Tyre Compound

[Baz]

This is one thing I have always notice people overlook when choosing a tyre that is right for the job. People always have the generalisation that if you cannot maintain traction with a set of 205's, buy some 235's and you will get better traction. While this is mostly true most of the time the case in that more contact patch means more traction the tyre compound is often overlooked.

If you have ever felt what some drag slicks or semi-slicks feel like they are always a very very soft compound. This means that being a softer compound allows them to stick much better to the surface rather than spin. Also why people run a lower tyre pressure is due to the fact of trying to make the tyre much softer.

Now one of my mates run's 225/50R16 Simex's on his car. Simex's are one of the more cheaper brands of tyres but run a very soft compound. While this is a good property to have there needs to be a compromise between straight line traction, cornering and wear. Obviously with a harder compound sidewall flex would be minimised and tyre wear would be extended. I am running 245's on my car at the moment and these tyres grip less than what my 205 maxis's do in a straight line mainly due to there rock hard compound.

That said when you go looking for overcoming traction problems don't get sucked into thinking the fact that buying 245/35R18's will benifit you with straight line peformance when a set of correctly selected 225/50R16's can be up to the task most of the time.

My 2 cents

Edited December 20, 2005 by Baz

[benl1981]

I had savas on the back and they were SCARY. Maybe they had been sitting around for ages but they were as hard as rocks.

I know have michelin premacy on the rear (still 205s) and I probably have more traction in the wet than I did in the dry with the savas...

These 205s hold on pretty well, unsure if wider would help a lot - but you have to give it quite a bit before the back steps out. I don't do it much now because tyres are expensive. On the savas - who cares if you chew them up (I couldn't though) they are virtually like plastic.

[Duncan]

why do wider tyres give a bigger contact patch?

but yeah there is no doubt that good 225s can give better grip than bad 255s!

For god sake if you are going to buy a sports car buy decent tyres!

[Baz]

* Edit.. I meant Simex's Sava's are crap. I know cause I give them out on a day to day basis.

[someonestolecc]

Ssava are great!! It's what I have on my barina.

The stock michelin tyres they give you wore out within the first 6k (the car was new).

The ssavas were recently changed at 26k now I've got Federals LOL

Nothing but the best of the cheapies on my cefiro however - Nankang all the way .. DORIFTOOoo... better than on my flatmates 32.. all he puts on that is the worst federals you can get...

...

lol

[Silver-Arrowz]

Lets face it, most people wouldn't give two hoots about tyres and would spend that money else where. I grew tired of arguing that same principle but they just don't get the idea. It's a piece of rubber that's black and little "bling" factor.

Some people just grasp the concept that it's the only thing coming in contact with the surface.

[Baz]

Well a turbo is just a device that spins around off exhaust gases and compresses air. The point I'm arguing is that people generally believe that putting a wider tyre on means they will always get better traction. Which I think is pointless considering that a cheapish 16" tyre can maintain better traction than a wider 18" tyre in most cases.

[Josh]

Savas are absolute shit, although they aren't bad for rear tyres - pretty hard compound -on the front wheels tho they = shit.. not bad for drifting haha

Edited December 21, 2005 by Josh

[GTshortie]

I have to agree with Baz,

a few years ago i purchases brand new 255/35/18's FALKEN 326's!!.. done about 3000-5000kms on them since new, AND THEN

i pick up some second hand dunlop sp2050 off the accord euro with 30% and only 205/55/16's stock tyre sizes... and you guessed it.

the 30% OLD 205 dunlop's GRIPPED better for straight line traction then the 255 falken's!. but then again its the FALKEN's are the worst tyres in the world (IMO) other then KELLY CHARGER. haha.

around the track wakefield, i got very similar times.

OPINION: If you can't afford decent brand rubber or something to suit your application, save up or sacrifice, get better tyres in a smaller size. SIZE isn't also everything quality is very important.

thats my 2c, but what do i know.

[scathing]

If you can't afford decent tyres or brake pads, pull of your brand name intercooler / gearshift knob / exhaust, put on a no-name brand one and buy them.

Very little shits me off more than people who brag about their HKS intercoolers, Tein suspension and Trust exhausts...but then whinge about how they don't want want to spent a couple of hundred dollars on a decent set of brake pads or roll on shithouse tyres wrapped around cheap and nasty chromies.

[hrd-hr30]

This is one thing I have always notice people overlook when choosing a tyre that is right for the job. People always have the generalisation that if you cannot maintain traction with a set of 205's, buy some 235's and you will get better traction. While this is mostly true most of the time the case in that more contact patch means more traction the tyre compound is often overlooked.

If you have ever felt what some drag slicks or semi-slicks feel like they are always a very very soft compound. This means that being a softer compound allows them to stick much better to the surface rather than spin. Also why people run a lower tyre pressure is due to the fact of trying to make the tyre much softer.

