wide wheels

[Andrew S]

Hi all,
Could someone please confirm what is the widest size of wheel/tyre combination that will fit on the front of a Montecarlo with standard width springs, i.e. NOT Ledas?

Thanks, Andrew.

[davidb]

W/5.5J x 13" wheels I was told 195s is the limit in front. I went
w/that & 215s in the rear. I could see by swapping them that
195s is as wide as one can go up front. The 215s would scrub.
My suspension/hubs/brakes: all stock. Tires: Sumitomo.

[Will]

That depends largely on the backset, but I'll second David's number of 195. I run 15x6.5 and 195/55's that just rub at full lock. I cannot notice any difference in turn-in between 175's and 195's, maybe I am just not a good enough driver, but I suspect the difference is negligible if anything. A stock scorpion has such low horsepower on tap that larger wheels/tires really work against you, IMO. A worked Monte, different story.

[sprintcarfan]

My Scorpion had 205's on the front when I bought it. 13" bowties and stock struts. It didn't rub anywhere, but there is a lot of variation in actual tire size brand to brand for a given size. I don't think there is anything to gain by 205's on a 5.5" wheel, apart from extra weight.

[DJ]

My Scorpion arrived with Yokohama A509s on stock wheels and stock struts all around. No issues with rubbing other than one very small dime-sized rub spot behind the driver-side wheel a full left lock. No problems other than that small annoyance.

It steered like a truck at low speed, though and I didn't like them. I'm currently running 15-inch 195s up front and 205s on back but that doesn't count because I have Ledas now.

For a while I ran 14/195s on Beta wheels and no additional spacers but that, again, was with the Ledas.

[davidb]

I could'nt fine 205's SprintFan when shopping 6 months ago.
The 195s I have on the front appear to provide sufficient
clearance to the spring platforms. 205s in the front might
be scary close when flexing/cornering. I took Will's advise
back then & went w/195s. Looks safe clearance-wise to me.

[pabeaver]

Hi. I run 15x7 wheels on the fronts and rears with 205/50/15's. My wheels required 20 mm spacers and the wheel rim clears the front strut spring lower perch (Koni's) by about 10 mm. I get some rubbing of the tire on the plastic wheel well liner at full lock. I don't know if it is my tires (Falken) but the steering effort, even when sitting still, is suprisingly low.

[Andrew S]

Thanks guys! Excellent info as ever.
Pabeaver- 7" and 205? Do they protrude from the arch at all? That has surprised me.
6.5 as Will says was what I was expecting to be the max really.

Andrew.

[pabeaver]

Hi. The tires clear the inside of the stock flare and wheel well liner at the maximum 'up' travel. The outermost sidewalls of the front tires are about 3/4 inch inside the top of the flare and the rears about 1/4 inch inside, measured horizontally, when the car is at rest. I don't need the 20mm spacers on the rear but used them any way.

I made tire templates out of thin cardboard and dummy spacers for the wheel and used them to get the maximum tire size I could use and correct spacer thickness. It helped that one of my Alfa's had the same size tire I could use for dimensions. My tire guy sold me the new tires and mounted 2 and said if I didn't drive on them and they didn't fit, he would take them back.

I know of at least one other Scorpion with the same size wheels and tires as mine. His has 'psuedo' 3-piece wheels and I don't know about his spacers as such.

My Koni's have the front lower spring perch 'flattened' to give more clearance between the strut and the wheel, about 10 mm. I don't know if the stock ones do this.

[DJ]

My wheels are the "pseudo 3-piece" wheels which are replicas of the wheels used on the European Fiat 124 VX Spiders. They are also 15x7 and even though the offset is slightly less than the stock Scorpion wheels (21 mm Vs 25 mm) there is no issue with them extending outside the wheel wells. You can get a sense for this in the attached pics in this thread. If you'd like I can get some additional pictures from different angles when I get home on tSunday.

http://lancisti.net/forum/showthread.php?t=2161

[davidb]

All your wide wheels look great Gentlemen. And enormo tires.
Any increased steering effort @ slow speeds? Lastly & most
importantly is all this for show or go? That being on a ser-
petine road can you navigate faster than w/13" wheels/tires?
And I mean BALLS OUT.

