Saturday, April 24, 2010

Wheels and tires

I seem to be accumulating wheels and tires before even getting on the road. Currently have some 15" disk wheels with junk yard tires for rolling around the various paint and restoration shops.

Yesterday acquired a set of 4 Dayton 15" wire wheels with Dunlop SP40 a/s P215/70R15 tires for show to supplement the 17" wheels for go that have not been on the ground yet (previous post).



Of course, being the geek that I am had to plot the differences in performance:

For show:
Tyre:- Dunlop 215/70R15
Top Gear gives 27.738 MPH/1000 RPM and a top speed of 171.975 MPH at 6200 RPM

Engine speeds in top gear:-
30 MPH = 1082 RPM 40 MPH = 1442 RPM 50 MPH = 1803 RPM 60 MPH = 2163 RPM
70 MPH = 2524 RPM 80 MPH = 2884 RPM 90 MPH = 3245 RPM 100 MPH = 3605 RPM

Top Speed in 1 gear = 62.082 MPH
And changes into 2 gear at 3962 RPM dropping 2238 RPM
Top Speed in 2 gear = 97.155 MPH
And changes into 3 gear at 4871 RPM dropping 1329 RPM
Top Speed in 3 gear = 123.652 MPH
And changes into 4 gear at 5124 RPM dropping 1076 RPM
Top Speed in 4 gear = 149.618 MPH
And changes into 5 gear at 5394 RPM dropping 806 RPM
Top Speed in 5 gear = 171.975 MPH

For go:
Tyre:- BFGoodrich 205/40ZR17

Top Gear gives 24.170 MPH/1000 RPM and a top speed of 149.854 MPH at 6200 RPM

Engine speeds in top gear:-
30 MPH = 1241 RPM 40 MPH = 1655 RPM 50 MPH = 2069 RPM 60 MPH = 2482 RPM
70 MPH = 2896 RPM 80 MPH = 3310 RPM 90 MPH = 3724 RPM 100 MPH = 4137 RPM

Top Speed in 1 gear = 54.097 MPH
And changes into 2 gear at 3962 RPM dropping 2238 RPM
Top Speed in 2 gear = 84.658 MPH
And changes into 3 gear at 4871 RPM dropping 1329 RPM
Top Speed in 3 gear = 107.746 MPH
And changes into 4 gear at 5124 RPM dropping 1076 RPM
Top Speed in 4 gear = 130.373 MPH
And changes into 5 gear at 5394 RPM dropping 806 RPM
Top Speed in 5 gear = 149.854 MPH

Four sets of rims. These two plus the 15" roll arounds and the 16" original disk wheels.

No problems with the speedometer. Autometer Cobalt electronically calibrated hall effect pickup. Just reset and drive 2 miles to calibrate and set to go.

1 comment:

PiTo said...

Difference in unsprung weight. Wire wheels and tires are 53 pounds each (212 lbs total) vs 40 pounds each (160 lbs total).
Can hardly wait to try them both out after scouring the dead rubber off the roll arounds :-)