KONI Sports for Classic Z's

[KONI Lee]

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.

[KONI Lee]

22 minutes ago, jonathanrussell said:

@KONI Lee....Also...one question from me regarding the new Koni / MSA Yellow offering. Some of us have noticed that when installing gas charged strut inserts on our cars, compared to non-gas charged like the Koni Classic, the ride height rises an inch or so.

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.

[Jason240z]

What spec springs are these designed to work with? The softer/long US market springs?

[jayhawk]

On 2/7/2019 at 5:25 PM, Zed Head said:

....  Today's world is littered with old well-known brand names on low quality parts.

You mean like these, recently removed from my '73?   <grin> 

(this brand name was well known in the '70s and 80s, but has now disappeared completely)

[KONI Lee]

1 hour ago, Jason240z said:

What spec springs are these designed to work with? The softer/long US market springs?

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.

[gundee]

Looking at one of my old Koni's and I do mean old, it shows 8641-1031

and underneath that it reads 8703.

I am going to call to see if I can send in all 4 to be tested. The adjustments seem to have quit working.

My version.

Edited February 14, 2019 by Lumens
add photo

[NVZEE]

5 hours ago, jayhawk said:

You mean like these, recently removed from my '73?   <grin> 

(this brand name was well known in the '70s and 80s, but has now disappeared completely)

https://www.classiczcars.com/forums/topic/61602-mulholland-shocks

 

Edited February 14, 2019 by NVZEE

[dutchzcarguy]

Well.. Thank you very much Mr. Lee Grimes!   Here some pic's from the shocks i've got laying around in my (big?) pile of parts for z/zx..

 

Front shock 82-R1811

 

Rear shock 82R-1812

 

 

 

front shock

 

rear shock

Edited February 14, 2019 by dutchzcarguy

[dutchzcarguy]

As said earlyer, these Koni's are new old stock.

I've heard that these were the shocks that where used in the south african rally cars?

About my spring pic..  I'm 98% shure it's the Original Datsun 280zx 2+2 1979 (rear) spring..  I think technicians can tell what type of spring it is using the 2 colored spots on them, if someone could explain more i like to here it!

[Carl Beck]

2 hours ago, dutchzcarguy said:

As said earlyer, these Koni's are new old stock

....  snipped..cjb...  I think technicians can tell what type of spring it is using the 2 colored spots on them, if someone could explain more i like to here it!

 

The different colored paint dabs help identify the Spring Rates, as well as the position on the car.  I don't have the information for the 280ZX, but as an example see: http://zhome.com/240ZSprings/EuroSpecSprings.htm

[dutchzcarguy]

17 minutes ago, Carl Beck said:

help identify the Spring Rates, as well as the position on the car

Nice Carl, Thanks.. So the 240z has 2 different spring rates in the front.. i learned something! ?

[KONI Lee]

6 hours ago, dutchzcarguy said:

 

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.