Outer Limits 4x4 Board

How do you upgrade IFS? By upgrading I mean all things good: Height, up and down travel, strength, (comfy ride maybe)... Mostly flex. My IFS has no flex, but I've seen some pics of IFS with great flex!

How's this (in increasing severity):
1. Longer springs / coil spacers / wind up torsion bars, trim bump stops
2. New shocks (with longer travel, if that has been limiting things)
3. Diff lock / aftermarket diff & CV's (stronger)
4. Lower diff (spacers??)
5. Aftermarket control arms (some sort of kit???)
6. And finally, SAS (Ha, beat you to it!)

Its a pretty expensive business. In the states (i think they are starting to appear here aswell) you can buy complete changeover aftermarket kits with longer a-arms, coilovers etc that will acheive the things you are looking for, however come at a price, running into several thousands of dollars.


There are certain 'backyard' options such as trimming bumpstops, spacer kits/dropped x-members and the like, but the main limiting factor is the angle at which the CV's bind, and also the angle at which ball joints bind.

What vehicle are we talking? that is the bes place to start sounding for ideas as it will dictate what options you have available. Do a search for kits such as skyjacker and calmini as a start.

A good place to start with flex is to unbolt your swaybar when offroad, whilst this can render vehicle unroadworthy etc, its a cheap (no cost) place to start for improving flex and ride in the rouch stuff.

Getting ride and travel out of IFS really revolves around a couple of areas -

Keeping CV angles acceptable
preventing ball joint bind, normally on the top ball joint

This is normally achieved in the US by increasing track width (which adds travel on its own but can add travel AND reduce operating angles, but sometimes includes new/modified knuckles fitted with uni balls or machined ball joints.

lowering the diff is done to retain usable CV joint angles. This is normally done for lift only and might gain no improvement in wheel travel.


The type of spring and shocks used with an IFS have no bearing over its travel- the arms must contact bump stops before the spring or shock can have any effect on range of motion. if properly sorted, torsion bars can ride great.

The biggest issues you will have to deal with are budget and the car you are starting with. Some cars, like hilux/fourrunner already have high travel parts available for them - from somewhere like total chaos in the US, but others will have nothing.

Adding track width though will be the biggest single improvement, but bear in mind there's lots of $$$ here - arms, axles, steering etc.

Steve.

Thanks for the ideas! I've got a prado, but I don't want to limit the discussion just to the prado... I'm discussing it mostly for general knowledge rather and I'm not about to rush out and spend heaps of money on it! However, if there are any simpler things I can do cheaply I will.

So.... the aftermarket kits usually lengthen the control arms (and the track), replaces the ball joints with something that handles more flex, lowers the diff (to keep CV angles small) and lengthens the axles / steering to suit... right?

Generally, unless they're a cosmetic "lift kit" they'll be trying to avoid lowering the diff, this kinda defeats the purpose.

It's worth bearing in mind that the stuff I spoke about has a very small market, even in the US and is often really, really expensive. It's almost never a bolt on kit either.

As you own a prado though, you can use parts intended for the US market Tacoma and FJ Cruiser, so at least you have parts available.

http://www.chaosfab.com/96504.html

Interestingly though, they are claiming 8" of travel for the FJ Cruiser/Tacoma, less than I was expecting for the $$$.

Steve.

SAS the playdoh

I've emailed totalchaos for kit prices... I don't think I'm really serious about it, just curious

My CV's are pretty level in the 'normal' position, with 2" lifted OME springs. Maybe I should try flexing them up and down to find out what is limiting travel.

Another problem would be the forward and backward swing as well.

depending on the joint used some are actually on an angle so when they are pointed directly outwards they are straight but once you turn it forwards it'll go up in angle and when going backwards it'll go downwards in angle.

if there's no angle in the wheel joint then you won't get the up and down swing angle.

on that web page it looks like a level swing forwards and backwards, so your able to simply raise up the upper A arm, dump in a longer shock.

Gwagensteve wrote:
Adding track width though will be the biggest single improvement, but bear in mind there's lots of $$$ here - arms, axles, steering etc.

Steve.

could you just put wheel spacers on? say 3" each side... technicaly unroadworthy with them on, but if you have a 2nd pair of wheel you could just chuck em on when you swap tires over

macca81 wrote:

Gwagensteve wrote:
Adding track width though will be the biggest single improvement, but bear in mind there's lots of $$$ here - arms, axles, steering etc.

