Parts Weight list

[suffolkpete]

When I've taken my car for the MoT I've stated the brake test weight as 1000kg as advised by Roy.  The brake performance was so good that I was accused by the tester of understating the weight.

[GP]

@ GP.

That is a nice rear window on the picture.
Is this after market or own produktion?

Hi,


Aftermarket: http://www.plastics4performance.com/

Made from the mold of their Porche 911 1/4 light. Not cheap but exactly what I wanted.

I have a homemade polycarbonate rear screen fitted at present (with a support bracket in the middle) which is looking pretty shabby now. Weight 8kg.

Future discussed plan is to deliver an original glass rear screen to them and they will thermal form a  copy, with the same curvature and OEM black edging.

Cheers,

Graham

[njesper]

What are you trying to achieve with this list? Are you trying to turn your Murena into a race car?

Well Jon, personally my needs and wants are not essential for this thread. 

Weight reduction has always been an easy source of gaining power, and having an old sportscar, that by, some people is regarded as lacking power (well I think that even Matra mentioned it themselves one time), this thread could end up creating a good overview for enthusiasts, wanting to reduce weight, to gain power, without getting in serious trouble with for instance, legislation.

Whether or not you wanna have a stripped down sportscar, or you wanna loose some pounds, by for instance replacing with lighter parts, that could still make the car look great/original, I found this idea a good one. Loosing weight, does not necessarily mean "race car". 

****************
Danish legislation for example, has some very tight rules, for people wanting to up the bhp of their cars.

Rule of thumb: 20% increase is allowed, but can still create problems, every time going to the mot, you still need papers on the upgrades from the manufacturers, especially if the parts mean changing "the construction" of the driving abilities of the car. 

Between 20% and 40%, means going to an approved by the government test laboratory (costly), for getting tests and papers done. 

And beyond 40% effect increase, FORGET ABOUT IT!  (if you wanna do it the legal way).
Because then you have to take the 2000km test, meaning the car is driven for 2000km (at a test track i guess, making the risk of having a 25 year old car breaking down at least 10 times during that), then disassembled totally, and each part analyzed for fatique.  Ehhhh... how do you do that with an old sportscar with already worn parts??? you don't I guess... not to mention costs, of both the tests, analysis, documenation, and all the delays, re-testing for everytime your car throws a leak etc.  you do the math.. 
This test, I guess, is only for the car manufacturers, kleeman tuner companies etc, or veeery wealthy people, who are very bored, combined with a seriously scary patience. 

thereby, this thread re-explained - now in details

[Oetker]

Few things that come up.
Kick all seats out, and put 2 ultra light sport seats in.
Kick the spare wheel and replace it with a can tyrerepair stuff.
Kick all vacume out, and replace it with a simple UP28 Brakepump in the front.
Get out all stuff related to the headlight, and use the foglights to make it work.
The standard carpet is heavy, kick it out and replce it with a lighter synthetic.
Make fueltank half the size.
Put on the ferrarie hood and all windows plastic except the windscreen (safety).
Leave the plate that covers the engine at home.
Get of the airfilter an replace it with a pancake type.
Put on 1 light sportmirror on the left and put the shitty Vitaloni's in the bin, or better, sel them on ebay.
And so on

When i am at home, I  put some things on the scale.

[njesper]

I would think very carefully before you remove the trunk, if that's your plan.  It probably contributes a lot towards the structural rigidity of the car.  Replace all the glass with Perspex.  That would save a lot of weight, though don't go for the Ferrari back.  It weighs more than the glass hatch.

I totally agree on the trunk part. Just curoius to know what that tub actually weighs. Maybe one could make a lighter version.
Just thoughts. 

I have that glassfiber back also, I think I wil weigh it sometime in the future. Until then if anybody else, have the figures, it would be nice to know the difference.

Best,

Jesper

[njesper]

I would love to know the weight of the following Parts:

1. Trunk (the actual tub) (as I wrote earlier)
2. 2.2 rear trailing arm
3. 2.2 left/right drive shaft
4. rear glass window

Best regards,

Jesper 

[Oetker]

2.2 rear trailing arm 10,5 kg compleet right side
2.2 short axle 7,0 kg
2.2 long axle 9.7 kg
Engine cover 5,2kg

[GP]

Oetker: What is the weight of your exhaust system on display?

A Titanium Exhaust would reduce weight on ones car (and wallet) and reduces the Polar Moment of Inertia.

Polar Moment of Inertia:

This term refers to how difficult it is to get an object to rotate on an axis. The farther away from the axis of rotation the mass is, the harder it is to make it turn. Conversely, if the mass is concentrated near the centre, it is easier to make it turn. Mid engine cars usually have a low polar moment of inertia which makes it easier to make them rotate, and therefore easier for them to turn. However, mid engine cars will react more quickly to changes in tire angle (they turn faster) but this also means that they are inherently easier to spin as well.

Magnesium Alloy wheels would also reduce weight on ones car (and wallet) and reduce the Unsprung Weight.

Sprung vs. Unsprung Weight:

Sprung weight is any part of the car that is supported by the suspension, and only moves when the suspension is active. That means that unsprung weight is any part that is directly connected to the road without cushioning from the spring, i.e. wheels, brakes, suspension arms.

Removing unsprung mass is a more effective than reducing sprung mass as it does have handling benefits. The lighter the wheel and other unsprung components, the easier it is for the tire to follow bumps in the road. On a vehicle with extremely high unsprung weight, the inertia of the wheel and associated assembly can't move fast enough to follow the road, resulting in a jarring, crashing ride.

