Diff ratios

More
01 Jul 2019 03:33 #21 by Holmz
Holmz replied the topic: Diff ratios

outyonda wrote: have you felt the temp of shokysafter corrogations, single hot, dual warm.


I was thinking more of how it feels in terms of ride, not how the damper feels in temperature??

Does the extra dampening of the duals actually result in a better ride on the cooregations? And then if so, why not three dampers or four?

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 07:21 #22 by Alister McBride
Alister McBride replied the topic: Diff ratios
Did you actually read what i wrote Brett...? Your reply was covered.

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 07:22 - 01 Jul 2019 10:22 #23 by Alister McBride
Alister McBride replied the topic: Diff ratios
(Can someone delete this duplicate post please?)
Last Edit: 01 Jul 2019 10:22 by Alister McBride.

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 11:31 #24 by Harry
Harry replied the topic: Diff ratios
What a nice bull bar you have made Chris and so very easy to fit you are a credit to your profession these should be on everyone’s wish list I recon

Oka 045 the WIDE Motorhome 6bt cummins 500 watt solar diesel heating gas cooking up grade LSD front and rear diffs to 4:56 from 4:88 . 320 lt fuel 153 lt fresh water in 3 separate tanks 3 house batteries 1 start battery 176 lt upright fridge/freezer Black dog security
Attachments:

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 12:26 #25 by Alister McBride
Alister McBride replied the topic: Diff ratios
Would love to see someone lift the steel one like that! Only thing i changed on mine (versus original) was i made it with a pivot at the bottom so i could fold it down out of the way of the grill if i needed to get in there... bit of a pain otherwise, it's a bit weaker but more convenient. Chris definitely makes some decent products.

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 13:08 #26 by Holmz
Holmz replied the topic: Diff ratios

Alister McBride wrote: Would love to see someone lift the steel one like that! ...


If I saw someone lift a steel one like that I would be inclined to give them any lip... lest I end up with a fat lip.

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 13:14 #27 by Holmz
Holmz replied the topic: Diff ratios

Alister McBride wrote: After having one on the front and changing to two and experiencing both i would say from my experience two is crap on corrugations and bumps in general but better for 'race performance' around corners! Two just makes it stiffer in my opinion. Maths and engineering would suggest the same!. I haven't taken the second one off yet but will do when i get the time...


Thanks Alister!
I must have missed this earlier... but it seems like you observation is in-line with most engineering knowledge,

It is a conundrum to get a good road ride and a good corregation ride, but as I would like to have would like both... then I'll keep scratching the chin(s).

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 15:10 - 01 Jul 2019 15:12 #28 by Peter_n_Margaret
Peter_n_Margaret replied the topic: Diff ratios
Shockers suitable for a particular road surface will depend on the valving.
Twins with open valving could be the same as singles with more restricted valving.
And they have to be correct before you start comparing.
Maybe the optimum answer is twins with adjustable valving?
Certainly twins take less of a thrashing each and hence will last longer than singles

As an aside, we previously had an F350 4WD camper. It had parabolic front springs and literally ate shockers. On one trip I fitted a pair of new shocks immediately before a trip west from Adelaide. Before we had completed the Gun Barrel, they were stuffed and I had to buy new ones in the west. The vehicle was almost undrivable without good shockies.
The OKA on the other hand is incredibly kind on shockers and they last years. Twins also provide for some back up for when one fails.
Cheers,
Peter

Cheers, Peter.
OKA196 tinyurl.com/OKA196xtMotorhome
Mob.0428171214
Last Edit: 01 Jul 2019 15:12 by Peter_n_Margaret.
The following user(s) said Thank You: Holmz

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 15:53 - 01 Jul 2019 15:58 #29 by Holmz
Holmz replied the topic: Diff ratios

Peter_n_Margaret wrote: Shockers suitable for a particular road surface will depend on the valving.
Twins with open valving could be the same as singles with more restricted valving.
And they have to be correct before you start comparing.
Maybe the optimum answer is twins with adjustable valving?
Certainly twins take less of a thrashing each and hence will last longer than singles
...


All ^that^ Valving discussion seems consistent with my understanding.

Peter_n_Margaret wrote: ...
As an aside, we previously had an F350 4WD camper. It had parabolic front springs and literally ate shockers. On one trip I fitted a pair of new shocks immediately before a trip west from Adelaide. Before we had completed the Gun Barrel, they were stuffed and I had to buy new ones in the west. The vehicle was almost undrivable without good shockies.
The OKA on the other hand is incredibly kind on shockers and they last years. Twins also provide for some back up for when one fails.
Cheers,
Peter


What made the F350 "eat the shocks"?
Did they get cooked? Or over extended?, or slammed into the bumps and broke?


