Tyre situation, Need help.

[Boags]

Yah I see what he means but I wasn't asking for a driving lesson, just some suggestions on what tyres are good and what are outright dangerous with a turbo

That's the point though; you can be outright dangerous without the turbo using R888 if you don't drive sensibly.

Show me a race car that will hold traction if you redline and dump the clutch. It just doesn't happen. I know you just want good traction/$$$, which is a good way to go, but at the end of the day you can smoke slicks if you try hard enough.

Happy to share experience, looking forward to your PM. I want to hear all about your plans actually, if I had my time over I would definately buy Begi.

I saw from your "My Ride" thread that you already have a pretty good brakes setup, sorry for not researching before posting.

Boags

[fattima]

I've got Falken RT615s in 14s and I'm pretty impressed with them, came in at $187 each fitted. I would tend to keep a set of R specs for the track and another set of tyres for the road if you can.

[[Will]]

Thanks for the replies.

So does a wider tyre actually give you more grip? I read in a few places that going wider makes the contact patch smaller or not much bigger. This is since the weight is spread more so it doesn't mush the tyre into the ground as much, so the contact patch gets wider but thinner too.

I don't get it, why would you go wider tyres then? Corvettes have like 375mm tyres, surely a wider tyre will give more grip. What about in the wet??

Contact patch stays theoretically the same with wider tyres if you run the same pressure. Pressure = Force/Area. Since the mass of the car and tyre pressure are the same, then the areas (contact patch) is the same. However, wider tyres have more thermal mass and surface area to radiate heat, so you can run softer compounds to generate more grip.

You can go too far with this concept for a given size car too and go so wide that you can never get your tires up to temp. I'm not a tyre expert, so there is probably many more effects in addition to what I've mentioned.

Corvette's can run wider because of the mass of the car + power/torque.

I've never had aquaplaining with the r888s in the wet unintensionally, despite all the rain we've just had. Except maybe a few weeks ago since theyre basically bald, but nothing unmanageable at all. The GIIIs I had to always be very careful in the wet as the car was so twitchy and a real pain in the round abouts. Couldnt imagine them with a turbo.

My GIII's have been quite good in the wet. I have had bad experiences with good quality tyres when they're old. I'd go with cheap new tyres over old hard good tyres any day. I once had a major oversteer moment at about 70km/h in a FWD Astina SP because I was running cheap Kenda tyres front, but old Dunlops on the rear. I was certain the the front would push first, but not the case

[Sasso]

Yah I see what he means but I wasn't asking for a driving lesson, just some suggestions on what tyres are good and what are outright dangerous with a turbo

That's the point though; you can be outright dangerous without the turbo using R888 if you don't drive sensibly.

Show me a race car that will hold traction if you redline and dump the clutch. It just doesn't happen. I know you just want good traction/$$$, which is a good way to go, but at the end of the day you can smoke slicks if you try hard enough.

Happy to share experience, looking forward to your PM. I want to hear all about your plans actually, if I had my time over I would definately buy Begi.

I saw from your "My Ride" thread that you already have a pretty good brakes setup, sorry for not researching before posting.

Boags

Dangerous without turbo with semis? Thats VERY hard, Even if I tried to get the tail out it wouldn't, its easy to do on the track, but damn near impossible on the road without getting a big ticket. No understeer either, any corner, any speed, it will go around.
I never spun the tyres in the dry off the line (and rarely in the wet) with the R888's, even when I tried, I like my clutch and diff (and tyres) .

Ok When I say I want to be able to floor it without spinning tyres with 200whp, I dont meen clutch dumping from 7k, who does that? Did you see that skyline whos I think flywheel or something broke off and nearly sliced his legs off, another part put a hole up through the bonnet and high in the air.
What I want is to be able to take off like a sane person, then be able to floor it in a straight line through first and second without the wheels spinning. Its not too much to ask is it?
Every time I go to mania and mention superchargers they just say turbos are way better beause they're faster. I say what about lag and they say you get wheel spin from 2000rpm. Well I don't want that. Is this wheel spin in 1st generally accepted in the turbo mx5 community?

I'll see how I go today, I have lots of study to do, and going on a run tonight with some of the club boys and girls. (Shame I can't take my car).

Fattima, thanks for the reccomendation, its a little exe though. I'll have to look up some of the tyres people suggested. In the mean time I just ordered two R888's at $225 a piece.
I looked at my log book and was in shock when I saw that the GIIIs lasted 20,000km and the R888's lasted 8000km. Haha. That was most probably due to 3 very torturous track days. They should last longer this time.

Next set I'll probably get adrenalines or similar.

THanks for the explanation WIll. I'll have to see what teh balance is like with turbo, the car oversteers already, Might get wider rears to fronts next time around, with a bit of dish too

[Boags]

Ok When I say I want to be able to floor it without spinning tyres with 200whp, I dont meen clutch dumping from 7k, who does that?

Some people do. You just said you wanted it to take what you threw at it; this was the mental image I got.

What I want is to be able to take off like a sane person, then be able to floor it in a straight line through first and second without the wheels spinning. Its not too much to ask is it?

OK, you can (and I currently do) on C-drives. The aren't going to stick like semis in the corners, but they aren't crap and if you respect the clutch and diff the tyres will take the turbo.

Every time I go to mania and mention superchargers they just say turbos are way better beause they're faster. I say what about lag and they say you get wheel spin from 2000rpm. Well I don't want that. Is this wheel spin in 1st generally accepted in the turbo mx5 community?

I have no experience with more than 120rwkw (SP) so I can't say... Less than that though you have to be brutal with the clutch to get wheelspin at 2000, and it's only a chirp.

