1 (edited by Passaable 2021-06-04 10:19 AM)

Topic: Tires - is wider better for corners - or is it the weight of the car?

Hi - I noticed many of the Class A and a couple Class B folks pulling away from us at Thunderhill last weekend, zipping and zagging through the chicanes and corners. We have some tightened coil overs already on the car, and try to ride the corners until just before the tires are chirping, so it seems we are at the limit of traction with our current set up. At times we were right behind some of these cars so essentially following the same line and braking pattern.

We were running 235/40R-17 FALKEN AZENIS RT615K+ SL on 7" wide rims. The car is FWD weighing ~3000 with fuel and driver, about 60/40 weight distribution front to back and nicely balanced side to side.

I was wondering if jamming in some 10" wide rims and going to a tire more like 285/35/18 Hankook R-S4, would significantly help us  (that would increase our tire width 17%, ~2" from 9.3" to 11.2")?

Thanks for your insights!!

2 (edited by duthehustle93 2021-06-04 12:14 PM)

Re: Tires - is wider better for corners - or is it the weight of the car?

Holy heck, IMO that's way too much tire for a skinny wheel. I would be curious what a pyrometer and looking at tire wear will tell you, but most likely your sidewalls are rolling over. Does the car feel mushy and provide little feedback? (of course it does, it's a Lemons car! but less than you would expect out of X POS). Also, generally speaking, wider wheels/tires are going to be faster up to a certain point, the wider you go the more unsprung mass you carry and the harder the suspension has to work. Also, you increase drag and will lose some top speed on the straights.

Most of my experience is with time attack and miatas, but generally speaking we've found a 205/50 tire to be fastest on an 8-8.5" wheel, and a 225/45 to be fastest on a 9-9.5" wheel. Take that as you will since it's a different application, but generally tires like at least some stretch and you're running a lot of squeeze.

I run a 205 "super 200" compound on a 15x8-9 on my time attack miata because of classing limitations and it isn't noticeably slower than a 225 with stock power. I run a 225 hard compound w/ 15x9 on the Lemons miata because it has more thermal capacity and lasts significantly longer; I tend to overheat the 205's on the other miata but since I just need to squeeze out a few good laps it doesn't really matter.

Full Ass Racing
#455 Piñata Miata

Re: Tires - is wider better for corners - or is it the weight of the car?

We have 17x8 rims on the Caliber and run 215/40/17 tires.

We went from a 7" wide rim with 215 tires to an 8" wide rim with 215 tires, the handling improved noticeably.

Here is an article that discusses this issue: https://motoiq.com/how-to-properly-sele … ormance/2/

Re: Tires - is wider better for corners - or is it the weight of the car?

255/40-17 hankooks running 9in rims on a 3300lb RWD car for 7ish yrs.... about to go 10in wide.

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Re: Tires - is wider better for corners - or is it the weight of the car?

I have a similar question.  When I bought the truckI purchased some 17x7 steelies mounted with new tires from the seller.  2 tires are 225 and 2 are 245. I also picked up some burner mustang wheels which are 17x8.  Ever since I bought the truck we've run 15x8s.  We run out of gear at Buttonwillow so we're moving to the 17" wheel.  The mustang wheel is also 6lbs lighter than the steelies.

Questions: 
Is it worth the $100 to remount them onto the larger wheels?  I'm leaning yes.
Would you run the 225s in the rear or the front?  I'm leaning front

We're 3600lbs and whatever HP is left of the original factory 140HP from 30 years ago.

We are in contention for C Class wins.  Placing 5th and 2nd so far.  Broken Alternator cost us both times.

Re: Tires - is wider better for corners - or is it the weight of the car?

Bricoop wrote:

I have a similar question.  When I bought the truckI purchased some 17x7 steelies mounted with new tires from the seller.  2 tires are 225 and 2 are 245. I also picked up some burner mustang wheels which are 17x8.  Ever since I bought the truck we've run 15x8s.  We run out of gear at Buttonwillow so we're moving to the 17" wheel.  The mustang wheel is also 6lbs lighter than the steelies.

Questions: 
Is it worth the $100 to remount them onto the larger wheels?  I'm leaning yes.
Would you run the 225s in the rear or the front?  I'm leaning front

We're 3600lbs and whatever HP is left of the original factory 140HP from 30 years ago.

We are in contention for C Class wins.  Placing 5th and 2nd so far.  Broken Alternator cost us both times.

The 8's will give you better feedback and be faster, I can tell you that it's noticeably better on a miata but on a truck it's hard to say if that's the weakest link. We're not competitive enough in A to justify spending extra money, our decision is always swayed by the cheaper option, but if you're trying to win yeah it'll probably be worth it.

With an underpowered, front heavy vehicle your fronts will likely be working harder so I'd run wider up front.

Full Ass Racing
#455 Piñata Miata

Re: Tires - is wider better for corners - or is it the weight of the car?

duthehustle93 wrote:
Bricoop wrote:

I have a similar question.  When I bought the truckI purchased some 17x7 steelies mounted with new tires from the seller.  2 tires are 225 and 2 are 245. I also picked up some burner mustang wheels which are 17x8.  Ever since I bought the truck we've run 15x8s.  We run out of gear at Buttonwillow so we're moving to the 17" wheel.  The mustang wheel is also 6lbs lighter than the steelies.

