Tire sizes

On a 1991 MR2 Turbo. I am in the process of purchasing new wheels and tires for this project car. From stock 14’s I’m thinking of installing 16x7’s in the front with 205/45-16 tires. In the rear I want to install 17x8’s with 215/40-17’s. I know the additional weight, 18lbs per wheel front and 22lbs rear, will affect unsprung weight and the larger diameters will affect the speedometer. My question is will the difference in sizes front to rear adversely affect handling? I’ve already installed struts with springs that will drop ride height 1-1 1/2 inches.

My second question is electrical. I’ve installed another motor (JDM) in this car and when I turn it over I have no spark to the plugs. I’ve got 12 volts at the coil but it’s not jumping to the plugs. I’m a little lost on this since electrical systems are not my strong point. Should I be looking closely at the distributor as the source of the problem? The JDM engine went in as a total unit with it’s distributor already installed. I’m told that these cars are critical on the ground points being correct and as far as I can tell they are all attached correctly.

You need to find an MR2 forum, see what folks there have been able to do. Your ride will suffer, of course, but I’d be more worried about clearance.

Edit - I do remember Car and Driver having some handling problems with a long-term MR2 because they put the wrong combination of tires on it, they ended up having to retract some criticisms they made because it was their wrong choice that caused the problem. So I would definitely try and find some MR2 enthusiasts and see what works for them.

I hope your location does not require emissions testing…

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The lesser sidewall and the added tread width in the rear may induce understeer. Your fronts will distort more on a hard turn than your rears.

My recommendation to get to get the visual effect you seek would be to go with a slightly wider rim of the same diameter in the rear, with a tire of wider section width and lower aspect ration. www.tirerack.com and www.carbibles.com will have the information you need to select tire & wheel combinations that will keep the rolling diameter of the front and rear wheels the same.