847 replies to this topic

[mini13]

Yeah has your phone got GPS on it? Or use a sat Nav.

[minisilverbullet]

I have done about 100 miles today. 

 

I am sure my speedo is out. 

 

At 5000 rpm speedo reads 120kph / 74.5 mph.  I am sure I am about 10 - 15 mph over (though hard to tell)

 

I have 10 inch wheels a 3.2 Fd and a 7/18 worm and pinion ratio. 

 

Using Guessworks calculator at 5000 rpm speed should be 82(90)   Actual Speed vs (Speedo Reading) 

 

g) 

 Actual Speed vs (Speedo Reading) 

 

 

 

I guess i can see with a gps

 

 

Just as I thought at 5000 rpm in 4th the speedo reads 120KPH (74.5 mph)

 

However the actual speed is  135 KPH (84 mph). I guess i will look at finding an alternative to get a speedo reading. any suggestions: electronic pick up / GPS?

 

Also, When looking at Guessworks seems like my speed / rpm looks to be more like the 3.4 FD. 

 

 

[Midas Mk1]

I've found guessworks calc to be a little out on the 4 different fd speedo and pinion / worm gear combinations I've had over the years, more of a rough guide. Satnav or iPhone app is probably the easiest way to check, confirming the app with a modern car with digi readout will help confirm too.

Very jealous, would love a twin'k one day.

[nicklouse]

I agree on that, his calc gave a 3.4 diff ratio from sat nav and revs but it was a 3.2 when I looked at it.

[minisilverbullet]

So it was bit icy to tale the mini this morning, but I got a chance to test the GPS in my Audi. 

 

Appears that it is actually  6KPH under the what the speedo on the Audi states. 

 

So I guess my mini speedo is 15 - 20 KPM out

[fuzzy-hair-man]

That's about right, when my speedo was tested for engineering my micra conversion it had to read between the actual speed and 10% fast (so that you'd be going slightly slower than you thought) OEM speedos are generally setup the same way.

[Mini Manannán]

Yup, I've always understood that OEM speedos are 10% fast.

[minisilverbullet]

mine appears to be 10-15% slow 

[fuzzy-hair-man]

See if you can find a shop specialising in instruments they should be able to tune it for you.

[minisilverbullet]

So after a couple of days, some observations:

 

1. While it is really quick, I feel like it should be quicker. Looking at the sock filters, it looks like the bonnet might be restricting the air flow. So I have ordered 4 single KN filters, I will lose the ram pipes but gain better air flow. I will also book it in for a rolling road tune. 

 

2. Not the most fuel efficient in the world. Might look into adding a new tank.

 

3. the speedo is out as above. Not sure what to do, but I will order a cheapish GPS speedo for the time being.

 

4. I am no way as tough as I used to be. I  used to use it all year round. But the last days I have been frozen. Hats of those using their minis all year round. 

[minisilverbullet]

The sock filters i had have been on my mind it does seem that the front is very close to the bonnet and thus possible restricting the air flow. A number of mates and both test guys mentioned it. 

 

I fitted a set of K&N filters this evening (model number R-1070). the compromise fitting these is that I had to remove the ram pipes. Feels a little quicker and more responsive.

 

Alos look quite good:

 

 

[Northernpower]

_{The under bonnet picture does look good. Are you going to take it to a rolling road?} 

[minisilverbullet]

_{The under bonnet picture does look good. Are you going to take it to a rolling road?} 

yip next step rolling road. 

[mina08]

That is a snug fit, looks mint. Could you put small/large holes in the front of the bonnet to get airflow, or make a deflector from the front grill.

[minisilverbullet]

Just a small follow up on the brake servo, just in case someone else needs to do it. Actually works really well. 

 

There is enough vacuum and it definitely aids the braking. Pedal is a little harder than it was before. 

 

Onto the brake serve vacuum. Ordered the parts i needed: some Ts a Y, 4mm, 5mm and 9mm vacuum line a reducer and a nice little one way valve.