D2 Coilovers

MaysEffect · 09-25-2017, 11:13 PM

Quote:

Originally Posted by Hotrodz

You crack me up, I guess all spring then are created equal and there no difference between Swifts or any other spring. I will agree that all springs are equal as far the rating of 10k or 8k or whatever, however I must be all wet in thinking that springs would respond differently based on the materials they are made of or the thickness of the spring or how tightly the sping was spun.

Oh and I have a very sensitive butt!

Are you guessing or do you know forsure these factors are different? All of those factors come into play to create the spring rate. So more times than not the dimensions are extremely close for any given diameter and length per rate measured. In the case where materials are different, the force acting upon it should be linear in both rebound and compression, if not, this goes back to what i said about damaged. Noticing a difference between a 10kg x 5 inch eibach or swift would mean one or the other does not truly hold its rate in linear fashion. There have been no recent test that show swift springs falling short of its rates. i doubt the rates and lengths are actually the same if you are saying you've determined a noticeable difference with these absolute back to back test. In any case, why would you even make this change? Unless you actually damaged your springs or dampers.

Optimiser · 09-25-2017, 09:16 PM

Quote:

Originally Posted by asapZ

Im looking for coilovers on my 2012 370z, and found some D2 coilovers i herd they're pretty decent? But are there any better ones?

https://mcasuspension.com/

asapZ · 09-26-2017, 01:20 AM

What about PBM Coilovers they tend to make them customs for what you wana us them for??

MaysEffect · 09-26-2017, 02:25 PM

I was asking for clarification on the situation because you are the one making the claim about variations between companies claiming the same properties. There are too many variables in a suspension system that would render your analysis inaccurate. Certainly if the springs you claim are in actuality not the same in the first place.

There is a statement in the article suggest there are industry standards that allow estimated measurement values of 5% accuracy to the claimed rating. While this is true and the case between company and company, you'd still be hard pressed to notice a considerable difference here unless there were considerable design differences between the springs. Most linear springs from swift, hyperco and eibach use very similar design principles and dimensions, with materials and forming being one of the only open variable. Even still not different enough to change to overall behavior of the spring. If it's a linear spring we are talking about, it still needs to behave in such fashion. Now if you are talking about progressive springs, then of course they're will be considerable differences from the base spring ratings companies claim. There is absolutely nothing accurate about ratings for progressive springs, certainly when talking about dual rate springs. The differences can easily be above 200ib/in at 2inches of compression for instance.

With a 1000ib/in linear spring, a 5% variation is only 50ibs. In most cases 1000ibs is already greater than the corner load on most vehicles including the 370z and g37. So you'd need significant load transfer or bump aggravation to get those springs working. Add in damper force and tire compression, you're butt will need to be working at 200% to accurately measure what the spring is doing beyond supporting the weight of the vehicle.

This is also another reason why kg/mm is such a horrible measurement in any form. It allows a variable average of 55*ib/in both ways between ratings. Hyperco, Eibach and even swift don't even claim those exact levels of accuracy on there site in ib/in form. Hyperco make springs in 25ib/in increments as does eibach. So again this goes back to what i said that in reality the two springs you are claiming are not actually the same and can be different over 2kg or so. So is the swift spring actually softer? Sure, but that's by the virtue of it actually having a different rating all together. Not it's difference to compression and rebound behavior.

You and the article are right in saying the springs may not actually have the same rating, but this is not the same thing as saying; for one rating (if accurately measured), two springs behave different enough for you to tell pants to seat. Even in the article they used a scenario when they changed springs with slightly different ratings and couldn't tell the difference.

Quote:

For example, while testing at Charlotte, a car had a 375# tagged spring in the rear, the driver felt that the car was loose on corner entry and the Hoosier tire temperatures supported his feel. After stiffing the spring to a 400# tagged spring the driver did not feel any changes. The tire temperatures still supported his feel.

