Thread: Koni shocks long travel?

Originally Posted by PhilipA

I do not think shocks care where they are in their travel, except for "sensaride" types which have some grooves cut in the middle area.

I don't think anyone suggested that the dampers cared where they sat, what I was alluding to was that the balance of bump to droop had been altered, and this can have a significant impact off road as by fitting taller springs with stock length dampers you will be more inclined to start lifting wheels when articulating. I feel it's a sure fire way to lose traction.

I always wonder about the longevity of long shocks without moving the mounting points.
I have seen Ranchos with the top mount ripped out, which I attribute to crappy shocks and maybe long strong springs.This is opposite of what we are talking here.

Rancho are just crap. The top eyes aren't big enough to allow for a decent size bush on the rear of a Landy, and they are only attached marginally. It also doesn't help that the top mount is sitting at the wrong angle on Defenders or anything that is lifted.

If you put on a 2 inch longer shock the mounting points should be moved apart by 2 inches, or the bump stop moved down so that he shock does not bottom. This of course takes your travel back to standard!!! LOL

No. The mounts should be altered depending on the compressed length of the damper. This varies wildly from brand to brand and type to type. Obviously a mono-tube damper with an integral gas reservoir has a longer compressed length than a twin tube damper for an equivalent stroke. If a longer stroke damper is mounted so that it doesn't go metal to metal at full compression of the bump stop, why won't we have more droop travel ? (as long as the suspension doesn't bind up elsewhere )

I will bet a standard shock will bottom out after the bump stop is full compressed,so it is protected. You can be misled by compressing a shock , and comparing it to an uncompressed bumpstop.

yes.

I have never seen anyone analyse whether there is room for longer shocks with the standard mounts. Has anyone removed the springs and cycled the suspension to the bumpstop, and then seen how much travel is left on the shock?

Didn't know you where omnipresent. I'll be more reverential in future........

There should be about 25MM to be safe. Any longer shock and this must be prejudiced.

Yes. I only allowed 20mm, it was 5mm too short.......

I am interested in this, as itis a cheap way to get extra articulation, but I suspect not as simple as it seems.
If you look at a D2 which has longer travel shocks, you will see that the bottom mount is moved down, compared to a D1/RR.
Regards Philip A

it's not very complicated, it just takes a little analysing and measuring.

Off the shelf Koni's are not suitable for any lift according to Toperformance when i got a set for my rangie but i used them with a 2" lift in 2 vehicles with no adverse effects and are still good in my current disco.

I think this is all getting a bit above my head, but i understand the basics of what you're saying. But now that people are talking about moving mounts, what about this...

If i was to put (eg) a 2" spring lift in, and then space the shocks off (ie. compress them) by 2", they would be sitting at the same position as before and have the same travel in each direction. Is this correct? Obviously, there would be not much more travel, but there can't be any less...

From looking at the mounts, it looks like a 50mm block (a bit like a body lift block) under the rear shocks and above the front shocks would do the job. The block would be tapped top and bottom to take the shock "pin" and a bolt thru the mount.

Am i dreaming? (read: should i just open my wallet and reach into my non-existent money pit to replace some perfercty good shocks!!!)

Originally Posted by loanrangie

Off the shelf Koni's are not suitable for any lift according to Toperformance when i got a set for my rangie but i used them with a 2" lift in 2 vehicles with no adverse effects and are still good in my current disco.

That sounds like what i want to hear.
Thanks.

Rick, from your answer you have done the calculation.
Is there room for a longer shock without moving the mounts or changing the bumpstop? And If so which shocks in your experience can be fitted. Rear mainly, but front also if the exercise has been done.

I was always nervous to try this with the car in my tiny garage as there was little room to move, and the car moved sideways a lot when you jack up one side with no spring. So I never completed the exercise. Also of course you have to consider the spring length, as if you fit a longer shock with a too short spring it will fall out if not retained.

I totally agree with you point about correct length being the compressed length, I was really being specific to Konis, as a dual tube shock.

I thought it was so obvious that he shock is sitting 2 inches away from the middle when you increase the ride height by 2 inches I took it as given, and only discussed the valving aspects. The Rancho point is about what can happen with a lift and strong springs with short shocks. I have also seen the top mount torn out of a rear Bilstien. IMHO this was caused by rapid extension such as a Jump.
Bulldog

You would have to measure whether you had a sufficiently short compressed length if you shortened the distance between the mounts or the shock would bottom and break, with the suspension compressed to the bumpstop.
Regards Philip A

Originally Posted by Bulldog

I think this is all getting a bit above my head, but i understand the basics of what you're saying. But now that people are talking about moving mounts, what about this...

If i was to put (eg) a 2" spring lift in, and then space the shocks off (ie. compress them) by 2", they would be sitting at the same position as before and have the same travel in each direction. Is this correct? Obviously, there would be not much more travel, but there can't be any less...

From looking at the mounts, it looks like a 50mm block (a bit like a body lift block) under the rear shocks and above the front shocks would do the job. The block would be tapped top and bottom to take the shock "pin" and a bolt thru the mount.

Am i dreaming? (read: should i just open my wallet and reach into my non-existent money pit to replace some perfercty good shocks!!!)

The problem is that the bump stop is still in the same position and on a bad bump the shockie will bottom out before the bump stop comes into play. This will destroy the shockies.

