Staggered tyre set up - 225 instead of 215 - Toyota GT 86 Forums UK
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post #1 of 17 (permalink) Old 30th June 2020, 12:27 Thread Starter
BRZ
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Staggered tyre set up - 225 instead of 215

I am planning to change the rears from a 215/45 to 225/45 set up to make the car less tail happy and put power down efficiently on stock wheels. i am aware of that this is potentially putting the largest width tyre on stock rims and also that there will be a small speedo error ( circa 1%) and a potential loss in MPG. Has anybody done it and are there potential pitfalls to be aware of?
Thanks in advance.
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post #2 of 17 (permalink) Old 30th June 2020, 12:46
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The main thing you need to be aware of is the added sidewall flex you'll encounter when cornering.
I'd just double check the manufacture spec of the tyres your looking at and see if they recommend fitting them to a 7" wheel.

What tyres are you currently using?
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post #3 of 17 (permalink) Old 30th June 2020, 12:58 Thread Starter
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The main thing you need to be aware of is the added sidewall flex you'll encounter when cornering.

I'd just double check the manufacture spec of the tyres your looking at and see if they recommend fitting them to a 7" wheel.



What tyres are you currently using?
Thanks Will. Goodyear Eagle F1 Asymmetric 5 currently.

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post #4 of 17 (permalink) Old 30th June 2020, 13:01
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A wider front that rear tyre will also tend to increase understeer
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post #5 of 17 (permalink) Old 30th June 2020, 13:01
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Would you say your getting a lot of tyre slip now with the SC added?
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post #6 of 17 (permalink) Old 30th June 2020, 13:46 Thread Starter
BRZ
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A wider front that rear tyre will also tend to increase understeer
Hi Jeff, Its the other way round, wider rear (225) narrower front (215).
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post #7 of 17 (permalink) Old 30th June 2020, 13:48 Thread Starter
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Would you say your getting a lot of tyre slip now with the SC added?
Indeed. in lower gears (1,2,3) the TC lights up at full throttle in a straight line and just cuts power. Higher torque leading to tyre slip.
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post #8 of 17 (permalink) Old 30th June 2020, 13:50
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Hi Jeff, Its the other way round, wider rear (225) narrower front (215).
Sorry, that was my bad typing. I meant a wider rear tyre than front will tend to promote understeer on the 86
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post #9 of 17 (permalink) Old 30th June 2020, 14:47
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Indeed. These cars already with OE alignment and square tire sizing are already understeer biased which many doing performance/track driving dislike and tune out for closer to neutral grip balance. It seems very wrong to make it even worse by going staggered.
Just get 225 all around, this way you'll also retain ability to rotate tires to even out wear, will still be able to use spacesaver tire (which on cars with LSD like ours, requires in case of punctured rear for same tire to be fitted (normally - front) to rear, and spacesaver used on front), will simplify finding/buying tires, especially if partial replacement. There is absolutely no practical reason to go staggered except if one is nutjob with goal to fit widest tires possible without rubbing (a bit wider possible in rear) at expense of anything else. 225 are not that wide to need that. If wheels are also staggered width that adds inconvenience to sell them off later in future.
My friend, whose car had staggered tire sizing stock, hated several inconveniences from dealing with that. Now why change it, when you have from many viewpoints easiest to live with square sizing stock?
P.S. For less tail happy car i suggest two things. Better grippier tire model then simply going wider, and also add in alignment a bit more rear toe-in (well evened out at that).
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post #10 of 17 (permalink) Old 30th June 2020, 15:49
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If I was you, I'd look at getting a set of (atleast) 8" wide wheels and runnning a 225/45 tyre on them. I know several other SC member's are running this size without issue.
A 225/45 tyre won't affect the playfulness of the car and should give you that extra bit of grip without sacrificing turn in / sidewall flex when fitted on the wider wheel.

Now's a good time to order Michelin Pilot Sport 4's as they have money off at the moment.
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