Fulcrum control arms for PC Challenger anyone done this?

[Ent]

Hi

Time to make a reappearance to the forum and drag DOOSO out of his slumber as Nephew is the proud owners of his Dad's old Triton looking for adventure.

The issue I have though is after setting DOOSO for the failed Simpson Desert run by making him taller is I am getting noticeable tyre wear on the outside edges of the 235 x 85 x 16" tyres. I am told that the Challenger has none or limited ability to adjustment to fix this but noticed Fulcrum does new control arms with some claim they can adjust for this. Not sure how?

Has anyone got experience with the replacement Fulcrum front control arms for Challenger or Triton for that matter?

My aging memory has forgotten the EBH on the the front is but I think it is maximum of the specifications plus five mm. 568 or 572mm tends to stick in the mind.

Oh yes, the suspension is performing brilliantly otherwise. The Drummond Motor Sport front end works a treat with steel bar and winch plus full set of three bash plates. The rear end probably could do to have the Bilsteins re valved for a heavier spring rate as pogo's a bit on unexpected jump ups. Otherwise, DOOSO handles very well.

I am probably running the heaviest rear springs of anyone on the forum and the custom made variable wire diameter ones from Kings can only be describe as brilliant in supporting the Kaymar rear bar with twin jerry cans, spare tyre, long range tank plus rear fit out which includes battery and HF mast. The 80 series rubber overload stops are so good that they should have been standard equipment. In the unexpected washouts DOOSO gracefully bottomed out with no great thumping sounds. Indeed, hard to tell if he did actually hit the final bumpstops.

DOOSO is probably heavier than a small moon when fully loaded but handles this weight with ease apart from the usual 2.5 issues of lack of torque at low revs and manual gearbox that rebels in fast emergency changing gears. The aftermarket low range transfer gear means no issues in low range but tall tyres and heavy weight takes its toll in high range.

Just the issue of chassis rusting like mad. Yeap, their is a reason why the Challenger is one of the cheaper 4x4, and build quality plus rust (or lack of) protection is one point.

Cheers

[nj swb]

Hi Ent,

Good to see you back on the forum.

I know this is probably a silly question, but have you confirmed it's an alignment issue, and you're not simply enjoying DOOSO's handling too much? Do you have a printout from a recent alignment?

[old Jack]

Hi

Time to make a reappearance to the forum and drag DOOSO out of his slumber as Nephew is the proud owners of his Dad's old Triton looking for adventure.

The issue I have though is after setting DOOSO for the failed Simpson Desert run by making him taller is I am getting noticeable tyre wear on the outside edges of the 235 x 85 x 16" tyres. I am told that the Challenger has none or limited ability to adjustment to fix this but noticed Fulcrum does new control arms with some claim they can adjust for this. Not sure how?

Has anyone got experience with the replacement Fulcrum front control arms for Challenger or Triton for that matter?

My aging memory has forgotten the EBH on the the front is but I think it is maximum of the specifications plus five mm. 568 or 572mm tends to stick in the mind.

Oh yes, the suspension is performing brilliantly otherwise. The Drummond Motor Sport front end works a treat with steel bar and winch plus full set of three bash plates. The rear end probably could do to have the Bilsteins re valved for a heavier spring rate as pogo's a bit on unexpected jump ups. Otherwise, DOOSO handles very well.

I am probably running the heaviest rear springs of anyone on the forum and the custom made variable wire diameter ones from Kings can only be describe as brilliant in supporting the Kaymar rear bar with twin jerry cans, spare tyre, long range tank plus rear fit out which includes battery and HF mast. The 80 series rubber overload stops are so good that they should have been standard equipment. In the unexpected washouts DOOSO gracefully bottomed out with no great thumping sounds. Indeed, hard to tell if he did actually hit the final bumpstops.

DOOSO is probably heavier than a small moon when fully loaded but handles this weight with ease apart from the usual 2.5 issues of lack of torque at low revs and manual gearbox that rebels in fast emergency changing gears. The aftermarket low range transfer gear means no issues in low range but tall tyres and heavy weight takes its toll in high range.

Just the issue of chassis rusting like mad. Yeap, their is a reason why the Challenger is one of the cheaper 4x4, and build quality plus rust (or lack of) protection is one point.

Cheers

Hi Ent,

You a like a bear coming out of hibernation early, hope all is well in the Apple Isle.

RVCS suspension data for the PC is 542mm front and 552mm rear.

You need to maintain 2/3's of your factory suspension droop travel so from memory this is about 605mm EBH so 605mm - 542mm is just 63mm of droop travel therefore 1/3 of this is 21mm so you can only lift the front ride height by 21mm to 563mm. You can crib about 8-10mm extra droop travel by reversing the shark fin shaped droop stops so the highest part is orientated outwards. It is illegal to remove or trim drop stops but there is nothing in the rules to say they cannot be reversed! If you want to do this you need to make sure the the front struts do not top out, easy to check by removing the shark fin stops and jacking the wheel clear of the ground, if you have less than 10mm between the control arm and the chassis stop nib then you are ok to reverse the shark fin stops around.

