MatraSport Forum

Each model => Murena => Topic started by: njesper on May 11, 2006, 12:03:36 pm

Title: Newbee Q - Weight Reduction
Post by: njesper on May 11, 2006, 12:03:36 pm
Hi all,

I am also about to be a murena owner. I have already started thinking about how to get more power out of a 2.2.

In time, I want to play around with the engine, and exhaust, to get more HP, but I guess there is a reasonable limit to how much the 2.2 engine can produce power-wise.

So another great way to get more power is to save weight, I guess??

If anybody have ideas for saving weight in the murena, I will appreciate it.
I would be happy, if you write them down in the right order (best weightsavers first etc...)

I guess that this info will be of great use for everybody in here.

I am not talking about just ripping all the interior out, but perhaps replacing heavy engineparts, trailing-arms, etc. with lighter alternatives..

Well, every advice is welcome :-)

Best regards,

Jesper -DK

Title: Re: Newbee Q - Weight Reduction
Post by: Will Falconer on May 11, 2006, 01:55:53 pm
I think the short answer is that you are starting with the wrong car.  The galvanised chassis of the Murena is quite heavy although it is also very strong.

I can't actually think of anything you could take out to save weight, except maybe drilling the discs!
We looked at making tubular trailing arms but it wasn't practical,

The seats and upholstery are quite light so nothing to save there.

But you can increase the power:
Easy performance upgrades are 4into-1 exhaust manifold,  high-lift camshaft, lightened flywheel,  and a Weber carb/ Twin Webers / or fuel injection. Bigger pistons are also an option.
Or put in a lighter and more  upgradeable engine like the Peugeot XU9...

Title: Re: Newbee Q - Weight Reduction
Post by: Anders Dinsen on May 11, 2006, 03:21:11 pm
Will, there must be something he can do!

Drain most of the fuel off should save 40 kgs.
Get rid of the girlfriend will save him some 70 kgs.
Spare wheel is about 20 kgs?
No doors?
Remove body entirely (and replace it with canvas, at least it would be unique)?
Any more....? Any lightweight oils available? Helium bags?

The pros (when they build race cars) strip excessive paint, wire harnesses, interior, and sound insulation. There's a dutch racing team running a Murena - they stripped off the luggage compartment off the chassis and replaced it with a steel frame. Apart from doing the other things of course (including fitting a roll cage).

Jesper: Godt valg (means good choice in Danish)!

Title: Re: Newbee Q - Weight Reduction
Post by: Matra_Hans on May 11, 2006, 07:27:23 pm
The Murena engine is capable of producing quite a lot of horsepower.
Same engine but with a turbo was used in the Peugeot 505 Turbo (engine code N9T, N9TE or N9TEA). For production car races this engine developed up to 560 HP.
According to Polytecnicís home page you can order the turbo-engine at almost any horsepower level i.e. 180 HP to 550 HP according to your demand (if you are willing to pay their price)
I have been in contact with a bloke in Finland who had himself build a 350 HP engine for his 505 Turbo, and other 350 HP Peugeot cars should be around.
A few years back I talked several times to a guy in Odense (that is in Denmark) who had turbo charged his normal Murena engine to app. 300 HP (330 HP for the drag strip).

Regards Hans

Title: Re: Newbee Q - Weight Reduction
Post by: Matra_Hans on May 11, 2006, 07:54:37 pm
By the way:
I have at Matra meetings in Germany several times talk to a guy with a turbocharged Murena. He had reduced the weight by removing the boot i.e. more or less all steel parts behind the engine was removed, the cabin heater had been removed, he had no spare wheel, and the rear window and the side windows at the back (glass is very heavy) had been changed to very light carbon fibre covers. Further his battery was very small and the steel silencer had been changed to a carbon silencer (battery and silencer are two heavy components) and the original fuel tank had been replaced with a small aluminium tank at the front.
He claimed that the weight was down to around 900 kg.

