BC Racing Coilovers Si

[burningoilagain]

uhhhh, that is not quite right. please read the article i linked.

http://www.superstreetonline.com/how-to/chassis-suspension/sstp-1303-how-a-coilover-works/

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[j_babsR1]

Very smooth can’t say anything wrong but only that their springs rust up after like 3-4 years. Well it happened to a few of my friends but at the same time it’s not like they took their coilovers out to clean them up like I have. But I don’t think spring should rust up like that. Basically one of my friends springs just cracked and fell apart. And when I took it out for him it was all rusted up. But the ride quality is good that def no issues on that side. They make covers for coilovers not so they don’t get beat from the winters on the east. Ktuner makes them it’s like 45.00 I suggest getting those with your new coils!

Yeah definitely will order some of those coil covers thanks!

 

[Design]

http://farnorthracing.com/autocross_secrets6.html

Couple thoughts on the article as it relates to this thread.

• The author looks at suspension components strictly from a performance perspective. That usually translates to suspension tuning on perfectly flat surfaces and under extreme handling conditions 100% the time.
• BC and others seek to enhance their parameters to appeal to a wide range of enthusiasts and conditions. A "critically damped" system may not translate well on the streets of New York, for example. Honda knows this, and is the primary reason they have moved to offer ADS on their performance trims.

It's a good article and worth reading. But I didn't want our community walking away with the wrong idea about variable damping & rates.

 

[totopo]

http://www.superstreetonline.com/how-to/chassis-suspension/sstp-1303-how-a-coilover-works/

They don't adjust the travel, they adjust the force-velocity properties, and usually not very well. Springs provide a force based on displacement. Shocks provide a force based on velocity of travel.

 

[totopo]

Couple thoughts on the article as it relates to this thread.

• The author looks at suspension components strictly from a performance perspective. That usually translates to suspension tuning on perfectly flat surfaces and under extreme handling conditions 100% the time.
• BC and others seek to enhance their parameters to appeal to a wide range of enthusiasts and conditions. A "critically damped" system may not translate well on the streets of New York, for example. Honda knows this, and is the primary reason they have moved to offer ADS on their performance trims.

It's a good article and worth reading. But I didn't want our community walking away with the wrong idea about variable damping & rates.

You don't want critically damped, you want from like .3 to .6 depending on velocities. That page is more about the basics of shocks. He goes into more about buying and tuning shocks in the later pages. And shocks tuned for track work pretty well for bumpy streets, since it does decrease felt bumps as well. That's part of their job, to control bumps. It's hard for cheap shocks to deal with body motion and bumps well at the same time. The main difference between race cars and street cars is suspension travel and the wide range of unsprung weight that street cars have to deal with. The shorter the suspension travel the higher spring rates are best.

from: http://farnorthracing.com/autocross_secrets23.html toward the bottom, "How about the Street"

I'm convinced that this insensitivity is THE reason why so many of the Japanese shock manufacturers (and the Chinese clones of same) are valved so strangely. You can't "feel" a properly-valved shock, but if you've just bought some aftermarket performance shocks, you expect to feel some sort of change. It takes a very large change in shock force to really be detectable by an average driver so if you want the customer to feel like his money bought something, you have to valve the shocks with some pretty outrageous forces.

...

OK then, so what to do with a street car?

1. Put the car on the scales with just you and a nearly empty gas tank.
2. Fill the tank, add your typical luggage load, and weigh the car again.
3. Add a typical passenger, and weigh the car again.
4. Fill the car with the largest load you think you'd ever reasonably carry, and weigh the car a final time.
5. Run these numbers through the Dynamics Calculator. You now have a range of natural frequencies - and damping forces - that represents the operating environment of your car.
6. Pick springs and damping forces that put the natural frequency of the car in its nearly empty state at 1.8 Hz to maybe 2.0 Hz MAXIUMUM. If you have to err, err on the soft side.
7. Buy a set of Koni Yellows, Bilstein HD, or a similar good name-brand shock. Dyno them. If the shock forces fall somewhere in your operating range - good enough. If they don't then revalve with a view to 65% critical at the full empty state. But don't get wrapped around the axle here. Get it in the range, and you're done.

 

[burningoilagain]

They don't adjust the travel, they adjust the force-velocity properties, and usually not very well. Springs provide a force based on displacement. Shocks provide a force based on velocity of travel.

