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Pondering about Coilovers (KW v3 etc)


RobPhoboS

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Can you post up the damper curves for each click of adjustment for these please??

 

Shame you don't offer double adjustable versions.

 

The reason we don't offer double adjustable dampers is because we feel most owners will obtain better performance with a single adjustable damper.

All MeisterR dampers are compression & rebound combined adjustable mono-tube dampers.

What that mean is that the compression force adjust along with the rebound force, there is no need to have a separate adjustment to adjust the compression force.

 

Most Twin-tube dampers are rebound only adjustment as a single adjustable setup (KW V2, Koni Yellow Sport, etc).

That is why they need to add in an additional adjustment in order to control the compression force.

 

As the damping ratio are pre-designed within the adjustment with the MeisterR, this makes damping adjustment easier and eliminate the possibility of incorrect adjustments.

If an owner was not sure on how to adjust a 2-way damper, they could easily end up with a 1:5 compression to rebound ratio, and that will not be very good for performance.

This will not happen if the owners is using a compression & rebound combined adjustable damper.

 

We can to separate adjustable dampers, and it is in the plan.

This is more for race car and we will go straight to a 3-way adjustable with an external reservoir.

Because if any car require more than the GT1, then a 3-way with a high speed compression blow off will provide much better performance.

 

Here is a plot of the adjustment, taken at 140mm/s.

The line is full stiff, -5 clicks, -10 clicks, -15 clicks, -20 clicks, full soft.

 

We take the adjustments this way because 140mm/s is our "stick in the mud" point for vehicle dynamic analysis.

The same stick that Bilstein had been using since the 1970's, so most have been using this speed for vehicle dynamic ever since.

 

But you can see how the ratio changes as well as the cracking pressure (bleed), which is all the important thing we need to know in order to see how the damper will work on the vehicle dynamically. :)

 

ZetaCRDadjust.png

 

Jerrick

So how do you set the ratio of bound to rebound on adjustment to compensate for the unsprung mass of the 350z? Obviously you have tested every single car to come up with that ratio?

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So how do you set the ratio of bound to rebound on adjustment to compensate for the unsprung mass of the 350z? Obviously you have tested every single car to come up with that ratio?

 

The damper actually don't really care about the sprung and unsprung mass of a vehicle.

 

The sprung and unsprung mass of the car actually is part of the wheel frequency calculation.

The wheel frequency is a calculation of the springs rate, the car corner weight, and suspension motion ratio.

Once you work out what springs rate you need to achieve the wheel frequency you are after (Generally for road car, you want to stay under 2.0Hz).

Then you can pair the damper valving to the springs rate.

 

For a fast road car, you want to have around a 1:3 compression to rebound ratio, for more sporty type track cary, you can go down to 1:2, and I have seen some Ohlins run 1:1 but that is a bit too much even by our standard.

 

This ratio are than pair to the springs rate critical damping rebound force.

As you can only run so much rebound force before the damper start to stop the springs working in it's natural frequency, you can work that number out and make sure your damper stay under that figures.

Too much rebound force will start to stop the suspension from moving, causing the suspension to "jack down".

This create a lot of bad vehicle dynamics that you DO NOT want.

 

The damping adjustment is allows you to shift where you want to be at in regards to ride quality.

For a road car, generally you want to be between the 50% to 70% critical damping.

For a track car, generally around the 80% to 100% critical damping.

As the damping force are designed to the paired springs rate, and the springs rate are designed base on the car, the entire suspension system work together.

 

So now you know what springs rate you have, what is the maximum rebound force you can run with that springs rate, and then you can pair the compression force to that rebound force.

 

Compression force is the force that put load onto the tyres, they are what give you that sharp turn in that you want, or that compliancy that you want over uneven roads.

That have a lot to do with the "cracking pressure", which is the point where the first shims inside the damper "crack" open.

 

A good fast road & track adjustable suspension wants the follwoing:

1. High cracking pressure for track use, because this put force on to the tyres giving sharper turn in as well as traction.

2. Lower and more progressive cracking pressure for fast road use, because this allows the suspension to move to those uneven surfaces providing better comfort and better traction on uneven road surfaces.

 

All of the above are something you can calculate with some basic info on the car, if you have the software as well as the technical know how to do so.

But as you can see, the damper don't really care about the sprung or unsprung weight of the car, because all the damper really see is the springs that it is paired with.

The springs however do care about the weight of the car, and that is something that should be calculated in the first stage of suspension design.

 

The above procedure is the same for a Nissan 350Z, a Mazda Miata, or a Ferrari 458.

The car changes, the number change, but in the end the wheel frequency is a level playing ground that can be calculated and compared.

There are some changes and fine details here and there, but on the whole that is how you work out the vehicle dynamics of a car.

 

So in conclusion: That damping ratio works for ANY car.

