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View Full Version : Real tire sizes for ABARTH 16's



spydersniper
03-26-2013, 03:34 PM
I'mtrying to figure out the maximum size tires for Bullet. My car came with 195x40x16. They really look anemic! So I called a major tire chain and they told me that recomended maximum tire size is 205x40x16.He explained that that would changedimensions by 1/2 inch wider and 1/2 inch taller. That's not a lot. Does any body know if going to 215x40x16 is too much? Again the tire people at the tire place said it would change dimensions by 1/2 inch in width and height. Should I use 20mm spacers? Will they work all the way around or only on the rears? My Super-Bee had 245x45x20's on the fronts and 275x40x20 on the rears. I could shift left to right, and had no contact with frame or body.

JackandSue
03-26-2013, 03:41 PM
the rim on the 16" Fiat is 16x6.5" 205's are the max size for that rim. 16x7 would fit 215's.

mkawa
03-26-2013, 03:50 PM
this might be helpful

http://www.willtheyfit.com/

it doesn't tell you what will and won't rub on our cars, but no one seems to have organized that data yet regardless..

spydersniper
03-26-2013, 03:55 PM
Thanks. I still would like to widen the stance just a littli bit more. When I change to the 205 I'm thinking of going to the eibach 20mm spacer.

mkawa
03-26-2013, 03:59 PM
spacers are generally not recommended for safety and other relatively obvious reasons, especially as large as 20mm

spydersniper
03-26-2013, 04:12 PM
That's a neat gadjet! I'v never seen one before. Thanks!

spydersniper
03-26-2013, 04:25 PM
you'r right. 20mmis 3/4 inch,10mm is slightly less than 1/2 inch. Still too much? These are supposed to be hub-centric. They look like they would fit. I think it would move the tire pretty close to the fender without actually being able to hit it.

mkawa
03-26-2013, 04:36 PM
the spacer adds another mechanical junction that can break. generally not recommended if it's going to be driven hard. to add track properly one would usually replace eg the control arm in a mcpherson setup or the lateral links in a multi-link with longer, stronger units, as well as lengthened axles if appropriate. wheel hubs and the things attached to them experience a lot of mechanical stress under hard driving, and breakage can cause serious carnage.

Ryephile
03-26-2013, 04:38 PM
spacers are generally not recommended for safety and other relatively obvious reasons, especially as large as 20mm

Don't let the truth get in the way of a good story. :gtfo:

There's nothing wrong or unsafe with correct use of spacers.


you'r right. 20mmis 3/4 inch,10mm is slightly less than 1/2 inch. Still too much? These are supposed to be hub-centric. They look like they would fit. I think it would move the tire pretty close to the fender without actually being able to hit it.

RRM is using 16x8's with an et26. That fitment appears to be about as aggressive as anyone would want, and likely includes more camber to clear the fenders, but their car is also much lower than stock. Taking the factory 16x6.5 et35 and putting the outside lip at the same plane would require a 28mm spacer. That makes a 20mm spacer sound reasonable, but IMO still more than the average enthusiast would want to do, as it'll negatively affect the scrub radius.

If you want to play it safe, go with a 10mm spacer. Go big or go home? 20mm spacer. Just be sure your wheel bolts are long enough, or the spacers are using their own bolt/studs. 6-full-turns is the accepted minimum for safe lug bolt/nut engagement.

FWIW, some 215 wide tires will fit on a 6.5" wheel, it'll just look balloon-ish. Be sure to check individual tire model spec sheets for their recommended wheel width range. A 205 will universally fit on the 6.5" wheel, however.

mkawa
03-26-2013, 05:02 PM
Don't let the truth get in the way of a good story. :gtfo:

There's nothing wrong or unsafe with correct use of spacers.

hah! i'm sure. actually i was just reading a build log of some 100% serious professional drift car or other sillyness (but well engineered sillyness) that uses some pretty hefty 40mm spacers on all four corners! however, there's a huge difference between spacers on a car driven hard and rebuilt every N hours and your average spacer user, who tosses some cheap wheels and cheaper spacers on a car to get a more aggressive stance, does not bother torquing to spec, and then leaves everything untouched for 100k hard road miles + amateur mosport time...

jguerdat
03-27-2013, 08:45 AM
Just be sure your wheel bolts are long enough, or the spacers are using their own bolt/studs. 6-full-turns is the accepted minimum for safe lug bolt/nut engagement.

Here's the rub that no one was mentioning. Thanks for being the first to point it out.

