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Upgrades (non TDI Engine related) The place of handling, lighting and other upgrades that do not relate to the performance or economy of the TDI engine. In other words upgrades to your TDI that don't fit into TDI Fuel Economy & TDI Engine Enhancements.Please note the Performance Disclaimer

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Old March 2nd, 2007, 13:39   #46
peter pyce
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FSD

There are tow separate discussions on the this damper:

1. The principle - On paper, it is novel idea, something that brings the "Wow, why didn't I think about that!?". They like to talk about frequency (which in reality is true, they are frequency selective) but that whole definition kind of makes everything sound so complex and so out of this world. Yet, it is quite simple. It has an additional chamber mounted under the piston and with some washer and holes management, it provides "delay" for the pressure building in rebound. So, what really happens is if the strokes are short (like going over a series of small bumps, with very low amplitude), the damper has this almost free flow of oil into the empty chamber, therefore the damper has very little rebound damping. That gives a very, very nice ride, because the spring is left to extend as fast as it wants/needs and the chassis does not follow those ups and downs like when we have strong rebound dampers..... That is what they call "at high frequency". Then, at low frequency (which basically means long stroke, long extension of the damper) like for example when you turn and the car rolls all the way on the outer bump stops, that same chamber (which is pretty small) get filled up rather quickly and suddenly the almost-free-flow-of-oil is stopped and now the oil goes only through the main rebound valving, so the damper gets very high level of rebound damping.

This was in theory - great theory! Everybody was screaming - wow, the most amazing damper, there is no more compromise between handling and comfort, wow! But then we come to the:

2. Real life application - this is when you get a set and open them, see what hey are made, put them on a dyno and then put them on the car. Then there are so many questions and no one (from Koni) gives you an answer. Like for example why are the fronts Twin-Tube design and the rears Mono-Tube design? (which by the way IS the reason some of you had to go with the 10 mm spacer in front to level the car, because the rear gets a lot taller than the front with these dampers - at least on A4 it was the case). Basically the rears have high pressure nitrogen (de carbon - mono tube design) that even when static, provides about 40-50 lb "push" in extension, so in reality what happens your car sits like you have removed 100 lb from the rear - it sits taller. The fronts are pretty standard twin-tube Koni design, the same Yellow or Red body, same internals, just with the added chamber and related features.

Not only that, but the damping values (curves) from front and rear are very different. In the fronts, there is delay in building pressure and there is also reduction in pressure (rebound pressure) with higher frequency! In the rear, thought, there is NO delay in pressure (rebound pressure), just reduction in pressure with higher frequency. We could sit here all day and speculate why they did it, but the fact is it does not work so well. On may car (Jetta A4) I never liked the ride on the rear. It was like a pretty severe mismatch. Yes, the high compression in rear and initial lack of rebound on the front made for a nice "handler", but the ride was never nice enough and all that came from the rear. The main issue here perhaps is that all these dampers come in the "one-fit-all" form, so they are probably set to pass some test with a car that has max load, which translates in requirement for a very stiff rear damper, and which configuration we almost never drive (I can't remember when was the last time I even put people in the rear seats) and so the daily commute with one or two people in the front becomes uncomfortable experience. They also could have rushed the whole production (as it came out pretty fast after the announcement) and did not really spend enough time to tune (especially the rears) then to suit the main goals on this specific platform. There are so many questions, but the answers from Koni are so few..... There is something else as well (which I personally dislike) - the fronts have incredibly low compression force and combined with the stock springs, the car bottoms even easier than with the OE dampers. And the kick is that they can not simply "up" the compression because with the lack of rebound (the delay) in high frequencies - the car will jack up dynamically, so they have to keep the compression low and that results in easy bottoming and never liked it.

There are few dyno plots I have as well, if someone is interested, but the bottom line is - the real thing is not as impressive as on paper. Yes, it gives little bit different dynamics to the car (for the mentioned above reasons), but it is far from "wow"... At the same time it kind of fails the "best comfort" line (at least for me - but then again, I drive on roads that are bad). So, I would call it "a compromise", but not "best of both worlds" like the marketers call it. If it was really the "wow, omg" that solves all the issues - trust me, it would not be only 200$ more per set!