For your concern of weight, that is calculated and incorporated into the springs rate choice.

 

Jerrick

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I posted the link to this chaps YT channel before but as usual, it gets lost.

I highly recommend having a look for those that want to learn, understand more about suspension.

 

Thanks Rob, first I seen this video.

I heard of Fat Cat Motorsport as they are more heavily involved in the Miata community in the USA.

 

What he say have a lot of truth honestly, probably one of the most accurate video I have heard regarding dampers.

There are a few bits I don't agree with, mainly regarding the knob, and I'll explain a bit.

 

Design: Mono-tube vs. Twin-tube.

I agree with him pretty much, and that is why we are exclusive mono-tube supplier.

Twin-tube isn't bad, but the design mean they do have that "phase lag" as he speak.

 

Twin-tube also have issue with heat under hard usage, because it cannot cool off as well as a mono-tube damper.

This mean if you are to do a 25 minute session, the suspension will feel good in the first 15 minute, and by the last 10 minutes you feel like you could stiffen the damper 2 more clicks.

That is because the oil have heat up to the point where the viscosity had change, and therefore the actual damping force the damper is generating is less then when the oil was cooler.

 

Accuracy: Getting the damper to do what you want.

Very true, especially about the lack of compression from most dampers.

The reason for this is that most dampers actually lack compression because low compression damper ride nicer.

In order to give the sporty feeling, you have loads of rebound adjustment (to the point where it is out side critical damping).

So when a user want something that "feel" more planted, they put up the higher rebound force.

 

What this doesn't do is that it doesn't increase compression force, and that mean you are not putting any more load into the tyres.

You will get a suspension that feel planted, but it isn't generating any more traction because it isn't pushing the tyres harder.

That is why when people go from crappy suspension to good suspension, they see their lap time drop by a second or two, because the good damper is now generating proper compression force to work the tyres.

 

Another thing on this "ideal" damping is having less rebound mean the car "feel" less planted.

But that is because the suspension is now letting the car move, which mean the car now get to properly "use" it's tyres.

 

I get this from race driver all the time... we build them a proper race setup and they will tell me that it "feel" wobbly and less planted than the old setup

But when they look at the lap time and see it is 2 seconds faster, they all just scratch their head.

 

As Colin Chapman once said:

"Any suspension will work if you don't let it."

 

That basically hit a nail on the head...

You got to have good compression force relative to the rebound force, and you cannot have more rebound force than what your springs can support.

Over valve a damper at your own peril...

 

Precision: Mono-tube vs. Twin-tube.

As he say, that is another difference and it does illustrate if you are to damper match each damper.

A mono-tube have all the component that generate damping force located at the piston, the shims, and the bleed valve; all tie together under high pressure gas.

Basically if you have good component, you have accurate build; you will get very accurate and repeatable build.

 

A twin-tube damper have more parts, and therefore variance in each component will alter the damping force.

This typically make matching a twin-tube damper very difficult, because if everything are just off a little bit, you end up having a huge difference in damping force.

 

Psychology / Confidence: OEM sport suspension

Yep, again... agreed with him.

Been in one of those older Audi S-line car (it was an A3) and first thought was that the compression force was way too stiff.

I understand they are trying to give you that stiff sporty feeling, but that was just excessive for a road car and not needed.

The same goes for the 2009 Nissan GTR that I had as a test car, the OEM Bilstein was horrible.

 

I am glad to say that the OEM are now slowly waking up to this stiffer isn't always nicer even if customer wanted sport suspension.

Some of the latest OEM car I rode in actually are doing a pretty good job and getting closer to where it should be.

 

 

Adjusting the knob, what I don't agree with.

 

He say adjusting a knob is moving you away from an "ideal" curve assuming you have one.

That is true, if your car only have 1 "ideal" function.

 

For a fast road car that will not see track day (like his TT in Poland), there can be an ideal damping curve.

However, if you give that TT an ideal damping curve for Poland and then take the car on a track day at Silverstone Arena GP circuit, the car will feel a bit too soft and won't fully use it's tyres.

 

For a fast road & track car, you need that damping knob because you are shifting the car from a fast road function to a track day function.

By having adjustment to the amount of rebound force you make, and more importantly how aggressive the compression force are generated.

You can shift between a suspension that will ride nice on broken road and retain great traction, to a suspension that will push hard onto the tyres to generate traction and sharp steering response.

 

That is the point I don't agree with, because there are too many different function an all rounder fast road & track suspension have to face to just have 1 damping curve take care of all the functions.

Therefore, an adjustment knob is necessary to dial a suspension to the owner's preference, as well as the immediate function that the car has to perform (Going on track, or going home after the track day).

 

Interesting, I enjoy that video.

A lot of truth in it, and a lot of truth that many companies do not want to admit.

