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Location:
Pine Rivers QLD
Registered:
April 2005
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why don't i loose traction?
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Wed, 26 October 2005 13:23
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hey all
just learning about car dynamics and i used to own a 60rwhp Mazda that would easily chirp second with 205's on it. my 150 odd rwhp soarer won't though. just wondering what the cause of this is? is this the benefit of IRS? Its just the soarer seems to be able to hold the road much better then anything else i have owned, it has an single spinner and 205's.
Thanks
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I supported Toymods
Location:
Epping, Sydney
Registered:
May 2002
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Re: why don't i loose traction?
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Wed, 26 October 2005 13:25
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more weight in the arse, better tyres, different suspension, different power delivery
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Location:
Brisbane
Registered:
May 2002
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Re: why don't i loose traction?
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Wed, 26 October 2005 13:27
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There are a huge number of factors influencing traction, including vehicle mass, weight balance, weight transfer characteristics, suspension design, and of course the quality/design of the tyres.
IRS is a pretty major factor though. One of the major downfalls of a solid axle is the torque of the driveshaft will try to twist the whole axle, thus unloading one wheel slightly. Obviously this can make it much easier to spin that wheel, especially if the suspension is a bit ordinary.
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Location:
Melbourne - NthSubs
Registered:
January 2004
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Re: why don't i loose traction?
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Wed, 26 October 2005 13:30
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man, i wish i don't loose traction, need grip for the evil fwd setup 
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Location:
tallahassee FL usOFa
Registered:
May 2002
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Re: why don't i loose traction?
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Wed, 26 October 2005 15:09
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clutch
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Location:
Brisbane
Registered:
July 2005
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Re: why don't i loose traction?
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Wed, 26 October 2005 23:02
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What about the diff??? What kind of diff is in these soarers? Simmilarily, what about the crowns & mark II of same era???
My car has a simmilar condition... I basically have to punch it around a corner on a wet day to get any traction loss...
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Location:
Melbourne
Registered:
October 2004
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Re: why don't i loose traction?
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Wed, 26 October 2005 23:11
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| allencr wrote on Thu, 27 October 2005 01:09 |
clutch
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great input! 
chirping second isn't any great show of power, Im sure the way you are driving has a lot to do with it (fast and teh furiosity flat shifting would help). Also what transmissions are in each of the cars?
Who would want to lose traction in a rear wheel drive anyway? I hear the kids in japan love it but they crazy.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: why don't i loose traction?
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Wed, 26 October 2005 23:19
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| ndgcpr wrote on Wed, 26 October 2005 23:23 |
hey all
just learning about car dynamics and i used to own a 60rwhp Mazda that would easily chirp second with 205's on it. my 150 odd rwhp soarer won't though. just wondering what the cause of this is? is this the benefit of IRS? Its just the soarer seems to be able to hold the road much better then anything else i have owned, it has an single spinner and 205's.
Thanks
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to add to the responses...
wider tyres = reduced grip on light cars..
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Location:
Melbourne
Registered:
October 2004
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Re: why don't i loose traction?
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Wed, 26 October 2005 23:35
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oh don't go and confuse everyone oldcorrolas!
so does increasing tyre pressure
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Location:
Brisbane
Registered:
July 2005
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Re: why don't i loose traction?
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Wed, 26 October 2005 23:43
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corolla's - how does more contact area with the road = less traction in any scenario???
Incresed pressure = less contact area and less traction yes.
Corolla's im sure you will be able to tell me all about the diffs toyota used in their top end models of this era. Please do...
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Location:
Ryde
Registered:
September 2004
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Re: why don't i loose traction?
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Thu, 27 October 2005 00:38
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| mic* wrote on Thu, 27 October 2005 09:43 |
corolla's - how does more contact area with the road = less traction in any scenario??
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the wider tyres are less grippy esp in the wet because they spread the cars weight over more of the road ...thus reducing the amount of weight contact between the road and tyres.
ever noticed why rally cars use very, very skinny tyres in the wet and snow...
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Registered:
July 2005
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Re: why don't i loose traction?
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Thu, 27 October 2005 01:08
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not to mention many gt class cars (not the crazy japanese ones with huuge tyres) run 205 or 215 section tyres.. more pressure on the road = more grip. tyre compounds tehse days are super grippy, theres no real need to make a tyre really fat to increase grip levels.
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Location:
ACT
Registered:
September 2005
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Location:
Brisbane
Registered:
May 2002
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Re: why don't i loose traction?