[Andrew S]

Peter- fantastic info! There are basically three types of wheels that I like and none of 'em are available in 6 or 6.5, only 7". So now I know they will fit! I too made some cardboard templates; great minds think alike eh?!! I've only been using them to check the rears though up to now as they're gonna be wider still (modified arches).
DJ- I absolutely love your wheels! They are gorgeous and most importantly they suit the car. Are they available over here do you know?

Andrew.

[Darren]

Hi Andrew,

You can get those Rims through the Monte Hospital, but they ain't cheap - and that's an understatement!!!! You can get them from Spider Point, but you'd have to get them shipped in and they'd probably still be cheaper.

http://spider-point.com/framework.php/mode/catalogonline#

page 8!

Hope this helps

[Andrew S]

Oh right, yeah, thanks Darren I've seen that link before. At £222 each they're more than I want to pay, although not expensive for what they are.

Andrew.

[Will]

Didn't that guy in the Netherlands that's always selling stuff on ebay have some of those Spidereuropa style fake-modulars? If you drive the way I think you plan on driving, Andrew, it might be worth it for you to invest in a set of Keizers. They are real 3-pc modulars with aluminum or magnesium centers, any offsets, widths, etc. ('cause they are 3pc modulars), any bolt circle, starting at about $250/wheel. Since you are in the UK, my next choice would be Compomotives, although they weigh tons by comaprison- and the ones I have are 2pc, which eliminates sealing but defeats a lot of the advantages of a modular in terms of customization.

[SubGothius]

I seem to remember harping on this recently, but it came as a revelation to me when I learned it recently:

Wider tires do not necessarily put any "more" rubber to the road.

The contact patch area is a function of vehicle weight and tire pressure (weight / psi = sq. in. of contact patch). Moving to wider tires would only make the contact patch broader (transversely) and shorter (longitudinally). The tradeoff is that you gain some cornering adhesion and responsiveness at the expense of ride, directional stability, and accelerative/braking traction.

If you're going to be doing a lot of lower-speed extreme handling maneuvers and transitions a'la autocross, then wider wheels and tires might make sense. If you're going to be doing more sweeping-bend handling at high-speed on public roads and taking one hard corner at a time, then narrower tires will give you less-nervous handling both on long straights and in mid-bend alike, with more progressive (read: predictable) scrub at adhesion limits, while also maximizing the grip available for braking and accelerating, and providing a smoother ride.

Naturally, if you can find a wider tire with a grippier compound or a construction designed to increase the contact patch nonlinearly vs. its narrower cousins, that's a different matter; I'm only saying that a change in the width variable alone would theoretically not make the contact patch any larger (but see my .sig quote ;) ).

[1,6 HF]

I seem to remember harping on this recently, but it came as a revelation to me when I learned it recently:

Wider tires do not necessarily put any "more" rubber to the road.

The contact patch area is a function of vehicle weight and tire pressure (weight / psi = sq. in. of contact patch). Moving to wider tires would only make the contact patch broader (transversely) and shorter (longitudinally). The tradeoff is that you gain some cornering adhesion and responsiveness at the expense of ride, directional stability, and accelerative/braking traction.

If you're going to be doing a lot of lower-speed extreme handling maneuvers and transitions a'la autocross, then wider wheels and tires might make sense. If you're going to be doing more sweeping-bend handling at high-speed on public roads and taking one hard corner at a time, then narrower tires will give you less-nervous handling both on long straights and in mid-bend alike, with more progressive (read: predictable) scrub at adhesion limits, while also maximizing the grip available for braking and accelerating, and providing a smoother ride...

I think your basic premise probably correct; with a wider tire, the wheel weight is distributed over a wider area; theoretically there will be less deformation and a shorter contact patch in the longitudinal direction. In practice, much will depend on tire pressure and sidewall stiffness.

But, with all due respect, I think you have the relative handling merits of narrow versus wide a bit backwards. For autocross, with lots of transients and more dependence on agility than ultimate lateral grip, narrower tires will tend be more responsive (not the other way around), with quicker and more precise turn-in. Whereas the broader contact patch of the wider tire will tend to be most effective in pure lateral acceleration (parallel to the long dimension of the contact patch)--i.e., in long, sweeping turns taken one at a time.

