torsion bar vs coilover

[LCOman]

Hi all,

I have UZJ100 with AHC, it has torsion bars in the front and coilover rear.

Although, I'm new in the off-roading hobby, I want to modify this LC for better performance in the sand dunes. I want to fit it with 285/75r17.

My question is on torsion bars:
1) Is it possible to change the torsion bars on UZJ100 to coilover?
2) Will I get better performance and smooth ride compared to torsion bars?
3) If anyone did this change, how much cost we are talking about?
4) If I adjust the torsion bars for 285/75r17 will I face problems? will I get good performance?

When I go for a drive on the dunes, I feel the front travel and resistance is not sufficient for the weight of the car front + steel bumpers on some difficult dunes, and end up knocking the front of the car heavily on some landings.

I want to know your recommendations.


Thank you

 

[slimbuddha]

As of yet, no one has changed the front to a coilover suspension for the IFS. There are a few that have converted the front IFS to SAS. With the weight of these beasts, I think the $ is better spent on getting a sand-rail to tow and tear up.

 

[LCOman]

Thanks slimbuddha

But why nobody did this change? Is the torsion bars in UZJ100 better than coilovers?

If I adjust the torsion bars, will I be able to get 3" for 285/75r17 or 315/70r16?

Is it going to be smooth and stable on road and off-road?

Thanks

 

[slimbuddha]

As with everything, its cost. Previous estimates have been around $10k or more, at least, with the first one costing well north of that for prototyping it.

If you are looking to lift with the torsion bars, you will need to upgrade them to an OME or other vendor's upgraded torsion bars, shocks, and rear springs/shocks. 3" is not really achievable, but there are 2.5" lifts, which along with a body lift, can net you enough space to fit the 35" tires in there. Search the forum, you will see many examples.

 

[crimsonaudio]

You're not getting 3" with IFS, imo - not without custom axles.

 

[LCOman]

That's great, thanks for the insights.

As I have steel bumpers (front + winch) + (rear + tire & jerrycan carrier), I need the lift to fit 35s with no rubbing sounds.

OK, silly question: I have a rear diff lock which came from Toyota. I wonder will I be able to fit front air-locker and will it be beneficial ?

 

[LXColorado]

This video from /DRIVE might interest you. Obviously, it's a 200 series, but should give you some ideas for your LC.

I think the first thing you should do is remove the AHC. The AHC system is not designed for that type of use, and weight (steel bumpers, etc). Go for some new shocks, rear springs, and torsion bars.

 

[LCOman]

Yah, I have seen that video before

It interested me to sell my LC100 and buy the LC200. So when I checked the prices, I decided that LC100 is actually better off-roader than LC200, and got myself convinced.

Thanks for the information

 

[reznunt]

As with everything, its cost. Previous estimates have been around $10k or more, at least, with the first one costing well north of that for prototyping it.

You must not be talking about simply changing to coilovers, because there's no way a fab shop will charge $10k to make and weld in a coil bucket. 6" coilovers will cost you around $800, aftermarket UCA is about $700, and you can get a quote from my buddies at solomotorsports.com for the labor... clearancing the inner fender, plating the frame, and fabbing the buckets, etc. It didn't even cost me near $10k for a full front long travel kit, boxed upper and lower uniball arms, fully fab'd spindles, heim steering, shocks, air bumps, hardware, brake lines, but I did the install myself.

I think it's more because no one wants to cut up a beautifully stock 100 when TB's work just fine (in comparison), and coilovers won't net you any more lift because they aren't the limiting factor.

 

[Dzrtcrzr]

You must not be talking about simply changing to coilovers, because there's no way a fab shop will charge $10k to make and weld in a coil bucket. 6" coilovers will cost you around $800, aftermarket UCA is about $700, and you can get a quote from my buddies at solomotorsports.com for the labor... clearancing the inner fender, plating the frame, and fabbing the buckets, etc. It didn't even cost me near $10k for a full front long travel kit, boxed upper and lower uniball arms, fully fab'd spindles, heim steering, shocks, air bumps, hardware, brake lines, but I did the install myself.

I think it's more because no one wants to cut up a beautifully stock 100 when TB's work just fine (in comparison), and coilovers won't net you any more lift because they aren't the limiting factor.

View attachment 1296356 View attachment 1296357

 

[TeCKis300]

I know you're looking for an answer, and for the 100-series, converting to a coilover type suspension is really out of questions. It's architecture is built around a torsion bar, unless you're looking to spend big money to completely re-engineer the beast.

