What should I be revving to

[MIKEP]

Can one of you Spyder owners tell me what your revving at at 100 km in 5th

Seems a bit high to me.Any advice

[mknz]

Would help if I knew the gearbox and tyre, wheel combo for the math. For the 5 speed it should be about 3K.

[*84vvt]

Would help if I knew the gearbox and tyre, wheel combo for the math. For the 5 speed it should be about 3K.

6 speed is the same 3000 to 3200rpm @ 100Kmh

[psyguy]

I'm on 225/45/16 and six-speed gearbox so not sure if that's any help but can let you know tomorrow when we meet Mike

[GDII]

RPM vs indicated speed on the gauges is not affected by tyre size. Only everything from the speedo sensor, the diff and back to the clutch.
So you need to know your gear ratios and diff/final drive ratio and to ensure the speedo sensor is configured correctly. The sensor being wrong is most likely not a factor in most situations.

[psyguy]

I thought changing the overall tyre diameter affects the accuracy of the speedometer

[GDII]

I thought changing the overall tyre diameter affects the accuracy of the speedometer

Yes that's true. But no matter the size of the tyre, the RPM at say 3000 will always read at 100kph on the gauges. Numbers are an example, not the answer to your question. Take the wheels off the car and run it on stands and the RPM will still read the same as the speed.

If you are wanting to use GPS as your accurate speedo then the tyre size will affect what RPM you are at to acheive 100kph. Car speedos tend to read about 3kph lower than the actual speed on factory size tyres.

[psyguy]

So, the "real world" data (engine rpm vs vehicle's achieved kmph) does change with the tyre diameter but the calculated data (on the car's dashboard) stays the same regardless of the tyre diameter?

[MIKEP]

Thanks guys was only a query.My AW sits at 2000 in 4th it's still on 14s.My SW on 205/45/16 but beams powered is about the same.

it was my first highway drive today with Dorothy and I noticed it was 3K . It's ok the book says 3k I was just checking .im not going to lose any sleep over it

[GDII]

Thanks guys was only a query.My AW sits at 2000 in 4th it's still on 14s.My SW on 205/45/16 but beams powered is about the same.

it was my first highway drive today with Dorothy and I noticed it was 3K . It's ok the book says 3k I was just checking .im not going to lose any sleep over it

All good. I assume the AW and SW are auto? They rev much lower than the manuals at around 3K in 5th.

So, the "real world" data (engine rpm vs vehicle's achieved kmph) does change with the tyre diameter but the calculated data (on the car's dashboard) stays the same regardless of the tyre diameter?

Yes that's correct.

[*84vvt]

GD11 has a point about the calculated speed
my speed is Rpm vers GPS as my speed o is a long way out

[psyguy]

Can one of you Spyder owners tell me what your revving at at 100 km in 5th

3200 rpm

[EssDub]

3450 on a .815:1 6th and 4.51:1 diff, 205/50r15 tyre.

If you want it lower, get a C65 and have your 2900rpm @100k figure.

[psyguy]

Can one of you Spyder owners tell me what your revving at at 100 km in 5th

3200 rpm

Mike, this is on a 6 speed, (and the 5th gear is different to a 5-speed), so please ignore!

[EssDub]

5th gear is the same on all C56/65M boxes in Spyders.