You saying you could tell the difference with two springs with the SAME rating and noticing a significant difference draws skepticism. Sorry you don't see that. The test goes on to say, the springs were actually tested within 2ib/in of eachother in favor of the lower rated spring when rated only 1/2kg/mm(25ib/in) difference.

I don't know how you are reading my tone, but i haven't said anything with attitude or contempt. I was simply questioning the validity of your claims. Making claims like that suggests someone is lying about there products, and in a thread where people come to get information like this, that can be damaging to the reputation of the company you speak about. Making that claim alone can significantly shift someone's buying choice when the validity of the claim can't even be taken with face value. This is my reasoning for questioning it. I was not at all trying to belittle you, just trying to get an accurate depiction of the situation, so others can draw the right conclusion before changing their opinion. (seriously wasn't trying to rhyme there

)

I've literally been making the same questions and discussions since I've been here. My very first post almost gave Spooler an aneurysm lol. So sorry if i got under your skin. It's not at all personal

Hotrodz · 09-26-2017, 02:49 PM

Quote:

Originally Posted by MaysEffect

I was asking for clarification on the situation because you are the one making the claim about variations between companies claiming the same properties. There are too many variables in a suspension system that would render your analysis inaccurate. Certainly if the springs you claim are in actuality not the same in the first place.

There is a statement in the article suggest there are industry standards that allow estimated measurement values of 5% accuracy to the claimed rating. While this is true and the case between company and company, you'd still be hard pressed to notice a considerable difference here unless there were considerable design differences between the springs. Most linear springs from swift, hyperco and eibach use very similar design principles and dimensions, with materials and forming being one of the only open variable. Even still not different enough to change to overall behavior of the spring. If it's a linear spring we are talking about, it still needs to behave in such fashion. Now if you are talking about progressive springs, then of course they're will be considerable differences from the base spring ratings companies claim. There is absolutely nothing accurate about ratings for progressive springs, certainly when talking about dual rate springs. The differences can easily be above 200ib/in at 2inches of compression for instance.

With a 1000ib/in linear spring, a 5% variation is only 50ibs. In most cases 1000ibs is already greater than the corner load on most vehicles including the 370z and g37. So you'd need significant load transfer or bump aggravation to get those springs working. Add in damper force and tire compression, you're butt will need to be working at 200% to accurately measure what the spring is doing beyond supporting the weight of the vehicle.

This is also another reason why kg/mm is such a horrible measurement in any form. It allows a variable average of 55*ib/in both ways between ratings. Hyperco, Eibach and even swift don't even claim those exact levels of accuracy on there site in ib/in form. Hyperco make springs in 25ib/in increments as does eibach. So again this goes back to what i said that in reality the two springs you are claiming are not actually the same and can be different over 2kg or so. So is the swift spring actually softer? Sure, but that's by the virtue of it actually having a different rating all together. Not it's difference to compression and rebound behavior.

You and the article are right in saying the springs may not actually have the same rating, but this is not the same thing as saying; for one rating (if accurately measured), two springs behave different enough for you to tell pants to seat. Even in the article they used a scenario when they changed springs with slightly different ratings and couldn't tell the difference.

You saying you could tell the difference with two springs with the SAME rating and noticing a significant difference draws skepticism. Sorry you don't see that. The test goes on to say, the springs were actually tested within 2ib/in of eachother in favor of the lower rated spring when rated only 1/2kg/mm(25ib/in) difference.

I don't know how you are reading my tone, but i haven't said anything with attitude or contempt. I was simply questioning the validity of your claims. Making claims like that suggests someone is lying about there products, and in a thread where people come to get information like this, that can be damaging to the reputation of the company you speak about. Making that claim alone can significantly shift someone's buying choice when the validity of the claim can't even be taken with face value. This is my reasoning for questioning it. I was not at all trying to belittle you, just trying to get an accurate depiction of the situation, so others can draw the right conclusion before changing their opinion. (seriously wasn't trying to rhyme there

)

I've literally been making the same questions and discussions since I've been here. My very first post almost gave Spooler an aneurysm lol. So sorry if i got under your skin. It's not at all personal

You protest too much! You don't know me and give yourself to much credit. I only have one feeling and you are not even close to hitting it!!!

