[Nagz]

So the tow capacity of a sierra is .... well lets face it maybe a jet ski.
I like the size of my zook and dont really want anything bigger but i do want to tow an off road camper, be able to over take a moving car & keep up with the speed limit on a hill.

My question is, if you put bigger engine in it shold be able to tow more ( and i know that this means bigger brakes and other things aswell) but in theory this should work.
I will of course speak to an engineer before anything goes ahead.

And also what engine would you use if it was your zook (with in reason)

Cheers Pete

[ajsr]

1.6 injection

[Nagz]

would that be enough power to tow a camper that fully loaded?

[shep]

my oldies pajero 3.2 turbo diesel auto cant maintain the speed limit up hills when towing their camper.

[Fatzook]

Nagz wrote:

would that be enough power to tow a camper that fully loaded?

What sort of weight?

I've had my 1.6 sierra ute pull 1.75t trailer with another 400kg of cement on the tray. It did it, but was far from legal, or safe.

If its a shorty I would not recommend towing more than 600-700kg braked period! Any more and the SWB will not be able to cope safely.

And the Engineer is likely to demand brake and suspension upgrades at the very least.

[Rockhopper]

Sierra's have a 400kg towing capacity, and about 1100kg's if the trailer has brakes. In all honesty, your car is great for normal driving on the freeway, but tends to slow down at anything more than a slight hill. An injected 1600 will go a long way to fixing the problem, as it has a lot more power and torque than the standard 1300, but you'd have to make sure the motor you were replacing the 1300 in is in good nick. I had a mate with a Vit that could'nt keep up with the Sierra, because his engine was pretty flogged. The option I was going to go down (if I still owned the car), would be a 2" exhaust from the cat back (remember that's the original 19 year old exhaust on that car so there is a good chance the cat is partially blocked), replace the fixed fan with a vitara clutch fan, mild cam, and perhaps replace the carby with a vitara carb.

[Rockhopper]

oh, and if you want a good exhaust system, go see John at Precision mufflers in Elizabeth st, Croydon. I've been using him for 20 odd years and he does a top notch job

[zooky08]

I thought it was about how strong the towbar or chassis is, and the brakes
No matter how big the engine is still will be a 450kg tow rate
Correct me if I'm wrong

[Rockhopper]

zooky08 wrote:

I thought it was about how strong the towbar or chassis is, and the brakes
No matter how big the engine is still will be a 450kg tow rate
Correct me if I'm wrong

You're right

[boostedbrick]

There is a company that builds small campers that will fit behind zooks legally, i think there over in WA. Something like that with a 1.6EFI and correct gearing if you run larger tyres will hit 100 on the highway. Dunno about how much overtaking you would be doing tho.

[Nagz]

Fatzook wrote:

Nagz wrote:

would that be enough power to tow a camper that fully loaded?

What sort of weight?

I've had my 1.6 sierra ute pull 1.75t trailer with another 400kg of cement on the tray. It did it, but was far from legal, or safe.

If its a shorty I would not recommend towing more than 600-700kg braked period! Any more and the SWB will not be able to cope safely.

Yeh fair call

[/quote="Fatzook"]

Nagz wrote:

And the Engineer is likely to demand brake and suspension upgrades at the very least.

I did mention that in the original post

Yeh fair enough

[Nagz]

Rockhopper wrote:

zooky08 wrote:

I thought it was about how strong the towbar or chassis is, and the brakes
No matter how big the engine is still will be a 450kg tow rate
Correct me if I'm wrong

You're right

i can see the logic in that. I was just thinking that the power to weight & also the braking capacity would play a bigger part but i didnt even think about the chassis strength at all.

[Fatzook]

Rockhopper wrote:

Sierra's have a 400kg towing capacity, and about 1100kg's if the trailer has brakes.

You sure you have the right vehicle there?

Sierras have a 400kg payload limit including trailer and its contents; unbraked.

Braked is 750kg. There is no way that a sierra that weights 900ish kgs will have a legal tow rating of 1100kg under any circumstances.

