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KONI Lee last won the day on February 11 2019

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About KONI Lee

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    Hebron, KY
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    KONI Automotive Product Manager

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  1. The KONI distributor in the UK is RFT in Mytchett, Surrey. Ask for Trevor and tell him that Lee with KONI North America sent you. Although he cannot get the Datsun Z specific inserts, he can probably get the M48 x 1.5 using the part number from Holland. Performance Parts RFT Email: tleigh@rftgroup.co.uk Tel: 01252 494016 Unit One Mytchett Business Centre 57E Mytchett Road Mytchett, Surrey, GU16 6EG
  2. According to the drawings I am looking at that has most but not all of the measurements, the 8641 1033 Sport does step down from 43.5 mm OD to 42 mm OD a short distance from the bottom so there is an insternal restiction near the bottom. The 8641 1033 Sport is a straight 42 mm OD all the way down. The 1033 may have hung up on that diameter restriction before it reached all the way to the bottom and thus the length difference is not apparent when inside. All the more reason for you to get the 1031s that are needed for the smaller diameter early struts. It would be interesting to see if you car has the smaller diameter rear struts as well if you think they are original to the car.
  3. Hello Jonbill. Sorry that you have had an issue but I was able to dig into some specs to sort it out. If your car needs the M48 x 1.5 gland nut, then you have early ('70-'74.5) strut housings and thus need the 8641 1031Sport with the proper gland nut and a 42 mm OD insert diameter and 394 mm insert length. Based on the late 1974 build date, you bought the 8641 1033Sport which use a M52 x 1.5 gland nut, have a 43.5 mm (1.5 mm larger) OD insert diameter and a 384 mm (note that it is 10 mm shorter) insert length. Whether the cars is the UK were made with a later changeover date or maybe sometime in its life someone put earlier strut housings on your car, you have early struts and thus need the early strut inserts. Remember that you said it was a tight fit but the insert went into the housing, the later car's slightly larger OD insert body fit but barely? If you'd had the M48 gland nut, upon installing it you would have found that the later, shorter insert was too short to engage properly. Although you could stack some washers on the bottom of the tube to spacer it up to engage, there is also a difference in the reound damping force (a bit more on the later car) and compression damping forces (a bit less on the later car) that would also made a functional difference as well. The top mounting pin dimensions are the same between the two models but the later car's inserts actually extend about 5 mm longer and compresses 10 mm shorter than the earlier cars too. The rear struts are quite a bit different in length between the early cars and later cars but they have the same M48 and M52 differnces that you should check on your car as well.
  4. Digressive valving is not exactly "new thing" for companies who have been making performance dampers for a long time (KONI has been doing it for at least 50-60+ years) but it might be newer to companies whose products were more replacement grade and not really within the performance realm. It could be that their piston and valving component design might not have allowed the ability to really contour the damping curves very much but have moved in that direction. Many shock companies may not have been around that long or possibly just their marketing companies have simply latched onto "digressive" as a buzzword that they are using heavily now. Some consumer marketing messages may make a big deal about mono-tube or twin-tube design suggesting that one is always better than the other but it is simply not true. There are good and bad examples of both and different cars can have very different needs so it is more important that the damper function is tailored to the vehicle and it usage. Digressive and linear are general terms used to describe shapes of plotted dyno curves (however shocks on cars on roads never operate like dyno graphs look) but there are so many variables in car and damper design that you really can't just hang onto or use it as a "this is good" or "this is not good" gateway. Don't make your purchase on the use or lack of the word "digressive". You did not mention any specific shock brands but it is probably better that way anyway. As to your coil-over questions, it really depends on your usage and expectations of the car. To be a coil-over, it really only means that the spring is mounted on the strut of shock and all 3 of the early Z-cars do that already. Modern usage suggests that you are also wanting to make the lower spring perch height adjustable so you can customize your ride heights, corner weight the car if you want to, and have the flexibility to interchange spring rates is pretty easily. Beyond that, it is pretty wide open as to what your desired outcome will be and thus the path you should follow. With a coil-over, you can select a relatively soft spring rate for a compliant suspension and smooth ride, bump them up quite a bit for firmer ride and sporty control or run really big spring rates for a handling performance only/ don't care about ride quality set-up for mostly track use. It really boils down to what your uses and expectations for the car are. I would let that be the deciding point of whether you choose these Z-car specific Sport dampers or the much more aggressive RACE dampers that are clearly intended for Racing performance track duty with no comfort, no warranty, etc. in mind. Before these new Sports were introduced, there were few options for the car but now they offer more opportunities. Having looked at the damping specs of them all, the RACE units are much, much more aggressive on rebound and compression damping and not specifically fitted as a drop-in for the Z-car strut housings so some level of machining and fabrication may be needed depending upon your intended outcome. The Sport units are made to be a nice performance upgrade for the Z-car but still have a quite reasonable ride quality (so long as you don't overspring the car which will make it harsh), a standard lifetime KONI warranty against defects, be a drop-in solution to fit your housings, etc.. It all depends upon what you want, e.g. "Whats for dinner?" What do you want? Home cooked or eat out? Steak or chicken, Mexican or Italian, etc. Pick what you want to satisfy your interests as there is no specific one right answer for everyone.