 

Jerrick

Edited by MeisterR
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Excellent stuff, and really good to read your thoughts :thumbs:

I've been watching plenty of the videos today, and I'm sure for the next few weeks !

(luckily I can have them playing at work)

 

I imagine that, exactly like you said 'if your car only have 1 "ideal" function' - which is potentially what he might be referring to.

I can see both sides to it, ultimately it's what the 'knob turning' does.

 

 

If anyone is interested - check these two but do look at the channel, awesome resource !

 

 

(continued)

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Loving the detail in here. You can really tell Jerrick nerds out on this stuff for his job given the length of the replies, its reassuring to see at least from a bystanders perspective ;)

Hahahaha! You do realise that's all copy and paste from other sites. It's been doing the rounds for years!

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Hahahaha! You do realise that's all copy and paste from other sites. It's been doing the rounds for years!

 

Who's reaction to the video did he copy/paste then above where he was agreeing or explaining why he didn't to the points raised?

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Loving the detail in here. You can really tell Jerrick nerds out on this stuff for his job given the length of the replies, its reassuring to see at least from a bystanders perspective ;)

Hahahaha! You do realise that's all copy and paste from other sites. It's been doing the rounds for years!

You need to qualify that statement or apologise.

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I vote for Ohlins DFVs just to throw more spanners into the works :wacko:

 

I try to justify £2500 to myself on a daily basis. Havent quite got there yet :lol:

 

Would also state that Ive seen no evidence of KW v3's for £1250 as claimed earlier in the thread. You gets what you pay for I think ;)

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I vote for Ohlins DFVs just to throw more spanners into the works :wacko:

 

I try to justify £2500 to myself on a daily basis. Havent quite got there yet :lol:

 

Would also state that Ive seen no evidence of KW v3's for £1250 as claimed earlier in the thread. You gets what you pay for I think ;)

 

Totally understand that, that's why the only reason i bought them was because i grabbed a brand new set at £1400!

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I vote for Ohlins DFVs just to throw more spanners into the works :wacko:

 

I try to justify £2500 to myself on a daily basis. Havent quite got there yet :lol:

 

Would also state that Ive seen no evidence of KW v3's for £1250 as claimed earlier in the thread. You gets what you pay for I think ;)

 

Totally understand that, that's why the only reason i bought them was because i grabbed a brand new set at £1400!

Have you tried other coilovers, and if so how do the Öhlins compare?

Edited by BobbyZ
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I vote for Ohlins DFVs just to throw more spanners into the works :wacko:

 

I try to justify £2500 to myself on a daily basis. Havent quite got there yet :lol:

 

Would also state that Ive seen no evidence of KW v3's for £1250 as claimed earlier in the thread. You gets what you pay for I think ;)

 

It was me that bought them for that

Why would I need to prove it to you

If the op wants some I'll get hI'm them lol

Its a price that was granted to me so why would I need to flash the invoice around on here to satisfy everybody's needs

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Why? Perhaps because I PM'ed you as Im interested in a set?

 

I had a few people pm me and said once people had confirmed they wanted them I'd aproch my contact and see if I could get that price for the people that wanted them

Which I still will

When I get chance to sit down and go threw the people that wanted them I'll ask the question

I'm not saying it's a definite but that's what I got them for and can prove it

Don't feel I have to to anyone tho

I'm pretty sure James junior got them for not far of my price at demon tweeks if you look threw his posts on his thred ;)

Edited by nissanman312
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I vote for Ohlins DFVs just to throw more spanners into the works :wacko:

 

The Ohlins DFV is a very good suspension.

It is the "bar" we use to measure the MeisterR GT1.

 

I actually had a few customers who been in both Ohlins DFV and the MeisterR GT1, and most reaction is positive for both suspension.

"In Theory", the Ohlins DFV should handle big bumps better (such as curb strike / pot holes), and the MeisterR GT1 will handle smaller vibration (such as small bumps on country roads, vibration that you will get on motorway) better.

 

However, feedback seems to be the other way around, where some said the GT1 actually handle the pot holes better than the DFV.

There are very minor difference between the two in those area, but it is just what the owners pick up and send back to us as feedback.

 

Those feedback mainly comes from EVO and GTR owners as Ohlins been offering the DFV to those community for a bit longer than others.

 

The latest MeisterR GT1 uses a "Zero Bleed" CNC piston, and it allows us a lot more control over the dynamics of the damper.

So far they have been working great, and I am sure as time goes on we will get more reviews for them.

 

The GT1 being quite a bit cheaper than the DFV is also a bonus, but I personally feel at this price bracket the performance of the suspension is much more important.

 

Jerrick

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Jerrick, what options are there in terms of absorbing impacts that are 'sharp' vs 'non-sharp', i.e. in your example I think for a fast road set up the preference would be to absorb small vibrations and pot holes (that I would classify as sharp) and still have maximum control over larger, lower frequency deflections like rollers?