Rear ride height is limited to about 585mm to 590mm on the auto as you start to get driveline harmonics at 35kph to 45kph. I recall the manual trans is shorter so a longer rear prop shaft and rear ride heights of 600-605mm are possible.

My unladen kerb weight is about 2450kg and the front ride heights are set at 560mm with the Dobinson Monotube adjustable coilover struts and lifted but reduced spring rate front Dobinson coils. I changed out of the Lovells/Bilstein front struts and coils after 3 strut failures in under 90,000kms. I am still running the Lovells custom EHDVR coils and these are over 120,000kms old and they still carry up to GVM+150kg (2860kg) well, and the Peddars 5899 80 series bump stops are still great.

40,000kms ago when I changed the front coils and struts over, before a successful Simpson Crossing (#4 for this local), I also fitted Dobinson monotube rear shockers, they are slightly shorter in extended length than the Bilstein so I have lost some wheel travel but they are huge in capacity compared to the Bilstein. The Dobinson Monotubes are softer in compression and firmer in rebound than the Bilstein so they control the EHDVR rear coils and the pogo-ing bounce I used to get is no longer .

No experience with the Fulcrum control arm sorry. However I started running LT235/85R16 Cooper St Maxx tyres about 20,000kms ago, after having run LT245/75R16 for the previous 140,000kms. I had no abnormal tyre wear on the 245's that were 775mm in diameter and rotated them every 10,0000kms but on the 235's at 7,500kms I had heel and toe wear on both the outer edges of the front tyres so now I rotate the tyres every 5,000kms to keep this in check. Unfortunately I do not have a recoerd of the wheel alignment history to see if anything is changes but the current alignment is on spec. The only thing I can think of is the 235's are 38mm taller and are on standard P38 rims so the scrub radius has changed, I seem to recall your 235/85R16's are on P35 rims so in theory this should have compensated for the larger diameter tyres and negated the scrub radius change.

My auto PB still goes and handles like a 2.8 ton rally car off the bitumen, especially now I have throttle steer capability thanks to the MM4x4 TC lockup mod.

OJ.

[MartinDanger]

Great info about the suspension characteristics

Off topic apologies firstly.
Thanks OJ for the description of the quick compression slow rebound characteristics of your dampers (Dobinson Monotube adjustable).
I've been struggling to get much info about compression and damping rates (or at least a way to get an idea for what a damper will feel like before buying it) and what you describe is exactly what I want mine to feel like.
You see that kind of tuning in newer rally and off-road racing trucks (really slow rebound) and if you watch some WRC videos over the years, you'll see the evolution happen when the cars started to not bounce when the land.
Cheers :-)

[old Jack]

Off topic apologies firstly.
Thanks OJ for the description of the quick compression slow rebound characteristics of your dampers (Dobinson Monotube adjustable).
I've been struggling to get much info about compression and damping rates (or at least a way to get an idea for what a damper will feel like before buying it) and what you describe is exactly what I want mine to feel like.
You see that kind of tuning in newer rally and off-road racing trucks (really slow rebound) and if you watch some WRC videos over the years, you'll see the evolution happen when the cars started to not bounce when the land.
Cheers :-)

Hi Martin,

Getting the strut/shocker compression and rebound rates from the manufacturers is almost impossible. You are then faced with the complex calculation of the dampening rates as the struts/shockers are never mounted at 90 degrees to the suspension movement so this reduces the effective damping rates. Because the struts and shockers are mounted at an angle, this angle relative to the suspension arms of IFS, IRS and trailing arm suspension design means the dampening rates also change within the suspension travel.

Note; the Dobinson Monotube IMS struts have an adjustable lower spring seat so ride heights and the fine tuned, they do not have adjustable valving!
I recent drove a PB Challenger with a Tough Dog comfort suspension kit with adjustable rebound struts and shockers. It was set at level 3 and this resulted in a vey bouncy ride over undulating roads. The owner was going to trial level 6 and then level 9 to see if there was much difference.

OJ.

[MartinDanger]

Hey OJ, did your mate have any joy with the Tough Dog adjustments? Would be interesting to hear whether the adjustability feature actually makes a difference.

[MartinDanger]

I recent drove a PB Challenger with a Tough Dog comfort suspension kit with adjustable rebound struts and shockers. It was set at level 3 and this resulted in a vey bouncy ride over undulating roads. The owner was going to trial level 6 and then level 9 to see if there was much difference.

I did some more research and noticed that the Tough Dog shocks are twin wall shocks, not monotubes like the dobinsons, despite being adjustable. I'm still curious about how the Tough Dogs perform though. Twin wall isn't necessarily a bad thing depending on your application.

[old Jack]

Hey OJ, did your mate have any joy with the Tough Dog adjustments? Would be interesting to hear whether the adjustability feature actually makes a difference.

Hi Martin,

The Adelaide forum member with the Tough Dog with adjustable rebound is still unhappy with the handling of his Challenger and he is looking at changing struts and shockers over in the near future.

OJ.