Sent from my SM-N910P using Tapatalk

MaysEffect · 09-26-2017, 03:08 PM

Quote:

Originally Posted by Hotrodz

You protest too much! You don't know me and give yourself to much credit. I only have one feeling and you are not even close to hitting it!!!

Sent from my SM-N910P using Tapatalk

Why are you yelling lol.

I'm not trying to hit anything. I'm trying to get you to validate your claims.

and whyyyyy did you have to repost that long *** post lol.

Rusty · 09-26-2017, 02:54 PM

Next time. Include the whole thing.

a car had a 375# tagged spring in the rear, the driver felt that the car was loose on corner entry and the Hoosier tire temperatures supported his feel. After stiffing the spring to a 400# tagged spring the driver did not feel any changes. The tire temperatures still supported his feel. After the supposed spring change, the team then began to change shocks, sway-bars, and pan-hard bar heights. At the end of the day, the springs where rated. After viewing the data sheets we found that the 375# tagged spring was actually a 387# and the 400# tagged spring was a 385#. So the actual change in spring rate was not an increase of 25# as was intended but a decrease of 2#. This is why the driver and the tire temps showed no change.

What it amounts to is. There was a spring that what tagged as a 375#. But was measured 385#. They changed to a 400# spring, but it was measured at 385# later. That why they felt no change.

I'm at the point of

You haven't been around long enough in life to see everything that we have.

MaysEffect · 09-26-2017, 03:04 PM

Quote:

Originally Posted by Rusty

Next time. Include the whole thing.

What it amounts to is. There was a spring that what tagged as a 375#. But was measured 385#. They changed to a 400# spring, but it was measured at 385# later. That why they felt no change.

I'm at the point of

You haven't been around long enough in life to see everything that we have.

I literally stated both.

Quote:

The test goes on to say, the springs were actually tested within 2ib/in of eachother in favor of the lower rated spring when rated only 1/2kg/mm(25ib/in) difference.

In either case my point is still proven here. If two springs rates are about the same, you'd be hard to tell the difference. Regardless of its physical properties.

2011 Nismo#91 · 09-26-2017, 04:48 PM

Quote:

Originally Posted by Rusty

Next time. Include the whole thing.

a car had a 375# tagged spring in the rear, the driver felt that the car was loose on corner entry and the Hoosier tire temperatures supported his feel. After stiffing the spring to a 400# tagged spring the driver did not feel any changes. The tire temperatures still supported his feel. After the supposed spring change, the team then began to change shocks, sway-bars, and pan-hard bar heights. At the end of the day, the springs where rated. After viewing the data sheets we found that the 375# tagged spring was actually a 387# and the 400# tagged spring was a 385#. So the actual change in spring rate was not an increase of 25# as was intended but a decrease of 2#. This is why the driver and the tire temps showed no change.

What it amounts to is. There was a spring that what tagged as a 375#. But was measured 385#. They changed to a 400# spring, but it was measured at 385# later. That why they felt no change.

I'm at the point of

You haven't been around long enough in life to see everything that we have.

This is why I am so apprehensive with just buying and installing an adjustable coilover. You really don't know what your getting because your consumer level stuff is mass produced with little QA/QC. "It's like having a blind man adjust the focus on your camera. What's the point."