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Jerrick, what options are there in terms of absorbing impacts that are 'sharp' vs 'non-sharp', i.e. in your example I think for a fast road set up the preference would be to absorb small vibrations and pot holes (that I would classify as sharp) and still have maximum control over larger, lower frequency deflections like rollers?

 

If you think of "sharp" and "non-sharp" as piston speed, that will help it easier to understand.

When you are driving on the motorway, you get a lot of small vibration that isn't very fast, those I would say it's "non-sharp"

When you are driving down a country road and hit a pot hole, you get a very big and fast movement, those I would call "sharp".

 

Because those two event are two different piston velocity, it mean it is handled different in the damper.

 

The "slower" movement are part of the "bleed circuit".

You want the internal oil to flow pass the piston easily so those small movement are absorbed instead of being transferred.

This is where "harsh" ride from coilovers comes from, because race suspension don't really have a bleed circuit.

The don't want the bleed because it will put more force onto tyres faster and harder, and that is how you get damping response.

The issue with that on a road car is it will ride harsh like if the suspension did not exist... something I absolutely hate.

 

The GT1 use a "Zero Bleed" piston, but we control the "bleed circuit" by using a dual stack shims on the compression side.

What that mean is you have a stack that is very light that will open easily, but then it is limited by a second stack that is stiffer.

That way you can have bleed for ride comfort, but will not get sloppy steering response because the bleed are immediately controlled.

 

The "faster" movement are part of the "blow off".

When the suspension reach a certain velocity, basically it mean it is no longer vehicle dynamically relevant.

Because when you hit a pot hole, you don't really need any damping force to control it.

 

So this blow off tells the suspension to let it go, because you don't need to worry about it.

If your suspensions generate too much force, that is when you get this super jarring ride and your tyre lose traction... not good.

 

The GT1 internal shims stack have this blow off incorporated.

That is when 20 years of suspension engineering experience from a vehicle dynamic engineers really comes into play.

Basically, this is when Black Art Design start doing black arts... and make things work.

 

Building a suspension is actually pretty easy.

Building a suspension that works is the more difficult task.

And when it comes to engineering, I can tell you that us British still have it in a world class level. :)

 

Jerrick

Edited by MeisterR
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Hah, I certainly appreciate the input !

One thing I'm not massively concerned about is the body coating, as I tend to get the car on the ramp quite frequently, so always give them a wipe down, however yes the KW bodies always look great no matter the age.

The KW V3 is £1728 though.

 

What MeisterR suspension did you have, and was it from new ?

 

:thumbs:

 

I payed 1250 for my v3 they are epic I love them

PM me for details of who to speak to regards price :)

 

I dont want to be a tosser about it but this suggests anyone can get them for £1250 ......... not as part of group buy if there are enough other people and the vendor decides to go for it.

As it stands they are £1600 odd for my car and apparently £1700 for a 350Z which is a good few hundred more than Meisters and more than twice what HSD cost.

Edited by docwra
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Jerrick, what options are there in terms of absorbing impacts that are 'sharp' vs 'non-sharp', i.e. in your example I think for a fast road set up the preference would be to absorb small vibrations and pot holes (that I would classify as sharp) and still have maximum control over larger, lower frequency deflections like rollers?

What is a fast road set up? This is banded about on lots of forums and it is borderline cringeworthy. There is no such thing as a fast road setup.

 

But to answer your question the high speed damping and control of the KWv3 smashes the MeisterR. This is not just a benefit for roads, but track too as you can attack the curbs more aggressively without losing your wheel contact.

 

 

Hah, I certainly appreciate the input !

One thing I'm not massively concerned about is the body coating, as I tend to get the car on the ramp quite frequently, so always give them a wipe down, however yes the KW bodies always look great no matter the age.

The KW V3 is £1728 though.

 

What MeisterR suspension did you have, and was it from new ?

 

:thumbs:

 

I payed 1250 for my v3 they are epic I love them

PM me for details of who to speak to regards price :)

 

I dont want to be a tosser about it but this suggests anyone can get them for £1250 ......... not as part of group buy if there are enough other people and the vendor decides to go for it.

As it stands they are £1600 odd for my car and apparently £1700 for a 350Z which is a good few hundred more than Meisters and more than twice what HSD cost.

I must admit, it's a borderline unbelievable price. I hope it's true though!

 

Yeah, the v3 are more expensive than the HSD's and Mesiter's, but that's because they are better. The Ohlins DFV aren't as good and you're really paying for the name. For £2500 range you're looking at Nitron's and AST

 

http://www.ast-suspension.co.uk/shop/shockabsorbers/5200/ast-2-way-5200-nissan-350z-fairlady-z-detail

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