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KONI Lee last won the day on February 11

KONI Lee had the most liked content!

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About KONI Lee

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    Active Member

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    Hebron, KY
  • Occupation
    KONI Automotive Product Manager

My Z Cars

  • Zcars Owned
    Z fanatic but no car right now
  1. KONI Lee

    KONI Sports for Classic Z's

    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.
  2. KONI Lee

    KONI Sports for Classic Z's

    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.
  3. KONI Lee

    KONI Sports for Classic Z's

    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.
  4. KONI Lee

    KONI Sports for Classic Z's

    Looks like Week 3 (January) of 1987 production. Being the 8641 prefix, they are the externally rebound adjustable, twin tube low pressure gas version that were made for a few years in the 1980s. I believe that the 8641 versions were likely made primarily (and maybe solely) for the North American market and likely even built in a US factory in Virginia that operated from about 1982 through 1989 or so. If the adjusters are not turning (probably from jamming by hand or impact tool or internal bottoming most likely), then dyno testing them will be of no value and wasted money and time. Additionally, whomever tests them will need to have a dyno with fixtures to hold the Z-car's uncommon spindle attached strut housing. They could likely be rebuilt but it would actually be much cheaper, faster and have a full warranty if you were to simply purchase the brand new ones from Motorsport Auto. You would be much farther ahead to start with fresh ones than pay the labor and parts to fix the old ones which would still not be entirely new. It is definitely less expensive per unit to build new in a large production batch than rebuil;d them onesy-twosy paying for labor and parts.
  5. KONI Lee

    KONI Sports for Classic Z's

    Actually this photo shows that you have one each of the early, older generation seals and guides (fronts) with integrated gland nut threading and the later design (rears) with the different guide, modern Viton seal and a separate gland nut. What is interesting to me is that the 1980 date code on the newer design means that they must have started that conversion earlier than I'd thought. Since there are no 40ish year employees left from those days before major computerization, there is little to no record keeping and archives showing exactly when things happened. I'm pretty sure that happened over a period of time.
  6. KONI Lee

    KONI Sports for Classic Z's

    Any spring that you want to put on it, from any soft OE springs to any much higher rate aftermarklet performamcne lowering springs. As you increase spring rate, you need a little bit more rebound damping but it is a non-linear relationship so often doubling or higher the spring rate may only require a 20-30% rebound damping increase to control excess oscillation. Since these KONIs have a roughly 100% range of adjustment, they will work well with about any spring from stock to quite aggressive that you might use. You simply turn the knob adjustment a little higher to meet your ride and handling preferences for your car, roads, modifications, etc. There are many variables involved beyond comparing simply spring rate and damping rate so your being able to tune to your own preference and usage is the best answer. As I stated in the first post, most people will find their preferred adjustment spot in the lower half or less of the adjustment range for normal to aggressive street driving when new.
  7. KONI Lee

    KONI Sports for Classic Z's

    The new MSA Sports are twin-tube low pressure nitrogen gas charged (8641 prefix with the 4 indicating low pressure gas charge) and the Classics are 86 (twin-tube hydraulic non-gas charged). Generally an increase in internal gas charge can have a pretty minor if any increase in static ride height and can vary from car design to car design, I think your 1 inch comment might be overestimated as most cars are more likely to see 1/4-1/2" difference with several variables involved. Any static height changes are going to be related to a mix of things including the amount of gas charge itself (from zero gas charge to low pressure gas charged (3-5 Bar usually) to a mono-tube high pressure gas charge (10-20 Bar usually) in addition to vehicle weight, spring rates, damper piston rod diameter (effect is more on a large rod diamete, less on a small rod diameter), suspension geometry, etc. How well and consistently you make your before and after measurements and do the installation may likely have a greater impact on a height change than actual internal gas pressure difference. KONI is one of the few companies who makes all three different shock designs (T-T non-gas, T-T LPG & M-T HPG). Very few people understand what internal nitrogen gas really does or doesn't do in a damper however the gerenal public's limited info perception (mostly old ads from mass market, commodity shock brands) is usually that gas charged is better than not gas charged so often we will include a small gas charge to satisfy that "Is it a gas shock?" question if we don't have the abulity to discuss it technically. In fact, we are working on a KONI video script now addressing the very common misconceptions of gas charging or not.
  8. KONI Lee

    KONI Sports for Classic Z's

    The red KONI Classics that have been made in the last roughly 20ish years are the much younger siblings of the very old set that I discussed just above. Their part numbers will be 86 1811 and 86 1812 (for 240Z/260Z) and have the modern seals and low friction guides and pistons and 86 strut insert part number prefix that I discussed. These were out of production for many years but it was revived in the mid '90s when the car saw a popularity rise including Nissan's official revival/rebuild program on some early cars. They have stayed in low volume, limited availability since then. They are the internally adjustable (compress-to-adjust off the car) version so they are not as friendly to adjust for general tuning, going back and forth for street, autocross, & track day use, wear compensation, etc. Their valving is a bit softer (but certainly not a "soft" damper) than the new Sports that we have just developed with Motorsport Auto. These were of twin-tube hydraulic (non-gas charged) design so they won't self-extend if you compress them off the car but that has no relation to actual damper function on the car.
  9. KONI Lee

