Coilover Setup & Adjustment Questions
11-09-2011, 05:45 PM
#1
Senior Member
SL Member
Thread Starter
iTrader: (1)
Join Date: Jan 2008
Location: Springfield MO
Posts: 535
Coilover Setup & Adjustment Questions
What's up peeps,
It's been a while since I've last posted, here it goes.
Ever since I installed my STD coils I've been wondering how to set them up for optimal performance, namely Spring Preload, rear shock body length & travel, and dampening settings.
If you have information to share about these topics, please do! I think this could help coilover set owners regardless of brand
The.car handles great, but I want to make sure I'm gettin the full potential outta them
Thanks,
Austin
It's been a while since I've last posted, here it goes.
Ever since I installed my STD coils I've been wondering how to set them up for optimal performance, namely Spring Preload, rear shock body length & travel, and dampening settings.
If you have information to share about these topics, please do! I think this could help coilover set owners regardless of brand
The.car handles great, but I want to make sure I'm gettin the full potential outta them
Thanks,
Austin
11-09-2011, 07:28 PM
#3
Senior Member
SL Member
Thread Starter
iTrader: (1)
Join Date: Jan 2008
Location: Springfield MO
Posts: 535
I really like them, they changed the spring design on the rear, and even sent me the new ones for free. Great customer service
Any advice on setup theory and procedures is what I'm looking for!
Any advice on setup theory and procedures is what I'm looking for!
11-09-2011, 07:43 PM
#4
11-10-2011, 05:11 AM
#5
As long as you don't have to adjust the spring height itself to change the ride height(which would change the spring rate, and put a wrench in everything), it should be preset for your car. Now it's just a question of setting up your damping/rebound to your preference.
11-10-2011, 11:12 PM
#6
Senior Member
SL Member
Thread Starter
iTrader: (1)
Join Date: Jan 2008
Location: Springfield MO
Posts: 535
Well the front spring preload was just setup by hand tightening the collars on the springs, I've heard of a "jack each wheel up" method but I don't understand the concept lol
The preload and ride are independent on these coils btw
The preload and ride are independent on these coils btw
03-25-2012, 01:12 PM
#9
The correct way is to find the ideal ride height, which at this point I don't think anyone has shared that info. I sure don't know. Next step is to give it a bit of rake, nose slightly lower than rear, 1/4" to 1/2" roughly. Then put the car's tires on 4 seperate scales. Then tweak each spring preload to get an equal weight on each tire scale, left to right and in a "X" pattern as well.. Front to back weight bias, I am not sure of for this car. The damping is something you have to set to your driving style, without causing the damping to overpower the spring or vise versa. I used to do this all the time with rc cars and it made the difference between podium finishes and being a hack. Same principle for cars. There was a show on the Powerblock on Speed channel last week if I remember correctly. Anyways they showed exactly how to do this with a Cobra kit car on coilovers. I know finding a set of those scales would not be cheap. Speed shops would probably charge a good bit to do it as well. Also you need to set the camber and toe afterwards. I'm no expert on 1:1 car suspension, so any of you engineers feel free to correct me if I am wrong or missed something.
03-26-2012, 10:39 AM
#11
Banned
SL Member
Join Date: Oct 2010
Posts: 1,075
Since nobody knows anything about tracking this car with your Standard Suspension, your first step is set the car up flat…and then work from there. You will need an alignment rack, car scales and a tape measure.
The first thing you want to do is set your car up on the alignment rack with a scale under each wheel.
The next thing you have to do is set your ride height. The rake of the car will change the weight on each wheel, so this must be done first. There are two places to measure that from. Some people measure from the floor (alignment rack) to the top of each fender wheel opening (center of the axle at the top of the wheel well opening at the fender). And the other (my preferred location) is from the floor to the chassis just behind the front wheels and just in front of the rear wheels. These points are also along the wheel well opening. I just prefer to measure a solid point inboard of the fender, on the chassis. Now, do not rake the car! Set it up flat! You need a start point and flat is that point. Also, make sure that the outer suspension joint (lower front wheel) is lower than the centers of that same lower A-arm at the chassis bolts. If the chassis bolts are lower, the car is too low!