  5. As with pretty much all KONI dampers, these are digressive valvings on the Z cars. This means that as they initially begin to move, they build damping forces at a pretty steep rate to give very low piston speed, subtle body motion control but the rate of climb continues at a decreasing or digressing rate at target piston speeds across their working piston speed range so that they do not get too firm and causing handling, tire grip, and ride comfort issues once the suspension and body get into significant motion. A progressive damping curve would normally be a bad thing as it would have very little damping force and control in subtle suspension motions but it would rapidly increase the rate of climb becoming overdamped and harsh over big motions and bumps. A progressive damping curve on a car would be an extreme rarity and I can't say that I have ever seen such in my nearly 25 years in the business. Some cars and specific suspension designs (typically not struts) prefer a more linear damping curve meaning that that the rate of climb is relatively even across the piston speed range and typically have pretty limited initial low speed damping forces. Some relatively linear damping examples are a number of BMW rear shocks that are mounted well behind the axle and trailing arm with an overdriving or more than 1:1 motion ratio. Progressive rates can very often be a very good thing for performance car springs but would be a bad thing for performance car damping. Progressive springs and digressive damper valvings can be very well matched, especially when adjustable.
  6. Those white plastic rings are called "bump plates" and they are intended as an extra layer of protection for the piston rod seals for when the car compresses fast enough for the bump rubber to make contact with the end of the damper body. The bump plates have two different designs, one a closed ring with a somewhat waffle shape and the other are flat and C shaped with a gap in one side. Because bump rubbers are round, fast moving, and soft to compress, it is defintiely possible for a bump rubber impact to the top of the strut to drive a puff of compressed air and possibly some road grit into and past the seal lip and into the damper. The waffle or C shape gives a path for this to just blow out to the side and help protect the seal that much more. Because KONI dampers are expected to last a very long time, some extra seal protection can be helpful for longevity. After tightening the gland nut, the first step of reassembly is to just drop the bump plate ove rthe piston rod then reinstall your bump rubber, dust cover, etc. The Miata forum thread calls the bump plates "packers" which is a relatively common name from the Oval Track Racing world where you might stack several of them to make bump rubber contact happen sooner for a number of possible reasons but you also risk handling and tire grip issues as well. The comment about them being related to an old, multi-piece style of piston rod seal is something that the poster has made up themselves. Yes, in the early to mid '80s there was a change in the seal design (I talked about ti earlier in this thread) but bump plates having some involvement with that is just someone interjecting their own assumptions. I have explained the bump plate installation and usage many times over 23 years but never heard that one before.
  7. Hello All, sorry for the late response. I was away from the internet and emails for most of three day Easter holiday with family so I am just getting caught up to a flurry of activity here. Issues of the last few days: Oil in the strut housing around the insert is always a good idea but it does not really matter what type oil it is. The benefits are twofold, although one is real world and the other a bit more theoretical. As mentioned in posts above, some type of oil between the raw steel inside of the strut tube and the outside of the insert can reduce or eliminate the chance of rust forming between the two and making it very difficult to remove the strut insert from the housing many years down the road if any service or replacement is ever needed. Any kind of spare oil will do just fine so leftover used engine oil, any gear or motor oil left at the bottom of an open bottle, etc. will do just fine. Anything to fill the void so that water or moist air cannot accumulate and start to rust the internal surfaces. I do not recommend anti-freeze as it is water based and will very likely start to rust and make insert removal much more difficult. The more theoretical benefit is potentially improved from inside to outside heat transfer but honestly unless you are trying to race off-road with extreme sustained piston speeds and heat generation, there is no need for cooling the insert for its own function. When we had the KONI Challenge road racing series, we found that there was more wheel well heat generated from the brakes and hubs that might spread into the strut than there was heat inside the strut that needed to dissipate out. Regarding the fitment concern on Nils’ front struts, I think there may be an internal lip or edge that it is catching on and not letting it drop all the way to the bottom. These inserts are exact dimensional matches to the earliest KONI 86 series red strut inserts that were offered from the beginning. I checked old ‘70s KONI catalogs that simply state “1970-1974”so there was no exclusion for super early production strut housings or a later start-up date. I think Nils’ situation is an anomaly and exception and not the rule so they can get a deeper look on a case by case basis. If someone does have an issue, please let Joseph or KONI know.