And beside all this - the big mantra was that Lamborghini got the FSD as OE damper on the Gallardo and at that point everyone was "wow, this must be the ish" and Koni made sure everyone knows about it ..... But later on Lamborghini decided to get Bilsteins for the Spyder, and guess what the official line was? - "To smoothen the ride some"! ...... Which is kind of funny, when someone goes Bilsteins to smoothen the ride - imagine what the ride was before.

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Old March 2nd, 2007, 14:02   #47
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As with anything you go to market with what you have at the time. At the time Koni had not yet perfected their 80 series twintube FSD for the MKIV. The units out in retail should now be the new twintube design on the rear. They will have lower gas pressure and less lift.
You continue to describe it as such a non-feature, but there are real life experiences with this product that give it credibilty as well as the technology to back it up.
Ideas do not have to be complex to be good. Some of the greatest inventions are based on simple solutions. A post it note is a piece of paper with a weak adhesive, a simple idea. Does that reduce their value? There are very few examples of truely new hydraulic damper technology in the last 20 years, why do you choose to be critical. This technology continues to develope and evolve. Technology like FSD takes time to develope. It is currently being developed with McClaren in F1 as well as F3 for racing applications. No other aftermarket damper manufacture has offered any new technology for the MKIV. It is new technology, it does work and it will continue to evolve as KONI finds ways to improve apon it.
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Old March 2nd, 2007, 14:33   #48
peter pyce
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Oh, Bob is here! Man, I can't hide anywhere

I continue to describe it as what it is, Bob! It is great on paper and I admit it, it is great idea, great that Koni does something "different". there is no argument.

You can have 100 super satisfied customers and that cold be used to backup everything you want to say, but I am not "blown away" from the set I had, and I have no problem of saying it. It is free board where everyone can say their experience..... or perhaps is no longer that free to say what ones thinks?

Why do I chose to be critical? Because I chose to speak the truth about my experience. Koni may develop something in F1, but that by no means will end up in my volksie, not now, not in few years. I speak for the set I can buy for few hundred bucks - there is huge difference and you know it. Sure, it will evolve and then we will talk again later, when I get the "evolution" set. This one did not impress me. There is nothing to slam, and if you search older posts of mine - I tell people that the FSD are worth exactly what they cost - what is wrong with that?

Strange no one ever objected when I was saying few years back that the Koni Red (not available back then) were a lot better choice than the Koni Yellow. coincidentally Koni brought them here and now is selling unexpected amounts. Back then no one said I am so critical on the Yellow.....
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Old March 2nd, 2007, 16:17   #49
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Peter,

Thank you very much for the info on the FSD's. The more I learn, the more I feel I will be making an educated decision when I buy new dampers for my car this spring.

Can I assume from your above post that your experience with the FSD's is from the first round of them, and that you have not yet had a chance to try out the new twin tube rear models?

I have read a lot of your posts here, and a few on the 'tex as well. One thing I haven't come across is a kind of comparison between the Koni Reds, Yellows, FSD's and the Bilstien HD's. I'm not asking you to write one if it's not out there, just to point me in the right direction if it is.

Thanks again for the great info.
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Old March 2nd, 2007, 16:40   #50
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Peter -- Thanks for the info and taking the time to post.

Bob, I assume you are the Bob45228 from the Koni technical staff, whom I see over on Vortex?

I hope you two can have a civil discussion here on the next few pages, it looks like you have some differences and it looks like there is room to reach an understanding... which would be most educational for the rest of us.

Why not start with hashing out what the differences are between the FSDs you can buy now, and the ones that Peter evaluated/tested?

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Old March 2nd, 2007, 16:46   #51
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Quote:
Originally Posted by bob45228
As with anything you go to market with what you have at the time. At the time Koni had not yet perfected their 80 series twintube FSD for the MKIV. The units out in retail should now be the new twintube design on the rear.
I must say that the first sentance here is somewhat less than I would have expected from a company of Koni's stature. To an extent I guess that they are now reaping the result of that decision.

Bob, can you help us out by specifying the nomenclature (part numbers, revision codes, whatever) that reliably identifies the kits equipped with the new twintube rear design? Have there been changes to the front A4 application unit as well?

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Old March 2nd, 2007, 16:58   #52
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"I assume you are the Bob45228 from the Koni technical staff, whom I see over on Vortex?"

