Final drive calculation.

[Aram]

Thanks Mr. Bandit!

That is something I can work with.
I will check if those speed/rpm figures match with my current setup.

But something is not very cool.
If I give the second transmission set a final drive of 3.3 I do get the 130km @ 3300 rpm which appears on my speedometer now.
But then a 100kmh would be achieved at 2500 rpm. maybe not what I want.

Although the Z4 of a friend of mine does only 1800 rpm at a 100kmh and that pulls fine still.

And it would give a top speed of 295 kmh, nice if you want to scare the living sh*t out of yourself.

3.9 sounds better.

Aram.

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(11-17-2014 06:38 PM)oldeskewltoy Wrote:  The CableX is the simplest solution, albeit not the least expensive.

Tire diameter, as well as an in-accurate speedometer will cause havoc on accurate speed readings.

As far as running a 3.3 final drive.... I had a 3.58 final in my E7 Corolla, and with that I barely had a need for 5th gear..... I've since moved to a 3.90.

Do you remember what rpm at what speed you had back then, with the 3.58?

If the calculator sheet that Bean B. gave is correct than the data for 4.3 that I'm currently running:

120kmh = 4100 rpm
100kmh = 3300 rpm

Which sounds correct.
And that is not nice for long distance running, when going to UK or something you would be worn out before you get there.

3.9 then:

120kmh = 3700 rpm
100kmh = 3100 rpm

Which is better, but 3700 rpm is still a lot for only 120kmh, 3.58 might be better still:

120kmh = 3400 rpm
100kmh = 2800 rpm

And at 3.3 the speedometer would be correct again but:

120kmh = 3100 rpm
100kmh = 2500 rpm

Nice for cruising, but it will probably lose most of its pulling power over the range?


I'm at crossroads, I really don't want the car to be a slouch but at the same time I want to be able to cruise normally on the highway, what to do!!??
3.58 sounds about right at the moment for cruising, but what does it lose on pulling power?


Aram.

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(11-20-2014 02:00 PM)Uzelac Wrote:  

(11-19-2014 07:14 PM)Aram Wrote:  What do you mean with "4.3 is standard for AE86, 4.1 for AE86.", they both are common?

I made a typo, 4.1 is standard for AE85

Regarding sheet, i redone it, hope it is easier now. Everything is chosen and displayed on first sheet.

Sheet gives a error?