Oztec/Kings versus Dobinson Suspension

[Chris1972]

Hi all,
I’m new to the forum and have just purchased a PB Challenger. I’ve been looking to upgrade my suspension and have been reading these forums flat out.
My question is
Which is the better suspension (for me) out of the Oztec/Kings combo and Dobinson?
My wagon is stock std, no bull bar up front and no permanent weight in the rear. I often tow a boat with a ball weight of about 70kgs and occasionally a camper with about 80kg balls weight.. other than that, the wagon is empty 90% of the time.
The price difference between the two is $200 (Dobinsons are more expensive) but the mob fitting them up are only 15min from home and very well regarded locally. The guys supplying/fitting the Oztec Kings combo are over 2 hours away on the other side of Melb, so I’d be spending 4+ hours in the car for fitting plus 3-4hrs waiting around. Then I have to drive back again a week later for wheel alignment.
There seems to be quite a few members who are very happy with the Oztec Kings setup, but I can’t find much info (good or bad) about Dobinsons on the PB Challengers
Looking for recommendations and advice from the experts on this forum.

Cheers
Chris

[old Jack]

Hi Chris,

Welcome to the forum.

unfortunately there is not a "one size fits all" suspension upgrade that foes everything for everyone.

Actually being stock standard is a problem as it limits your options.
Before I can comment I need to know;
1. Are you planing yo fit any accessories that add permanent weight to the vehicle.
2. Are you after a suspension lift for off road purposes.
3. Are you want to carry or tow large loads, if so what?
4. Are you just looking at improving the handling of the stock suspension so the car is more road bias?

From my experience most suspension places tend to follow the manufacturers suspension bias where the front is firm and the rear is soft.

What are your expectations on ride, comfort, handling and load carrying ability?

OJ.

[Chris1972]

Thx for the reply OJ,
1. At this stage I’m not planning on adding any weight or fixed items.
2. I am looking for a bit of a lift, but mainly for looks. Most “off road” driving will be for accessing fishing, hunting, camping etc. No serious off reading.
3. No heavy towing for me. Camper gets used a couple times per year and I tow the boat about every second weekend, but this is only locally with just light gear for inland fishing.
4. Definitely looking for better handling around town and dirt roads.

Car has done 190kms, front suspension feels harsh and bumpy and rear feels like it floats all over the place. When I hooked the camper up the other day, the arse sagged quite a lot which didn’t surprise me.

As per some of your suggestions I’ve read in this forum I’ve had the KCFR-55T and KCRS-23 springs quoted along with the 54104 and 60090 shocks. Price is fair but distance to travel is a problem..
With the Dobinsons I haven’t looked closely into which springs/shocks to ask for, but keen to get your thoughts on what to select.
Cheers Chris

[old Jack]

Hi Chris,


What are your front and rear ride heights?
Measure from centre of wheel hub to underside of wheel arch in a vertical line, car needs to be parked on flat ground.

If you can post the part numbers of the Dobinson coils then I can look at this and compare them to the Kings.

OJ.

[nj swb]

I have Dobinson MRRs front & rear on my Pajero. When they work, I'm happy with their performance, but I've had my share of trouble with them, and I cannot recommend the "support" provided by Dobinson.

Go the extra distance.

[Chris1972]

Ok, ride heights are:
540 front drivers side
545 front passenger side
550 for both rears

When the camper went on the rears sagged to 510, and that was with the car pointing down the driveway.

Dobinsons supplier didn’t tell me exact part numbers, but I’m most likely looking at the C43-192 front coils and the C43-043V rear coils. Would possibly even consider the C43-045V rear coils if recommended.
Shocks are just their std twin tube gas ones.

Chris

[littleriver]

We have the oztech/kings lift set up

EBH
Approx unladen

570mm front
590mm rear
Here’s a write up I just found

https://www.whichcar.com.au/gear/suspension/oztec-outback-shocks-product-test

EBH
Fully loaded with rear seats down 2 passengers sits

550mm front
570mm rear
NB she looks level ... going by the side steps .... very pleased with results ( bash plates front on crossmember height went from 220mm to 250mm ) if my memory serves me correct ...

I don’t think you actually have to go back to that workshop a week later for a wheel alignment.. any other authorised workshop can do that for you, also inform them you just had the shocks fitted and ask them to check the tensions of all fittings ( keep receipts and measurements from alignment) ie send a copy to your email ... as we do with all our products and services ..

[Chris1972]

Thx Littleriver,
Can you tell me what model numbers are your springs?

[littleriver]

Thx Littleriver,
Can you tell me what model numbers are your springs?

KCFR-55 front

KCRS-23 rear ( don’t forget the pedders bump stops 5899)

....

