[zammit]

how does the jimnys flex compare to the trusty old sierra?

[Fatzook]

Stock for stock?

Jimny would be better. But thats only because coils offer a more progressive spring rate.

If aftermarket suspension is involved, then a sierra can easily be made to out flex a jimny ( also with suspension work)

[Gwagensteve]

geez, there's not much in it though. The Jimny sort of "cheats" some travel by having a longer wheelbase.

Shock travel is roughly the same for each car, and there's very little in it for roll stiffness.

Steve.

[monley]

My jimny with the 80mm lift has more flex on a ramp that aleins spoa sierra which is on lux leafs

[Gwagensteve]

SPOA - Meh.

Steve.

[Fatzook]

Gwagensteve wrote:

SPOA - Meh.

Steve.

X2.

[atari4x4]

monkey wrote:

My jimny with the 80mm lift has more flex on a ramp that aleins spoa sierra which is on lux leafs

what was your RTI from that gayflex ramp day?

[ajsr]

so is yours an exceptional jimny or is aliens sierra a stinking chunk of shit??

[Fatzook]

'Flex' is an irrelevant term.

What is far more valuable is balance. I'd rather have 8" of travel at each wheel, that performs in a predictable and equal manner under REAL WORLD conditions, than have 15" travel in the rear, 12" in the front and post massive RTI figures on some gay arse ramp.

[atari4x4]

ajsr wrote:

so is yours an exceptional jimny or is aliens sierra a stinking chunk of shit??

little bit from column A & a little bit from column B

[ajsr]

Fatzook wrote:

'Flex' is an irrelevant term.

What is far more valuable is balance. I'd rather have 8" of travel at each wheel, that performs in a predictable and equal manner under REAL WORLD conditions, than have 15" travel in the rear, 12" in the front and post massive RTI figures on some gay arse ramp.

shows what you know fat man, it all about the ramp man

[Gwagensteve]

Actually, for climbing, I'm 100% positive Alien's set up would destroy an 80mm lifted jimny, because all the articulation on Alien's car is in the front. That makes for a balanced and predictable climber.

Next time you are at a ghey ramp take an angle finder with you. Compare front axle angle in degrees with the angle of the body. For climbing, you really want the front axle to be doing twice (or over twice) the angle of the body. Less than twice the angle of the body means the rear is out flexing the front and that feels like poo offroad.

This is uncool:




this is cool:



even though the "uncool" car has more total articulation.

There used to be the full text of this article on line but I can't find it now:

http://www.pangaea-expeditions.com/gall ... index.html

I'd always give up potential flex to have the front work harder than the rear when climbing.

Fatzook is 100% on the money. It's all about balance, not ghey flex.

Steve.

[Fatzook]

ajsr wrote:

Fatzook wrote:

'Flex' is an irrelevant term.

What is far more valuable is balance. I'd rather have 8" of travel at each wheel, that performs in a predictable and equal manner under REAL WORLD conditions, than have 15" travel in the rear, 12" in the front and post massive RTI figures on some gay arse ramp.

shows what you know fat man, it all about the ramp man

Taken to skool again

[atari4x4]

slightly off topic, but still on balanced flex.

i'd like to keep tweaking this set up before hacking it for a sas.

my junk is tail heavy with flex being IFS even with no front sway bar, would it be worth while limiting the travel a little bit more in the rear of my vitara either by bumpstopping it more or by adding some roll stiffness by adding a rear swaybar & leaving the bumpstops?

an adjustable set up like joeblow's torsion bar style sway bar with the FWH would be cool.

edit: i haven't had a front swaybar since it got built.

