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The mkiv Supra Owners Club

Dropping down to 18's for better traction?


msupra1
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I have 19" wheels and car makes 700bhp.

 

I love the look of the 19's but I'm finding traction an issue after my new power upgrades.

This is with around -2 rear camber and a decent 285/30 tire.

Warmer weather it hooks fine in 3rd but usually spins out.

 

I'm about to order new tires but I'm contemplating about dropping down to an 18" wheel.

 

Current setup:

19x9.5 , 255/35

19x10.5, 285/30

 

I'm thinking of:

18x9.5, 245/40

18x10.5, 295/35

 

 

My tire choice is Pirelli P-Zero (have a discount for them).

 

If I have the same tire, just one series thicker sidewall, and a bit wider with 295, would that make a significant improvement for traction compared to the 19"

 

Another reason for the 18's is I feel like the Supra feels better on these wheels all around, feels a bit sluggish on the 19's sometimes.

 

 

Any advice?

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Ahh well I just find the 19's to look just right on a kitted MK4 but in terms of performance the cars feels significantly better on 18's.

 

But besides that I'm wondering if it would be significantly improve traction? lets say same tire and size just different sidewall

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Ahh well I just find the 19's to look just right on a kitted MK4 but in terms of performance the cars feels significantly better on 18's.

 

But besides that I'm wondering if it would be significantly improve traction? lets say same tire and size just different sidewall

 

Yes, it would, one of the biggest problems with low profile tires is that the sidewalls can't flex, which in turn means that it can become difficult to get the tires up to temp. Another problem is that there is no give in forward momentum, which means that they struggle to find grip, IMO, 18's should be the largest wheel a Supra should have, but I also think that 19's look to big, 18's look perfectly suited on the Supra.

 

I think on my next set up I'll run 18's front and 17's out back.

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They have modern suspension though designed for a bigger wheel. The supra is a 20 year old bus these days and was designed for 16 or 17" wheels depending on spec.

 

:yeahthat: Cars these days have a ton of ECU's controlling power to each wheel, slip, ride levels, etc, etc. The supra relies purely on mechanical grip.

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Just read this thread after having ordered some 19s... Now having second thoughts after hearing the traction related issues :blink:

 

My N/A lost traction in 1st-2nd and occasionaly 2nd-3rd gearchanges..................................I'll just leave you with that :D

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My N/A lost traction in 1st-2nd and occasionaly 2nd-3rd gearchanges..................................I'll just leave you with that :D

 

ETA: If you run 19s on a single, be sure to get some super sticky tires, somthing like R888's or RSR's, more normal tire will seriously struggle for grip.

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i don't get it, all modern cars as standard are 19, 20 etc with low profiles.

 

Yep, my friend's new BMW 320 came with 19's as standard.... but you'd be lucky to break any traction in that, one of the slowest cars I have driven!!

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My N/A lost traction in 1st-2nd and occasionaly 2nd-3rd gearchanges..................................I'll just leave you with that :D

 

My old supra running 600bhp and 19"s struggled to break traction past 2nd gear, i changed my wheels to 18"s (with wider tyres) and made the traction far worse, i could light them up up to 4th. Both premium tyres, zz3 on 19s, contis on the 18s, work that one out :D

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My old supra running 600bhp and 19"s struggled to break traction past 2nd gear, i changed my wheels to 18"s (with wider tyres) and made the traction far worse, i could light them up up to 4th. Both premium tyres, zz3 on 19s, contis on the 18s, work that one out :D

 

:think: zz3's are stickier than contis?

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My old supra running 600bhp and 19"s struggled to break traction past 2nd gear, i changed my wheels to 18"s (with wider tyres) and made the traction far worse, i could light them up up to 4th. Both premium tyres, zz3 on 19s, contis on the 18s, work that one out :D

 

My Supra had better traction with 265s on than it did with 275s...

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:think: zz3's are stickier than contis?

 

Mine were like chalk and cheese, the zz3s are the best tyres i've had on the supe by a mile. I've got conti contact2 on my current supe, 10.5" wheels and 275s and the traction isn't any where near as good as my single running 19"zz3s and 200bhp more either.

 

My Supra had better traction with 265s on than it did with 275s...

 

Maybe there is a sweet spot when it comes to tyre size, the zz3s were 265s on 10" wheels, the contis were 285s on 10.5" wheels.

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Modern cars run bigger wheels and tyres with smaller sidewalls because the suspension geometry is design around that principle. Something to do with the kinematics, I think. The Supra is at best and early 90's design and the suspension is predicated on 16/17" wheels (which were huge in the day).

 

Just because a tyre is of a given size, doesn't mean they're ALL identical. I only recently found this out on the GT-R. A 335/30/20 Michelin Pilot Super Sport will fit on a stock R35 rear rim. But, a Toyo 335/30/20 tyre will NOT fit on the same rim, because the Michelin is narrower. Go figure!

 

Your best bet in the Supra is to run something like a 265/35/18. I was in a similar boat to Gaz, I ran 285/30/18 and then I went to 275/35; the result was a significant improvement in grip and ride. Additionally, soften the rear up to allow more compliance. Rock hard coilovers with ridiculous spring rates will not aid traction at all if the contact patch isn't consistent.

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You need a sensible tyre that will warm up quickly in use, as much sidewall height as your taste can live with, correct pressure, supple suspension and a good diff.

 

I tried multiple 17, 18 and 19" wheel and tyre combos on my car along with three different suspension setups. My optimum was a 315/35/17 on the rear with a TRD diff, springs about 10% stiffer than stock, plus CW dampers to match. On a hot day on a good road I could just about get full torque (590lb.ft) down in 2nd gear after a couple of pulls to warm up the tyres.

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I had that set-up for a while. Bet is scares the crap out of you in the wet :D

 

After having different tire set ups, I quickly came to realise that if I was driving with R888s and it started to rain, the best course of action was to pull up to the side of the road, turn the engine off, put the hazards on, get out and back away from the car :D.

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Why have you got 2 degrees negative rear camber? That's far too much and an ultra low profile 19 inch tyre will have a large percentage of its tread unloaded, particularly as the rear squats and negative camber increases even more under hard acceleration!! What springs and dampers are on it? if it's been lowered negative camber gain in squat and roll will increase even faster. Nicest MKIV's I get to drive in the wet, or on bumpy roads are the ones still on 16 inch rims, at or near to stock ride height.

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