It sounds like you don't want to be brutal, so you should be fine with street tyres on the street.

Boags

[ampz]

your 1.6 clutch (standard, not heavy duty, etc)
Will make sure your tyres don't spin at 120rwkw or above....

[NMX516]

Forget the idea of semi's for the street. That will improve your wet weather traction on the road, reduce the purchase cost of a decent tyre, and increase your tyre life.

As you're not used to living with and driving a turbo'd car, get the best wet weather tyres you can!

A turbo doesn't suddenly mean you start loosing traction, your right foot controls that.

[marcusus]

kuhmpo ecsta ku31. You drove mine on the run (granted they were on the 16s) but they were only $110 a corner.

Good in the wet, although they are a good street tyre, they are prone to graining on a spirited run. I haven't tracked them, but if they hold up like the cdrives gthen they should only get squirmyafter 4 laps.

You should know when you're close to their limits because they squeal like a stuck pig before they let go.

Don't know about that. Went for a spin down McCarr's tonight with Kuhmo's all round. Taking a corner with a bit more power than I should have, the rear stepped out a bit without much warning at all. Didn't really hear any tyre squeals. It just gave out.

Now that I'm getting a bit more experience under my belt, I'm finding the Kuhmo's aren't really giving me grip when I'd like it. They were definitely fine for regular everyday driving, but I'm finding that in my eyes they're slowly deteriorating when it comes to spirited driving.

Track wise, it's much the same. They'll grip OK and all that, but they don't seem to grip when I want them to. There's also this odd sort of vibration that comes on at about 130km/h+, although I haven't really narrowed that down to the tyres though.

[Patty]

Thanks for the replies.

So does a wider tyre actually give you more grip? I read in a few places that going wider makes the contact patch smaller or not much bigger. This is since the weight is spread more so it doesn't mush the tyre into the ground as much, so the contact patch gets wider but thinner too.

I don't get it, why would you go wider tyres then? Corvettes have like 375mm tyres, surely a wider tyre will give more grip. What about in the wet??

Contact patch stays theoretically the same with wider tyres if you run the same pressure. Pressure = Force/Area. Since the mass of the car and tyre pressure are the same, then the areas (contact patch) is the same. However, wider tyres have more thermal mass and surface area to radiate heat, so you can run softer compounds to generate more grip.

Force(Grip)=coefficientOfFriction(COF)*NormalForce(=mass*gravity). Your COF remains constant since it's a property between the material of your tyre and of the road, and NOT related to contact patch. This means that your grip here is not related to tyre width but to the mass of your car, material of your tyre and the type of road Thats why RWD cars should be harder than FWD to wheelspin.

If wider tyres increases contact patch (which [Will] says doesn't) it would probably only work against you because it equates to lower force per area or less equivalent mass on you wheels.

[Adam_NAclubman]

Ok When I say I want to be able to floor it without spinning tyres with 200whp, I dont meen clutch dumping from 7k, who does that? Did you see that skyline whos I think flywheel or something broke off and nearly sliced his legs off, another part put a hole up through the bonnet and high in the air.
What I want is to be able to take off like a sane person, then be able to floor it in a straight line through first and second without the wheels spinning. Its not too much to ask is it?
Every time I go to mania and mention superchargers they just say turbos are way better beause they're faster. I say what about lag and they say you get wheel spin from 2000rpm. Well I don't want that. Is this wheel spin in 1st generally accepted in the turbo mx5 community?

Dude, its easier to spin semis than road tyres when you suddenly apply power (like, say... a turbo coming on boost) because they have stiff sidewalls. My RE55's and RE540's were way easier to do burnouts on in my Skyline than my normal tyres.

Yes, its generally accepted that reasonably powerful (for their weight/size) cars will wheelspin if you floor it in first. They all do it, especially if they have stiffish suspension (you did say you want coilovers in another thread didnt you?), its half the fun of having power. If you have a decent predictable diff and half a brain its not much of a problem when it occurs

[Adam_NAclubman]

oops

[Sasso]

There's also this odd sort of vibration that comes on at about 130km/h+, although I haven't really narrowed that down to the tyres though.

I think your flatspotginity is gone.


Rear wheel drive cars are harder to spin wheels because of weight transfer - not really what we're talking about atm. I'll have to look into the whole tyre width thing a bit more I think. I'll get back with the results later.

Adam, How does a stiffer sidewall make a wheel spin more easily? Maybe those semi's aren't as good in the cold as the R888's which are known to be fantastic all round tyre, just a little slower on the track when its hot, but they last longer.
Also curious as to how stiffer suspension makes less grip too, I would have thought better tuned suspension makes grip.

I suppose managable wheel spin is ok but prefer it to be rock solid. I suppose I can only wait and see.

I'm not going to be brutal mainly until I can afford a diff and clutch. It will be on the track though, however its more smooth than doing burnouts and drifting so shouldn't do too much damage.

[Fatty]

honestly for day to day driving on street tyres in all conditions, wheel spin is not an issue, unless you are a total nube with no idea about throttle control. i don't think you fit that description.

i get a chirp now and then, but that's more due to my new 8 puck clutch than the turbo.

[Patty]

Try this site Sasso:

http://www.newton.dep.anl.gov/newton/askasci/1993/physics/PHY2.HTM

[Benny]

Just my 2c worth.

Have you thought about buying a set of used tyres?
Many tyre dealers carry stock of various sizes and types, and sometimes you can pick up virtually new tyres for a song.
Often, they even come with rims, so you may get lucky and pick up a set of 15\" or 16\" tyres and wheels for less than buying 2 new tyres.

Personally, I'd prefer to drive on a good set of 2nd hand tyres than new crap.