All is not lost though. What you're looking for is a higher rate suspension setup for the front end.

While the 100-series is primarily a torsion bar front axle, the AHC configuration does lend it some additional front axle support from the hydraulic AHC shock/spring. This is a benefit the standard non-AHC setups don't have as it relies fully on the torsion bar. Note that the upper perch of the shock is not really strong enough to bear the full weight of the front end - preventing a full blown coilover type setup without serious re-engineering.

I would leave the hydraulic AHC shock alone. More on the benefits of this in a second.

The answer you're looking for is an easy one. Just find a higher rate torsion bar (than the stock AHC bar). You have the option to use the stock non-AHC torsion bar or various other aftermarket bars (e.g. OME torsion). Since you're in the middle east, you could even source an AHC diesel model torsion bar that is incrementally more spring rate.

As for those telling you to remove AHC.... Know that you'll lose some killer features. The ability to increase damping from the comfort of your seat. AHC by nature is already high volume in fluid, so it has waaay more heat sink ability (prob even morose than most aftermarket remote reservoir shocks) before heat soaking, for running in the dunes. It's also got active dampening and logic to smooth the ride over choppy stuff.

 

[bamabrock]

the answer is always Dana 60

 

[slimbuddha]

You must not be talking about simply changing to coilovers, because there's no way a fab shop will charge $10k to make and weld in a coil bucket. 6" coilovers will cost you around $800, aftermarket UCA is about $700, and you can get a quote from my buddies at solomotorsports.com for the labor... clearancing the inner fender, plating the frame, and fabbing the buckets, etc. It didn't even cost me near $10k for a full front long travel kit, boxed upper and lower uniball arms, fully fab'd spindles, heim steering, shocks, air bumps, hardware, brake lines, but I did the install myself.

I think it's more because no one wants to cut up a beautifully stock 100 when TB's work just fine (in comparison), and coilovers won't net you any more lift because they aren't the limiting factor.

View attachment 1296356 View attachment 1296357

the 10k number came from this thread if I recall, but I could be wrong: 100 Series IFS Long Travel Thread

And you did the work yourself, labor can often exceed the cost of parts.

 

[reznunt]

the 10k number came from this thread if I recall, but I could be wrong: 100 Series IFS Long Travel Thread

And you did the work yourself, labor can often exceed the cost of parts.

The link you are referring to is a complete long travel suspension setup. It is definitely not equivalent to getting just a coilover to work with oem arms.

The labor for my suspension wouldn't have cost much if I paid them to do it since it's mostly bolt on. But my point was there is much more cost involved in building those arms and spindles (which never even got close to 10k)... way more than fabbing custom coil buckets and all associated labor. I left the link to the shop in case the OP wants to get a quote.

 

[jLB]

The link you are referring to is a complete long travel suspension setup. It is definitely not equivalent to getting just a coilover to work with oem arms.

Excuse my ignorance, but what exactly would you gain with "just a coilover to work with oem arms"?

I thought the stock style UCA was already a bit tight without trying to cram a spring around the shock and through the UCA.

 

[duggy]

The link you are referring to is a complete long travel suspension setup. It is definitely not equivalent to getting just a coilover to work with oem arms.

The labor for my suspension wouldn't have cost much if I paid them to do it since it's mostly bolt on. But my point was there is much more cost involved in building those arms and spindles (which never even got close to 10k)... way more than fabbing custom coil buckets and all associated labor. I left the link to the shop in case the OP wants to get a quote.

You should compare apples to apples here. The Tundra already comes with a coilover setup and if you've ever looked at the stock shock brackets on a 100 you would see how much work it is to cut all of that out.

I think it can be done for less than 10k, but not much less.

 

[LCOman]

On the AHC

Once in the middle of a long drive in the dunes, the AHC decided it was enough dune bashing, and stopped working properly .

So that was because of heat, right ?
If it happens again, then what should I have done?

 

[TeCKis300]

AHC hydraulic system over-pressure. Likely from a hard jump or hit. Higher rate springs will go a long ways to making sure the AHC system does not carry the brunt of the load.

 

[LCOman]

Oh that's good

Team , any recommendations on torsion bars?

Through my search, I'm not sure if OME is the best option. Compared to its price range is it my best option?

Thanks

 

[jLB]

Since you're in the middle east, you could even source an AHC diesel model torsion bar that is incrementally more spring rate.

Although I have never actually touched a 100 series diesel torsion bar, it was my understanding that the petrol/gas torsion bars were not the same length as the diesel torsion bars, so they may not be a direct bolt in.