Lowering the unsprung weight and rotating weight yields multiple dividends, with better acceleration, better braking, better ride, better fuel economy, and better handling. Money spent to reduce unsprung weight may be great, but it's a much better payoff than with sprung weight.

Alles klar?

Cheers,

G.P.

[njesper]

A Titanium Exhaust would reduce weight on ones car (and wallet) and reduces the Polar Moment of Inertia.

Ehh... titanium exhaust reduces polar moment of inertia?? An exhaust is not turning is it? or am I just not the sharpest knife in the drawer? 

Apart from that.... I really think this thread is ROOOLLING! thanx all, keep it coming 

Best,

Jesper

[njesper]

2.2 rear trailing arm 10,5 kg compleet right side

What do you mean by "compleet"? is that including the wheel hub+bearing?

Please weigh as many parts seperately if possible, or write what the weighing includes
Anyhow, SUPER COOL... keep it coming..

Just trying to sort out, before adding to the list  

Thanx

Best regards,
Jesper

[Oetker]

Devil exhaust 15 kg
Wheel bearing 800 gram

wheel hub 1,7 kg
Just reduce the wait of the right trailing arm with this 2 figures.

cat 7,2 kg
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Sorry, couldn't resist.
 

[njesper]

Thumbs up Oetker! 

I understand you got tempted.... cat... hehe.... Well, our cars are non-cat I gues 
Though its a cute cat. 

Thanx for the weighing

[GP]

Rear Brake Caliper Assembly (No Pads) 3.5 kg.If someone could weigh the front Brake Caliper Assembly it would be appreciated.

Fuel tank with sender unit 5.2kg. (Suggested alternative, a smaller aluminium tank)

This Aluminium Fuel Tank was fabricated by a local firm in the U.K. to me called Brise:     http://www.brise.co.uk/fabrications.html

The fuel tank was fabricated using the drivers side, larger and deeper portion of an original plastic fuel tank as a pattern. Total width = 42cm. So it does not extend behind the engine at all, with a completely clear area in front and below the engine for the carburettors and a very large clear air flow from underneath. This tank gives me a 25 litre fuel capacity. Ideal for sprinting and hillclimbing competition.

See images for further details.

For installation it uses the original drivers side retaining strap, the original fuel level gauge assembly (with some bending and adjustments of the float arm) and all the original fuel filling hoses. An extra support bracket was attached to the new aluminium flange at the top for the fuel sender unit and bolted to the bulkhead ahead of it with some flexible bushes. I also have a roll over vent valve plumbed in (seen on the inner wheel arch at the top) as the tiny plastic vent valve at the filling point area could not cope with the fuel consumption and the tank would have imploded otherwise.

The weight of this tank is unknown to me, but very light. The original plastic tank with sender unit just weighed = 5.2kg

NB: I originally tried using a cut down original plastic fuel tank and having it professionally plastic welded over with the same material. This was installed but the welds all failed shortly after. You have never seen me run down the road so fast trying to get away!  

The problem was that the plastic was contaminated with the fuel residue. Even if the fuel tank is brand new I would not personnally recommend this procedure.

Cheers,

G.P.

[GP]

Suggested alternative for the front brake calipers.

Willwood Midilite 4 - Pot Caliper Part No. 120-7473 (Piston dia. 1 3/8") Weight 1.91 kg

Front discs (rotors)  are 283mm. dia. twin ventilated disc.

Parts and aluminiun HE 30 bar blanks, supplied as a do-it-yourself (with my father) kit from Rally Design Ltd. in Kent, U.K.

http://www.rallydesign.co.uk/contactus.php

http://www.rallydesign.co.uk/pdf/designing_4_pot_brakes.pdf

http://www.wilwood.com/

Pads fitted are Competitition use Mintex Midlite M1144. I have a set of EBC Greenstuff Pads which are quite good, but not as aggressive and more suited for road use.

Further nuts and bolts, machining of blank discs and fitting information provided by Hi-Spec Motorsport in Dartford, Kent, U.K.

http://www.hispecmotorsport.co.uk/

http://www.hispecbrake.co.uk/brackets.htm

http://www.hispecbrake.co.uk/fitting_instructions.htm

http://www.hispecbrake.co.uk/caliper_conversion.htm

http://www.hispecbrake.co.uk/Bleeding%20Brakes.htm

http://www.hispecbrake.co.uk/road_test.htm

http://www.hispecbrake.co.uk/bedding_in.htm

http://www.hispecbrake.co.uk/trouble_shooting.htm

The rear brakes are currently heavy Sierra Cosworth 4 x 4 Calipers with single cross drilled disc (diameter not known and too cold in the garage to measure right now!) See image

NB: the front  hydraulic circuit has a Willwood pressure reduction valve fitted and the rear hydraulic circuit has the pressure reduction valve (under the front of the rear offside wing) removed.  This gives the rear maximum pressure and I can then reduce or increase the front system pressure for brake balance and road conditions as required.

Cheers,

Graham

[roy4matra]

When I've taken my car for the MoT I've stated the brake test weight as 1000kg as advised by Roy.  The brake performance was so good that I was accused by the tester of understating the weight.

Far from it...  And if your MoT tester used the brake rollers and asked the weight and used that for his calculations then he did the test incorrectly anyway since he MUST do it with a 'G' meter such as the Tapley meter on the road - that is the ONLY Ministry acceptable way for a car not listed on their computer or weight charts.  He can be reported for doing anything else and any result (pass or fail) can be challenged.

All this is stated in my website FAQ.

As it happens your car may even be lighter than 1000 kg.  The reason the Murena brakes are so good, is that Matra designed the car well.  My car has always locked all four wheels on a brake roller and both rears with the handbrake - and you can't get any better!

Roy (Ministry MoT tester)