If you are refering to a Jimny, the suzuki website says 350kg unbraked, and 1300kg braked.

[royce]

I reckon you might find the limit brakes or not for a sierra is closer to 500kg

[shep]

my owners Manuel states max towing of 450kg

[MrRocky]

bigger donk, bigger brakes, wheelbase increase, pissy small trailer
dont you think it would be better to save all that money and buy a cheap 4by thats capable of meeting your requirements.

[Fatzook]

royce wrote:

I reckon you might find the limit brakes or not for a sierra is closer to 500kg

I have a manual here that says 450kg for both

Interwebs tells me 750 braked.

[royce]

as if youd believe the interwebs

my towbar says something like 1300kg, Suzuki says no though

[Nagz]

MrRocky wrote:

bigger donk, bigger brakes, wheelbase increase, pissy small trailer
dont you think it would be better to save all that money and buy a cheap 4by thats capable of meeting your requirements.

Yeh you probably right but its a good question tho. I wanted to know as i like my zook and dont want the usual 4wd.

[skyman]

Will be building a travel trailer sometime in the future for the zook, but because the zook is so light weight the trailer has to be even more so.

Look into "tear drop" trailers. They are pretty much just a bed, a very small outdoor kitchen, and somewhere to store stuff. They are perfect for two people, and perfect for a Zool if you get one that is light weight.

Sooner or later I will be building my own

[Rockhopper]

Just had a look in my Jimny manual and it's recomendded towing capacity it 450kg braked, 350kg unbraked. Don't know where I pulled 1100kg braked from. I'm pretty sure Sierra's are the same, but to be sure, have a look in your Sierra manual.

[DiscoS]

So this is this the towbar I've got fitted on my SJ80:
http://www.haymanreese.com.au/parts/01494-3003969

The numbers of importance are:
Rating/Ball Weight: 450/50

But, I don't want to tow a trailer, I want to fit this:
http://www.mototote.com/motorcycle-carriers.html

So I need a Ball weight (tongue capacity) of around ~150, but getting it up to 200kg would be ideal, Anybody know what the actual limiters are on the ball weight?
Beefier mounting system, stiffer suspension?

The total load isn't the issue, I just have a rare circumstance where I'm trying to boost ball weight massively and I don't care about actual towing capacity!
Anybody have some insight to share?

[Gwagensteve]

The simple answer is no, it's not wise or feasible to hang that much weight off the back of a Sierra.

Here's the TL,DR version because I'm on an RDO, sitting in front of my computer and eating my breakfast.

There are a number of hurdles, some can be overcome, others can't.

Firstly, those dirt bike racks mount with 2" receiver hitch. Even the heavy duty towbars for Jimny's don't use a 2" receiver, they use a 40mm receiver. The low tow rating doesn't justify the weight and bulk of the larger hitch. (I also suspect it's deliberate to prevent the use of load distributors and other accessories designed for high towed weights... like dirt bike carriers ) Your towbar has a simple bolted tongue.

So you'd have to fabricate a hitch that suits a 2" receiver. This is going to be difficult as most fabricators won't want to be involved in anything related to a towbar due to certification requirements. I'm sure its surmountable though.

I AM going to talk about the tow bar/system in terms of tow capacity, because that's the easy way to look at mounts and strength of the chassis and compare what you have to vehicles with a 2000kg tow capacity and therefore 200kg of tongue weight.

Obviously the new towbar will be quite heavy taking into account it will need to be designed along the lines of a ~2000kg trailer weight. The factory mounting bolts are only in one plane and are all in a row at the end of the chassis. This places lots of leverage on the bottom rail of the chassis. Any car with a ~2000kg tow capacity has mounting bolts on two planes of the chassis rail, and/or spread over quite a long distance down the rails, to prevent the bottom of the 2.5mm thick rail tearing out. The chassis of the sierra was only designed for 450kg/50kg (in fact, it probably wasn't really designed for towing at all) I guess you could install crush sleeves though the sides of the rail to get the bar onto two planes and spread the load further along the chassis. This would really need to be subject to an engineers report.