Questions: 
Is it worth the $100 to remount them onto the larger wheels?  I'm leaning yes.
Would you run the 225s in the rear or the front?  I'm leaning front

We're 3600lbs and whatever HP is left of the original factory 140HP from 30 years ago.

We are in contention for C Class wins.  Placing 5th and 2nd so far.  Broken Alternator cost us both times.

The 8's will give you better feedback and be faster, I can tell you that it's noticeably better on a miata but on a truck it's hard to say if that's the weakest link. We're not competitive enough in A to justify spending extra money, our decision is always swayed by the cheaper option, but if you're trying to win yeah it'll probably be worth it.

With an underpowered, front heavy vehicle your fronts will likely be working harder so I'd run wider up front.

Thank you.

Re: Tires - is wider better for corners - or is it the weight of the car?

To the OP:

When I first started doing track days I would drive until the tires squealed and say "I'm at the limit of traction, I can't go any faster."

I've since learned that "the limit" is a moving target and there are lots of things you can do to shift weight and increase the limit of traction such as trail braking, rotating the car, not to mention special techniques for FWD cars.

If you haven't already, I'd recommend some HPDE time with an instructor to improve your driving techniques before you cram some 10" wide wheels on your car.

Re: Tires - is wider better for corners - or is it the weight of the car?

I'm surprised and somewhat disappointed nobody else has posted this in response...

https://www.youtube.com/watch?v=5YlBh1TUcLo

Re: Tires - is wider better for corners - or is it the weight of the car?

Spank wrote:

I'm surprised and somewhat disappointed nobody else has posted this in response...

https://www.youtube.com/watch?v=5YlBh1TUcLo

I'm surprised and disappointed that you didn't use this video.

https://youtu.be/HHCxxe3_qNc?t=185

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Gone bye-bye
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Re: Tires - is wider better for corners - or is it the weight of the car?

Camper Van Someren wrote:

To the OP:

When I first started doing track days I would drive until the tires squealed and say "I'm at the limit of traction, I can't go any faster."

I've since learned that "the limit" is a moving target and there are lots of things you can do to shift weight and increase the limit of traction such as trail braking, rotating the car, not to mention special techniques for FWD cars.

If you haven't already, I'd recommend some HPDE time with an instructor to improve your driving techniques before you cram some 10" wide wheels on your car.

Big agree. Ideally, shifting weight and trail braking is tuned into the car. I like to set up a car to have a hint of understeer if the handling balance were to be setup in a skidpad. That way, the car will force you to properly trail brake and it gives you a margin to change your handling bias with braking. If you set up the car neutral in a skidpad, it'll make you nervous to trail brake

I've noticed that a lot of newer drivers (Looking back at some of my time attack videos from a few years ago, I'm 100% guilty) tend to drive nervous, giving the car aggressive inputs to almost spot check what the car is going to do, or to force the car into an oversteer or understeer condition so they aren't surprised by what's going to happen. Reactive, rather than smooth/calculated, driving is going to lower the traction limit Camper is talking about.

Full Ass Racing
#455 Piñata Miata

Re: Tires - is wider better for corners - or is it the weight of the car?

That tire is way too big for that rim. We run a slightly wider tire on 17x9.5's.

"get up and get your grandma outta here"

Re: Tires - is wider better for corners - or is it the weight of the car?

May I piggyback on this topic and ask a question here?

My FWD Focus has 215/45R/17 tires on 17x7 wheels... I need new tires and could get 205 width tires.

From the conversation here it seems like I'm better off with the 205s than the 215 stock size. Does that sound right?

2005 Ford Focus ZX3

Re: Tires - is wider better for corners - or is it the weight of the car?

AXC1 wrote:

May I piggyback on this topic and ask a question here?

My FWD Focus has 215/45R/17 tires on 17x7 wheels... I need new tires and could get 205 width tires.

From the conversation here it seems like I'm better off with the 205s than the 215 stock size. Does that sound right?

Assuming a decent 200TW tire, the 205 would be faster and give better driver feedback than the 215. However, since this is endurance racing, a wider tire is nice because it has a larger thermal capacity/more rubber and would be less likely to overheat and wear prematurely. For stock powered miatas I run a 205 tire on 15x8 for time attack and a 225 on 15x9 for endurance racing. The 205 overheats/wears fast but is lighter and 225 is heavier but a 225 RS4 easily gets us through 24 hours. Anything above 2000 lbs will likely start to overheat a 205 tire in endurance racing, but your side walls will likely buckle more on the 215. I'd suggest getting a 9" wide wheel but completely understand this is Lemons, we would probably be on stock wheels if the car didn't already come with 9".

TLDR: Pros and cons to each, just get whatever is cheaper unless you want to buy wider wheels.

Full Ass Racing
#455 Piñata Miata

Re: Tires - is wider better for corners - or is it the weight of the car?

From reading this thread, we'd love to try some wider wheels and see how that goes.

The biggest challenge we have now is trying to find some wide options > 8" for our crappy 5x110 bolt pattern. It seems our ability to change the hub to some other pattern is no simple task on a SAAB.

Does anyone know of possible wheels / brands which may support such a wide option?  we current run 17" , though could likely stretch to maybe 19".  Obviously we would like to keep the weight down. Our hope is if we know of some options we can then comb offerup and other spots to try and narrow down the search. Simply looking at all the options is too cumbersome.