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Author Topic: Murena high fifth gear  (Read 124615 times)
Oetker
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« Reply #15 on: June 24, 2009, 12:04:41 am »

188........No License for 6 weeks.
215........No license for 3months.
246........Probably dead penalty over here.

It is nice that it is possible, but my car wil never run at that speeds, even not at a circuit.
In the first place it is 27 years old, and 2nd I don't want the fun of something breaking down at those speeds.
Not that I didn't try it out, but that was only one time to see if it is in the car.


With this speed you have to watch out for the special equipment of the police.



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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Lennart Sorth
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« Reply #16 on: June 24, 2009, 01:39:15 am »

With this speed you have to watch out for the special equipment of the police.
Nice one. :-)

Just for clarification I did 243k (GPS) in my Peugeot 406 Coupe, north of Essen a quiet evening last summer, on a derestricted stretch of German Autobahn - this is on the way back (my son driving me taking the picture, we're not that dumb :-) ) where we only nudged 240k (149mph - surprisingly precise comparing to GPS) - we found an apparently quite new stretch of Autobahn in the middle of the Ruhr district :
  
And I have to say, as fun the Murena is, the 406 Coupe is much better suited for those speeds, larger car, larger wheels, nice big Brembo brakes etc etc.

The Murena I'm quite happy to keep well below 200k and even 80k can be fun on the right roads.


mind you, I have calculated that at the above speed, my V6 drinks 1.1 liter of petrol per minute :-)


/Lennart
« Last Edit: June 24, 2009, 01:47:46 am by Lennart Sorth » Logged

Lennart.Sorth@matrasport.dk
Murena 1983 1.9i silver // Honda e '20 Charge Yellow  // VW Polo '22 1.0 tsi silver//
michaltalbot
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« Reply #17 on: June 24, 2009, 09:07:22 am »

188........No License for 6 weeks.
215........No license for 3months.
246........Probably dead penalty over here.


 Cheesy Cheesy Cheesy

Are your policemen really so hard? Here the top speed on highway is 130km/h but when you're driving 130k, you have all the time someone 30cm behind you trying to push you out of the street. As my average is 400km/day (in a company car) I am also using highways in 150 - 180 km/h commonly. The stationary radars are only in cities and everybody knows where, so the trafic goes fast - than slowly passing the radar - than fast  Cheesy and on highways there are only few Passat R36 and Mondeo ST - so when you see this car, you drive slowly, that's all. And also all GPS navi systems are informing about radars, the same all radio stations are informing about places where police is maesuring the speed. I say, that, in this situation, if somebody is measured, he has to be so dumb that he can kill somebody driving so reckless, so good that he is punished. If I had to drive max 130k on highway I had to be thinking that I'm sleeping behind the steering wheel...

« Last Edit: June 24, 2009, 09:11:52 am by michaltalbot » Logged

Oetker
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« Reply #18 on: June 24, 2009, 09:31:19 am »

 Quote Michael.
-------------------
I am also using highways in 150 - 180 km/h commonly.
And also all GPS navi systems are informing about radars.
If I had to drive max 130k on highway I had to be thinking that I'm sleeping behind the steering wheel...
====================================================================

Driving in the Netherlands with those speeds, and you loose your'e license in a few days for sure, or at least give you speeding tickets that wil make you feel a poor man that month.

My last ticket was in april.
I drove 86 km/h, where 80 was alowed Shocked
I know it, I am a speedpirat Tongue

GPS don't know about laserguns and we have a lot of unrecognisable flying policecars on the road.

You get used to slow driving, the distance between the bigger places are not that much overhere.
If you do that long enough, 150 km/h gives the feeling that your'e flying.

100- 120km/h is max allowed overhere on the highways.
Sleeping with those speeds is impossible.
There are enough idiots on the road that keep you awake.
« Last Edit: June 24, 2009, 09:46:51 am by Oetker » Logged

I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
michaltalbot
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« Reply #19 on: June 24, 2009, 09:50:38 am »

Wow, it's not good  Embarrassed fast driving is the best relax and I can't be every second day on the circuit, so it's fine that our cops are more benevolent. And true is, that those people, who think that speed is the biggest reason for crashes, are absolutely out, because when you drive fast, you are concentrating for it much more than people who are bored by traveling at 100km/h. If someone is stupid, he can kill himself or someone else at 30km/h  Roll Eyes
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Oetker
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« Reply #20 on: June 24, 2009, 10:04:38 am »

Quote Michael
---------------
And true is, that those people, who think that speed is the biggest reason for crashes, are absolutely out, because when you drive fast, you are concentrating for it much more than people who are bored by traveling at 100km/h
=====================================================================

Our country is small and very populated.
On a bad day we have 400km traffic jam on the roads.
Nobody expects someone driving 200 km/h behind him.
The only speedy driving we can do is in the night from 02.00 AM til 05.00 AM.

