IS F (2008-2014) Discussion topics related to the IS F model

BC Racing Coilovers

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Old 05-20-11, 07:23 AM
  #106  
TLcoats
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Couldn't it just be from the springs sagging a little bit more on that side than the passenger side due to the added weight?
Old 05-20-11, 11:07 AM
  #107  
Joe Z
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Originally Posted by TLcoats
Couldn't it just be from the springs sagging a little bit more on that side than the passenger side due to the added weight?
Every IS I have owned since July of 2000.. Has had a driver's side lean straight from Japan...


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Old 05-23-11, 05:39 AM
  #108  
caymandive
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So I had some time this weekend and installed the BC coilovers myself. Very happy with the quaility and was pleased to see a 10lb total weight reduction. The drop out of the box though was pretty extreme for me though. It was a 1.5" drop all around from the factory ride height and it looked tucked on all four corners. Not my cup of tea!

So the install was the easy part. The tough part for me as it turns out is getting the car to sit at the height I want and staying there. Can you guys give me some advice on how to adjust the height? I've been jacking up one wheel at a time and making adjustments, but i've heard it may be best to jack up and do one side front and rear together then going to the other side. (Thoughts?) I had the car sitting exactly the way I wanted, went out for a drive, filled the tank and when I got back the measurements were all off again. I knew the rear would go down a tad with the fuel, but it seems that there was more change than from just the added fuel, because the front dropped as well. I can only think it's from the positive camber when lowering the car back to the ground without taking it for another drive.


For reference, below is a picture of the car sitting exactly the way I wanted it to prior to me driving down the road for fuel. It's lowered close to 1" from stock in the front and I kept the stock rear height as I thought it was perfect. I measured from fender to the floor down the center of the wheel.



A few more questions/concerns:
1. When adjusting the coilovers. Is .5 inch adjustment on the coilover body equivalant to say .5" ride height change? See link, if the distance between 2b and 2c is increased .5 inches does that correlate to .5 inch increase in ride height?
2. Car is also pulling to the right now. I'm assuming the car is now out of alignment. How soon after coilover install do you recommend getting the car aligned and what is adjusted to fix the pull to the right? (Castor?)
3. What are you guys setting the dampening to? I have it set to -10 clicks from full hard, but was wondering what you guys have found works best.

Thanks!

Last edited by caymandive; 05-31-11 at 05:35 AM.
Old 05-23-11, 07:44 AM
  #109  
CCColtsicehockey
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Looks good. Looking to see the answers people have for your questions as I should be installing mine in the next week.
Old 05-23-11, 09:23 AM
  #110  
FIGS
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James, its not a direct correlation because the coilover is at a leverage point. I would need to measure the pickup length the get the exact numbers. I would take 70% as a good number for correlation. Meaning a change in 1" at the spring might net 1.4" at the wheel. I will pull the info and get better figures. On a strut car, these will be pretty close because the puickup is close to the outside hub.

On damping, with 14K,10K I suggest 9 out front and 14 out rear for aggressive driving. and 10 clicks further out for a comfort setting.

On the higher spring rate setup I would expect a 5-8 click difference, meaning the damping window can slide back that far. This would put the aggressive setting at nominal midrange of the damping settings for the 16K and more like 20 clicks out on the 12K rear. Its all preference though, so tune it to what you can tolerate and where the performance meets your needs.

Its important to mention that coilovers are just tools to tune to your preferences. This is why there are so many differing opinions. Ride height, powerlevels and braking are all variables in the equation. In the end its what ***** you can turn to get the ride quality you want.
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Last edited by FIGS; 05-23-11 at 09:28 AM.
Old 05-23-11, 09:56 AM
  #111  
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Originally Posted by FIGS
James, its not a direct correlation because the coilover is at a leverage point. I would need to measure the pickup length the get the exact numbers. I would take 70% as a good number for correlation. Meaning a change in 1" at the spring might net 1.4" at the wheel. I will pull the info and get better figures. On a strut car, these will be pretty close because the puickup is close to the outside hub.

On damping, with 14K,10K I suggest 9 out front and 14 out rear for aggressive driving. and 10 clicks further out for a comfort setting.

On the higher spring rate setup I would expect a 5-8 click difference, meaning the damping window can slide back that far. This would put the aggressive setting at nominal midrange of the damping settings for the 16K and more like 20 clicks out on the 12K rear. Its all preference though, so tune it to what you can tolerate and where the performance meets your needs.

Its important to mention that coilovers are just tools to tune to your preferences. This is why there are so many differing opinions. Ride height, powerlevels and braking are all variables in the equation. In the end its what ***** you can turn to get the ride quality you want.
Thanks Mike. I'll play around with the dampening settings later. You are the standard for customer support.

