Weight of a tr7 v8????

[Brianc]

Anyone got a stat of the weight of a tr7 v8 dhc. ?

Just wondering what the max weight is that I should be towing?

Hope you can help

Brian

[Hasbeen]

The weight is around 1100 kilograms, but basing your towing capacity on the weight of the vehicle is a bad idea. Some will easily tow more than their weight, & some much less. A short rear overhang will handle a much heavier tow than something with a long overhang. The further the tow ball gets from the back wheels, the more the trailer will control the car.

Back in the day I used to tow my Brabham in an enclosed 4 wheel trailer, all up 1.5 tons behind a 1966 Hillman Minx weighing about 0.9 tons. It did a better job than a V8 Chrysler of 1.5 tons.

I have towed a single axel trailer all up weight with load about 750Kg & a twin axel horse float of similar weight behind my 7, both quite happily. It did notice the twin axle more than the single. It did much better with both of them than a Suzuki 4WD of about the same weight & power.
1/- because the 7s lower centre of gravity.
2/- Because the torque of the 7 is much lower in the rev range.

Don't put too much weight on the draw bar of the 7 if you have stock springs, 50Kg combined in boot load & trailer draw bar weight, on stock springs is about max that is comfortable.

[Brianc]

So when you were pulling the singke axel with 750 kg - were you on stock springs?

Didnt quite understand the bit about 50kg - please excuse my ignorance !! N

[saabfast]

I think Hasbeen means the weight of the stuff in the boot (luggage, tools etc) plus the nose weight of the trailer draw bar should not exceed 50kg to reduce load on the springs. The nose weight can be adjusted by how you load the trailer to an extent. More load in front of the axle will increase it and more behind the axle will reduce it (ie the axle acts as a pivot).

[Hasbeen]

Yes saabfast, that's it.

I once loaded 100KG of kitty litter for my daughter in the back of the 7. It had so little weight on the front wheels it was positively dangerous.

Yes Brianac, 750 total weight of a single axel box trailer & load was fine, on stock springs in perfect, reset condition. This would require at least overriding brakes on the trailer if you plan on traveling far at main road speeds. You probably require them by law, we do.

This was a heavy duty trailer, many have soft springs & have a total weight limit of only 500 KG.

One thing you have to be careful of is weight distribution in the trailer. You want at least 25 KG weight on the draw bar, [tow ball] from the trailer. If the trailer sways as speeds you need to increase the weight on the tow ball. It would be wise to not carry anything in the boot, so you can increase the weight on the drawbar if necessary.

Hasbeen

[Brianc]

Really good information here guys.


What i have is a single axel trailer and Im trying to pull it with a couple of scooters on it. They are each around 175kgs each and the majority of the weight sits above the axel.

Brian

[saabfast]

You might need to lash them forward a little to get some noseweight on the hitch if the trailer is balanced when loaded. Maybe put them on facing the rear so the engine weight is forward of the axle.

[Hasbeen]

I learnt about trailer weight distribution by error, my error. In the early 60s no one knew about this stuff, & we had to learn the hard way.

My Lotus 20 formula junior came with it's custom built twin axel fully enclosed trailer. The car pushed backwards into this, with good hold down gear.

The trailer did not tow very well, so we checked the axles on my wheel alignment pit. [I was a steering & suspension specialist]. We found neither axle was straight, & neither pointed straight ahead of the trailer. We fixed this, but the trailer still did not tow well.

We now bent the axles to give some toe in, 3/32" on the front axle & 3/16" on the rear gave the best results, provided the axles still pointed absolutely straight ahead. I could now tow the trailer at 85 MPH quite happily. Surprisingly this did not result in high tyre wear. [We often had to do 500 miles over night, Friday night after work, to get to a race meting].

The Lotus had 4" by 15" wheels. I was offered a set of 5" front 6" back wheels pretty cheep for it, & grabbed them. With them fitted, the back track was too wide for the trailer. To get it in, we had to fit the old back wheels, & carry the new wheels, a bit of a pain. To fix this we built small extensions 3" wide on either side of the back of the trailer body.

We had to put the car in nose first of course, which we did.

DISASTER. with the car nose in there was virtually no weight on the nose of the trailer. It started to away at 25 MPH, was getting dangerous at 30 MPH, & I was not game to go past 35 MPH so violent was the swaying.

Putting the car back to reverse in returned about 60 Lb. weight to the nose of the trailer, & the trailer to a well behaved unit.

Hasbeen

[darrellw]

Here is a really cool video illustrating the differences with weight distribution:

https://www.youtube.com/watch?v=4jk9H5AB4lM

[Hasbeen]

Great video Darrell, it really highlights the effect of trailer nose weight.

Hasbeen

[seven]

I have certainly learned from not having any weight on the draw bar, I had a Hillman Hunter and collected another on the trailer and headed off home, once I got to the motorway and my speed increased to about 55mph all hell broke loose and we got the big fish tail and covered 3 lanes and 200yards Luckily with having little motor racing experience I was able to curb the fish tail and carry on at a nice steady 40mph all the way home
My son went with a mate of mine to collect a 5 series BMW with his Commodore, the idiot loaded the Bemmer on backwards, my son said that was interesting, we fishtailed all the way back to the workshop
My best idiot moment was when I A-framed my E37 Charger behind the wife's Toyota Corolla during winter
When I think about it now, OMG what an IDIOT I was.....................Talk about doing stupid stuff when we were younger

[Hasbeen]

I towed my Lotus 20 then the Brabham in an enclosed twin axle trailer, [about 1.3 ton all up] behind a few cars. This included a 1966 Hillman Minx. The Minx was a lot lighter than the trailer, but was a fairly successful tow vehicle.

I developed a "sway stop flick" in the Chrysler Royal, which with it's long rear overhang was most effected by the trailer swaying.

I would watch in the drivers rear view mirror, for the rear of the trailer to be swinging to the right. As it appeared from behind the trailer I would flick the steering wheel hard left, then back straight again. Thus with the back of the trailer swaying to the right, I would turn the front of the car momentarily to the left, which swung the back of the car, & the tow ball also to the right.

With the hole trailer now trying to move to the right, the thing would give a shudder, & stop swaying.

I don't know how effective this would be with a short overhang vehicle, but it worked equally with my 1.5 ton crew cab Daihatsu ute with it's long overhang, & the horse float. I used to get the Lucerne hay, [alfa alfa] cheap from a farmer, but had to pick it up from the paddock as he was bailing. I would load the ute & the horse float. Due to the shape of the float the load would end up tail heavy, producing very good swings on the way home.