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Thu, 27 October 2005 01:19
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Actually wider tyres have the same size contact patch as smaller tyres; the only thing that changes is the shape of the contact patch.
The contact patch area is influenced by two factors only:
- the force exerted on the tyre
- the tyre pressure.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: why don't i loose traction?
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Thu, 27 October 2005 02:52
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| Norbie wrote on Thu, 27 October 2005 11:19 |
Actually wider tyres have the same size contact patch as smaller tyres; the only thing that changes is the shape of the contact patch.
The contact patch area is influenced by two factors only:
- the force exerted on the tyre
- the tyre pressure.
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yup 
and tyre grip is a complex thing.
there are maybe 3 main components.
chemical grip (bonding to the road) but this is not really big for road tyres,
pure friction coefficient between the areas in contact,
and lastly, grip due to deformation of the rubber into the "terrain" of the road surface, which is never perfectly smooth.
larger surface area = lower force per unit area, and this results in less deformation of the tyre surface into the road "terrain" (i forgot the proper word for the measure of roughness;))
although as Norbie said, the actual contact patch may be the same... hmmmmm.. need more thinking....
ok.. say you have a 6" tyre and a 10" tyre at same pressure, will the 6" tyre have exactly the same area in contact with the road? i confess i do not know enough to calculate pneumatic loading or such....
hmmm.... there is a point at which a tyre will start to lose grip because you are going from a situation where rubber contacts _most_ of the road surface, to a situation where the rubber only contacts the high points of the road surface..
for wet surfaces, larger surface area = less grip, and so is the case for ice...
and my personal experience was that 215's on an old corolla are dangerous, but 185's had more grip than 175's (but alas they were all shitty tyres)..
i dunno 
anone want to ask the tyre companies whats what?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Location:
Brisbane
Registered:
February 2003
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Re: why don't i loose traction?
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Thu, 27 October 2005 03:59
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Interesting thread. What about a thin tyre streached over a wide rim? Maybe I should back to 185's or 195's on the sprinter.
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Location:
tas
Registered:
June 2002
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Re: why don't i loose traction?
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Thu, 27 October 2005 04:27
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Back to the OP.
I have the same problem. Found it very hard to spin the back wheels up and show off bogan style.
Whent from a 3.9:1 Diff to a 4.3:1 diff and it's possible loss traction thru flooring it but nothing special.
It's not apparent why, besides the IRS and good sticky tires i have. The worn suspension at the back wich is so soft and bouncy lets the car squat it's weight down heaps!
But i tell you this is the way it should be! getting all that power to the ground simply kicks ass! In drag situations I'm unbeatable here in tas, have no been beated in a drag yet! (auto really helps too, my days of that are over, learnt me lesson, been driving around on 1 demerit point for nearly a year now)
But often when the auto changes to second gear the back wheels lose traction pretty easily probably becuase the rear squat has reduced somewhat. I also notice when i'm traveling along at say 80km's and i step on it hard enuf to get a gear change back to 2nd the car is just spinning the wheels for a good few seconds before gripping and taking off. I put it all down to soft suspension at the back and the weight it shifts onto those back wheels.
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Location:
Tassie
Registered:
October 2003
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Re: why don't i loose traction?
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Thu, 27 October 2005 04:44
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if you want to do burnouts and it's not working then give it more revs when u dump the clutch... simple.
Thanks old corollas,norbie and everybody else who explained the grip thing.
the old boy had 11 inch wide wheels on the old 4x4 (yes the did rub) off road it was untouchable but when it rained the tarmac handling was shocking it was worse than ice. fair enough the tire pattern allowed minimal rubber to road contact beacuse of the "Lug" design.
Now to rectify this problem day bought some shitty narrow wheels on old toyota split rims and the car was handling like a dream again.
only now do i understand why this happened.
thanks guys
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Location:
Melbourne
Registered:
August 2005
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Re: why don't i loose traction?
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Thu, 27 October 2005 05:11
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Its a great thing, mean you can go harder into corners!!!
If you want wheelspin - put some oil or soapy water on the road 
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Location:
Melbourne - NthSubs
Registered:
January 2004
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Re: why don't i loose traction?
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Thu, 27 October 2005 05:51
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u neeed hektic driftSpec black Steelies on the rear as seen on most sik commodores
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Registered:
October 2005
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Re: why don't i loose traction?
