Leeboy

If one has had a Quaife LSD fitted, should this have any affect on speedo accuracy - i.e. where does the speedo take its drive from? I ask this because after having one of these fitted, when I drive at the speed limit, I seem to be wanting to go faster than those around me. Today for instance, my speedo was indicating about 25mph following cars in a 30 zone although the speed felt about right. Likewise, at 6000 rpm in second, the speedo is not at the 60 mark, I'm sure it use to be. Any suggestion, I need to know before Mr Speed Camera gets me!!!

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Lee

Want to be carbon-neutral while driving? Hold your breath!

TaviaRS

Lee,

Here are the ratios for the RS box, they might help....

Gear ratios/mph per 000 as follows:
1st = 3.3/6.2
2nd = 1.94/10.5
3rd = 1.31/15.6
4th = 1.03/19.8
5th = 0.84/24.3

Therefore max speed at 7k is

1st = 43
2nd = 74
3rd = 109
4th = 139
5th = 170.1

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A jolly sensible Mercedes E class saloon in a rather fetching bluey grey colour. No it isn't fast, no it isn't modded, and yes, it will still eat your Fabia for breakfast.

Official mobile chicane for Briskoda trackdays

boyced

whats the do then? any good?

Have you got anysort of satnav? as this will give you a speed reading...

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lozgti

I'm not trying hard enough with 4th and 5th

delcac

Do you happen to know what they are for a 6 speed 02M box, oh wise one.

Just asking on a friends behalf you understand.

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The Red Devil

Leeboy

Yes, makes a big difference on drive out of corners when you boot it, cuts out power induced understeer drift, car goes in the direction you want, almost makes it feel 4wd (not that I have driven one, so how I can say that I don't know, but this is how I would want one to drive.... erm)

No Sat Nav, perhaps I will get my other half to drive at 30 in her car and I can follow.

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Lee

Want to be carbon-neutral while driving? Hold your breath!

boyced

where's the fun in that then ? Have you got a 6 speed box ?

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delcac

Lee,

If you have a 6 speed (02M) and new dif it's as much as 8 MPH out@100, well my friends one is anyway.

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The Red Devil

boyced

Isn't the speed sensor connected to the gearbox?

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Leeboy

Your friend is quite a one for fiddling with his/her motor, you should introduce us all at some point .

Back to the box, no it is still the 02J 5 sp. box. Does your friend still possess that GPS timing device gadget, famously used at the Funky Jutel Mega Meet 0-60 sprint trial? Perhaps that could help answer my question.

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Lee

Want to be carbon-neutral while driving? Hold your breath!

delcac

It is indeed, just telling like it is, err friends is.

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The Red Devil

delcac

He does indeed, but I would have thought a GPS device would be better for you. Anyway my friend seems to still be able to spin both wheels for some unknown reason.

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The Red Devil

Nigel26

maybe another vRS would be a decent test re the 30mph thing if you have another owner in the area !?

other than that a GPS device would be best.

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Sea Grey Mondeo Titanium X

ColinD

IIRC 3k RPM 5th is 70 or near as dammit...

I'll try to get some speed (GPS) and rpm forgear as I'm on the 02j but without lsd...for now

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DGW

The speedo relies on an electronic speedometer transducer which measures the rotational speed of the transmission final drive and converts this into an electronic signal which is sent to the speedometer module in the instrument panel. The signal is also used as an input by the engine management system ECU. The position of the sensor on the rear transmission casing varies between different types of manual gearbox ie 02J, 02K and 02M. (The 02J's is directly on top of the drive pinion; the 02M's is in the rear of the transmission).

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Denis

2002 Octavia 1.8T 4X4 turbo Estate - rebreathed on by Jabba ... 31.93mpg
2007 Fabia vRS - CC, ESP and full leather trim by Seat Surgeons ...48.57 mpg...

TaviaRS

Des, would your friend happen to have a genuine 02M gearbox or a modded 02J box with the 6 speeds jammed inside?

IIRC the ratios are:

3.417
2.105
1.478
1.133
0.922
0.757

What final drive ratio is "he" running?

__________________
A jolly sensible Mercedes E class saloon in a rather fetching bluey grey colour. No it isn't fast, no it isn't modded, and yes, it will still eat your Fabia for breakfast.

Official mobile chicane for Briskoda trackdays

Leeboy

Further investigation has revealed the source of inaccuracy. I followed my other half to work this morning (her driving a Pug 206) and we "hands-free" communicated when she was doing 30, 40 and 50. My speedo was consistently about 5mph lower.

Later, I noticed when stationary, that the needle is resting over a spot on the dial below the zero mark. Should it be resting on the zero (with engine running)? I think this could be the source of the problem. The complete dashboard has recently been removed, maybe this could be the source of the problem. I assume from what DGW says, the gauge is electronic and does not have a cable like old fashioned cars would.

Anyway, at least I now know.....

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Lee

Want to be carbon-neutral while driving? Hold your breath!

delcac

AIR he has an 02M with some stronger bits in it. Final drive, mmm.

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The Red Devil