Looks like lots of possible paths from singles like the Tough Dog Ralphs over to dual shocks setups in the direction that Hal Harvey did with the Bilstien 7100s he had.

I am trying to find the best performance for mixed surface, which I believe translates into being able to change the valving like some sort of an adjuster...

The heat management and preventing known failure modes comes into play.

I am starting to head back towards thinking that dual shocks may not be the correct answer for corregations and bumps... but are probably just dandy in the road.
So if the dual shocks and cost for the mounting is not going to give an improvement then that could be money wasted, which could be going into some adjustable damper/shock...

And as usual this is ground gone over with lots of past posts, and chin scratchings.
But I have multiple finger tips and chin(s) :whistle:
Last Edit: 01 Jul 2019 15:58 by Holmz.

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 16:01 #30 by Peter_n_Margaret
Peter_n_Margaret replied the topic: Diff ratios
The F350 shocks aerated and overheated due to the lack of friction with the parabolics..
Cheers,
Peter

Cheers, Peter.
OKA196 tinyurl.com/OKA196xtMotorhome
Mob.0428171214

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 16:12 #31 by Alister McBride
Alister McBride replied the topic: Diff ratios
Holmz, double shocks should be fine for corrugations if you change the valving to standard rather than just doubling up on the same standard shock. Peter has a good point about adjustable damping shocks, i'm not really up with what options are out there and costs etc though...

Holmz see this thread for pics of my double front shock setup, was relatively easy to do... to get the benefit of durability of dual shocks you just need to reduce the damping rate:
www.oka4wd.com/forum/september-2012/15-s...ations?start=20#2616
The following user(s) said Thank You: Holmz

Please Log in or Create an account to join the conversation.

More
01 Jul 2019 16:37 - 01 Jul 2019 16:42 #32 by Holmz
Holmz replied the topic: Diff ratios
If I find some temp sensitive stickers - that change to record the highest temp, then maybe I'll send some out for a data gathering exercise...

I still like the idea of adjusting it firm when on the bitumen (around the race track), And then soften em up for the corregations.

Alister McBride wrote: Holmz, double shocks should be fine for corrugations if you change the valving to standard rather than just doubling up on the same standard shock. Peter has a good point about adjustable damping shocks, i'm not really up with what options are out there and costs etc though...

Holmz see this thread for pics of my double front shock setup, was relatively easy to do... to get the benefit of durability of dual shocks you just need to reduce the damping rate:
www.oka4wd.com/forum/september-2012/15-s...ations?start=20#2616


Thanks those look more economical than ones posted earlier on.
The earlier ones looked great, but would be a waste if I only need one damper/shock.
Last Edit: 01 Jul 2019 16:42 by Holmz.

Please Log in or Create an account to join the conversation.

More
02 Jul 2019 10:49 #33 by Alister McBride
Alister McBride replied the topic: Diff ratios
Need is a strong word Holmz... Most of us probably don't 'need' an oka or especially 'need' to play with them mechanically but we do. Single shocks are fine but can break the mount and/or wear out a bit faster but as Peter said above not in any significant way. If you want to take it a bit further and have a bit of a fiddle mechanically go dual shocks... I would definitely suggest it for the rear as it has extra load, but again not a 'need'.

Please Log in or Create an account to join the conversation.

More
02 Jul 2019 18:19 - 02 Jul 2019 18:33 #34 by Holmz
Holmz replied the topic: Diff ratios
Yeah I agree it is just a first world "need". ;)

The minister of finance is fairly rational and says, "you should be disinclined to have a spend up on a modification that ends up making it worse."

The last time it saw scales the front was at 2.4t and the rear at 2t.
It was not overly happy on bumps, but I'll branch off my ravings to a different thread if I encounter any wisdom not previously uncovered.
Last Edit: 02 Jul 2019 18:33 by Holmz.

Please Log in or Create an account to join the conversation.

More
03 Jul 2019 21:41 #35 by Outback Jack
Outback Jack replied the topic: Diff ratios
Other reason for dual shocks was to help reduce body roll.

One of the guys who helped do engine conversion on Hals OKA, had a fair bit to say about OKA setup. Couple things that stuck is twin shocks should be valved differently and that OKA dont have a lot of distance between bump stops. Saying with a long springs OKA have, he thinks there should be a lot more of distance between bump stops at the front. A lot of OKA`s are getting round with bent bump stop brackets up front.