The next thing you need to do is put approximately your weight in the driver’s seat (I use four 50-lbs water softener salt bags), have half a tank of fuel and read the scale weights. Add up all four scales to get the total weight of the car. Then add up both front weights and both rear weights to calculate the weight bias front to rear. This car should have about 65% front, 35% rear. You will get some weird number. Jot it down…it is very important! Now add up the weights of the left side wheels and the right side wheels. Proportion the right side total to the weird number you’ve calculated above and that is your ideal weight for each wheel on the right side. Repeat this exercise for the left side. Adjust each spring preload to get your target weights. Check your ride height that you have not changed it by adjusting each preload. Adjust as needed.
Now set your wheel alignment. I would set my front camber to 0.00 and toe to 0.00. Since this is a FWD car, the pull of the front wheels from the drive of the engine will take the slop out of all the suspension joints and give you some toe in. That is enough. Remember, we are setting a start point of zero here. Set your rear camber to -0.40 degrees. This is Toyota’s/Scion’s minimum setting. We are going for flat, so use that. I like to set 0.02 degrees of toe in on the rear. This helps significantly in transitions from straight ahead to start of turn and not enough wear the tires. The rear will follow the front’s inputs much better. The rear end is not as loose with this much toe in at the rear. Again, we are trying to get a zero start point. These alignment adjusts will have changed your previous settings. Go back and adjust your ride height, wheel weights and again your alignment. You will do this about three times to get it right.
Now for your shock/damper settings – set both compression (jounce) and rebound to minimum damping. Some people have the feel to bounce on the fender of the car to set a closer start point of the rebound only. As you drive the car, if the car continues to oscillate after a bump, increase the rebound damping one click at a time. You still want this at the minimum as possible. Keep your compression damping at the minimum for now. This is the last adjustment you will change to get the feel that you want.
You now have your start point…go tracking and only change one item at a time. If this is a street only vehicle, this zero point will impress you. This will work very nicely for the street.
The first thing you want to do is set your car up on the alignment rack with a scale under each wheel.
The next thing you have to do is set your ride height. The rake of the car will change the weight on each wheel, so this must be done first. There are two places to measure that from. Some people measure from the floor (alignment rack) to the top of each fender wheel opening (center of the axle at the top of the wheel well opening at the fender). And the other (my preferred location) is from the floor to the chassis just behind the front wheels and just in front of the rear wheels. These points are also along the wheel well opening. I just prefer to measure a solid point inboard of the fender, on the chassis. Now, do not rake the car! Set it up flat! You need a start point and flat is that point. Also, make sure that the outer suspension joint (lower front wheel) is lower than the centers of that same lower A-arm at the chassis bolts. If the chassis bolts are lower, the car is too low!
The next thing you need to do is put approximately your weight in the driver’s seat (I use four 50-lbs water softener salt bags), have half a tank of fuel and read the scale weights. Add up all four scales to get the total weight of the car. Then add up both front weights and both rear weights to calculate the weight bias front to rear. This car should have about 65% front, 35% rear. You will get some weird number. Jot it down…it is very important! Now add up the weights of the left side wheels and the right side wheels. Proportion the right side total to the weird number you’ve calculated above and that is your ideal weight for each wheel on the right side. Repeat this exercise for the left side. Adjust each spring preload to get your target weights. Check your ride height that you have not changed it by adjusting each preload. Adjust as needed.
Now set your wheel alignment. I would set my front camber to 0.00 and toe to 0.00. Since this is a FWD car, the pull of the front wheels from the drive of the engine will take the slop out of all the suspension joints and give you some toe in. That is enough. Remember, we are setting a start point of zero here. Set your rear camber to -0.40 degrees. This is Toyota’s/Scion’s minimum setting. We are going for flat, so use that. I like to set 0.02 degrees of toe in on the rear. This helps significantly in transitions from straight ahead to start of turn and not enough wear the tires. The rear will follow the front’s inputs much better. The rear end is not as loose with this much toe in at the rear. Again, we are trying to get a zero start point. These alignment adjusts will have changed your previous settings. Go back and adjust your ride height, wheel weights and again your alignment. You will do this about three times to get it right.
