Rooftop tinny and wind drag

Definitely makes a very noticable diferane I dont travell without my tinny now. It is only 10 foot long V nose, In a headwind good 45 degree cross wind not as efective hope that helps.

Thats really good news!!

I am stuggling to hold 100kph with the cruiser and the 18.57 expanda, and I think its the wind, as it even struggles downhill!!!

Very good argument to but a tinny!!

I hope more people can also vouch for this! Cheers

This is all true. There is so much extra weight when carrying a boat aswell. I just need to work out if it is thw wind or the weight that is the problem.

I have plenty of power off the line and up to 70-80, and the motor pulls well. It is just having trouble keeping egts down when sustaining high speeds. Therefor I though it might be wind - especially downhill, where weight should help.

I am happy to drive at 85-90 all day, but not when that is on the limit of the motor.

Yes, I sympathise with you. Having 'nothing left' on the power front is very disconcerting!
But my point is that, even if the LC delivers enough grunt, you must be close to (or probably over) the GVM with 200 to 250 kg on the ball, plus 300 kg of tinny rack motor and accessories on the roof/in the back of the LC, plus full fuel tanks, plus people, and a few items in the back already. like tools, extra spare, etc.
The bloke sitting on the left of the bloke on my right knows all about being overloaded but feeling quite 'safe', but that doesn't make it legal!!
Hope you can work through all this, and then get on with some fun!

Yes I can almost guarantee most 4x4 with the boat on the roof and towing a trailer/van are overloaded.

I don't really know what to do short of selling the 105 and getting a factory 4.2 TD cruiser or the 76 series wagon. Even a dirty old 4.2 Patrol would do the job....

The tinny idea was just an attempt at seeing if wind drag could be decrased by having one on the roof.

Just wanted to see if other people could notice a diffence at high speed cruising with the tinny acting as a deflector or not.

I have an 80 series 1HZ and have solved wind or weight argument for myself with several years of testing with the 3 trailers I tow regularly.

I have a 24 ft trailer sailer on tandem trailer that weighs 2.5T as well as a 10ftx6ft tandem box trailer that weighs about 750kg empty.
When towing the yacht the car easily does the speed limit and i just have enough in reserve occasionally to overtake and hold my own on most hills. With the tandem box trailer I struggle to hold 90kph even when empty. It has a big flat front on it with wide mudguards that catch a lot of wind.
I have also tried various combinations with my 7ftx5ft offroad box trailer full of motorbikes etc. and the car still struggles from wind drag even when empty. It is actually slightly better if there is a tonneau cover on which tells me again it is wind drag inside the trailer causing the problem. I am confident that the nice big pointy nose on the front of the yacht, which sticks up about 3ft above the roof line on the landcruiser, helps to pierce the air and cause minimal drag.
The 1HZ does not have a lot of torque and as such it is driven right at the limit of it's towing ability even with a relatively small load. Because of this it is much easier to determine the difference that is made by trialling different ways of loading or covering the load to minimize wind drag.
All the above performance observations are backed up by reduction in fuel consumption figures too further supporting the argument that it is wind drag and not weight causing the poor performance on the highway.

I think a v'nose 10 ft punt as low as you can get it on your roof should help not hinder your cruising speed on the highway.

Brett

Thanks Brett. Sound like you've done some research into it for a while now.

I have been convinced that the weight, 2.5t, isn't really the issue, as I can take off, even up hill without too much trouble and build speed up to the point when the wind gets too much around 85-90 kph. Even if I get it tuned to go faster, I am sure it will involve much more fuel.

I will try a small tinny on the roof rack, it will be cheaper and easier than building a wind deflector.. and probably more fun too.

Now to find a cheap rooftopper!

Thanks, This is what I want to find out.