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1st drive with 13" wheels and R888s
whitestu - 15/1/12 at 02:53 PM

Went out for the first time yesterday following a switch from heavy 15" TSW alloys with Yoko A539s to Team Dynamics pro race 1.2 13" wheels and Toyo R888s.

Not much grip to start with as the tyres were new, but after a few miles they were good, though I wasn't pushing it.

The biggest difference at normal road speeds is how much better the car deals with bumpy B roads given the reduction in unsprung weight, and surprisingly it self centres much better as well.

Looking forward to getting it on a track now!

Stu

eddie99 - 15/1/12 at 02:58 PM

Sounds good, I'm on track next week testing actual track time differences between 15 r888 and 13 a048

daniel mason - 15/1/12 at 03:03 PM

let us know eddie. i have 205/60/13 a048's on my new mnr. 195/50/15 on my last one
does the larger sidewall of the 13" tyre make a big difference?

coozer - 15/1/12 at 03:03 PM

Whats the ride like? Any better feed back?

afj - 15/1/12 at 03:22 PM

Pictures please

Proby - 15/1/12 at 03:41 PM

This is something Ive been considering. I've got 15" rims on the F27, but used to run 13" with A021R on my Westfield. Tyes are cheaper too on 13's which is a bonus!

dlatch - 15/1/12 at 04:21 PM

i have actually gone the other way
my reason being was there is actually a far better range of road tyres for the 15" size (what cars these days use a 13" wheel? ) and as mine will do just the odd trackday also having light 15" wheels offsets the difference and i could still keep my old 13" for track work anyway so best of both worlds i guess.

whitestu - 15/1/12 at 04:40 PM

quote:

Whats the ride like? Any better feed back?


Ride is definately better, and a bit more feedback but not a massive change in that respect.

Stu

fullpint - 15/1/12 at 05:57 PM

Stu; What size are the 13's? as in rim width.. I'm also on 15's running 195/50 but would like to down size. I sell a couple of sets in the For Sale section that are 13" x 6", I think mine are 15 x 7 ..
And as said 13" rubber is cheaper. Ok my car is mainly road use but having good rubber is a must..
Sounds like the R888 work for you

whitestu - 16/1/12 at 03:54 PM

quote:

Stu; What size are the 13's? as in rim width..


They are 7" wide. I have 185s on the front and 205s on the back, but they should fit on 6" rims.



Stu

RK - 18/1/12 at 12:54 AM

I too am going to 15 after having 13's. I never got the pressures right I don't think, so handling left a lot to be desired. However, I need the clearance offered by the 15's and the tyres were actually cheaper, as they were ex-Miata/MX5 spec tyres in the States, and they switched to RA1's or something. Brand spanking new R888's. Can't wait!

martynrich67 - 27/1/12 at 05:28 PM

Did you have any problems with clearance over brakes and/or suspension/hub components, etc?

What wheels have you used?

I'd like to go from 15" Pro Race 1.2s to 13" Revolutions, but by all I have read, it looks like I might struggle.

[Edited on 27/1/12 by martynrich67]

rdodger - 27/1/12 at 06:56 PM

I have Pro race 1.2 13" wheels over midilite calipers and 260mm discs. There isn't a lot of clearance but there is clearance.

RK - 27/1/12 at 10:57 PM

My 13's are over Mk 1 MX5 brakes. Barely fit, but do not rub.

fullpint - 28/1/12 at 05:11 PM

I REALLY must get a set of 13's with decent rubber on.. My current 15's with rain master tyres are totally SH1T.. Perhaps I can borrow a set for an hour to see the feel the effect!!

INDY-R ZZR - 28/1/12 at 05:21 PM

The pro race 13" wheels look very nice too

Not Anumber - 24/4/12 at 06:18 PM

i'm going to bracket a spare on the back of the car, in a cover so it doesn't have to look anything like the wheels on the car. Will a standard 13" Sierra wheel be any use as a spare on an Indy, will it fit over the uprights ?

The road wheels are 15" - not sure if the builder actually needed this size to get over the uprights or just cos they looked nice.

RK - 24/4/12 at 09:51 PM

Make sure you have enough ground clearance with 13's. I have a destroyed engine and immobile car for quite a long time ahead of me because of hitting the road with my sump.

Not Anumber - 25/4/12 at 06:40 AM

With a high profile bog standard 13" tyre i'm confident the ground clearance wouln't be much different and we are only talking about in the event of a puncture. I'm more concerned about whether the inside of the rm has enough clearance against the upright ?

RickRick - 25/4/12 at 08:20 AM

I'm in the same boat, about to change rear brake calipers, and thinking of fitting pro race 13" when these tires are done, would someone be able to measure the inner diameter of the 13" pro race wheels in about the position the disk sits in

Thanks

loggyboy - 25/4/12 at 08:25 AM

Is the MK sierra based, IIRC it is. My sierra donor has 13inch steels, so I would guess they should fit fine, providing you havent uprated the brakes over standard sierra dia.


quote:
The biggest difference at normal road speeds is how much better the car deals with bumpy B roads given the reduction in unsprung weight, and surprisingly it self centres much better as well.


Also just to add to this, the better dealing with bumps will be largely down to the increase rubber height rather than unsprungwight.

whitestu - 25/4/12 at 08:44 AM

quote:

Also just to add to this, the better dealing with bumps will be largely down to the increase rubber height rather than unsprungwight


That makes sense. I put the 13" wheels against the 15" before I fitted them and the 185/60 13s on the front had the same diameter as old 195/50 15s, and the 205/60 13s on the back were actually a bit bigger.

Stu