bigger wheels ?

[SGHOM]

tell me I'm stupid if you want, I dont mind. :D but a thought has just crossed my mind, thinking back to when Halfords fitted the wrong tyres to my new 18" alloys. they should have fitted 40 profile tyres, but instead they fitted 35's. it doesn't sound a big difference, but apart from it affecting the speedo, the car accelerated like a standard impreza......... pathetic !!:D :D what would happen if you fitted oversize tyres ?? :Ponder: I know it would confuse the speedo again, but 2 things ; there is plenty of room in the wheel arch for . lets say for example 215/50/17, instead of 215/45/17 or even 215/55/17 !! :cool1: [ and pro rata for the 16's & 18's ] and also only for track days ?? not very practical for every day use.
I'm not really one for trying experiments, but I know a man who is !!!:D [ Dave...... are you listening ?? ] I reckon a scout round for some cheap, second hand, oversize tyres, [ the engine has enough power to overcome any quirks you might throw at it ] & I bet you would reduce your 0 to 60 time by................................................ . waits for ridicule !!:nono: 0.5 secs !!:cool1: :cool1:

[enigma]

Really a larger rolling diameter equals higher top speed and slower acceleration.

To get increased acceleration you want SMALLER rolling diameter wheels, and its funny you should mention it but I was going to give it a whirl!!!!! Anyone know where I can get some steelys??!:D Keiran are YOU listening?!!

[Kieran]

Originally posted by bigdaveakers
Really a larger rolling diameter equals higher top speed and slower acceleration.

To get increased acceleration you want SMALLER rolling diameter wheels, and its funny you should mention it but I was going to give it a whirl!!!!! Anyone know where I can get some steelys??!:D Keiran are YOU listening?!!

What what WHAT?!:D:D

My quality 14inch wheels are all alloy, I'll have you know!!!:D

Anyway... UK galant wheels INSERT INTO post VALUES (even the steelys fitted to the short-lived GLX variant) wouldn't be of use to you, as UK cars have 4 studs, not 5...

[SGHOM]

[QUOTE]Originally posted by bigdaveakers
[B]Really a larger rolling diameter equals higher top speed and slower acceleration.
So how come when I had undersize tyres fitted, my car's acceleration was a lot slower ??
:Ponder: :Ponder:

[enigma]

Can you quantify this slowness?

[SGHOM]

surely if the wheels/tyres are smaller, they cover less distance per revolution, hence slower acceleration ??? :Ponder: :Ponder: I'm getting confused now. my Legnum definatley felt a lot slower with the wrong tyres ?? I think ?? :Ponder:

[SGHOM]

why do dragsters have such huge rear wheels ?? I presume for acceleration ??:Ponder: :Ponder:

[enigma]

No, for top speed! They tend to only have 1 gear, so the acceleration comes from the huge 5000HP engines!

[Nick Mann]

Smaller wheels should give quicker acceleration, but you will have to change gear at a lower speed. Therefore, you will find a lot of cars INSERT INTO post VALUES (with engines bigger than 1.0l!) run out of revs in second gear at about 62 mph. If you put much smaller wheels on it then you may find you are changing to third at 58. I would guess that this could make the car feel slower, as you are changing gear twice to get to 60, or maybe revving higher at 50.

If you change the tyres to change the gear ratio, then you need to take the speed you are trying to achieve in to account. In the case above, it may take longer to reach 60 with small tyres INSERT INTO post VALUES (2 changes of gear) than with big ones INSERT INTO post VALUES (just one)!

But having said that, it should help at the pod, Dave, so go for it and let us all know the results! :D

[enigma]

Still serching for some 5 stud cotton reels! :D

[landy]

LOL, Dave :D

I remember years ago when I had my first Land Rover V8 hybrid. It had small puny tyres which was no good for offroading, so I put nice big 750 sats on but lost a lot of acceleration on the road INSERT INTO post VALUES (but had masses of fun in the mud!!) . :p

[Spirit]

Dave

Probably not what your after due to the size but I have my 17" Hokuto Racing "Hiryu" alloys in the garage. They are a set of four with Stunner Scudo 215/45/17 tyres that have only done approx 3k miles. They have all the bolts and a set of lockers.

