How much grip is too much - Is more grip always better

[snshami]

Hi, I recently started a topic viewtopic.php?f=30&t=45953 about losing grip in my MX-5 in the rain. I have fairly new Turanza ER592 (this was the original fitted tyre to the NB, albeit in size 15). I got some great replies and suggestions on tyres and wheel alignment. The consensus seems that one of the very good tyres to fit is the Bridgestone RE001.

I was discussing this with a few colleagues, both very knowledgeable about ride and handling. One was a race mechanic for Dick Johnson Racing and the other a chassis development engineer for Lotus. The Lotus guy was responsible for the M100 Elan. While they did not dispute the need for grip they had an alternate view about increasing grip too much. They both felt that the car was deliberately developed with less grip to make it handle better and that the chassis stiffness was in itself a limiting effect in the grip. The Lotus guy told me that when the M100 Elan came out and the media praised its grip one of his colleagues who was the tyre development engineer was quite concerned for his career. He had apparently been given the brief by the M100 program managment to limit its available grip.

I can see their points of view and also the points of view of many people in this forum. So I am a bit divided. I do want a bit more of a safety margin but also do not want to lose any of the fun of the car.

My question about the RE001 is whether they have too much grip. Is there a possibility that the car will lose some of the fun factor.

BTW, so far the best price I am getting in Melbourne is $124 from Bridgestone Tyre Centres. That is balanced and fitted and with the club discount.

[hks_kansei]

more grip can reach a point where it can cause issues.

cars are designed with a slip factor where the tyre will slide before the car rolls, if you have too much grip there can be a risk of the car having not slip and rolling in a hard turn.

HOWEVER.

this isn't really an issue on the road, to give an MX5 enough grip to roll would require a very grippy tyre, probably a slick or something.



you will be very hard pressed to find a legal road tyre than can generate anywhere near enough grip to be risky. (assuming you don't have wider wheels, if you add wider wheels/tyres this can increase grip by having more rubber down, but again, to be a risk you'd need to be at the extremes with VERY wide wheels/tyres) again, if your wheels are legal width it won't be even close enough to be risky.




as for the RE001 specifically, I found them to be a great tyre and if anything I found they add to the fun factor (being able to hold higher corner speed)
my only issue was that my set were pretty average in the wet, but my set are pretty old and worn.

[project.r.racing]

don't over think things. and don't campare apples to oranges.

unless you are running a 225 or wider tyre, then you ain't gonna have a problem with grip levels.

also, you have a stock suspension, so you ain't maximizing your total grip anyways.

[snshami]

don't over think things. and don't campare apples to oranges.

unless you are running a 225 or wider tyre, then you ain't gonna have a problem with grip levels.

also, you have a stock suspension, so you ain't maximizing your total grip anyways.

Am I that obvious. I do tend to over think sometimes. I guess I don't want to risk losing the magic feel of the mex.

[ForceMajeure]

Honestly, I would just take it easy in the wet with an MX5, there are plenty of dry days to fully appreciate the handling capabilities of the MX5.

Every thread ive read about the RE001 says they suck in the wet, so i think your way off track here anyway.

If you want (better than average) wet weather grip you will likely have to look at Michelin pilot sports........ch-ching!

[Alex]

I don't think it's an issue of having too much grip but some tyres will sacrifice response/handling for grip and seem to grip then they will suddenly let go which can be more dangerous than a tyre with lower grip levels but a smoother transition.

[snshami]

My Turanzas were very easy to catch. It was early in the morning so I was probably not at peak alertness and was also not expecting it, given my daily dose of dynamic stability control That probably means they are progressive.

Would the RE001s be the same but just let go at a slightly higher loading?

[Guran]

On a wet road the RE001s would possibly let go sooner than the Turanzas. Reverse that for a dry road. RE001s are mainly about dry grip.

BTW the RE001s are far from excessive in their grip levels. If you want proof, check out my YouTube videos from Wakefield Park. I regularly four-wheel drift through turns 2, 3, 4 & 5 in the dry. It's great fun!