Yep, that's him, for better or for worse...
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Old March 2nd, 2007, 17:54   #53
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Peter, I respect and appriciate what you have to say. I will answer the questions in the post above and bow out of this discussion. I was not trying to shut down the discussion, but interject with my unique perspective.

The 2645 rears that you have were replaced about a year ago with an 8045 they will be stamped on the rear shocks. The only reason for the change was to reduce the rear lift created by the mono-tubes.
A4 fronts have not changed.

Quote:
Originally Posted by EddyKilowatt
I must say that the first sentance here is somewhat less than I would have expected from a company of Koni's stature. To an extent I guess that they are now reaping the result of that decision.
All products evolve if they did not you would be talking about rear engine aircooled VW. The early product was not substandard it was better than the competition and exactly as described. As our technology improved and we developed fsd in a twin-tube small bodied shock, our 8045, we put that in the kit.
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Old March 2nd, 2007, 18:31   #54
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Bob, do not need to bow out! These people actually need YOU, not me! It does not happen every day that an official representative for a product participates in a forum on the internet, so you are the one who should actually take the microphone and answer their questions, explain to them how things work and all the why and what about the products!


The goal here is to cover everything possible ONCE and keep it written, explained, documented, so it is a source of knowledge and people can finally make educated decisions and know exactly what they are buying. It is about the truth about these products! As you said, all products evolve and huge part of the evolution is customer feedback and this is what we are doing here. My goal is not to "slam" a product, but to show it from all the different views. It is what a journalist suppose to do, or an independent tester, but then do not, so we have to do whatever we can in the name of progress and education. We want to know (and have to know!) more today than yesterday - otherwise there is no point.


If you sit down and think deeply - we have dome more good (to Koni) than bad! You do not have to admit it, I know it! But as with every story, there are at least two sides and you, as a Koni employee can not always tell us both sides (but they do exist!) so I am trying to keep things little bit more real, so people don't go "yeah, wow" all the time. Because at the end, the sad reality is as you mentioned above - nothing major had been done in the last 20 years and we are buying 70's technology, repainted, repackaged, rebranded, sold as the "must have ish", but below is the same old stuff, and things will never change if people do not know all that..... if no one raises their voice, we will be driving the same dampers for another 20 years and that is really sad ....
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Old March 2nd, 2007, 20:39   #55
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O.K. Now I'm a bit confused. Would Bob and Peter both chime in please? I just ordered a set of FSD's for my 2003 Jetta Wagon. Peter, you recommended a set of 10mm spacers in the front to level out the car, but Bob, you are saying that they might not be needed because of the design change doesn't raise the rear of the car as much as the 1st gen FSD's?

I'm not trying to stir the pot, I just want to make sure that the car keeps it's attitude.

Thanks to both of you for informative posts! Now I know what to look for on my FSD's when they arrive.
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Old March 2nd, 2007, 21:28   #56
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Convert - I put the front spacer on pretty much every damper that goes in the front, as I like clearance and I like the car taller (have a soft spot for rally looks) and like pretty much everything that allows me to never slow down because of clearance/bottoming. So, the extra 10 mm were very welcome in my car and did not care how it looked. I know folks remove them as they like their cars lower, then others put them as they like their cars taller. It is personal decision of yours.

That said, the older FSD (mine was from the very first import, if memory serves me well) were low pressure front and high pressure rear and other folks put the spacer to level the car as on a bone stock springs TDI, the rear was jacked up and the front was normal and some did not like the look. If Bob is right and they made the rears twin-tubes (lower pressure, if any), then perhaps your car will look as it is stock. You can still put the spacer regardless and give some more lift in the front, where you need it most in a low pan TDI, but you do not have to. Hope this helps.