Regards Hans

Title: Re: Newbee Q - Weight Reduction
Post by: Anders Dinsen on May 11, 2006, 10:45:18 pm
Hans, last year you mentioned you were testrunning a 505 turbo engine... have you made any progress?

Title: Re: Newbee Q - Weight Reduction
Post by: njesper on May 12, 2006, 01:44:40 am
Hi all,

First of all, I am very happy with all of your replies, both serious, funny etc.

I get the feeling, that there are some parts, that could be adressed, and still maintaining a roadcar-look, and feel. For example, smaller battery, no rear-window, instead, a fiber-cover, as I have seen on a couple of Murenas.

I am happy to hear, that power is not the issue. The only thing is, that I have heard, that, in Denmark, you are only allowed to increase the power up to 20% of a cars original effect, meaning that a 118 hp engine would be legal, if it were pushed up to approx. 140 hp. Anything beyond that is illegal by danish law I think.

Please somebody prove me wrong in that matter. Well this matter, was why I have started thinking about Legally "shaving of" some kilos, because I see that as "free HP"  ;D

For instance, I know somebody who has a Lotus Europa, weighing about 700 kilos, and even with "only" 150 hp, you get a superfast sportscar, because of that low weight. If you could get the murena down to about 900, as you mentioned some guy had done, you are pretty close to that, with the 2.2 tuned up to 140 hp.

LAST Q for this time, if anybody has the answer: Does ANYBODY know exactly how much the galvanized chassis (only the chassis, not trailing arms etc.) weighs?

Sounds like its a delicate matter to shave of kilos of the actual chassis for more than one reason (1. ruining the galvanization, 2. weakening the strong chassis, 3. safety issues arising, etc.), so thats why I would like to look at the "rest" of the remaining carparts, to reduce weight.

All comments, thoughts, ideas are still welcome on the main issue. 8)

Best regards,

Title: Re: Newbee Q - Weight Reduction
Post by: Anders Dinsen on May 12, 2006, 11:39:12 am
Regarding your question about danish law... as far as I can read the rules, it is legal to tune the engine with which the car is type approved as much as you desire. Using the turbo engine from the 505 is ok, since it's the same engine.

But if you want to mount another engine, you may not increase power by more than some percentage.

The rules are available on the web, somewhere from - or you can even ask them a question on their forum.

- Anders

Title: Re: Newbee Q - Weight Reduction
Post by: njesper on May 12, 2006, 12:56:31 pm
Super thanks, Dines,

Well, then there is only one way: buy the car, throw out the girlfriend, stop eating junk food, and crank the engine up to 500 hp  8)

....or was it... buy car and be thankful!  :P ;D

Best regards,


Title: Re: Newbee Q - Weight Reduction
Post by: Matra_Hans on May 12, 2006, 03:44:40 pm
Hi Anders an other matra-maniacs,
Regarding my own turbo-project: It has been on stand still since I have been working in Kenya since September last year, however I managed to get hold of an additional turbo engine just the day before I left (I like to have spare parts in the store). I am now back in Denmark and I am using my Rancho as my daily drive and the Murena has been taken off the road, so maybe I will start installing the engine later this year.

Regarding the Danish rules for installing engine with more power it is my understanding that:
1. If you install a differing engine you may only increase the power with 20% As the Murena Preparation 142 and the S had 142 HP the limit in Denmark must be 142 + 20 % = 170 HP.
2. If you are tuning the original engine there is no limit according to the custom/tax-people but the car must still be able to pass our bi-annual safety inspection. (As there is only few Murenas the inspection people have no idea what to look for).

regards Hans

PS the guy i Germany with the 900 kg turbo Murena always shows up with a girlfriend at the Matra-meetings, however it has been a new girlfriend every time.

Title: Re: Newbee Q - Weight Reduction
Post by: Anders Dinsen on May 13, 2006, 08:09:26 am
Hans, have you considered whether this German guy's replacement of girlfriend every year is actually a way to do weight reduction? Just a thought! ;)

You are a lucky man to have two 505 turbo engines in store, I understand they are very rare!