Steve.

could you just put wheel spacers on? say 3" each side... technicaly unroadworthy with them on, but if you have a 2nd pair of wheel you could just chuck em on when you swap tires over

Like all ideas, most things IFS aren't that easy.

Techniclly you could do it, but you would massively increase your scrub radius and supply considerable leverage forces to the stub axles, bearings, and upper/lower ball joints. You would also need to respring to accommodate the extra leverage outside the present "arm". There would be alignmentand handling issues if you didn't pick the right sized tyre (getting the castor/camber/tyre centerline pivot point near enough to where it was contacting with the ground with the smaller tyres). I did all this when sizing up the larger rubber and different rims for the Kia.

You can get away with spacers with a beam axle because some of the extra leverage force through the bearings/hub is transferred to the diff along the length of the halfshaft. It will result in worn bearings, but not at the rate of an "unsupported" IFS. The bearings will be the pivot on a seesaw between the wheel and the diff, instead of having the forces acting perpendicular to the bearings without the spacers.

Hey, I do tech too......

carrot i have a IFS hilux and im in the same situation wanting to upgrade off road capabiltity but feel so limited.....

my question to everyone is would it be better to spend a few grand on doin a solid front end conversion then tryin to upgrade the ifs???? thats what ive been considering

toight toyota wrote:carrot i have a IFS hilux and im in the same situation wanting to upgrade off road capabiltity but feel so limited.....

my question to everyone is would it be better to spend a few grand on doin a solid front end conversion then tryin to upgrade the ifs???? thats what ive been considering

If it isnt locked then lock it. After that if you need more then do a sas complete waste of time and money stuffing around improving IFS.

booflux wrote:If it isnt locked then lock it. After that if you need more then do a sas complete waste of time and money stuffing around improving IFS.

I'll back this up. I can not think of a single modification to an IFS front end that can net as much improvement as a locker.

For the cost of new arms and such, you can easily set up an Air Locker and between a basically stock front end locked and a barely improved front end unlocked, i know which one will go further.

Gwagensteve wrote:Generally, unless they're a cosmetic "lift kit" they'll be trying to avoid lowering the diff, this kinda defeats the purpose.

It's worth bearing in mind that the stuff I spoke about has a very small market, even in the US and is often really, really expensive. It's almost never a bolt on kit either.

As you own a prado though, you can use parts intended for the US market Tacoma and FJ Cruiser, so at least you have parts available.

http://www.chaosfab.com/96504.html

Interestingly though, they are claiming 8" of travel for the FJ Cruiser/Tacoma, less than I was expecting for the $$$.

Steve.

PT# 96500 (UCA's and ball joints) retails at US$689 for the set and PT# 96000 (UCA and LCA, various other hardware, axles not included) retails at US$2632 for the kit.

I've got a front locker. For that kind of money, I'd rather put a rear locker in.

carrot wrote:I've got a front locker. For that kind of money, I'd rather put a rear locker in.

Locktup4x4 has them on their site at $588 for All-Pro UCA's

http://www.locktup4x4.com.au/catalog/7a ... 08804.aspx

But still for that money, you could hunt down a second hand Air Locker for the rear, as it's only an RD23, which is the same as a Hilux and every other Toyota 8" diff, so they do pop up occasionaly.

Upgrading IFS is really all about going fast - the mods are generally about increasing travel to let the car hit stuff faster. If you want to crawl stuff with the car an SAS will be the go.

Steve.

Gwagensteve wrote:Upgrading IFS is really all about going fast......

Didn't work for me - everything I do ends up going slower.... The angry mice just arn't up to the job.

j-top paj wrote:SAS the playdoh

Go on, you know you want to

r0ck_m0nkey wrote:

booflux wrote:If it isnt locked then lock it. After that if you need more then do a sas complete waste of time and money stuffing around improving IFS.

I'll back this up. I can not think of a single modification to an IFS front end that can net as much improvement as a locker.

I agree. Front locker has made a world of difference to my Paj.

And don't underestimate freeing up the rear end. It may seem counter-intuitive, but by freeing up rear travel (such as removing the rear sway bar) it's possible to keep all four wheels on the ground (a little) more often.