[BertZook]

I totally agree in wht u say steve

but again that cool car pic it seems more stable is bcose the front wheel is in down travel (in a hole), rather than the uncool car hes going uphill where the front flex meet the limit and start tipping the car over and showing the rear flex (if im not wrong )

wht I try to say is that those two pics dnt necessary show witch rig is better as they re in different flexing scenarios..... i bet u if u swap the cars they both would behave the same



if u put the "cool car in a travel ramp in reverse it would show the exact (or pretty similar) flex like the one that is showing up right now... difference is because the nature of the ramp the car would look on a side bout to tip over jsut like the uncool car....... photoshop the cool car, cut it out of the pic and place a ramp under it... you would have to rotate the image to make it fit.... end result it woudl look like the uncool car but in reverse



I dnt really know..... I know wht u mean, just pointing out that those pics although show ur point, they dnt make it enough justice

[monley]

That's why I said on a ramp, I have 'more flex' but in the real world alein dose have more front end travel.....

[alexvitara]

edit: im a dickhead and misread

[monley]

I still have a bit more travel in the front but the shocks are to short.

[Gwagensteve]

And that's just proving how superior the balance of Alien's rig is for climbing.

Steve.

[alien]

didnt get on here at lunch so i've missed this thread...

monkey's got way more flex in the ass end than mine has in the ass end... my rear is very stiff flex wise and the front very soft (even though its running the same spring and shock combo front and rear) - the only thing stopping my rear working the same as my front is weight over the axle, and the rear springs being slightly more outboard that the front to encourage more rear roll stiffness in the ass end.

while this may be the case it has to be taken into account that mine is daily driven and was built as an "all purpose" vehicle - it also had to pass the lane change test, which as most of you saw in the crappy youtube vid of it passing that, the rear end actually slipped out sideways on the last bend in lieu of lifting a wheel (which is a fail on the test). That behaviour alone says we got it right in the build. (Engineer was very excited at this handling aspect).

[ajsr]

Gwagensteve wrote:

And that's just proving how superior the balance of Alien's rig is for climbing.

Steve.

heres your climbing rig.
jimnys pfft

[Gwagensteve]

BertZook wrote:

if u put the "cool car in a travel ramp in reverse it would show the exact (or pretty similar) flex like the one that is showing up right now...

Sadly, I couldn't find the original "twist off" article on line, which did have photos of those two cars on the ramp. This is best I could find from my iphoto librar, both cars on the ramp, but not from the same angle.





The "uncool" car had cranked radius arms in the front for high front roll stiffness and stuff all rear roll stiffness.

The "cool" car runs a three link front and a arm rear for very evenly matched roll stiffness.

Whilst the car with all the rear travel actually went further up the ramp, the mismatch in roll stiffness put the body on a way scary angle compared to the three link front car.

This was very carefully measured and graphed - there were quite a few cars compared with everything from stock to radical suspension.

So yes the photos were unhelpful, but the two cars actually do have very radically different suspension behaviour and the car with lower front roll stiffness than rear performed by far the best. (at full flex, from memory, 56% of the car's wheel travel was being done with the front) The car with the stiff front end was under 30% from memory.

Stock jimnys have quite good balance front to rear, the catch is they have lower rear roll stiffness compared to a leaf sierra, and a relatively high centre of gravity in the rear. That makes them spooky compared to a sierra of the same articulation off road, even though they might feel better on road.

IMHO for off road use lower front roll stiffness is advantageous. For on road use, lower rear roll stiffness is advantageous. It's one area where different use dictates different setup. However, if our 2wd roads were all 30 degree climbs, road cars would have lower front roll stiffness too.

Steve.

[Highway-Star]

Gwagensteve wrote:

IMHO for off road use lower front roll stiffness is advantageous. For on road use, lower rear roll stiffness is advantageous. It's one area where different use dictates different setup. However, if our 2wd roads were all 30 degree climbs, road cars would have lower front roll stiffness too.

Steve.

Leafy with a removable sway bar

[Gwagensteve]

Well, anything with a tunable/removable front sway bar.

I generally quite like the feel of a car with low front roll stiffness on road, so long as it has enough caster, but I will say that I recent road drove my 1.0 trayback with a bolt out of the rear radius arm setup and it was a little bit spooky, but it cornered amazingly well, up until the point the inside front wheel started to lift.

It made the spool almost undetectable.

Interesting.

Steve.