the spring or "concrete" Therefore takes more spring to counter act the same force of the wheel movement then on a strut equiped car.
This concept is "wheel rate" or the force it takes to move the wheel up and down, which ultimately what matters. So two different cars may handle bumps or feel as equally "stiff or soft" to one another, but one may run a 6k spring and another run a 10k spring
the fit is so tall, i want to keep the body roll controlled. in the last autocross, i loved that the car would rotate, but its behavior is so wild because of the stock springs and the car was all over the place. i really needed to tone my driving down and make my inputs a lot smoother.
The fit is tall but, its where the stiffness and weight it that matters. Most of the weight is all low, so that thin layer or sheet metal and air up there isnt really affecting how much it rolls.
And your last sentence should be true no matter how solid or well the car handles. To be fast you need to "slow down" and be super smooth. It has nothing to do with the car really. Stiff springs will just mask these driving mistakes with marginally better times from stock, but in reality you need to drive that smooth if not more so to be fast. This is way so many people say learn on a stock car and go from there.
Last edited by SHG_Mike; 03-08-2009 at 01:29 AM.
#18
03-08-2009, 01:55 AM
i know it's harder to drive with stiffer springs, but that just forces you to be smooth with your inputs.
in a strut suspension geometry, more displacement means the more the alignment is going to be off, right? so the stiffer it is, the more effective your alignment is going to be. you won't need as much camber.
i don't really think that all our weight is low...our hatch definitely needs structure, so that's heavy up top, there also has to be structure more to be safe in case the car rolls over. the seats are also pretty high compared to other cars.
in a strut suspension geometry, more displacement means the more the alignment is going to be off, right? so the stiffer it is, the more effective your alignment is going to be. you won't need as much camber.
i don't really think that all our weight is low...our hatch definitely needs structure, so that's heavy up top, there also has to be structure more to be safe in case the car rolls over. the seats are also pretty high compared to other cars.
#19
03-08-2009, 09:16 AM
It has nothing to do with harder to drive... if you cant absorb bumps you cant absorb bumps and you hop skip and slide.
Yes to a point. typically strut cars run more neg camber because they dont gain it in compression, like wishbone etc. Camber is also determinate on your tires. All of our spec miatas we ran 3.0 front 3.5 rear on RA-1's With the new R888 our tire temps were way off and we dont need as much. probably 2.5 3.0 but wont know until further testing
Yes to a point. typically strut cars run more neg camber because they dont gain it in compression, like wishbone etc. Camber is also determinate on your tires. All of our spec miatas we ran 3.0 front 3.5 rear on RA-1's With the new R888 our tire temps were way off and we dont need as much. probably 2.5 3.0 but wont know until further testing