Now one of my mates run's 225/50R16 Simex's on his car. Simex's are one of the more cheaper brands of tyres but run a very soft compound. While this is a good property to have there needs to be a compromise between straight line traction, cornering and wear. Obviously with a harder compound sidewall flex would be minimised and tyre wear would be extended. I am running 245's on my car at the moment and these tyres grip less than what my 205 maxis's do in a straight line mainly due to there rock hard compound.

That said when you go looking for overcoming traction problems don't get sucked into thinking the fact that buying 245/35R18's will benifit you with straight line peformance when a set of correctly selected 225/50R16's can be up to the task most of the time.

My 2 cents

<{POST_SNAPBACK}>

I definitely agree with the principle. I 'only' run 225/50*16 semi-slicks on my GTR on the standard rims for track days. Sure a set of 245-255 17" race rubber would be a bit better, but I just didn't see it justifying the additional cost.

i have to disagree about why people run lower pressures though. in a drag racing situation I guess you mean? They are doing it to increase the size of the contact patch, and more importantly to make the contact patch longer which will help straight line traction. maybe that is what you menat by "make the tyre much softer"? Notice that drag racers tend to fit the tallest tyre they can? That's also because it lengthens the contact patch.

Now one of my mates run's 225/50R16 Simex's on his car. Simex's are one of the more cheaper brands of tyres but run a very soft compound. While this is a good property to have there needs to be a compromise between straight line traction, cornering and wear. Obviously with a harder compound sidewall flex would be minimised and tyre wear would be extended.

don't confuse the rubber compound with sidewall construction. you can have a very soft compound on a very stiff construction, as is the case with most semi-slicks, or very soft compound and soft sidewall as it normally the case on DOT drag tyres. For normal street radials the same is the case, but all sidewalls are at the softer end of the scale, and compounds at the higher end of the scale.

For the record, I agree Simex are a pretty good road tyre at a very good price. The bigger name brand tyres street are not much better IMHO, and hurt the hip-pocket alot more. SOme cheap tyres are actually very good. And others are simply rubbish.

Edited December 22, 2005 by hrd-hr30

[benl1981]

How much are simex for 205/55 16s - if they are ok I might grab a set.

[Beer Baron]

but then again its the FALKEN's are the worst tyres in the world (IMO)

<{POST_SNAPBACK}>

i don't know how you can form an opinion on a manufacturers whole range of tyres based on your experience with 1 model. you bought the cheapest, nastiest tyres they make (aimed squarely at tightasses) and complain that they aren't any good? more fool you. Falken make some pretty good tyres. FK451s are quite a good road tyre. RT215s are quite a good weekend tyre for the price. And athough i haven't peronally used them my friend tells me their slicks are quite good too.

Yes, FK326s are pretty crap tyres. but they are priced that way too.

[hrd-hr30]

How much are simex for 205/55 16s - if they are ok I might grab a set.

<{POST_SNAPBACK}>

I bought a set of Simex SM8000 225/50*16 for my HR30 recently for $130ea, so it should be somewhere around that.

[benl1981]

And they're ok I guess. I rang a few places. $145...cheapest I found was $115 each - but none in stock. I'll try and get some from them after xmas. I'll get the 225/50s. Good price. I need to get a wheel alignment aswell so I don't chew tyres out. The fronts are wearing on the inner edge severly.

But then I should get new front shocks aswell before the wheel alignement.

$230+ for tyres

$485 bilsteins

$60-70 wheel alignment.

thats almost $800 bucks

[GTshortie]

sorry if i wasn't clear with my initial post but the point i was trying to get across was,

i must admit FALKEN do make decent tyres FK451, RT215 etc, ( I MEANT SPECIFICALLY the compliance tyres FALKEN ZIEX's 326's) they are usually the FREE tyres that come with tyre packages and tyres used for compliancing.

STAY AWAY from them.. very scary in the rain..

[wrxhoon]

Falken 326 and 512 are just the same crap, but fk451 and st115's are quite good .

[benl1981]

Anyone know about the simex in the wet?? Are they ok?

Cheers

[FATGTS-R]

I agree that the compound plays a big part in tyres grip as opposed to the actual width.

I have a rubber hardness tester at work which the higher the number the harder the rubber is.

My 265 rear Yokos which I have always known to be rubbish for traction measured "70" on the durometer. They must have been sitting around a long time before I got the car (they came with them) as I have measured everybodys tyres at work, including light commercial tyres and nothing has come up as hard as my yokos. The average hardness across all cars at work, about 10-15 is "55-60".

The boss has a serious car and his MT slicks measured "40". He also has a set of MT ET street radials and they were the identical hardness of the full slicks at "40".

The only upside to my tyres is they dont look they have worn a millimetre in 2 years lol. Note that I NEVER do burnouts etc. The only time they spin is when coming onto boost with the pedal down and they still light up hitting boost in third. And with only 320rwhp the tyres are obviously a major problem as this should not happen.

[krzysiu]

I have a set of SAVA 235's all round. When im driving normally in second then put my foot all the way down the back just goes out and i need to ease off the accelerator to straighten it up. They arent THAT bad but i couldnt afford $1000 for tyres lol