"Let me make this as clear as I possibly can: THE ADJUSTERS ON YOUR SHOCKS ALMOST CERTAINLY DO NOT DO WHAT YOU THINK THEY DO. Unless you have something high-end, like a Penske, and you've taken the time to clock the adjuster window on the shock dyno, the knobs on your shocks cannot be trusted to work. Most shocks of the same model DO NOT match each other on the same adjuster setting, and each click DOES NOT make the same change in force. Most shocks make very large changes per click near the "full hard" setting and make very little to no change near the "full soft" setting." - Autocross to Win (DGs Autocross Secrets) - Shocks

MaysEffect · 09-26-2017, 05:45 PM

Quote:

Originally Posted by 2011 Nismo#91

...Unless you have something high-end, like a Penske, and you've taken the time to clock the adjuster window on the shock dyno, the knobs on your shocks cannot be trusted to work. Most shocks of the same model DO NOT match each other on the same adjuster setting, and each click DOES NOT make the same change in force.

A great article indeed.
That is the problem with relying on shocks to tune overall force. This is why it's just as important on choosing the right spring setup over anything else. The damper for all intensive purposes should be doing as little work as possible. With cheap coilovers that use both inaccurately gauged dampers as well as inaccurately matched springs usually ends up with poor ride quality over time, if not immediately. Even if you have an poorly adapted damper, you still should be able to get reasonable control if you have the right spring setup and have the damper adjusted to the least intrusive rate.

One of the biggest points on the article is about gas pressure. So many rules of thought still floating around saying its not as important as it is or should be used in other ways other than valve attenuation, when in reality it can make or break your handling, certainly over time. It's also another reason why i'd never suggest anyone use a twin tube shock.

Quote:

Happy Fun Fact: Formula One cars use non-adjustable shocks. They get away with this by running the car on a seven-post shaker rig that plays back suspension movements recorded previously on that track, using the data the collect on the rig to tune the shocks, and once the shocks are tuned, those are the shock forces they use at the race. Once they're right, they're right

Fun fact- This is vague an slightly inaccurate. But that is an entirely different argument. Fact of the matter, F1 cars generally remove the aid of adjusters because it increases weight and bulk. Teams have entire garage zones dedicated to re-tooling or simply replacing dampers and spring rates at race events. Its never one and done.

Secondly most of the bump and rebound is controlled by the tire, not the damper. The dampers and "roll eliminators" primarily serve to control yaw, roll and pitch. Where as on our road cars the dampers have to control this plus bump and rebound as well as squat and dive independently. So adjusters are still valuable, as they are on anything short of an LMP1 or gp2 car.

2 cents.

D2 coilovers? I would actually like to know how they handle. compared to more expensive kits.

KamiSpeed · 09-26-2017, 03:44 PM

Jhill · 09-27-2017, 04:56 AM

I think what hotrodz. Was getting at is the swifts "feel" softer which probably means more compliant. If we take for example a spring that is 400lbs per in and a block of rubber that is 400lbs per inch they may both be the same rating but their ride characteristics couldn't be more further apart.

I know what he is talking about as I have switched spring for off-road bike (which has a much more direct connection to ground than a road car) and I noticed a difference. I actually switched just for the weight savings (to a light weight alloy) but after switching the characteristics and liveliness of the suspension was noticeable, maybe not night and day but it was noticeable (could I notice the difference in a car? I'm doubtful). One would think just speeding up the low speed rebound on the normal spring would do the same thing but it really doesnt, I can't say why but I do know it isn't the same. Ti springs used to always hold a reputation for having a different ride feel as well.

MaysEffect · 09-27-2017, 11:24 AM

Goddamnit Jhill i was just now mentally trying to back out of this argument lol. Now i have to go into thought again about potential material properties and here say theories again

.

For one rubber does not and will never hold spring tension like metal. So measuring the cycling rates of one to another is irrelevant, regardless if they hold the same pressure at a given measurement (highly unlikely). But in the case of measuring one steel vs another of fairly similar properties, it is much more likely the cycling rate would remain almost identical if they both are rated and designed for linear force output.