To get your droop travel back, with a spring lift, you have several options:

1. do similar to what you suggested, but lower the bump stops by the same amount as the shockie mount was moved, to prevent the shocks bottoming out. The bump and droop travel will remain standard. The springs may dislocate on full droop, if not retained.

2. Fit longer travel shockies and lower the bump stop by the difference in the compressed length of the shockie from stock. The droop travel will be greater, if the suspension does not bind. The bump travel will not be increased. The springs will probably dislocate on full droop, if not retained.

3. Fit longer shockies and raise the top mount so the shockie does not bottom when the axle housing compresses the bump stop. This increases both the bump and droop travel, which is better when longer springs are used for the suspension lift. IMHO, this is better for articulation off road. If higher rate springs of similar length were used, then you may rarely see the benefit of the increased bump travel.

Originally Posted by PhilipA

Rick, from your answer you have done the calculation.
Is there room for a longer shock without moving the mounts or changing the bumpstop? And If so which shocks in your experience can be fitted. Rear mainly, but front also if the exercise has been done.

at the rear, the only shock I'm aware of that will bolt straight up and give an increase in usable travel is one that fits the leaf spring rear GQ/GU Patrol, (Monroe 610mm/358mm, OE 550mm/350mm) but beware that a leaf spring places less demands on low speed rebound valving, and generally use less bump. I did an experiment on my 130 with some from the wreckers (Monroes), and eventually changed the oil to the heaviest I had (Silkolene Pro RSF 15wt) which just happens to be the heaviest shock fluid you can buy and the rear damping was still unacceptable with miles too much float (not enough low speed rebound) although the ride was nice and they performed ok on rough roads, but the main thing was to see what fitted off the shelf and these do, although the bottom pin is a bit too undersized for my liking. The valving will probably be acceptable on a RRC or Disco.
A GU coil rear shock may be a better bet using a pin to eye converter on the bottom and although I have a set of Koni GU shocks here I've never got around to trying them. I'll measure them up later, I can't find the numbers in my file.

Nearly forgot, a LC 80/100 Series Bilstein (B46-1478) is 591 open/380 closed and works fine inverted. That closed length may be a bit marginal, and the ability of the eye to stand up to the abuse of that dodgy stock mount could be an issue....
LRA used to sell an angle kicker, what looked like a taper wedge that went between the stock top mount and the chassis to correct the wrong angle.
<edit> I do have more open/closed lengths of different models/brands, but it was info mainly compiled over 5 years ago so may be a little out of date. I mainly concentrated on the front end as i felt that's where the problems lie </edit>

Fronts.
OE Whitehead ANR6598 is 546mm open, 328mm closed

From the open/closed lengths one of the fella's posted on OL it looks like the OME N73 (LC 80 series) bolt straight in to the front without needing the towers raised. Sorry, can't find the exact numbers, but I think open was around the Koni LC front, with the closed length being about 10mm shorter. It provided over a 10" stroke.

Koni 84-1189 is 568mm/342mm . This used to be the RR air susp. damper and was used by Toperformance and Proven Products as their long travel recommendation. I think this number may now be superceded. It's a straight bolt in.

Koni 82-2385's (LC 80 series) definitely need the towers raised otherwise they will go metal to metal. (617mm open, approx 370mm closed) I got away with just packing the towers 6mm and using thinner urethane bushes on the body side of the pins top and bottom (can't remember the exact thickness, they were ones I had here on the shelf. ) <edit> forgot to add that when using thinner bushes, the bottom pin needs to be shortened to avoid fouling the diff housing. memory is getting a little lost after five years</edit> The thinner bushes allowed for 20mm bump rubber crush, which wasn't enough. The internal rebound adjuster ears had a meeting with the foot valve. It wasn't pretty. The extra 6mm has solved the problem. Most blokes just raise the tower by 3/4" and be done with it, I was just trying to squeeze the maximum droop I could. It's surprising how often the bump rubbers are hit as my spring pads are pretty well polished and I'm using 220lb springs, were 17" free length new, but have sagged a little but still have over 105/110mm between bump stops.
As Max pointed out above, longer front shocks need different radius arm bushes to get the benefit, ie. Haultech slotted, otherwise you'll only end up with around stock articulation anyway. The other thing to watch is that with longer dampers the driveshaft will hit the front anti roll bar, so it would have to be removed. I found this just cycling the suspension on the jack when first fitted. At the time I was just going to run disconnects, unfortunately that idea was scuttled quickly and the front arb removed.

Brake lines also need to be replaced with longer ones if longer dampers/more travel is used.



To give you an idea of how much leeway there is at the rear, there are two versions of Koni's Raid damper for Defender rears, one for stock and one for lifted suspensions. (30-50mm) The 90-5401 is extended in body only so it is only standard stroke and I've seen no recommendations that extended bump stops be used .
Extended length is 607mm, closed 409mm. OE is 550/350 (centre of eye to base of pin)

I run the landcrusher 80 series bilsteins front & rear, valving is close enough. Git a little more travel, not much, but every bit helps. its been a trouble free conversion too, about 100,000 kms up now.

Packing out bumpstops is appealing coz its easy, but remember you're limited up travel. That's not good for stability when crossed up on sideslopes. Lifting shock mounts is better in this scenario.

Theres a good writeup of the OME shock options on expeditionexchange.

Regards
Max P