Now for your shock/damper settings – set both compression (jounce) and rebound to minimum damping. Some people have the feel to bounce on the fender of the car to set a closer start point of the rebound only. As you drive the car, if the car continues to oscillate after a bump, increase the rebound damping one click at a time. You still want this at the minimum as possible. Keep your compression damping at the minimum for now. This is the last adjustment you will change to get the feel that you want.
You now have your start point…go tracking and only change one item at a time. If this is a street only vehicle, this zero point will impress you. This will work very nicely for the street.
04-26-2012, 02:09 PM
#12
Senior Member
Scikotics
SL Member
Join Date: Nov 2004
Location: Minneapolis, MN
Posts: 9,731
You have googled a lot (and dont even have coilovers per your own posts) but you are not getting the whole picture.
For best handling on this car (still street driven) you should be running more negative camber in the front than the rear. About -1.25 degrees is fine on the street. Run a tad less in the rear. Toyota sets it up the way they do (more camber in the rear) for the same reason most fwd's are set up this way. It makes the car push more rather than snap oversteer ... safer for the average joe driver in the rain. You can assume if you are tracking and autoxing the car you will start with at least -1 degree if you want a starting point. I run almost -3 up front for autox events and about -1.5 or so on the street.
That "zero point" you post will be horribly unimpressing (well, it will be just like stock) even for just a street ride.
You also describe corner balancing wrong. You make the CROSS weights equal , not the total side weights.
For best handling on this car (still street driven) you should be running more negative camber in the front than the rear. About -1.25 degrees is fine on the street. Run a tad less in the rear. Toyota sets it up the way they do (more camber in the rear) for the same reason most fwd's are set up this way. It makes the car push more rather than snap oversteer ... safer for the average joe driver in the rain. You can assume if you are tracking and autoxing the car you will start with at least -1 degree if you want a starting point. I run almost -3 up front for autox events and about -1.5 or so on the street.
That "zero point" you post will be horribly unimpressing (well, it will be just like stock) even for just a street ride.
You also describe corner balancing wrong. You make the CROSS weights equal , not the total side weights.
04-27-2012, 06:28 AM
#13
Banned
SL Member
Join Date: Oct 2010
Posts: 1,075
This is an old thread…just stirring the pot I guess.
04-27-2012, 02:10 PM
#14
Senior Member
Scikotics
SL Member
Join Date: Nov 2004
Location: Minneapolis, MN
Posts: 9,731
No, you dont. Corner balancing does just that, best equalize the application of grip (and that is why anyone serious about setting up a car will corner balance it). If you get the side to side weights equal, you then throw the rest off. You can never, on any practical road car, get the corner weights perfectly equal. That is why you make the cross weight percentages equal.
The steps are to:
Figure out the angles, corner weights, roll centers, roll couples, motion ratio's ,etc AND the suspension frequency you want to target and choose springs from there
Dampers are then chosen from the above springs
Or you can start with off the shelf coilovers, but they wont be perfect since you cant choose the suspension frequency you want first. But if you are really going serious the above needs to be done first.
Set the ride height from the math you did above and some measurement, possibly some trial and error, etc get it as even as you can.
Then put it on scales and CORNER balance it.
Then start aligning the car.
The steps are to:
Figure out the angles, corner weights, roll centers, roll couples, motion ratio's ,etc AND the suspension frequency you want to target and choose springs from there
Dampers are then chosen from the above springs
Or you can start with off the shelf coilovers, but they wont be perfect since you cant choose the suspension frequency you want first. But if you are really going serious the above needs to be done first.
Set the ride height from the math you did above and some measurement, possibly some trial and error, etc get it as even as you can.
Then put it on scales and CORNER balance it.
Then start aligning the car.