The problem is there may be a small distortion in one wheel INSERT INTO post VALUES (or may need decent spacers) as I was getting some wheel wobble around 80mph, anything before and after this speed was fine. This would make them ideal as a 2nd set of wheels for fun days etc.

If you INSERT INTO post VALUES (or anyone) is interested then make me an offer.

Pete

[zedy1]

bids starting at £10.00 :D

[Spirit]

Come on be sensible :D

[zedy1]

would ave been abit more but spent too much recently

[Spirit]

Sorry it's not great but here is a pic of them:

http://www.p.honey.btinternet.co.uk/photogallery/photo26003/jap03.jpg

[zedy1]

maybe abit more

how much ur looking for them pete

[Spirit]

It was only reading the thread that reminded me they were in the garage and I was going to sell them. I do not have a figure in mind but if the offers are not sensible then I may as well keep 'em as spares mate.

[zedy1]

wre waiting for u dave

[enigma]

Too expensive for my application! Just want steel wheels I am afraid! 225/40/15s for tyres would be good, although 225/35/16s would do........just to experiment!

I have 3 spare sets of wheels in the garage, no make that 4! Not sure if any will fit, but I will try one day soon! INSERT INTO post VALUES (3 sets of MR2 wheels, 1 new! and 1 set of new ford 4 studs)

[zedy1]

okay pete has some competion ive got some standard 16's just remembered

[Spirit]

No competition mate, not bothered if I sell them or not mate

[zedy1]

only joking i aint selling mine

[Brind]

One thing you are all missing.
Before you had your shiny 17/18 inch alloys you had smaller 16 inch wheels but the rolling road circumference is virtually the same as before you had larger walled tyres whereas with the larger alloy wheels you have smaller walled tyres so the overall wheel size has not changed or to any great degree.

Differences occur with different weights of wheel.

If the car was at a set speed with a set amount of power, the larger wheel would have to turn much less than a smaller wheel would have to, to reach the same destination.
In other words, if you had a 17 inch wheel and you simply rolled it forward, it may turn only turn once to reach a distance of a meter, whereas a wheel the size of that used on a radio controlled car would have to turn a 100 times to reach a distance of one meter.
However the smaller wheel doesn't require any where near the power a larger wheel needs to turn, so the larger the wheel the harder it is to turn which in theory will slow the wheel down considerably but then compared to a smaller wheel, it doesn't have to turn that far to reach a further distance, so if the gearing and the power is the same, smaller wheels will lose out to bigger wheels, acceleration is down to the power and how much distance you want to travel.

Could be talking from my arse and I probably missed a bit, but that sounds logical to me.

To clarify.. if you want to cover a distance of ' METER' the larger wheel doesn't need to travel as far as the smaller, so the larger reaches the '1 meter' distance first which consequently makes it faster to reach a METER.

[venomboy]

Sorry to throw a spanner in the works here but a smaller wheel will give you greater acceleration due to increased mechanical efficiency on two levels. Firstly lower gearing means the engine revs rise more quickly moving faster into the band where more horsepower is being producedINSERT INTO post VALUES ( though this is offset by use of the clutch, what's that smell?, and as has been mentioned, the need to change gear more often as you run out of revs quicker). Secondly and more tellingly there is the greater mechanical advantage gained by changing the ratios, just as it is easier to accelerate your pushbike by selecting a larger toothed front sprocket, effectively the same as decreasing rear wheel diameter, so less effort is reqired for a given torque to overcome inertia over a shorter distance! Sorry when I started this I thought I could explain it clearly, I now see what a foolish notion that was. I will be back to answer any questions later . I have students waiting to be beaten up.
Cheers VB

[enigma]

I understand perfectly, just couldn't get it down on paper INSERT INTO post VALUES (electronic paper):D