Regards to new versus old. It's also possible you guys felt a difference simply because the old spring has settled into fatigue and spring sag, loosing it's original overall force output. That is not the same as saying two new springs with measurably equal rates will behave different enough to noticeably feel under load.

Similar to worn tires compared to new tires of the same size and model, or even a different model. In most cases we're remembering and comparing the end state of the old vs. the immediate state of the new. This is not a fair analysis and in most cases does not show the whole picture.

I actually have to work today so I'll conclude at this for now and allow you guys to rip into my opinions

.

Rusty · 09-27-2017, 01:44 PM

Just give it up. You're going to get beat until your ears bleed.

Retired with 2 engineering degrees. In my experience. What is in a book and what SHOULD happen does NOT always happen as predicted. I've come across too many things in my work that has blown my mind. I've come across other engineers that think like you. Most cases, they don't make it far unless they change the way they think and realize that things are not the way they seem to be sometimes. Experience is the best teacher, along with failure.

Give you credit. You make good points on suspension overall, and have good knowledge on the subject. But there are times, like this. You can not, will not see the other side of things. And are unwilling to accept a different outcome.

MaysEffect · 09-27-2017, 03:36 PM

I'm not sure beat is the right terminology when you guys are not presenting valid or even accurate facts against my argument. I've asked hotrodz 3 times already if he can validate his testing other than the vague statement that swift springs are generally softer. All I've heard so far is that I'm being difficult, argumentative and/or wrong. The closest thing i can do to accurately proving the statement wrong is by going out and actually measuring one against another under dyno tests. I'm not sure winning this debate is worth 150 dollars.

I also stated my only problem with these statements is that it slightly tarnishes the reputation of the company by associating a non tested or inaccurately proven claim that there is something ingenuine of products ratings.

Jhill was so far the only one making valid claims about spring retention with his statements, and i believe i refuted it reasonably.

09-26-2017, 02:54 PM	#7 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 69 Posts: 35,372 Drives: 2011 Nismo GM 6M Rep Power: 2684438	Next time. Include the whole thing. a car had a 375# tagged spring in the rear, the driver felt that the car was loose on corner entry and the Hoosier tire temperatures supported his feel. After stiffing the spring to a 400# tagged spring the driver did not feel any changes. The tire temperatures still supported his feel. After the supposed spring change, the team then began to change shocks, sway-bars, and pan-hard bar heights. At the end of the day, the springs where rated. After viewing the data sheets we found that the 375# tagged spring was actually a 387# and the 400# tagged spring was a 385#. So the actual change in spring rate was not an increase of 25# as was intended but a decrease of 2#. This is why the driver and the tire temps showed no change. What it amounts to is. There was a spring that what tagged as a 375#. But was measured 385#. They changed to a 400# spring, but it was measured at 385# later. That why they felt no change. I'm at the point of You haven't been around long enough in life to see everything that we have. __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

09-26-2017, 03:44 PM	#11 (permalink)
KamiSpeed A True Z Fanatic Join Date: Feb 2011 Location: Orlando, FL Posts: 5,888 Drives: 09 370z Rep Power: 26	Rusty, Hotrodz and Stright_Drop like this. __________________ KAMISPEED \| SHOP 370Z PERFORMANCE PARTS & MODS \| SUPPORT@KAMISPEED.COM KAMI SPEED REVIEWS \| FINANCE YOUR PARTS WITH US \| MILITARY & FIRST RESPONDERS PRE-ORDER DEPOSIT PROGRAM \| HKS MASTER SELLER

09-27-2017, 04:56 AM	#12 (permalink)
Jhill Track Member Join Date: Mar 2016 Location: San jose Posts: 854 Drives: 2013 370z sport Rep Power: 3385	I think what hotrodz. Was getting at is the swifts "feel" softer which probably means more compliant. If we take for example a spring that is 400lbs per in and a block of rubber that is 400lbs per inch they may both be the same rating but their ride characteristics couldn't be more further apart. I know what he is talking about as I have switched spring for off-road bike (which has a much more direct connection to ground than a road car) and I noticed a difference. I actually switched just for the weight savings (to a light weight alloy) but after switching the characteristics and liveliness of the suspension was noticeable, maybe not night and day but it was noticeable (could I notice the difference in a car? I'm doubtful). One would think just speeding up the low speed rebound on the normal spring would do the same thing but it really doesnt, I can't say why but I do know it isn't the same. Ti springs used to always hold a reputation for having a different ride feel as well. Rusty, Hotrodz and littlejuanito like this.

