will you loose acceleration time when fitting 17"

RBSX · Post by **RBSX** » Tue Jun 05, 2007 9:09 am

Ok heres my understanding

Im going to fit 225/40/17

but smaller tires mean better accelaration but lower top end
YES / NO

when i say smaller tires im mean the diameter, exculeding the weight difference.............ok

Now judge from the smaller diameter from the 205/50/15 on there
to the bigger 17"

its gonna get slower

ive got a stock s13, what should i do , i plan to lower suspension later
but i want the max width i can go without touching

Gary57 · Post by **Gary57** » Tue Jun 05, 2007 9:19 am

By changing your mags to 17inch you dont increse to wheel diameter by 2inches over your stock 15inch mags, because you tyre profile is smaller.

Yes if your wheel diameter is bigger your "torque" (its actually tractive effort) on the wheels will be lower, so yes you will accelerate slower.

I have 225/45 R17 all round with no problem of touching or rubbing.

RBSX · Post by **RBSX** » Tue Jun 05, 2007 9:45 am

HI Gary

Ok i did some calls, i really dont want to loose my acceleration

the original March 1992 car magazine road test which i have
the car was fitted with 195/60 / 15

now the diameter is 615

215/45= 625
225/40=611 ( the closest choice, but where do you find them @ a good price)

225/45= ? where can i get the diameters

i actually want 245 in the rears is it possible whats the diameter,
thinking ahead of my RB26

Gary57 · Post by **Gary57** » Tue Jun 05, 2007 9:49 am

Call a wheel shop and they will help you out. Jacks are the cheapest for tyres.

If you are fitting an RB then I doubt that difference in diameter will have much of an effect, the car will still haul ass.

veecee · Post by **veecee** » Tue Jun 05, 2007 9:57 am

i doubt that you will even feel a difference in acceleration if you diameters change by 4 mm.

i have the same size as gary, and my baby even drifts fine on them.

mine rub all over the place, in front because i think i need to move the wheels forward (they seem to be a little rearward in the arches) and at both ends because i have 25mm spacers installed!

Gary57 · Post by **Gary57** » Tue Jun 05, 2007 10:01 am

But VC your car is also low.

RBSX · Post by **RBSX** » Tue Jun 05, 2007 10:02 am

Ok this is a balls up

The car orignally came with 195/60/15 = 615
ive got 205/55/15 = 606
that explains the cool take off

heres the different diameters of 17"
205/45 = 616
215/45 = 625
225/40 = 612( the best option but you cant get them )
225/45 = 634 ( gary that doesnt seem like a good option)
235/40 = 620( second best option)
245/40 = 628

What to do

can i go 235/40 in the rears and
and maybe 225/45 in the front ,

yes / no

Gary does yours touch on turn in

Gary57 · Post by **Gary57** » Tue Jun 05, 2007 10:06 am

Mine doesnt touch anywhere. 225/45 R17 are very std so you will always be able to get.

veecee · Post by **veecee** » Tue Jun 05, 2007 10:08 am

it wont touch on turn in if your car is stock height and you are not using spacers!!!

but this also depends on the offset of the mags that you are using.

dude - a friend of mine is running 265's all round on his s14, without rubbing anywhere.

take gary's advice and go to the store - they know what they're doing.

if you're serious about getting an RB motor, then i would suggest getting wider rims and putting 245's as a minimal size!!!

veecee · Post by **veecee** » Tue Jun 05, 2007 10:09 am

@ gary.

yes my car is very very low!!!

on hard turn in the rear sill goes over the tire.

had to have the arches rolled! and the rear spacers trimmed to 23mm.

Gary57 · Post by **Gary57** » Tue Jun 05, 2007 10:11 am

Worrying about wheel diameters, I think you are spliting ball hairs here.

If this RB dream is to become a reality, I would fit the biggest tyres possible.

veecee · Post by **veecee** » Tue Jun 05, 2007 10:28 am

is there an echo in here????

RBSX · Post by **RBSX** » Tue Jun 05, 2007 11:31 am

ok the problem is 8.5j and 9j are impossible to find at a decent price
so 265 are out

im going to try and fit 245/40 in the rears
and 225/45 in front

will that be okay

veecee · Post by **veecee** » Tue Jun 05, 2007 11:51 am

its really up to you!

The Calibrator · Post by **The Calibrator** » Tue Jun 05, 2007 11:52 am

Explanation of tyre terminology.
225/45ZR17

225 = width of tread in MM
45 = Aspect Ratio in percent IE: sidewall height is 45% of 225
Z = Speed rating S=180 H=210 V= 230 Z= over 230 Y= 300

This is sustaned speeds you can exceed these briefly.

Now these are nominal sizes fitted size will vary depending manufacturer and width of rim.
However if you know the width and aspect ratio you can calculate your overall dia and be pretty close.