So what do you think of the car now pulling to the right? Strickly alignment issue?
Old 05-23-11, 10:30 AM
  #112  
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Originally Posted by caymandive
Thanks Mike. I'll play around with the dampening settings later. You are the standard for customer support.

So what do you think of the car now pulling to the right? Strickly alignment issue?
Steering link inclination angle and alignment, especially if you leveled both sides. The side that is now higher will be toe out from where it was.
The rear toe is probably off as well, which has more to do with steering that most people realize.
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Old 05-30-11, 10:29 AM
  #113  
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Default BC coilovers installed and corner balanced





I installed my BC coilovers last weekend myself. Having little to no background on how suspensions work I thought it was a matter of install/set preferred ride height/alignment/done. I got the ride height close to what I wanted, but out of frustration I decided to take it to FunKtion Auto so they could dial it in and do an alignment. I have never been there before, but they are close by and have a very good reputation (though pricey). They asked me if I ever race the car and I replied that I do plan on taking it to a track one of these days. What that told them was I needed this car corner balanced and not just setup aesthetically with ride height. (hence my numbers below)

When I brought the car to the shop and they got it up on scales, wow it was way off! 37% balanced! Having driven the car about 10 miles with the coilovers I knew it was way off and that % certainly verified things.

After roughly 6 hours of adjustments the car was nearly perfect with cross weight percentages of:
-50.8% front left to rear right.
-49.2% front right to rear left.

Does the car now sit like a show car? Not at all, but it is slightly lower than stock especially the front and it drives incredibly! I can't tell you how pleased I am now with driving this car. The car inspires more confidence in long sweepers (off-ramps), drives straight and the jittery stock feel is gone. The uneven wheel gap does bother me some, but it's not something easily noticed and the sheer joy of how the car feels now more than makes up for it.




Details
Ride height is what I was measuring being the distance from the ground up through the center of the wheel to the fender. <<This aesthetic measure is not encouraged!
Coil pre-load is the distance I measured from the top coilover thread to the black plastic piece holding the bottom of the spring.
Coil perch distance is the distance between the 2nd from top perch to the lower perch. There are 3 perches on each coilover.

Last edited by caymandive; 10-27-19 at 08:42 PM.
Old 05-30-11, 11:39 AM
  #114  
Supraman16
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Looks great Cayman. The corner balancing really makes a difference with coilovers...I found out the same thing with my BC Coilovers. What are your dampening settings that you finally settled on? Have fun and drive safe...Darshana S...
Old 05-30-11, 11:54 AM
  #115  
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Originally Posted by Supraman16
Looks great Cayman. The corner balancing really makes a difference with coilovers...I found out the same thing with my BC Coilovers. What are your dampening settings that you finally settled on? Have fun and drive safe...Darshana S...
Thanks Darshana! I had only heard about corner balancing prior to coilovers, but wow I'm a true believer now. Well worth the money to have the car setup right. The dampening is set to -10 clicks on both front and rear and the car feels as firm as stock, but much more compliant.

Last edited by caymandive; 03-22-13 at 06:52 PM.
Old 07-12-11, 01:52 PM
  #116  
Evil Teo
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i got my BC from FIGs with 14k/10k setup I believe. I went with his recommendation on the dampening settin of 10 in the front and 14 in the rear to be as close to stock. loving them so far. I should have done this long time ago. Now I am happy driving my from home to work and vice versa. even the wife think its better. before I had that sagging feeling with the stock setup and going over bumps it would hit the bump stop, not to mention everytime i start the car i hear this vibration coming underneath the car and the dealership think its the exhaust and tires. replace it with BC and now i can hear the smooth Joe Z exhaust without any vibration. will corner balance when i put on the new tires.

Last edited by Evil Teo; 07-12-11 at 01:56 PM.
Old 01-30-12, 05:44 AM
  #117  
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Originally Posted by Evil Teo
i got my BC from FIGs with 14k/10k setup I believe. I went with his recommendation on the dampening settin of 10 in the front and 14 in the rear to be as close to stock. loving them so far. I should have done this long time ago. Now I am happy driving my from home to work and vice versa. even the wife think its better. before I had that sagging feeling with the stock setup and going over bumps it would hit the bump stop, not to mention everytime i start the car i hear this vibration coming underneath the car and the dealership think its the exhaust and tires. replace it with BC and now i can hear the smooth Joe Z exhaust without any o
vibration. will corner balance when i put on the new tires.
Question about the settings. When you say 14/10, is that from the soft or hard setting?
Old 01-30-12, 04:05 PM
  #118  
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^^no, those are the spring rates. 14 kg/mm front and 10kg/mm rear.
Old 01-31-12, 04:23 PM
  #119  
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Great info and details, thanks for sharing!
Old 01-31-12, 10:14 PM
  #120  
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damn i need to get me a pair of some coils so i can corner balance them bad boys..but i would need to find a shop out in oahu that does that kinda stuff..


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