Its no problem.
The best fun driving the Murena, is on the smaller countryroads.
« Last Edit: June 24, 2009, 10:10:38 am by Oetker » Logged

I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Jon Weywadt
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« Reply #21 on: June 25, 2009, 08:47:56 am »

Ussualy the information you are requesting is listed in the user manual...
Given as speed in highest gear at 1000rpm.

You are right. I searched the repair manual from Simon and found that on a 1.6 with 195/60 X 14 rear tires, at 1000 RPM the speed is 30.91 kmh. On the 2.2 with 195/60 X 14 tires, at 1000 RPM, the speed is 33,79 kph. So at 3000 rpm the speed shoulld be 101,37 kph.

That is interesting, because on my 2.2 I am pretty sure that at 3000 RPM it goes about 120 kph. Grin
I will verify that this weekend. Of course it also depends on how accurate the tachometer is.  Any ideas on how to check that? Huh
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Matranaut par excellence Cool
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« Reply #22 on: June 25, 2009, 12:58:36 pm »


You are right. I searched the repair manual from Simon and found that on a 1.6 with 195/60 X 14 rear tires, at 1000 RPM the speed is 30.91 kmh. On the 2.2 with 195/60 X 14 tires, at 1000 RPM, the speed is 33,79 kph. So at 3000 rpm the speed shoulld be 101,37 kph.

That is interesting, because on my 2.2 I am pretty sure that at 3000 RPM it goes about 120 kph. Grin
I will verify that this weekend. Of course it also depends on how accurate the tachometer is.  Any ideas on how to check that? Huh

I have just the same: 3000RPM at 120km/h. Seems to be rather usual, due to inaccurate tachometer.

Jan
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Jan Verdam
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« Reply #23 on: June 25, 2009, 04:06:55 pm »

You can check it very easily - go on highway and reach speed 120km/h on your tacho, than you have to make 1km (hope that you also have the signs in the middle of the highway each km as we have) in 30 seconds. If it will be more, than your tacho shows more than is real. For example if you need 33 sec for driving 1km than your real speed is 108km/h. BUT this experience (tacho shows more) I have from all Talbots and Simcas, but in all 2,2 Murenas AFAK the speedometer shows exactly the true (sometimes a little less - 200 when real is 203) but the rewmeter shows less than is real! So when it shows 3000 rpm, your engine has 3550 rpm real. And that's more dangerous Wink
You can check your real rews with stroboscope which is usually used for setting the pre-ignition.
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roy4matra
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« Reply #24 on: June 25, 2009, 08:54:00 pm »

Hi Roy.

I was wondering if, without opening the gearbox, there is a way to tell if a previous owner has installed the 5th. gear kit. It should be possible to tell if you know how fast the car should drive in 5th gear at a given RPM, and with the standard tire size. Do you know if that kind of information is available anywhere?

First let me say that all the rev counters (tachometers) on Matra cars are inaccurate, whilst the speedometers are usually quite accurate, so you cannot use the standard instruments and compare them with the book figures.  The handbook and manual gives you the gearing for all the gears, but since we are only talking about a higher 5th gear we will only look at the 5th gear ratio.

Since there are many cars out there with non-standard wheels and tyres, I am only talking here about standard cars.  For anything different you will have to calculate for your differences.  The Murena 1.6 has a 62/13 (4.769:1) diff. ratio and 195/70 x 13 rear tyres and gives 31.65 kph per 1000 rpm in 5th (or 30.96 kph if on alloys with 60 profile tyres like the 2.2).  The 2.2 has a higher 61/14 (4.357:1) diff. ratio and 195/60 x 14 rear tyres and gives 33.89 kph at 1000 rpm in 5th.  (Please note the Murena hand book 3 for the 2.2 has mistakes in the gear speed calculations as they have used the wrong 1.6 diff. ratio!)