I hope we'll see you and your Ranco to the Matra meeting here in DK in september?

Just for the record, there are two things that *really* needs to be considered when a more powerfull engine is fitted to Murena: High speed aerodynamic stability (more downforce) and brakes. I know you have done your thoughts about the latter. Have you made any progress in your research to the matter? Bernhard has some considerations online (in German) on (

- Anders :-)

Title: Re: Newbee Q - Weight Reduction
Post by: Matra_Hans on May 14, 2006, 04:43:48 pm
I will take the installation step by step. First install the engine and get it running. There are several problems that have to be solved in order to get all the components into the car. Several solutions can be found at
When the engine is in and running I will start considering improvements to the brakes. So far I can have found the following possibilities:
1.   WH-racing in Holland are in the front using brake callipers from a Talbot 1510 that are larger in diameter than the Murena ones. This does not change much however WH-racing is racing with a rather powerful Saab turbo engine so the brakes performance must be acceptable.
2.   It is my understanding that the Norwegian Murena Alfa V6 is using brakes from a Peugeot 405 Coupe. Adapters will have to be made but parts are cheep (also for future purchase of pads and new disks. There is however nothing about the brakes on the homepage.
3.   Jos in Holland has Hi-Spec brakes on his car, this seams to me to be a very good solution. You get adapter (bell) for the car and separate bolted on a brake disks. You can get 4 or 6 pot calibres and different sizes of brake pads.
4.   The German company Movit is basically supplying brakes made the same way as Hi-Spec but it is my understanding that they are more expensive. They use to sell their brakes as Porsche Bi-turbo brakes for every car but the bi-turbo is no longer mentioned.
5.   A cheep and my favourite solution will be to use a set of old Murena disks for the adapters/bells and a set of big ventilated Peugeot disks as donor for the disks and Greenstuff pads. But then I need to find an experienced guy with access to a machine shop. But this type of brake setup should be used on many rally or track cars so I just need to get in contact someone in this circles.

It was a coincides that I got the 2nd turbo engine. On the Danish Peugeot forum I posted the question I they had any member who had a 505 Turbo as I needed some technical clarification regarding some electrical connection. The Danish Peugeot club did not and does not have any member with a 505 but I got a mail from someone who asked if I wanted to buy a complete car as the owner had passed away and the family was trying to sell the car and some spares. I did not want to buy at the price they were asking for, but I wanted to have a look at the spares. The whole basement of their house was full of extra doors, seats etc but in the garage I found an engine. The engine is complete except for the ECU (a new ECU costs 22.000kr!) Searching through the garage and the basement I found an intercooler, extra starter etc. plus an air valve and an in tank fuel pump that needed badly.
The mileage and the condition of the engine was unknown, but anyway it can provide many spare parts for the little money I paid.

Regards Hans

Title: Re: Newbee Q - Weight Reduction
Post by: Anders Dinsen on May 14, 2006, 09:49:47 pm
I hope you have the ECU for your other engine, otherwise it will probably not be too difficult to wire a programmable ECU up for the system. Prices for computer parts in cars are outrageous - there's probably nothing special about it. I have a friend in Holland who tunes Renault ECU's - it should also not be a problem to hook one of these up on your system.

About brakes, I really find your considerations interesting. I also understand why you take one thing at a time - there'll be plenty to do just to get the engine running!

One thing comes to mind, however, and that is balancing the brakes between front and rear if they are upgraded - a different reduction valve may be needed to get it right.

Fitting the larger cylinder calipers of the Talbot 1510 will certainly change the balance towards the front, but may be ok if the suspension is lowered & stiffened. And for racing where pedal pressure is high, the difference is probably very little (the reduction valve only kicks in for moderate to high pedal pressure, so for everyday road use the rear brakes are actually taking a good deal of the braking).

But I really like the idea about upgrading to a completly custom brake system from ( - their collection looks convincing. Perhaps they can be convinced to make a Murena upgrade system...

- Anders