High Revving

[millydred]

Hi again - my car is doing 5,000 revs at 70 mph - it is a US import - any ideas of how I can lower the revs.

[PoB]

Hi
Sounds like a diff issue, change it to a uk spec ratio or even a 2.88 xjs diff, don't forget to check the replacement is a power lock. There should be 2 tags bolted on the diff cover one stamped PL the other with the ratio.

Regards

[nick320]

For 5,000rpm at 70 mph you must have a diff of about 5:1 (assuming standard 185x15 tyres). The standard US diff for an Auto box was 3.31:1 which would give about 110mph at 5000rpm. Alternative ratios could be requested but I don't think any went up to 5:1.

Do you think the speedo and tacho are reading correctly ? Is the 'box getting into top gear ?

Nick

[DaveK]

Nick,

I have a '61 manual box with 3.31:1 diff and it doesn't hit 5000 rpm at 110 mph no where near I would guess that its not getting into top gear.

Dave

[vellis48]

Still saving up for an E-type, but my Mk2 automatic pulls just over 70mph at 5000rpm in 2nd gear, so it does look like you're not getting in to top.

Reminds me of the slightly silly American song from the late '50s "Beep, Beep", with the punchline "Hey buddy how do I get this car outa second gear?". But that was a Nash Rambler doing 120 in 2nd gear! Don't make songs like that any more.

Vince

[PoB]

Hi Milidred
Can you confirm the E Type, is it series 1 2 or 3 2+2 and if its a manual or auto/ Also how are you determining the rev's and speed

Regards
Pat

[millydred]

hi it is a 1.5 2+2 and automatic

[PoB]

Hi

It sounds like its not getting into top, can you count the changes, also tryu and have someone follow you and flash when the get to say 50mph, 60mph and 70. This would confirm your speedo calibration (approx) and then check off against the revs.

The next thing would be to check engine revs to tacho with a strobe light as some have revs built in.

I am still suspecting not hitting top gear.

Regards
Pat