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Thu, 27 October 2005 06:33
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The way someone made me click, the contact area ahould be roughly the same nomatter what tyre. It's just wider tyres have a wider contact area and less of a flatspot on the botom. Skinny tyres still have the same weight applied, so their sidewalls flex giving a flatter bottom but still roughly the same total area. So the main improvement in 195's over 175's might just be the slightly wider track.
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Location:
Melbourne - NthSubs
Registered:
January 2004
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Re: why don't i loose traction?
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Thu, 27 October 2005 06:36
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ok.. so how do i get more traction?
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Location:
Hobart, Tas
Registered:
May 2002
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Re: why don't i loose traction?
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Thu, 27 October 2005 07:00
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| myne wrote on Thu, 27 October 2005 16:33 |
So the main improvement in 195's over 175's might just be the slightly wider track.
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Tyre width doesn't affect track - track is the distance between the centrelines of each wheel.
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Location:
Pine Rivers QLD
Registered:
April 2005
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Re: why don't i loose traction?
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Thu, 27 October 2005 09:22
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| oldcorollas wrote on Thu, 27 October 2005 09:19 |
to add to the responses...
wider tyres = reduced grip on light cars..
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yeah i have sorta known this too. First of all i am not trying to do burnouts or anything it was just something that i have noticed, i seem to have far supierior road holding abilities in this car.
I have a W55 with a Heavy Duty (fairly heavy to push in) clutch and a F282 diff, i think it is about 4.2 or something.
Yes i believe i have dodgy suspension as i went to a skid pan day (video available http://users.tpg.com.au/phiele01) and i had serious body roll with the car, and i am wanting to head out to the drags again to see how it goes now its TT, this wasn't really a thread to learn how to pull "fully sik burnouts" i was just curious.
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Location:
Pine Rivers QLD
Registered:
April 2005
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Location:
Brisbane
Registered:
July 2005
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Re: why don't i loose traction?
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Thu, 27 October 2005 23:38
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Its sound theory that when the weight of a vehichle is constant that there is a trade off between contact area and pressure applied per unit contact area, which both affect overall grip.
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Location:
Ulverstone
Registered:
June 2005
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: why don't i loose traction?
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Fri, 28 October 2005 03:14
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maybe the wide tyre, light car thing is just a result of road imperfections, ie rough/uneven surface, loose gravel, wet etc...
i'm still a little confused about the actual reasons.. but it seems everyone else i talk to is also not so sure....
and the magic formula is based on empirical measurements, as opposed to anything fundamental....
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Location:
Kilsyth, Melbourne
Registered:
September 2004
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Re: why don't i loose traction?
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Fri, 28 October 2005 04:11
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| Norbie wrote on Thu, 27 October 2005 11:19 |
Actually wider tyres have the same size contact patch as smaller tyres; the only thing that changes is the shape of the contact patch.
The contact patch area is influenced by two factors only:
- the force exerted on the tyre
- the tyre pressure.
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i don't quite understand this. are you saying that a wider tyre has a smaller area because it is wider left to right but not front to back. where as a a skinny tyre has more contact front to back than left to right or is this wrong
Cheers
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: why don't i loose traction?
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Fri, 28 October 2005 05:12
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No, he's saying that they'll have the same size patch. The wider tyre, will have the wider patch, but not as long. Because the amount the tyre deforms into the road is relative to the amount of weight on it, a skinnier tyre will deform more and hence have a "longer" contact patch.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: why don't i loose traction?
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Fri, 28 October 2005 05:14
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*NOTE: This is only relevant if the tyres are of similar construction and have the same tyre pressures.
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Location:
Kilsyth, Melbourne
Registered:
September 2004
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Re: why don't i loose traction?
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Fri, 28 October 2005 06:22
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yeh thats what i figured.
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Location:
Northeast US
Registered:
September 2005
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Re: why don't i loose traction?
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Fri, 28 October 2005 17:15
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| KLR16V wrote on Wed, 26 October 2005 20:38 |
| mic* wrote on Thu, 27 October 2005 09:43 |
corolla's - how does more contact area with the road = less traction in any scenario??
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the wider tyres are less grippy esp in the wet because they spread the cars weight over more of the road ...thus reducing the amount of weight contact between the road and tyres.
ever noticed why rally cars use very, very skinny tyres in the wet and snow...
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i think the reason rally cars have skinny rally tires is to make sure they dig and grab faster
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Location:
Northeast US
Registered:
September 2005
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Re: why don't i loose traction?
