4250rpm @ 70mph in 5th - normal?

[Luigi]

Back from Norfolk in my 2000 Spyder and I’m heading towards this car being more for country lanes than motorways.

The engine noise is unbearable at legal speeds.  The ratios are spaced well up to 4th but 5th does nothing to help the engine cruise. It feels like there should be a sixth gear.

Or am I being too 21st century again?

[WestonE]

2 options. The first is find a VX gearbox which has a higher final drive. The second is get busy with the Dynamat/ Dyna foam or equivalents. Assuming this is engine noise focus on a bonnet liner and firewall lining.
Are your exhaust silencers past their best?

[Luigi]

So it sounds like it is normal then 

I’ve been looking at a bonnet liner so looks like I’ll be bringing that purchase forward.

[lancialulu]

cheaper option is ear plugs! But seriously why do you not like the Lampredi engine noise?

[rossocorsa]

I don't think that rpm in 5th isnormal for a 2000. It should be about 3600rpm at 70 mph I suspect that someone has fitted a 1300 gearbox, 16.7mph per 1000 rpm in 5th! Very sporty but obviously busy sounding.

[peteracs]

Hi

Yes, sounds like low ratio diff box which would indicate 1300. My 1600 is well below that at 70. Obviously also depends on tyre size.

You can check what diff ratio you have as it is (faintly) stamped on the gearbox housing.

Oh and yes the Spider is noisy, I find having the rear hood down far more enjoyable than with it up.

Peter

[A Ross]

This is exactly where my 1300 saloon cruises. She's very much singing at 70mph. I thought briefly about fitting the higher ratio diff, but then thought better of it as I need that low ratio around town and to keep originality. My 1600 coupé is cruises at 70mph just under 4000rpm. All of this seems ridiculously high when you daily drive a Golf TDI but it's part of the charm!

I'm going with the theory set out by rossocorsa below that a 1300 gearbox has been fitted at some point probably to improve "off the lights" performance.

[Ferrit]

Yesterday the A3 just felt the wrong place to be, B roads are so much more fun.  I will check my car tomorrow on a run down to be left with the tuning people.

Funny I was talking yesterday to my friend on the same subject. His 35 Lagonda he was driving at a couple thousand rpm, on his rev counter there is a green section just before the 5k readline of about 1000rpm, the owners club told him this is where you drive it 

[neromoto]

Here are some documents.

[HFStuart]

So it sounds like it is normal then 

Very much not! I have an original road test that gives the mph/rpm figures  - I'll fish it out to see what it should be.

[peteracs]

Hi Luigi

The graphs above shows 4250 = approx 85mph in 2000

Peter

[Nigel]

Late input here from my vx box:

At an indicated 75mph, engine is spinning at 3250.

When I first proposed using this box on a standard carb 2000 there were
concerns that performance would suffer. That is quite likely still, but the trade
off in relaxed cruising makes it all worthwhile.

Nigel

[HFStuart]

Spider 2000
5th 19.7 mph/1000 rpm
4th 15.8 mph/1000 rpm

HPE VX
5th 22.3 mph/1000 rpm
4th 17.9 mph/1000 rpm

Coupe 1300
5th 16.7 mph/1000 rpm
4th 13.3 mph/1000 rpm

You, my friend have a 1300 gearbox fitted! Or at least the 4.5:1 ratio diff from one.

[Nigel]

Posted elsewhere on here, but for future reference as it
pertains to this chat, the gearbox ratio is stamped at this location.

Normally difficult to photograph, in the drawn rectangle above the drive flange
is the mark.
In this case, it's the 17/64 from my 83 HPE

Luigi, this box is complete but numerous bearings are noisy, except for the diff
bearings which I replaced. It would need an overhaul.