    KONI Sports for Classic Z's

    You were told the correct era for those particular parts. The 82R prefix tells us they are early strut inserts used before KONI made many major part number and component updates in the 1982-1984-ish era. Early on, 82 could mean shock, full strut, or strut insert. After the changes, all strut inserts were called 86, full struts were called 87 and 50-55mm OD body shocks stayed as 82s. The alphabet letter was dropped at that time too. So the red Z-car inserts after the mid 1980s would have been called 86-1811 and 86 1812. There were many internal upgrades during this time period as I alluded to above. The only externally visible major difference is the piston rod guide and seal assembly where the chrome rod goes into the body. The old style like yours will have a couple concentric rings visible on the end of the insert and usually a couple tool slots in them that created pressure on the old seal system of stacked felt and rubber rings. The newer design used since the mid-80s is flatter and has fewer concentric rings and a longer lasting, better sealing Viton oil seal in addition to newer bronze guides with Teflon and other low friction coatings to reduce friction and wear long term. So your 82R-1811 705 would be from 1977 Week 05 or early February production. Your 82R 1812 007 would be from 1980 Week 07 or late February production. Both will have the older guide and seal system and may not last the longest now 40 years later and not have the low friction updates. The Special D was a product designation for all red painted KONIs, the main color KONI used until they diversified in the 1980s to include yellow paint (KONI Sport) and much later black (KONI Classic), bright orange (KONI STR.T), and gold (KONI FSD). The red is also now used on other truck and car product lines are well. I have no info on your spring pic because it has no KONI connection. They could be either OE or some aftermarket springs but they are not a KONI spring that I have heard reference to in my 20+ years here. KONI has dabbled off and on over the decades with selling damper & spring combo packages, more in the USA than in Europe. Hope that helps some.
  10. KONI Lee

    KONI Sports for Classic Z's

    Yup, KONI has always been a Dutch company, founded in 1857 as a horse saddlery in the little town of Oud Beijerland, about an hour south of Amsterdam. The main factory/world HQ is still located in the same town about about a mile or so away from the original saddlery, which is now a museum. There is a 3 or 4 digit manufacturing date code stamped into those old KONIs right near the part number. If you are interested and want to get me that number, I can tell you how old they are. There were major technology updates (mostly friction reduction and longevity extending) to the pistons, seals and top guide bushings in the early to mid-'80s so yours could be from before or after then. It would almost certainly be possible to service your old ones however done individually the labor cost with parts would probably be higher than buying brand new ones that have all new parts, the full warranty, and features.
  11. KONI Lee

    KONI Sports for Classic Z's

    Hello all, my name is Lee Grimes and I am the Automotive Product Manager for KONI Shocks. I have been working with Greg and Joseph to get these new Z-car parts to market and help answer some questions. He pointed me to this discussion to maybe give some clarity or assistance. I won't be able to stay as a regular contributor but I will be happy to check in for a little bit to help people understand the new parts. A bit over a year ago, Motorsport Auto came to KONI to see if we could revive and modernize our offering for the early 240Z, 260Z, 280Z and 280ZX. Needless to say we jumped at the chance to offer proper products for these important cars. Off and on through the years KONI has offered the tradtional red painted KONI Special strut inserts with internal (off the car) adjustment for 240Z through 280ZX. In the late '70s-and early '80s KONI also offered an externally adjustable version for these cars excluding the ZX but they were discontinued by the mid-'80s. Now was time for an update. With Motorsport Auto as an exclusive partner stepping up to take full production run volume, we developed and tested new externally rebound adjustable (knob adjustable on the car) yellow painted KONI Sport strut inserts for these cars and a externally adjustable rear shock for the ZX. We started with the external adjustables from the 1980s as the launching point and even used the same part numbers this time with the SPORT suffix in the part numbers. We then updated the internals a bit (it was no slouch to begin with back then though) to more modern seals and guide components and set the valving to work well with either factory stock springs (starting baseline adjustment at or near full soft) or performance lowering springs for perforamnce street, autocross, track day, etc. use (starting baseline adjustment about 1/2-3/4 turn up from full soft setting). Like all KONIs, the adjustment range is about 100% so they are twice as firm at the maximum setting than at the minimum setting. This is a very large range of adjustment so we suggest that you start in the lower end of the range, drive it for a bit to get a feeling for it, and then tune accordingly from there for your ride and handling preference. I think it will be very rare that people will use more than 1 turn (about 50% higher than full soft) for normal use when they are new. Because the adjustment range is so large, it allows you to compensate for wear over extended time, tune it high for an autocross or track day, and then quickly turn it back down for street use. Because the range is so large, it is possible to overdamp the car for your needs and actually make it more harsh and have less grip than needed so do not just turn it way up figuring that "more is always better". Although these could be used for a dedicated track and racing car, their needs and expectations are different and we do have other racing options (e.g. 8610 RACE and 8611 RACE) where street handling and ride quality, high mileage longevity, etc. are no longer important. These new Z-car Sports are targetted to take you from stock Z- car to just shy of all out racing. They carry KONI's limited lifetime warranty against defects and materials to the original purchaser as long as tht person owns the car registerd for street use. Regarding the discussion about bump rubbers, you can use a good condition OE type bump rubber for a Z-car, one of the black urethane ones that Motorsport Auto sells, or the KONI Racing Silastic bump tops made for use on a 22mm piston rod. KONI does not have a specific bump stop length suggestions as different ride heights and springs will determine what length you need. The imporant part is that you have some bump rubber installed to keep the strut or shock from bottoming out internally which can cause internal damage that will cause loss of function and will not be covered under warranty. The first production runs of the fronts and rears for the 240Z, 260Z, and 280Z are currently in-transit from KONI in The Netherlands due in mid-March. The 280ZX fronts are in-transit as well but the 280ZX rear shocks are awaiting final production due to to different compponent sourcing but will be here ASAP. Please be clear that these were specifically developed only for these Z-car applications and they are not crossovers from ome other vehicle. Because these parts are exclusive to Motorsport Auto and no other KONI dealer has access to them, we will not be listing these part numbers on our official KONI websites for North America www.koni-na.com or Europe www.koni.com. If you have any questions, pelase contact our Technical Staff at info@koni-na.com or 859-586-4100 Option 6 from M-F 8-5 Eastern time.

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