  8. It is a good example of how these cars are regulary upgraded with more modern wheels, tires, springs, bushings, etc. that many people use today. Each of those steps takes some compliance out of the suspension's motion and sharpens the feedback up to the driver and passenger. These cars will normally use a slightly higher initial rebound damping adjustment setting than will a truly stock car with softer springs, taller sidewall tires, etc. might. The stock cars will normally be adjusted to at or near the full soft adjustment setting and the modified car will likely have a higher initial setting however it will rarely be even halfway into the full available adjustment range. This helps show that the new KONI Sport option meets its goal to cover a broad range of enthusiast Z-cars, whether fully stock, upgraded with modern parts but still needing a very streetable characteristic, or for even more aggressive cars for autocross. track days, etc.. If we had fixed damper valving with no damping adjustment to help work with a range of stock or upgraded performance parts, then there would be greater concern about needing multiple strut part numbers to cover the range of cars. Being adjustable lets the car owner match to his own upgrades, handling and ride preferences, local road conditions, weekend competition goals if any, and also compensate for long term wear.
  9. I don't have a Z-car damper readily at hand to check one but most KONIs have a roughly 2.0 to 2.25 turn adjustment range from the stop at full soft to the stop at full firm. Depending on any minor stack height difference of the internal valving components used in that application, there is some possible variation but rarely does it go less than 1.75 turns or more than 2.50 turns. Because all KONIs have greater than 1 full turn of adjustment, having external numbered markings like the Tokico would not work.
  10. Thanks for the review and feedback, Ian. For clarification on knowing where your KONI adjustment settings are, just use the physical hard stop at the full soft setting (clockwise until it stops) and then the number of full or partial turns counter clockwise up from that point. Example: Full soft, 1/4 turn from soft, 1 1/8 turn from soft, etc.. This is always repeatable and easily matched side to side, front to rear if desired. In general most people probably use 1/4 turn adjustment increments but you can do larger or smaller increments if you want. We have a highly respected and picky BMW tuner whose recommendations go to the 1/16th of a turn. If you can discern judge that small an incremental change in your car, more power to you but most people are probably more in the ¼ turn range. Unlike the Tokicos that had only 5 defined adjustment settings, the KONIs can be adjusted to many more settings across a larger overall adjustment range min. to max. with broader affect across the working piston speed range.
  11. The new Z-car KONI Sports are a perfect drop in, easy fit to the factory Z-car strut housings so there is no need for any modifications to make them fit. The KONI RACE inserts are not Z-car specific but are a generic fit-all insert valved specifically intended for racing usage with a range of dimensional options in a wide range of cars including Mustangs, Porsches, Nissans, Mazdas, etc.. There are a number of vehicles that really respond well to the RACE valving but the factory strut housings are very tight such that one might need to take extra efforts to increase the ID of the strut housing (hone or bore) or decrease the OD of the RACE inserts (sanding down paint, etc.). If the car is a dedicated racing car, the extra effort to fit the KONI RACE into a Z-car is worthwhile and has been proven with a number of championships. If the car is used for the normal and performance street driving, autocross, track days, etc. but not up to the level of racing with very high spring rates, the KONI Sports are the right answer. Also, the KONI Sports do carry the full normal KONI Warranty because they were made for street use on that specifica car whereas the KONI RACE carry no warranty because they were specifically designed for racing on a wide range of cars.
  12. With the adjustable KONIs, you are adjusting the rebound (the upward stroke) damping forces generated when oil flows through the piston (the "plate" you reference) valving. By turning the knob higher or lower, you are closing or opening piston rod orifices and increasing or decreasing spring preload holding valves closed against the piston blocking other piston orifices. This provides changes in damping force from the slightest piston motion through very high pistons speed and lets the KONI Engineers finely contour the damping curve for optimizing both control and comfort. The lower the adjustment setting is, the more open or less restrictive the damper valving is and the softer the damping force is. That means you have less motion control but that doesn't necessarily mean that you have a softer or more comfortable ride quality because sometimes insufficient control can provide an uncomfortable ride quality.