[snshami]

On a wet road the RE001s would possibly let go sooner than the Turanzas. Reverse that for a dry road. RE001s are mainly about dry grip.

BTW the RE001s are far from excessive in their grip levels. If you want proof, check out my YouTube videos from Wakefield Park. I regularly four-wheel drift through turns 2, 3, 4 & 5 in the dry. It's great fun!

Guran, there are obviously two schools of thought on the RE001 and they appear diametrically opposite.

Your video seems like fun. What is the speed you were doing at the entry to these turns. How many laps can you do before you wear out one of these tyres.

[manga_blue]

Lots of misinfo in this thread, isn't there? The size of the contact patch has nothing to do with the width of the tyre, just the shape. Contact patch size is dictated by the weight on the tyre and its pressure.

Wide low profile tyres will have shorter, wider but same sized contact patches as high profile skinnies. They have the same grip level (providing the rubber is similar). They will turn in faster and let go faster with less warning. Low profile feels better than high profile but you can be faster, more consistent and safer on high profile. Just check Guran's lap times.

BTW I'm into my third set of Bridgestone RE001s on 2 cars now. Their native home is the wet, foggy, drizzly, B-grade mountain roads all around me. They're brilliant in the wet. I love the softness of them and the way they comply and move over the potholes, puddles and corrugations.

[zombie]

As you probably gathered from my post in your other thread, I'm firmly in the camp of more grip = more better

I run the stickiest tyres I can legally get away with, and it has definitely improved the fun level for me. There's no substitute for the G-forces enjoyed in high corner speeds.

[Guran]

Guran, there are obviously two schools of thought on the RE001 and they appear diametrically opposite.

Yep and I don't think you're getting any closer to the definitive answer you seek (though I wonder if you're only interested in provoking debate?). Feel is a subjective thing. Best for you to give them a try and make up your own mind.

Your video seems like fun. What is the speed you were doing at the entry to these turns. How many laps can you do before you wear out one of these tyres.

Minimum speeds in those corners are 83, 110, 87, 81km/hr respectively (give or take ~5km/hr). All in third gear. I get a full year of club trackdays out of a set before I change them to pass rego. The outside shoulders tend to chip. Still plenty of tread depth though.

[de Bounce]

The RE001 debate - got to love it when we compare red and green apples.

[Hellmun]

Let me give you an example of too much grip in a context I'm familiar with and how it's worked around. On my car I went from a car setup for an open diff when I first started modifying it to a very tight Tomei Traxx 2 way diff. These used to be a pretty popular drifting diff as they really tight out of the box. When I installed it I got absolutely chronic understeer on turn-in with no other change to the car. This is because under braking/off throttle it's still forcing both wheels to turn at the same speed (2 way). So when I turn in still off throttle I have the rear wheels locked and pushing the car wide, this is because there isn't enough slip available both in the diff clutch plates and tyres to change direction. So I have too much grip at the rear for the front which is because I've ruined the bias with the sudden diff change. To work around that I needed to stiffen the sway bar at the rear of the car so that as I turned in the inside rear wheel was being lifted somewhat and that helped restore the balance as it took grip away from that tyre allowing slip

In a standard road car though you don't get adjustable swaybars, shocks and extremely tight LSD's. They set the car up from the factory to be balanced and it's similar with suspension too. Run Slicks on a stock suspensioned road car and you will start making the car reach suspension geometry angles that it wasn't designed for. Likely in that scenario you'll be riding the bump stops in corners constantly. It'd still be close as to whether it's faster/slower than a perfect street tyre but it makes the slicks an incredible waste of money and it is probaly also damaging the suspension. That's an extreme example though to exaggerate the effects.

Personally even if you get a road tyre massively better than what the tyre the factory car was designed around you won't notice it on a street car. Not something you need to worry about unless your on the track.

Also just add to Phil's point, grip = coefficient of friction * weight. Only tyre compound or weight will add/remove grip, everything else just moves where that grip is biased towards. Well except for downforce but that's a whole other can of worms.

[manga_blue]

The RE001 debate - got to love it when we compare red and green apples.

Listen, we only throw in all the RE001 plugs because it upsets some people so much.