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Re: tire size

Posted: Thu Apr 08, 2010 10:58 am
by Hans Efde
The Toyo's 175/65 R13 I had did chafe, but I suppose anything smaller will do.
The 175/50 R13 tyres are the smallest in diameter and limit topspeed. I have them but prefer the bigger tyres. I am going to test the 165/60 R13 ones from my brother and see if that's an improvement in cruising. With 120+ bhp power on tap, the engine should be strong enough the pull the car through, even with the now fitted 3.105 diff.
On my first coupe with a 1400 Avonbar engine and a 3.105 diff it would not pull past 5500 rpm in 4th gear with the Toyo tyres (that was the time there were no gatso's around). That was an engine with about 90BHP. Realistically a Midas with a 3.105 diff and with the bigger tyres, it would need at least 100bhp to make full use of the engine rpm band.
In Sheepherd case it would be interesting to know what top speed he now can do. At least he can go as fast as he likes on the Autobahn. Lucky him!

Re: tire size

Posted: Thu Apr 08, 2010 6:01 pm
by The Sheepherd
Hm, I don't think the 165/60's are longer available, at least I don't find any new, that's why I changend to the 175/50's.
After 2 days driving them now I can't say anything bad about them, no rubbing, great on autobahn too, but didn't tested the topspeed by now (and didn't do so before, damn 10 year old ...).
At least I will test it out once, hope the poor one doesn't scream too much...

Summa summarum: I'm happy and I always get excited when is see my coupe with the new tyres :D :D :D

Re: tire size

Posted: Thu Apr 08, 2010 6:05 pm
by The Sheepherd
I'm not really looking for topspeed, anything faster than my Mini is ok, prefer comfortly cruising ...
Speedometer now shows about 5 km/h less, but want to test it out with a gps-navigation...

Maybe I'm lucky because of the no-speed-limit-autobahn, but believe me, I enjoyed really much the driving in the netherlands without all the german speed-weirdos around,
it was soooooooo relaxing ;)

Re: tire size

Posted: Fri Apr 09, 2010 8:35 pm
by graemedench
Cars looking really good there. bit more work to mine and I'll be looking for tires. Doing the dash just now. white flowcoat to match the outside. nice and clean.

Re: tire size

Posted: Sat Apr 10, 2010 2:21 pm
by The Sheepherd
Sounds good

Re: tire size

Posted: Sun May 09, 2010 1:06 pm
by The Sheepherd
Ok, after oil-change and check on all other fluids I reached on the autobahn on the way home 175 km/h (around, including the 5 it shows to less) at 6000 rpm...

Re: tire size

Posted: Wed May 12, 2010 10:44 am
by Hans Efde
That's a disappointing topspeed. But since you ran out of rpm this is due to your tyre size and diff. It is similar to my Midas, so you must have a 3.105 diff. With the 185/55 tyres you would have reached 185 kph (about 6% faster). The coupe is aerodynamic enough to get to 200kph with just 90 bhp, but 4 gears and the 13 inch wheelsize kill it. Changing the diff to a 2.9 would adversely affect the lively feeling of the car on B-roads, unless the engine is upped to 120bhp. But A-series engines don't last long with this kind of power. It would be nice to see how the coupe does with a modern small engine and 5speed gearbox. I have a wild plan for a coupe, but first need to sell the convertible (unfortunately) to make room and fund the project.

Re: tire size

Posted: Wed May 12, 2010 8:00 pm
by The Sheepherd
Hm, I'm not dissapointed, not really ... I know there should be more, or could be more, but at least it's only a 4-speed, and former owner used it mostly on small- and middle-size roads too,
but I'm not really that into top-speed and it's fast enough to travel with my friends of my Mini-club ... thought about diff-change too, but won't kill the livelieness...

Re: tire size

Posted: Tue May 18, 2010 3:55 pm
by Hans Efde
This weekend I installed the Revolution wheels from my brothers Midas. He had his car in storage for 3 years, so it was time to get the flat edges of his tyres! He has Falken 165/60 tyres, while I have 175/50 Pirelli tyres on Dynamic wheels. We noted that the offset of the Dynamic wheels is 1cm less than the Revolutions, i.e. the Revolutions stick out 1cm more. Here's a pic of both configurations:
wheels.jpg
wheels.jpg (92.34 KiB) Viewed 10276 times
We tested both wheels on the highway and found a difference of less than 5% in speed. But the behaviour of the car was different. The Pirelli 175/50 tyres make the Midas sharper and a bit more nervous. The Falken 165/60 turn the car into a cruiser, softer and more stable. They seemed quieter as well. I think for general use of the Midas it is the better tyre. But the biggest drawback of the Falken tyres I found is the turning circle. It is greatly increased because the tyres rub against the inner wheel well at maximum steering. In fact maximum steering can not be reached, while with the 175/50 tyres I don't have a problem at all. I have to make a tight turn to get my car into the garage and couldn't make it in 1 go with the Falken tyres. Well I thought it could and now there is a blue smear on the recently white painted walls.
I hadn't expected these problems with the 165/60 tyres and suspect the 185/55 tyres may be even worse with turning. So I just stick to my 175/50 tyres and accept the higher rpm on the highway. Should you think about bigger tyres on your Midas then keep in mind they will increase the turning circle of the car.

Re: tire size

Posted: Tue May 18, 2010 4:42 pm
by manifold
Hans, the narrower track of your wheels will make the car more nervous. That might also (partially) explain the rubbing on the arches with Revolutions. The falkens have a broad shoulder...and the offset will push the wheel towards the arch on full lock. I noticed that when comparing wheels to the 'Factory' Compomotive MS wheels which have a better inset. Like on the Red Midas Convertible Brochure.

One of the advantages of going split rims was I could get the offset spot on. The nervous behavior can partly be adjusted for in the tracking.

Offsetting the wheels in or out will have a direct impact on the overall front suspension geometry. Maybe a halfway house, using falkens on your wheels or pirellis on Revos might get some of the right balance (but not the high revs).