  13. The 80 psi gas charge that you saw in the damper does not equate to an 80 psi increase in the spring rate, it doesn't work that way. It does add some quite limited preload boosting effect in conjunction with the preloaded spring rate when the weight of the car is loaded onto it and the damper gets closer to full compression. In the past I have heard engineering generalizations that internal Low Pressure Gas charge effect might have some similarities to a 7-8 psi spring rate increase but even that is not exact because it doesn't really work that way between gas charge and spring rate. I definitely disagree that one should try to change your spring rate or installed length to compensate for internal gas charge, especially when there are so many ways throw off ride height measurements. The most common that we see is taking measurements before the car has had an opportunity to move enough to settle from being raised in a droop situation, or from tightening control arm and similar bushings when in droop then putting the car on the ground with some lifting effect og bushing wind up in it. There are certainly others but those alone can cause measurements to be unintentionally off by greater amounts than the gas charge itself alone. I do not have any records to see if the factory Z-car dampers were originally LPG or non-gas charged so we don't know if there gas any gas effect or not in the factory info. That doesn't really matter though. If the limited effect of the LPG charge is still bothering you so much and you feel that you absolutely must must must have a non-gas charged, one could pretty easily degas the dampers oneself. This is a trick that has been used for years (only in a T-T LPG, not M-T HPG!) in Stock/Street class autocrossing and can be beneficial mostly on slight weight, light sprung independent suspension cars that get some camber change with ride height change. I am not going to explain how one would degas them on a public forum for a host of reasons but it can be done with no ill effects. Technically this could put your warranty at risk but the damper's actual function or longevity will not be altered if done properly.
  14. KONI is not outsourcing any services. We handle our warranties internally (replacement with brand new dampers when possible) and we still build our own prototypes and our own internal damper work as needed. We no longer offer automotive damper rebuild/revalve services to consumers directly ourselves because far less than 0.1% of KONI dampers ever get serviced and there are three independent outside companies who have decades of experience at it. It's just like an independent auto mechanic shop servicing someone's car except that we first require significant training, tools and component parts for them to be authorized. When we offered it, complete dyno testing was usually about $30 each to cover the time required for testing and that was waived if the there proved to be an issue that required internal service work. Since your stated that your adjusters are stuck, I would see no use to dyno test them because we already know that some internal service would be needed to get them fully functional. If the adjusters are stuck because the damper bottomed internally (similar to bending engine valves by hitting piston tops if you break a timing belt in an "interference" engine), then the ends of the piston rods will be bent and the compression valve cartridges will be damaged. Replacing those parts would further raise service costs far above the price of brand new. Its all about the best balance of time and money to get to your desireed end result. Making a KONI warranty claim is something completely different and not connected to having your existing dampers serviced by one of the outside shops. If you meet the warranty criteria (which it sounds like you do since you bought them new and still have the car), then we can start a warranty claim by using that link posted above to get the shocks inspected to see if the issue is warrantable or not. Once inspected and the trouble root issue is identified, then we follow the best path for resolution from there.
  15. A. There is no longer a KONI North America Automotive damper service facility as it was integrated into our Railway shock service facility several years ago. There are 3 outside businesses that are authorized KONI Automotive rebuild facilities in the US and their info is listed in the right side column of this link that can do testing and service for you: http://www.koni-na.com/en-US/NorthAmerica/Locator/ but you will have to pay them for their work. The Datsun Z strut with the attached spindle (used sometimes on ‘70s cars like RX7, 2002, etc. but rarely used since) is neither common nor simple so most companies with shock dynos do not have proper fixtures for strut housings, much less ones with spindles attached. We have a special dyno fixture for inserts which must be compressed within an outer structural shell for testing but that is very uncommon outside a company like ours. B. If you bought them brand new and have a purchase receipt in your name, have a current vehicle proof of registration still in your name, and there is an identifiable internal manufacturing or materials defect in the damper that is causing the problem, then it certainly is a candidate for warranty replacement for as long as you own them. Because those dampers were discontinued 25+ years ago, that causes some complications but they can be addressed. The warranty does not transfer to a non-original KONI purchaser, if sold on the car to a new owner, does not cover non-defect damage caused by external means (bottoming damage inside from hitting something, incorrect installation or usage damage, etc.). In my 20+ years of experience, stuck adjusters are almost always of external cause and not internal defect cause. It could theoretically be stuck from a defect cause but that is extremely rare and also extremely unlikely to happen to all four of the dampers in a single car set. Your comment about having them tested and possibly serviced made no reference to defects or warranty so I commented based on that. If someone is going to pay for service to be performed, the labor and parts cost will almost always cost more than a brand new one if an off-the-shelf modern replacement is available and you do not need a customized unit for racing, special needs, etc. If the above warranty info fits your situation, then KONI North America will be happy to address it that way. Most people 30 years later likely don’t fit that so a modern updated version is often the cheaper, faster, and better route for the future.