[Giddyup]

I've got Dobinsons mrr shocks and wouldn't get them again. One front strut has a slow oil leak from new, looks like the shaft seal is letting some oil out. One of the rears has been rubbed by the sway bar.

Also have the c43-043v rear springs. Unloaded ride height was a bit over 600mm (too high) and they are firm. Though they are 200kg constant load, which is what you'd want for some sort of comfortable ride. Dobinsons suggested linear rate springs to start off with, though they are too short to be retained (not that Dobinsons cared).

Would like to know how the rate of these compare to the kcrs-23.

Ok, ride heights are:
540 front drivers side
545 front passenger side
550 for both rears

When the camper went on the rears sagged to 510, and that was with the car pointing down the driveway.

Dobinsons supplier didn’t tell me exact part numbers, but I’m most likely looking at the C43-192 front coils and the C43-043V rear coils. Would possibly even consider the C43-045V rear coils if recommended.
Shocks are just their std twin tube gas ones.

Chris

[old Jack]

I've got Dobinsons mrr shocks and wouldn't get them again. One front strut has a slow oil leak from new, looks like the shaft seal is letting some oil out. One of the rears has been rubbed by the sway bar.

Also have the c43-043v rear springs. Unloaded ride height was a bit over 600mm (too high) and they are firm. Though they are 200kg constant load, which is what you'd want for some sort of comfortable ride. Dobinsons suggested linear rate springs to start off with, though they are too short to be retained (not that Dobinsons cared).

Would like to know how the rate of these compare to the kcrs-23.

Sad that there are more MRR failures, only hoping my Dobinson MT do not suffer an early demise as my Bilstein/Lovells combination had 3 front strut failures in 90,000km.

Spring Data;

C43-043V Free Length 400mm Spring Rate 3.059 to 5.812 kg/mm.
C43-045V Free Length 410mm Spring Rate 4.079 to 6.628 kg/mm.

KCRS-23 Free Length 375mm Spring Rate 3.038 to 4.018 kg/mm.
KCRR-23 Free Length 395mm Spring Rate 3.038 to 4.018 kg/mm.
KCRR-23HD Free Length 395mm Spring Rate 3.661 to 5.179 kg/mm.


OJ.

[Giddyup]

Sad that there are more MRR failures, only hoping my Dobinson MT do not suffer an early demise as my Bilstein/Lovells combination had 3 front strut failures in 90,000km.

Spring Data;

C43-043V Free Length 400mm Spring Rate 3.059 to 5.812 kg/mm.
C43-045V Free Length 410mm Spring Rate 4.079 to 6.628 kg/mm.

KCRS-23 Free Length 375mm Spring Rate 3.038 to 4.018 kg/mm.
KCRR-23 Free Length 395mm Spring Rate 3.038 to 4.018 kg/mm.
KCRR-23 Free Length 395mm Spring Rate 3.661 to 5.179 kg/mm.


OJ.

Great info there OJ. Certainly confirms what it feels like. I suspect that the rate ramps up pretty quickly so the 'compliant part' of the spring is mostly compressed by the weight of the car.

[old Jack]

Great info there OJ. Certainly confirms what it feels like. I suspect that the rate ramps up pretty quickly so the 'compliant part' of the spring is mostly compressed by the weight of the car.

Without having a coil to measure I can only calculated the load a progressive rate coil will carry for a given compressed length based on a lineal progression in spring rate.

Rear coils on the Challenger, the 1st 3rd of the compression range is taken up by supporting the vehicle's weight and determines the unladen ride height. The 2nd 3rd of the compression range is the normal operating range when the vehicle is unladen or lightly laden. The last 1/3 of the compression range is for when the vehicle is at GVM and when operating in severe conditions. Fitting Peddar 5899 cones will substantially increase the last 3rd compression rates and protect the spring.


OJ.

[Chris1972]

Thx all for the great info. Has anybody had issues with the OzTec shocks? I’m starting to lean towards them, and will definitely be getting the Pedders cones. Another question? Supercheap Auto sell Kings springs and they are A LOT cheaper than what I’ve been quoted, and that’s before any trade discount.. Are they the same springs?
Chris

[old Jack]

Thx all for the great info. Has anybody had issues with the OzTec shocks? I’m starting to lean towards them, and will definitely be getting the Pedders cones. Another question? Supercheap Auto sell Kings springs and they are A LOT cheaper than what I’ve been quoted, and that’s before any trade discount.. Are they the same springs?
Chris

My Trade pricing on King Coils ranges from $145 to $185 per pair depending on what coil it is. Normal retail/online pricing is $180 to $260 a set and also online pricing may have freight extra!



OJ.