Here is a quick picture that shows how that spacer looks and where it goes, with part number as well:

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Old March 2nd, 2007, 21:57   #57
peter pyce
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Quote:
Originally Posted by Varkias
... One thing I haven't come across is a kind of comparison between the Koni Reds, Yellows, FSD's and the Bilstien HD's. I'm not asking you to write one if it's not out there, just to point me in the right direction if it is......
There is a comparison, but it is not direct, even if all the info is in one single thread. Have you sen this:

http://forums.vwvortex.com/zerothread?id=1648157&page=1

The thing is, when that thread started, the FSD were not avaialbe, so we concentrated on what was on the market. For FSD stories you have to read towards the end of the thread. It is very long read and is not easy, because we made so many mistakes and wrong assumptions as we were learning, but if you find the patience to read everything, at the end you will learn what we learned, and you will follow the way we learned it (with the mistakes we made). There are of course so many that disagree with us, but notice how no one really spends the time to explain why they disagree and then teach us the "right way". So, take it for what is worth. There are many things that I would re-write in that thread, I just lost the desire to post in there. The sad part is that if you go and read today, you will find out the same folks talk about the same old things in the exact same old way and everybody repeats the same old song they knew before, and it turns out that huge amount of work and money was kind of wasted, but perhaps it will help you some.....

This off-topic, but wanted to share with some of the followers of the old now "What Is Handling" thread that our special guest Ceilidh (Winston from Boston) started some time ago ....... wanted to say that few months ago he actually came to the visit for about a week and we finally managed to meet and had some quality time here in the Bay Area. He really is an amazing man, so educated and intelligent, and we had plenty of time to talk about all the things we wrote about for few years now. It was a fantastic meeting and there are plans to repeat it in early summer. Some times really good things can happen to you through the Internet
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Old March 2nd, 2007, 22:35   #58
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Peter, I don't disagree with what you're writing about the FSDs in concept, but in execution I have had a different experience. And as you know, I've had Bilstein HDs (20K), Koni Reds (40K), and now FSDs (18K) on my Jetta wagon, all with the stock springs and Shine rear bar. One thing I didn't like about the Reds in my wagon was when loaded it felt soft in back. So the pressurized rear dampers were really a plus for me, since I often drive the wagon with a lot of stuff in it. And also, wagon springs are, if I'm not mistaken, among the longest and stiffest springs in the MKIV world, so the front ride height is fine. The rear sits a bit taller when empty, but comes down quickly with even a mild load. And perhaps it's the longer springs, or the sport bumpstops, but I can't think of more than two or three times when I've hit the bumpstops. It happens less than it did with the Reds, and the Reds didn't bottom often (unless I had 800 lbs of oil in the car).

I've driven my A3 on the track with Reds, and the A4 with FSDs. The A4 felt much more controlled, even though it was seriously under-tired. And finally, I feel the FSDs ride a bit firmer than the Reds. Maybe they're different than the early set you tried.

Don't get me wrong, I love Koni Reds. And I'd buy them again, but try the wagon-specific rears (which I have but haven't put on the site--gotta do that). The moral of the story: drive before you buy. So much of this stuff is subjective that everyone has to form his or her own opinion.
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Old March 2nd, 2007, 23:35   #59
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You have a Wagon, it is heavier in the rear. Heavier car makes even Bislteins to be nice dampers. I have friends who drive with their trunks full, so their rides get acceptable. It is the Golf owners I feel for, if they live in area with bad roads..... but then again, if the rear FSD are now different, then perhaps it is not an issue anymore. And if they have done the rears like the fronts, then the compression force could be even less than the one provided by the Reds, and then it will be more "hello bottoming". Have to get a set on the dyno and we see.....

But market price does not lie, after all - you get what you paid for and everything is more or less worth what it costs. Of course, there are always exceptions, but I am talking in general.

Edited to add: We have put on the dyno OE dampers from a Wagon, actually! I have not posted about that experience, but maybe here is the place to say that the compression force of the rears from a Wagon is alot higher than those from Sedans. It is natural that every off-the-shelf-not-specific-for-a-Wagon damper, when mounted on a Wagon would feel softer then. The car is just the right amount heavier to overcome the extra force from "sportier" dampers and make the ride a lot more acceptable compared to the same put on let's say a Golf.

Last edited by peter pyce; March 2nd, 2007 at 23:48.
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Old March 3rd, 2007, 05:18   #60
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I'll measure the ride height of the car like it is now with almost 100K on the clock, then again with the FSD's installed. I'll make sure to keep the car's weght the same (fuel, etc.), and mark the floor so the measurement is made in the same spot. It'll be a month or so before they are installed.

Peter, what's a convenient, repeatable measurement point for the front and for the back?
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