So at 3000 in top the 1.6 should be doing 94.95 kph  Let's call it 95 kph.  Because of the rev counter inaccuracy you will find that at 3000 rpm the speedo will read higher.  This is because the revs are actually higher.  Similarly the 2.2 at 3000 rpm should be doing 101.67 kph but it will often read more than 110 kph!  Again it is because the revs are actually higher.  When I first got my Murena 2.2 I noticed the power peak appeared to be at just over 5200 rpm, and it was best to change up around 5200 to get the best acceleration, but the engine peak according to the spec. is 5800 rpm.  Well that 5200 on the rev counter was actually 5800!  So don't ever take the engine to the red line (assuming you could get it there) on the tacho (6300 rpm on my 2.2) as you will actually be pulling about 7000 rpm - well over the rev limit!

The high 5th gear will add approx. 9 per cent to the top gear ratio, so for a given speed the revs will be lower.  So lets go back to my car as an example.  At 3000 rpm it was indicating 110 kph in standard set up.  With the high 5th gear it now shows 2700 rpm for the same speed.  The new 5th gear should now be giving 36.766 kph at 1000 rpm.  Therefore you can see that at 6000 rpm the original 5th gear gave 203.3 kph top speed and the new one should give 220.6 kph

It was reported in the press that the Murena 2.2 did indeed have a 200 kph top speed on test.  Now any car that can achieve top speed in top gear shows that it is under-geared.  Top gear should be a cruise gear (except in a racing car!) yet because of its good aerodynamics and under-gearing the Murena could pull the max. revs in top gear, which shows it is capable of more.  With my high fifth gear and extra power slightly above the 'S' (mine measured 145 bhp on a dyno) my car has pulled max. revs in 5th again (yes, it was showing off the clock on the speedo and a true 135 mph and when we checked another club members car we actually got 138 mph both cross checked for accuracy with GPS) and proved that it can actually cope with an even high ratio.  However, it is much more suitable than the standard and doesn't feel under-geared anymore, which it always did with the original.

Finally, to answer your question, can you tell without taking the box apart?  Well I could, because when you drive them, 4th and 5th are too close together, and if the high 5th is fitted, there is a bigger gap.  It is not too big a gap but it is noticeably better.

Roy
« Last Edit: January 12, 2020, 08:46:34 pm by roy4matra » Logged

roy4matra
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« Reply #25 on: June 25, 2009, 09:05:02 pm »

Yes, question is - how high the top speed than will be? And if we'll find an used CX gearbox, how we recognise that it is the right one?

I think topspeed wil not change if you not push some extra horsepower out of the engine itself.
Possible that topspeed is even lower.

No this is not true in this case.  It would only be slower if it was over-geared as a true top gear should be.  Because the car is still not over-geared even with the high fifth, it will still pull well in top and give a higher speed.  I have fitted a 2.2 Murena that had a totally standard engine with this high 5th, and this performed better too.

The point though as Hans said is not to have a higher top speed, but to get more relaxed cruising, and it has worked out that on a long run where you spend more time in top, the fuel consumption does improve slightly.

Roy
« Last Edit: January 12, 2020, 08:48:07 pm by roy4matra » Logged

michaltalbot
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« Reply #26 on: June 25, 2009, 09:50:23 pm »

Well, Roy confirmed my words Wink and I am really interested in it! It is really much more clever than some dirty (and often more expensive and complicated) conversions...
Wow Roy, thank You for sharing this genial improve! I have to find some CX 2,5 TD gearbox...
PS: and I was not so far with my imagine of reaching 225km/h. Well, 220km/h is very nice, because speedometers in all other cars are lying cca 7% so when they shows 240km/h the reality is 223km/h... BINGO!
« Last Edit: June 25, 2009, 09:58:50 pm by michaltalbot » Logged

michaltalbot
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« Reply #27 on: June 25, 2009, 10:46:27 pm »

Is this, what we see on the picture, the gear wheels which have to be changed?

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Jon Weywadt
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« Reply #28 on: June 25, 2009, 11:02:07 pm »

Is this, what we see on the picture, the gear wheels which have to be changed?


Yep, those are the 5th. gear wheels Smiley
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Matranaut par excellence Cool
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« Reply #29 on: June 25, 2009, 11:24:32 pm »

Well it's not necessary to have them brand new, so used CX gearbox must be good too. Time to search one...  Grin
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