Next - weight transfer. Most of the load in a sierra is carried within the wheelbase. (and remember payload is 450kg from dry) Even if you put 4X75kg people in the car, full fuel load and odds and ends, probably taking the car to GVM, all that load is on or forward of the rear axle barring the 32kg of fuel, so it's loading both axles pretty evenly. Most importantly, the car will behave correctly under brakes and steering because the load is borne within the wheelbase. It will feel pretty ponderous, but it will still drive safely.

Now do an experiment. put a 5m long bar out the back of the car and hang 350kg out there. obviously, the front wheels would lift off the ground and the car wouldn't be drivable. it wouldn't steer and it would be very dangerous under brakes. Even though the car is still "only" at GVM, the effect of where that load is is paramount. The further past the rear axle you add load the bigger the effect. That's why semi trailers have a gooseneck and apply their "tongue" load over the rear axles. Next time you see a family sedan with three bicylces on the back take note of how tail low/nose high the car is sitting - and that's 50kg of carrier and bikes on a 1500kg car, not 150kg-200kg of carrier and dirt bike on a 1000kg car.

You can fix the cosmetics with heavy springs, but it doesn't change the weight distribution. You could do some maths I can't be bothered doing and work out the equivalent load if it was applied directly over the axle, but I'd suggest the car is going to drive like it's well over GVM. (therefore not very safely) In the event of an accident, I imagine your insurer would be quite interested in what you had done.

The heavy duty 4WD's I've seen carrying dirt bikes in this way always look like they're very tail heavy and they probably aren't exceeding the tongue weight they are rated for.

I'll use another example of the criticality of tongue weight. I'll use the FG falcon ute as an example (because I've been researching this for other reasons) A falcon ute weighs around 1800kg. In line with convention its rated for 160kg of tongue weight and 1600kg max tow capacity with the factory light duty towbar. However, you can buy a 2300kg rated towbar with a 50mm receiver hitch, BUT Ford state to tow 2300kg you must use load distribution, which are springs that reduce tongue load and apply force to the front axle of the vehicle - so Ford's engineers are pretty confident tongue weight can't exceed 160kg or a bit under 10% of the weight of the vehicle even if the ute is rated for >600kg payload. That's because of how far behind the rear axle the weight is applied.

As I said, it's not wise or feasible to hang that much weight off the back of a Sierra.

[sideways]

I reckon you'd be able to pull some killer wheelies.

[Technotron101]

Buuuuut you need horsepower to wheelie... This is a sierra we're talking about...

[Gwagensteve]

Not with 200kg hanging out the back you don't. You'd probably be able to lift the front end off the ground by hand.

[Technotron101]

Yeah I know just kidding haha

[MrRocky]

Did 450+ km on the beach and dunes with my camper trailer in 1.6 lwb sierra. Gearing should be considered mandatory unless you plan on carrying a spare clutch. Also its easy to find yourself hung up with open center diffs, depending on the type of track lockers are a massive help picking trailer friendly lines

[barrybanks]

I put my camper trailer in a unbelievable sandy camping spot at black point in WA with my standard Jimmy. I got bogged at a four way intersection and was just about to get towed out by my mate, when I learned how to drive properly and drove straight out.

A good trailer with a Zook is a good capable cheap setup

I towed my camper over 20000km with my first Jimny, when it got written off at 105000km It'd had a 600kg camper on the back for 1/5 of its life

When I weighed it in Perth, I freaked out a bit and put some brakes on it. It still didn't make it legal, but I felt a bit better about myself towing with an overloaded vehicle.

The new ones with ABS are legally allowed to tow 1300kg.

[MrRocky]

Economy with the 1.6, transfer gears, 32" mud terrains and towing the camper with roof top tent on it was 13.4 ltrs per 100km averaged out over 1200km including half of it offroad between augusta and wapole