In other words, there's a reason that rally cars generally run narrower, higher-profile tires than LeMans prototypes. Of course, we're really talking about a farily narrow band of difference, whether on the street or in competition--it's not bicycle tires versus a road roller.

And there's little question that wider, lower-profile tires will tend to compromise ride quality unless the springing and damping are also addressed. But this is probably as much a function of the reduced sidewall height as the increased width.

In any case, keep in mind that this is coming from someone who's running 175/80-13s, to maintain the original look. (But the turn-in's great...)

[Andrew S]

Tye, Ed,
Your technical know-how will get no arguments from me. However, there is one massively important point that you both fail to mention: wide wheels and tyres on a sports car are horny!!! Yes, I enjoy a spot of spirited driving the same as anyone but I'm no Schumacher. I won't be taking it on track days and I won't be racing 17yr olds from the lights in the town. I will be enjoying it on fast, deserted roads with sweeping bends (we have loads of 'em here) and some fat wheels and tyres, I believe, will suit it. And Ed, 185/80/13 isn't original (at least not over here it wasn't). 185/70/13 was the S1 size.

Will,
Which guy in the Netherlands?
I've had a look at Keizer's website- a lot of the terminology and technology on there I don't understand as my knowledge on the subject is limited but I'll give them a call as the prices you mention are exactly the area I'm reckoning on. I understand sizes, backspace, offsets and pcd's but that's about it.
3 piece Compomotives, totally gorgeous as they are, are seriously expensive and way out of my budget. If I bought them I'd have no funds left for the tyres...


Andrew.

[1,6 HF]

And Ed, 185/80/13 isn't original (at least not over here it wasn't). 185/70/13 was the S1 size...

185/70-13 was the stock tire size for the US Scorpion as well. But when I spoke of the tires I was running, I was referring to my Fulvia HF, which did indeed come with 175/80-13s--a real step up in width from the 'normal' Fulvias, which boasted 145/80-14s!

But if 295/30-19 PZeros on 8.5" rims really do it for you, who am I to quibble? They do look really sexy on a Gallardo.

[Andrew S]

Ah! Fulvia! Right. Yes, as you say, a big step up from the skinny 145's. And ha,19's might indeed look sexy on a Lambo but I'm the first to admit they would look...ahem... rather silly on a Monte! I'm thinking more on the lines of the 245-275 range for my gp4 rear arches; hopefully 15" but perhaps 16". The 16's are waaaay cheaper for tyres but 15's are better looking, more 1970's.

Andrew.

[1,6 HF]

Andrew,

One thing to consider is the front/rear balance. Although I'll readily confess it was a very long time ago, when I drove a Scorp I was struck by the extent to which it understeered compared to the (slightly modified) X1/9 I was driving at the time. I'll add the caveat that the Scorp wasn't my car, it had the stock tire size (there's those 185/70-13s again), and I didn't have a chance to check or adjust the tire pressures. But the car was much less 'tossable' than my X (even with its 6"-wide ATS alloys and 70-series Pirellis), and the front end washed out on tight switchbacks--no lift-throttle oversteer like the Fiat.

If my impressions were in fact correct (see caveats above), then the last thing you'd want are wider tires at the rear than the front. They may indeed look great, but they'll tend to increase understeer.

Just something to keep in mind.

[Andrew S]

I hear what you're saying and I intend to do the usual improvements to the suspension set-up/anti-dive/camber angle etc. to at least ensure it works as well as possible. Also, I would imagine the Scorpion feels different from the Montecarlo as it sits an inch higher. I can honestly say the Montes I owned in the 90's and the one I've just sold didn't suffer from noticeable understeer. Maybe I didn't drive 'em hard enough!!! I too have had the pleasure of an X1/9 and in terms of "tossability" I agree it beat the Monte hands down. It was even better than the 308 I had after it.

Andrew.

[davidb]

Understeer/oversteer, on throttle/off throttle so what's the
handling diff. between Scorps w/and w/o the rear anti-sway
bar. I think it's the rear? Been answered before but I forgot.
And yes Ed the 1ST Gallardo I saw up close, they look like
"run flat" tires.