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DSC-off

Member Since: 16 Oct 2014
Location: North East
Posts: 1432

2015 Defender 110 Puma 2.2 XS CSW Aintree Green

Tell everyone you started with a Discovery 3, saved 900kg and achieved all your goals?

20th Aug 2018 10:05pm

redline

Member Since: 28 Jun 2015
Location: Mountains and Lakes
Posts: 221

What am I trying to achieve? I've always liked Mr Chapman's mantra of "adding lightness" --> Well Chapman was talking about racing cars, where the dynamics and performance (measured in fractions of second) are hugely influenced by weight.

and I needed the 110 to meet a number of criteria, soft top, carry the boats, the dog and the family --> Ditching boats, dog and family will save you a lot more weight / far more easily / cheaply than any of the ideas listed so far.

and enable us to access entertaining places --> Have you been unable to access anywhere with the vehicle "as-is" currently? And are you sure that is because of the weight?

The weight loss is designed to facilitate better performance and better economy --> What exactly do you mean by performance, and by what magnitude would you hope to improve it? Economy by the way is mostly influenced by how you drive, and the unfortunate laws of aerodynamics, where drag squares with speed.

without compromising the on or off road capabilities of the veh --> You will definitely be compromising on road comfort if you ditch seats. Ditto for bodywork. Sound insulation is a moot point in a soft top, but gains would be minimal.

Bottom line for a potential lightening project: Its likely to cost you a small fortune, lots of time, without achieving what you expect, and most likely compromising your vehicle in a number of ways.

Suggested re-think: From the description of your usage, sounds more like you need a capable overlander. Many on this and other forums have done just that, which usually involves adding weight, and have ended up with a vehicle which better suits their intended usage. I frankly cannot see how lightening a Defender will make it any better at what you want.

PS - I don't in any way mean to diminish your ambitions / aspirations. However having built a number of special vehicles; racing, off-road, touring etc... the best piece of advice I think of is that you should start with a platform which is already as close as possible to what you want to achieve, and think carefully about how each modification is going to help you reach a specific outcome, and factor in the cost vs. benefit. In your case I think you will find that adding "lightness" to a Defender is a pointless exercise in the context of what you want to achieve.

Last edited by redline on 25th Aug 2018 10:25am. Edited 3 times in total

24th Aug 2018 4:30pm

Wild Card 90

Member Since: 03 Dec 2014
Location: Gerlingen
Posts: 1060

2012 Defender 90 Puma 2.2 SW Indus Silver

One important factor to keep in mind is that the un-sprung weight of a Defender is atrocious.

What with long trailing/leading arms cast in steel, live rigid axles and the heavy duty (and pre-war) swivels up front. Add to that over-dimensioned after market wheel and tyre combinations making the legs on your already lightweight bodywork (soft-top) almost a quarter of the overall mass of the vehicle. Yes, i do have over dimensioned wheels and tyres on mine.

If you make a Defender body lighter, you will reduce itÂ´s (already limited) ability to dampen and control the imputs from road and off-road surfaces. The handling will get worse. Within reason, weight does not affect the economy or the top speed. It will improve acceleration and braking, but our Defenders are so far off the scale as far as those talents are concerned, I wouldnÂ´t bother. YouÂ´d need to lose a 100 Kg to really feel a difference.

Even in the realms of track day cars and off road buggies, the type of ancilary stripping (seats, trim, heater, radio, wiring, sound proofing) that needs to take place to make a worthwhile difference often ends with the vehicle being left in the garage and eventually sold because it can only excel in one discipline.

Having said that, our 90 has two Recaros and a few extra bits of chequer pate and a snorkel, and in comparison to others i have driven feels extraordinarily lively and agile. It does however have the extremely stiff (and heavy) KONI HTRÂ´s and can feel extremely pre-war on short frequency bumps.

As Timo K mentioned, the economy is directly related to the lack of aerodynamics. And believe me, there is nothing you can do to a Defender to improve that. Due to the flat and squared off shape of front end (the radiuses are not big enough to help) driven at over 50 mph the vehicle punches a hole in the air about size of a dual wheeled Transit. 1.5 times the width and height of the actual body.

Make sure the engine is delivering full power, breathes easily (intake and exhaust), keep the tyre size down (235, not the 255Â´s

). 1998 Tdi 90 SW,
2008 Td4 90 SW,
2012 2.2 90 SW,
2" raised Trailmaster/Terrafirma
Heavy Track Raids, 255 MT´s,
Recaro CS´s, anorak, wellingtons

24th Aug 2018 6:33pm

zsd-puma

Member Since: 09 Aug 2016
Location: Kent
Posts: 2720

2010 Defender 110 Puma 2.4 USW Santorini Black

Quote:
the economy is directly related to the lack of aerodynamics. And believe me, there is nothing you can do to a Defender to improve that.

Remove the roof, windscreen and doors. Then buy a toneau cover, a flying hat and some goggles. That's probably help a fair bit.

24th Aug 2018 8:14pm

redline

Member Since: 28 Jun 2015
Location: Mountains and Lakes
Posts: 221

Wild Card 90 wrote:
One important factor to keep in mind is that the un-sprung weight of a Defender is atrocious.

The ratio of unsprung to sprung weight is important. Big heavy wheels influence a heavy vehicle less than they do a light car.

Also the context of the energy input into the suspension (governed by what you are driving over and the vehicle speed) and the handling characteristics you are trying to achieve are important.

For example: in my Caterham relatively small changes in the unsprung weight (lighter rims and tyres) made a significant difference to the handling on fast driven B-roads. So much so that I had to adjust the damping to suit. A lighter wheel / tyre combination on my 110 would not have made a perceptible difference to driving the same road at normal Defender speeds.

25th Aug 2018 10:43am

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