04-27-2012, 04:39 PM
#15
Banned
SL Member
Join Date: Oct 2010
Posts: 1,075
04-27-2012, 04:40 PM
#16
Banned
SL Member
Join Date: Oct 2010
Posts: 1,075
I want to watch you do that first…without putting the car on scales…I’ll even pay money to see that! I’ll bring a video camera…that should be a great YouTube moment. Figuring out is significantly different from measuring…or estimating.
04-27-2012, 05:57 PM
#18
Senior Member
Scikotics
SL Member
Join Date: Nov 2004
Location: Minneapolis, MN
Posts: 9,731
Umm, who said i would do it without scales? Do you pop pills before you post? My car was corner balanced on a set of scales. I like how you try to pick out the parts you can attempt to answer with rude comments (although failing ones). The difference in you and I is that I try my best to share good information I have learned, experienced, etc. Your motive is to try to make everyone on here think you know way more than you do. People can read the various suspension items I and others have posted years before you existed on this site , or on ystc, or what people like Dennis Grant and others have out there and see what is fact and fiction. This site needs more over generalized google regurgitation like we all need an a$$hole on our elbow, especially from someone hellbent on nothing but making the unknowledgeable think they are an expert. So when you have an intelligent reply to share that actually makes sense, then share it. Otherwise you are wasting space.
Your reply about corner balancing again shows a lot of error in your understanding. So corner balancing just shows the TWIST in the chasis? No, it does no such thing. The proper formula for a properly corner balanced car is (corner weights are what is being shown): LF+RR = RF + LR
That in no way is meant to measure twist in anything. It is THE way to balance out the car once you have ride height set. It is how to ensure your car turns in both directions equally well.
Your reply about corner balancing again shows a lot of error in your understanding. So corner balancing just shows the TWIST in the chasis? No, it does no such thing. The proper formula for a properly corner balanced car is (corner weights are what is being shown): LF+RR = RF + LR
That in no way is meant to measure twist in anything. It is THE way to balance out the car once you have ride height set. It is how to ensure your car turns in both directions equally well.
04-28-2012, 02:30 AM
#19
Banned
SL Member
Join Date: Oct 2010
Posts: 1,075
No need to call names...just read...don't try to interpret, because so far you've been wrong about me. Nowhere did I say I was seeing, showing, extrapolating, deducing, measuring or calculating the twist in the chassis. I said acknowledge...that means you know it is there (but in your case, I see now that I’m wrong…you actually don’t) and do nothing about it...it's just there. Your formula is correct for corner balancing. Again, that is not what I’m doing! Now that you’ve got those numbers…what do they mean? What does your formula mean? Hmmm, reread what I’ve said…don’t interpret. Then reread my instructions on how to balance the corner loads for a consistent handling car.
04-28-2012, 05:22 AM
#20
Banned
SL Member
Join Date: Oct 2010
Posts: 1,075
Here is an example with number…since engifineer is so enraged that he can’t see and has not thought it through. Refer to attached figure. I’ve just designed a car with a 200-in wheelbase and a 100-in wheel track. Any car will do, since these calculations are for any car. I’ve set the center of gravity of the car at 65% of the weight on the front wheels and the CG off to the right by 5%...the engine is to the right, so I thought this was a reasonable estimate of a car that weighs 2500-lbs. Calculating the weights on each wheel, I got 731.25-lbs on the LF, 893.75-lbs on the RF, 393.75-lbs on the LR and 481.25-lbs on the RR. These are your target weight as I’ve described and I’ve shown the calculations to get you there. This is statics…we have not even gotten to the dynamics of your car yet. You need to get the statics right before you go to dynamics. Now my cross weights come out to be as engifieer suggests 731.25-lbs + 481.25-lbs = 1212.5-lbs. Now for the other cross weights, we get 893.75-lbs + 393.75-lbs = 1287.5-lbs. Hmmm! 1212.5-lbs does not equal 1287.5-lbs. If I try to cross balance the car as engifineer suggests, the statics don’t work out! And if you can get there, you’ve just tweaked in a twist into your car. Or just throw in a 75-lb bag of cement in your car and drive around that way.
Last edited by 2tCornot2tC; 04-29-2012 at 01:41 AM. Reason: added total weight and figure