6500rpm in 4th = ?

[Mark_BT52]

I was too busy to look at the dial, all I know is that the change up light at 6500rpm lit up and I was in 4th gear.

It's a Tuscan S, but I'm not conviced it has a close ratio box (early 2003 car).

Can anyone tell me what speed this gives?

Mark

[T88CAN]

20.0mph/1000 rpm on 18`s with standard gear ratios 6500rpm = 130mph
:weresmeanorack:

[dannylt]

That can't be right? 7000 in my Cerbera was 160ish?

[Mark_BT52]

Thanks for that. That means probably 135ish before braking into Redgate as the 6500rpm light was on for a second or so before I lifted off.

No wonder it looked so fast watching from the pitwall, that's a good 20mph more than I get in the Exige!

[T88CAN]

dannylt said:

That can't be right? 7000 in my Cerbera was 160ish?

get me the spec i.e wheels, age, 4.2/4.5/SP6 ect and i will work it out

[T88CAN]

21.5mph/1000rpm 4.5Cerb on 17s 7000rpm in 4th =150mph
21.8mph/1000rpm 4.2 on 16s 7000rpm = 153mph
19.8mph/1000rpm SP6 on 16s 7000rpm = 138mph
difference is speedo error

[bilton_d]

what about running 18's with either 35 or 40 series tyres?

[jsr]

Assuming tyre width of 245 and sidewall of 40, then 6500 in 4th is 139mph. If 35 sidewall, then it's 133.

I made a gear ratio and wheel radius calculator in Flash Actionscript. Will put it on my website soon, as it's quite useful.

[whitey]

dannylt said:

That can't be right? 7000 in my Cerbera was 160ish?

I'm sure I don't change into 5th until about 160ish in my Tuscan either, on an airfield of course

[andyvdg]

Previously I have been told :

Speed @ 7000 rpm

gear Normal Close ratio
1 51 62
2 77 96
3 113 121
4 151 150
5 189 188

Which makes 6500 in 4th on a standard or close ratio box 140 mph.

[andyvdg]

jsr said:

Assuming tyre width of 245 and sidewall of 40, then 6500 in 4th is 139mph. If 35 sidewall, then it's 133. I made a gear ratio and wheel radius calculator in Flash Actionscript. Will put it on my website soon, as it's quite useful.

Does that mean my standard Tuscan on 245/40 is faster than an S ? Maybe not, as the S wears 255/35s.

Cheers,

Andy.

[Alf Essex]

Mark_BT52 said:

I was too busy to look at the dial, all I know is that the change up light at 6500rpm lit up and I was in 4th gear. It's a Tuscan S, but I'm not conviced it has a close ratio box (early 2003 car). Can anyone tell me what speed this gives? Mark

Well I have the March'03 model and it has the close ratio box...

Alan.

[Mark_BT52]

Ah, well looking at the info it appears that there's virtually no difference between 4th and 5th gear between the normal box and the close ratio.

I was judging by how low 5th gear was... so maybe I have got the close-ratio after all.

[mad-doug]

hi Mark
answer is 130 - I did exactly the same at Silverstone (ran out of confidence re hitting red lights, never mind going into 5th)