As for tire sizes, the choices are absolutely the pits for competition purposes. You DON'T want to raise the car any more and almost every larger tire size in either the 16s or 17s will increase diameter, sometimes dramatically. It's not the width that bites you first, it's the height. And if raising the car isn't an issue for you, the accompanying reduction of acceleration should be. A ton of folks are adding power but effectively taking some away with taller tires (not to mention heavier). If you're into bling, so be it. Otherwise, consider mods, including tires, as part of a whole system. They don't operate separately in the end...

mkawa
03-27-2013, 09:01 AM
it's another point where spacers often fall down as well (and are hence not used safely). an eibach style 20mm spacer, which does not have its own bolts, is not safe on factory hubs because the exposed hub bolt is too short. hence, it's easiest to just not recommend them. any performance you might potentially gain by widening your track a bit will be completely lost if your wheel falls off the next time you dip a wheel off-track.

if you want really big contact patches on these cars you either need to roll or flare your fenders or run small diameter low ET wheels like eg RRM is doing. you're absolutely correct in that you don't want to raise the cg of this car any higher than it is stock.

Abarthman
03-27-2013, 10:18 AM
I talked to RRM about their 16 x 8" wheels, and ended up going that way (instead of spacers with my 17" wheels) for my autocross wheels and tires. RRM recommends NOT going to wider 215 series tires, so I bought Hoosiers in the 205 width. These wheels look very, VERY wide - can't wait to try them out. We'll see, once they are fitted, if there is any room for 215s, but I'll wear the Hoosiers out before buying more...

mkawa
03-27-2013, 10:25 AM
weights, please!

Jjm4life
03-27-2013, 10:27 AM
I bet a 205 Hoosier is as wide as many 215s.

Spacer are safe as long as you have enough stud. I ran 20mm spacers before for brake clearance. Had huh centric spacers with extended studs built in. Never had any issues

mkawa
03-27-2013, 10:31 AM
I bet a 205 Hoosier is as wide as many 215s. i know many folks born and bred in indiana who would bristle at this comment ;)

speaking of adding track, does anyone know what kind of suspension components the cup cars run?

Jjm4life
03-27-2013, 10:53 AM
^^ lol. Im sure its sadly accurate.

Abarthman
03-27-2013, 12:26 PM
i know many folks born and bred in indiana who would bristle at this comment ;)

speaking of adding track, does anyone know what kind of suspension components the cup cars run?

Last time I spoke with Phil Wicks, who is prepping the cars, he said that he is going to sell suspension kits using the same components. He was not freely talking about what the components are, but said they are manufactured in England. I suspect they are coil-overs, plus who knows what. I am sure he is also using 15mm spacers; and I suspect, a bigger rear bar; but we'll see what he comes out with....

mkawa
03-27-2013, 12:38 PM
Last time I spoke with Phil Wicks, who is prepping the cars, he said that he is going to sell suspension kits using the same components. He was not freely talking about what the components are, but said they are manufactured in England. I suspect they are coil-overs, plus who knows what. I am sure he is also using 15mm spacers; and I suspect, a bigger rear bar; but we'll see what he comes out with.... awesome!

jguerdat
03-28-2013, 08:16 AM
I bet a 205 Hoosier is as wide as many 215s.

Exactly right. The 205/45-16 Hoosier is 8.7" section width and 8" tread width. The Dunlop 215/40-17 ZII is 8.6" section width with the same tread width. No 205 Hoosier in the 17s but I believe the 225s were being used at last year's Nationals.

spydersniper
04-01-2013, 11:39 PM
tire rack says 215x40x16 will fit the stock wheel for an Abarth.

Seafarer61
04-02-2013, 12:22 AM
My .02

For me, that would be an unacceptable size tire for a 16x6.5-inch wheel. For example, a Yokohama S-Drive in 215/40/16 has its measurements derived from a 7.5-inch rim width. They don't even recommend diving down to a 6.5-inch wheel. If that occurred, the tire would lose a half-inch of tread width by the time it was pinched on a 6.5-inch width wheel. For every half inch deviation from measured mounting width, add or subtract .20 inches from tread width. The measured tread width of that 215/40/16 S-Drive is 7.7-inches. Subtract nearly half inch from that and by the time that tire is mounted on the OEM Abarth wheel, your tread width has been reduced to 7.3-inches, barely above the OEM 195.

The stock tread width of the Pirelli 195/45/16 is 7-inches, so you've essentially only gained .15 inch on each side of your tire while creating more rotational weight since the 215/40/16 is a heavier tire (usually by one-pound) and is slightly taller in diameter, bringing the rotational force further from the hub as opposed to the stock tire. Many just look at the width of the tire size and assume that is going to determine tread width when the reality is, it's the wheel width used for a tire that also plays a factor in what eventually gets to the asphalt.

jguerdat
04-02-2013, 07:33 AM
The whole tire size issue is one that depends on the usage. Autocross folks stuff the biggest tires that fit the fenderwells regardless of design specs. Track junkies probably are more attuned to using the specs, matching tread width to wheel width. Street folks would be wise to stay close to the specs unless they're willing to play with tire pressures and monitor potential areas of unintended contact (liners, suspension, fender lips, etc.).