09-27-2017, 11:24 AM	#13 (permalink)
MaysEffect Enthusiast Member Join Date: Aug 2016 Location: SoCal Age: 32 Posts: 383 Drives: Infiniti FX35 Rep Power: 36	Goddamnit Jhill i was just now mentally trying to back out of this argument lol. Now i have to go into thought again about potential material properties and here say theories again . For one rubber does not and will never hold spring tension like metal. So measuring the cycling rates of one to another is irrelevant, regardless if they hold the same pressure at a given measurement (highly unlikely). But in the case of measuring one steel vs another of fairly similar properties, it is much more likely the cycling rate would remain almost identical if they both are rated and designed for linear force output. Regards to new versus old. It's also possible you guys felt a difference simply because the old spring has settled into fatigue and spring sag, loosing it's original overall force output. That is not the same as saying two new springs with measurably equal rates will behave different enough to noticeably feel under load. Similar to worn tires compared to new tires of the same size and model, or even a different model. In most cases we're remembering and comparing the end state of the old vs. the immediate state of the new. This is not a fair analysis and in most cases does not show the whole picture. I actually have to work today so I'll conclude at this for now and allow you guys to rip into my opinions . littlejuanito likes this. Last edited by MaysEffect; 09-27-2017 at 04:46 PM.

09-27-2017, 01:44 PM	#14 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 69 Posts: 35,372 Drives: 2011 Nismo GM 6M Rep Power: 2684438	Just give it up. You're going to get beat until your ears bleed. Retired with 2 engineering degrees. In my experience. What is in a book and what SHOULD happen does NOT always happen as predicted. I've come across too many things in my work that has blown my mind. I've come across other engineers that think like you. Most cases, they don't make it far unless they change the way they think and realize that things are not the way they seem to be sometimes. Experience is the best teacher, along with failure. Give you credit. You make good points on suspension overall, and have good knowledge on the subject. But there are times, like this. You can not, will not see the other side of things. And are unwilling to accept a different outcome. 2011 Nismo#91, Hotrodz, Spooler and 2 others like this. __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html Last edited by Rusty; 09-27-2017 at 01:53 PM.

09-26-2017, 01:20 AM	#3 (permalink)
asapZ Base Member Join Date: Jun 2017 Location: Calirfornia Posts: 36 Drives: 2012 Nissan 370Z Rep Power: 8	What about PBM Coilovers they tend to make them customs for what you wana us them for??

09-27-2017, 03:36 PM	#15 (permalink)
MaysEffect Enthusiast Member Join Date: Aug 2016 Location: SoCal Age: 32 Posts: 383 Drives: Infiniti FX35 Rep Power: 36	I'm not sure beat is the right terminology when you guys are not presenting valid or even accurate facts against my argument. I've asked hotrodz 3 times already if he can validate his testing other than the vague statement that swift springs are generally softer. All I've heard so far is that I'm being difficult, argumentative and/or wrong. The closest thing i can do to accurately proving the statement wrong is by going out and actually measuring one against another under dyno tests. I'm not sure winning this debate is worth 150 dollars. I also stated my only problem with these statements is that it slightly tarnishes the reputation of the company by associating a non tested or inaccurately proven claim that there is something ingenuine of products ratings. Jhill was so far the only one making valid claims about spring retention with his statements, and i believe i refuted it reasonably.

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