They don't adjust the travel, they adjust the force-velocity properties, and usually not very well. Springs provide a force based on displacement. Shocks provide a force based on velocity of travel.

What doesn't adjust the travel ? You saying dampers don't control the travel but then you saying shocks provide a force based on velocity of travel ??? So confused. Dampers and shocks are pretty much the same thing.

 

[Design]

And shocks tuned for track work pretty well for bumpy streets, since it does decrease felt bumps as well.

That's not necessarily true. Increasing the fluid resistance on the compression and/or rebound stroke results in increased chassis response/chassis movement under high speed damping. Good for handling, bad for comfort - and occasionally bad for stability. Per your quote, a street car has a much wider range of parameters compared to a typical race setup. Accounting for the wider spectrum requires making sacrifices elsewhere, UNLESS you have active control over resistance forces. Hence, why we've seen the proliferation in adaptive suspensions ranging from magnetic to continually variable valving - particularly with German platforms.

Without commenting on quality, passive setups like BC seek to achieve similar results through manual valve adjustments. Opening the valve results in lower resistance, thereby allowing the spring to compress/uncompress at a faster rate. Much more desirable for the street.

Additional reading here:
https://nasaspeed.news/tech/suspens...hock-absorbers-and-their-effects-on-handling/

 

[xxbodkinxx]

I wish these would come out already! i have ran BC on my last three cars and I intend to on my SI coupe. I dont want springs quite frankly because I want to get my ride height just right as well as value front camber adjustment. Not to mention running springs is just going to kill the life on oem struts which run something like $300 a piece to replace. I dont really care or mind that i lose active dampening because I dont use it much as is, and dont really plan on autox and track. I have the money to buy my wheels and suspension in hand but not going to pull the trigger until these come out. Any updates?

 

[burningoilagain]

I wish these would come out already! i have ran BC on my last three cars and I intend to on my SI coupe. I dont want springs quite frankly because I want to get my ride height just right as well as value front camber adjustment. Not to mention running springs is just going to kill the life on oem struts which run something like $300 a piece to replace. I dont really care or mind that i lose active dampening because I dont use it much as is, and dont really plan on autox and track. I have the money to buy my wheels and suspension in hand but not going to pull the trigger until these come out. Any updates?

I def feel you bro!! I ran BC on plenty of my cars too and I’m just waiting it out with you!
They said to give them by the middle to maybe end of summer. It’s a little slow on their R&D side of things I’m guessing. But I def not running D2’s or any springs!

 

[cmunoz1795]

I wish these would come out already! i have ran BC on my last three cars and I intend to on my SI coupe. I dont want springs quite frankly because I want to get my ride height just right as well as value front camber adjustment. Not to mention running springs is just going to kill the life on oem struts which run something like $300 a piece to replace. I dont really care or mind that i lose active dampening because I dont use it much as is, and dont really plan on autox and track. I have the money to buy my wheels and suspension in hand but not going to pull the trigger until these come out. Any updates?

I messaged them about last week, and they said they had a kit coming in for testing so within 30 or so days they would be available. I’m just like you waiting for them, constantly checking the website if they go live.

 

[burningoilagain]

I messaged them about last week, and they said they had a kit coming in for testing so within 30 or so days they would be available. I’m just like you waiting for them, constantly checking the website if they go live.

Lol that's good to hear! that waa the problem they didn't have a vehicle for r&d and remember them asking me but I live way to far haha. But that's def good to know. Ill keep bothering them as well in a few weeks and see hows things going! and update this forum.

 

[cmunoz1795]

Lol that's good to hear! that waa the problem they didn't have a vehicle for r&d and remember them asking me but I live way to far haha. But that's def good to know. Ill keep bothering them as well in a few weeks and see hows things going! and update this forum.

Well let’s hope this stays the case. I messaged them a couple months ago and they said the same thing. So now we wait and see.

 

[xxbodkinxx]

Still no news. I want to go coilovers and wheels but no luck yet.

 

[Cscott_xGen]

Will there kit include a sensor to delete the engine code?

 

[cmunoz1795]

This was about 2 weeks ago.

I’ve been waiting so long for these, I loved them in my 15 Si, I’m definitely getting them when they go live

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