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Fri, 28 October 2005 17:22
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other that engine HP, drivetrain components(clutch, LSD etc) and tire quality - another thing that would affect it all is the suspension dynamics. for example things like wheel hopping are fixed by suspension realignment. i think if you stiffen your rear suspension the car wont effectively pin down the rear tires making it break traction easier. give it a shot
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I supported Toymods
Location:
Frankston, Victoria
Registered:
April 2004
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Re: why don't i loose traction?
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Sat, 29 October 2005 14:22
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Wouldn't rim size be a contributing factor too? Let's say you have a 6" wide rim and chuck tyres with the equivelant surface are of a 10" wide rim, it would mean you'd have extremely harsh tyre wall inabilities, meaning your car would move side to side, but your tyres would still grip the road, whereas if you chucked the equivelant of 5" width tyres, you would have less surface area and the tyre walls would be damn tight, meaning that your wheels would slip rather than the tyre walls moving.
Argh, tired and half-pissed, hope i made a bit of sense.
I have a bit of trouble on my car. I'm running 185s on my 14x6 rims, and the fronts are having tyre wall problems due to the the negative camber putting alot of sideways force into the tyres. Pumping them up past recommended pressure helps a bit, but wondering whether some thinner tyres would still give me the great grip that negative camber induces, but wouldnt have the front tyre wall sway problem that i currently have?
Kev.
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Location:
new castle
Registered:
July 2005
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Re: why don't i loose traction?
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Sun, 30 October 2005 09:32
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wouldnt heat come into this somewhere as well? i thought hotter surfaces generally girpped better (not all case's) but isnt that why drag cars do a burn out before a race, because it made the wheels stick better
so wouldnt you get differnt traction results say after waking up in the morning and doing a burn out just out of your drive way, compared to say a 100kph hour journey down the freeway for an hour?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: why don't i loose traction?
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Sun, 30 October 2005 09:36
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| havabeer wrote on Sun, 30 October 2005 20:32 |
wouldnt heat come into this somewhere as well? i thought hotter surfaces generally girpped better (not all case's) but isnt that why drag cars do a burn out before a race, because it made the wheels stick better
so wouldnt you get differnt traction results say after waking up in the morning and doing a burn out just out of your drive way, compared to say a 100kph hour journey down the freeway for an hour?
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how does this have any bearing whatsoever on tyre width?
and don't you find that your tyres are warm after a freeway drive anyway?
LOL @ burnout on driveway....mmmm bogansville 
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Location:
Brisbane
Registered:
May 2002
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Re: why don't i loose traction?
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Sun, 30 October 2005 14:06
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Racing tyres are a completely different kettle of fish. The tyres used on drag cars are uber-sticky and the compound is designed to work best at higher temperatures... that's why they do a burnout before racing, to get the tyres up to their operating temperature.
Road tyres on the other hand are designed to work at much lower temperatures, and will actually grip much less when they get hot. The gimps doing huge burnouts on normal road tyres at street meets aren't doing themselves any favours, but it seems like the done thing so everyone does it! A small burnout isn't a bad idea to scrub any crap off the tread, but you don't want to get street rubber too hot.
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Location:
Melbourne
Registered:
August 2005
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Re: why don't i loose traction?
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Mon, 07 November 2005 22:27
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Here's a thought for everyone - back in the day, don't give me grief, but i had a 4.0L straight six Ford EB Wagon for about a year. I know i know but i got the car for free so i wasn't complaining and it was in perfect nick. Anyway, it had 195's all round. Wasn't happy, so i put 205's on the front and 235's on the back along with some sports suspension. Handling increased dramitically and i had no understeer in the dry and very little in the wet, pretty good for 6m+ wagon. What got me was the fact i could drift the wagon on 235's but i could only get a little fish tale using the 195's. Funny hey? I figure its got to do with weight distribution vs surface area. The road/tyre has a certain coefficient of friction. My guess would say that the heavier the car is the greater the coefficient but if distributed over a large surface area the coefficient will drop. Thus wider may not neccessarily be better, you have to match the weight of the car with the right tyre size, trial and error maybe but you could also go to narrow and the tyres jut spin. A way to test this theory is to get on dirt. A wide tyre may have good surface area but the weight is distributed over the whole area and the tread won't dig into the dirt, kinda float over the top. On the other hand if you choose a narrower tyre, the weight onto the tyre has a smaller spread onto the dirt and will force the tread to start digging! Just a thought folks.
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