Please Log in or Create an account to join the conversation.

More
04 Jul 2019 06:51 - 04 Jul 2019 06:55 #36 by Holmz
Holmz replied the topic: Diff ratios

Outback Jack wrote: ...
..
One of the guys who helped do engine conversion on Hals OKA, had a fair bit to say about OKA setup
....


Was that Dr RC or the fellow in the gold fields? Or someone else?

Outback Jack wrote: ...
Couple things that stuck is twin shocks should be valved differently and that OKA dont have a lot of distance between bump stops. Saying with a long springs OKA have, he thinks there should be a lot more of distance between bump stops at the front. A lot of OKA`s are getting round with bent bump stop brackets up front.
...


And... we put in a 1" springs pins to solve the effect that causes the bent bump stops? :whistle: :whistle: :whistle:

Outback Jack wrote: Other reason for dual shocks was to help reduce body roll.
...


Spring rate also affects body roll.
Damper affect transient roll rates, but parked on a hill sideways is all spring rate, theoretical roll centres and centre of mass.

It is uncommon to not even have a roll bar.
Last Edit: 04 Jul 2019 06:55 by Holmz.

Please Log in or Create an account to join the conversation.

More
11 Aug 2019 13:56 - 11 Aug 2019 14:05 #37 by Harry
Harry replied the topic: Diff ratios
Oka 045 now has long range steel fuel tanks from Chris in Kununurra and I got 1002 km out of one tank and used 161 liters .. the tank holds 169 liter of diesel I ran the 6bt with an waste gate turbo “ No intercooler “ and a 3 inch exhaust the Oka weight is 5.6 ton perhaps a little less as Jenny has all but drank the stock of red wine . I ran the Oka exactly at 1900 rpms which is 92 / 95 kilometers per hour the boost was was between 4 and 6 pounds and the Egt was 300 to 320 the outside temperature was 35 degrees in the shade and the radiator temp stayed at 83 degrees this is with the 4:56 diffs and 19.5 x 70R x 305 hankook tyres and a very good head wind this also included starting and stopping for morning tea lunch and afternoon tea for 3 days ...
The next day with no head wind old 045 got 450 km and used 71 liters of diesel .... I am real happy with that
I think for me going 456 diff ratio was a good move
Again thank you Paul and Ian for doing such a great job on the Machanic s and Chris and H for the bull bar and tanks and steps at least Chris I gave you something different to do rather than the same old same old cheers

Oka 045 the WIDE Motorhome 6bt cummins 500 watt solar diesel heating gas cooking up grade LSD front and rear diffs to 4:56 from 4:88 . 320 lt fuel 153 lt fresh water in 3 separate tanks 3 house batteries 1 start battery 176 lt upright fridge/freezer Black dog security
Last Edit: 11 Aug 2019 14:05 by Harry.
The following user(s) said Thank You: Dean and Kaye Howells, Holmz

Please Log in or Create an account to join the conversation.

More
11 Aug 2019 14:28 #38 by Harry
Harry replied the topic: Diff ratios
Old 045 with a No intercooled waste gate turbo Dodge Ram 1992 Oka weight 5.5 ton give and take a few liters of red wine
It has 4:56 diffs
I did 1002 km and put in 161 liters of fuel the tank holds 169 liters thanks Chris from Kununurra
I had a good head wind for the three days
Outside temperature was 35 degrees
Radiator temperature day on 83 degrees
The Egt sat on 300 to 320 degrees and the turbo boost was on 4 to 6 pounds
That was starting and stopped for morning tea and lunch and afternoon tea for the 3 days
On the next day I did 450 km and used 71 liters but no head wind the temp and boost stayed roughly the same as it was a little uphill
For me the 4:56 diff ratio with 19.5 x 70 R x 305 are a perfect match
In all road conditions as we did around 3000 ks of 4w driving in this trip
Thank you Paul and Ian for your Machanic s and a great job you both have done for me
And Chris for your great work on tanks bull bar and steps

Oka 045 the WIDE Motorhome 6bt cummins 500 watt solar diesel heating gas cooking up grade LSD front and rear diffs to 4:56 from 4:88 . 320 lt fuel 153 lt fresh water in 3 separate tanks 3 house batteries 1 start battery 176 lt upright fridge/freezer Black dog security
The following user(s) said Thank You: 210greg

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum