Jellybean Posted November 25, 2010 Share Posted November 25, 2010 Currently BPU, 10.5 with a 275 rear Goodyear eagle F1 tyres On take off up to 3rd I have issues putting down the power, any advice? Maybe a 285 rear tyre? Quote Link to comment Share on other sites More sharing options...
bodilx6 Posted November 25, 2010 Share Posted November 25, 2010 No, you shouldn't need that. Espesially not for straight line traction. I have had NO issues at all with 245 on a 8" wheel @ BPU in dry conditions. Lightly moist I would spin when the 2nd turbo went online, but dry no issues. A few times when it was really cold I would have light traction issues in 2nd but never in 3rd. All of this with 245/35-18 Goodyear assymetric. If you are running 19" it might be why. I would think you might need a geo done? Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 No, you shouldn't need that. Espesially not for straight line traction. I have had NO issues at all with 245 on a 8" wheel @ BPU in dry conditions. Lightly moist I would spin when the 2nd turbo went online, but dry no issues. A few times when it was really cold I would have light traction issues in 2nd but never in 3rd. All of this with 245/35-18 Goodyear assymetric. If you are running 19" it might be why. I would think you might need a geo done? Hmmm, I never use to ; it is in the dry too but in saying that I got a puncture 2 weeks back so the Driver Tyre is New and the passengers is 12 months old now This might be the issue Quote Link to comment Share on other sites More sharing options...
Thorin Posted November 25, 2010 Share Posted November 25, 2010 It's cold and frosty out there, that's not great for traction either. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 It's cold and frosty out there, that's not great for traction either. The 3 degrees is great for boost, wasnt too frosty late yesteday afternoon. I just had to take off fast at the lights and wheels were spinning through to 3rd I am sure the Cold affects the Tyre Pressure Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 25, 2010 Share Posted November 25, 2010 What spring rates and dampers are on it? Is it lowered? Sometimes a narrower wheel and tyre will give better traction than a wider one. Real world example, Andy Middlehurst, when racing the Skyline R32 before it was banned form UK saloon racing for being unbeatable, found a drop down from 245 section tyres all round to 225 section gained significant time at Cadwell, in the dry. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 TRD Shocks-- Fixed rate Made by BILSTEIN TRD Springs-- Front K=107.8N/mm; Rear K=92.1N/mm (Lowering at approx. 15mm) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 25, 2010 Share Posted November 25, 2010 You have a spring rate circa 520 pounds inch on the rear, which is far too stiff for good traction, plus it's lowered, with wide tyres and rims. You could go a lot softer, and narrower on wheel and tyre and make it a lot better for normal road usage. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 You have a spring rate circa 520 pounds inch on the rear, which is far too stiff for good traction, plus it's lowered, with wide tyres and rims. You could go a lot softer, and narrower on wheel and tyre and make it a lot better for normal road usage. Thanks Chris, you would think TRD would have the optimum setup Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted November 25, 2010 Share Posted November 25, 2010 Thanks Chris, you would think TRD would have the optimum setup I think you've just opened a can of worms Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 I think you've just opened a can of worms Gone Fishing, Just dangling the worm infront of Chris Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 25, 2010 Share Posted November 25, 2010 Well, you could say they do have it right, for specific usage. Smooth, dry roads, on stock wheels and tyres, and mild track usage. If an all round better grip / comfort package was attainable Toyota as in the car maker would have fitted those dampers and springs, at no extra cost. By buying sport suspension you move the compromise goal posts in certain directions. Even in racing with cars with no significant downforce, suspension set ups for wet, dry, bumpy and smooth tracks vary enormously. It will probably be quite good round a smooth dry track, but quite dire round bumpy, wet roundabouts. Quote Link to comment Share on other sites More sharing options...
bodilx6 Posted November 25, 2010 Share Posted November 25, 2010 What are the spring rates for your springs, Chris? Just to be able to compare his setup with mine that I know grips on 245, 8" rears. @ jellybean; How was you traction a few months back when the weather was warmer? Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 What are the spring rates for your springs, Chris? Just to be able to compare his setup with mine that I know grips on 245, 8" rears. @ jellybean; How was you traction a few months back when the weather was warmer? No issues when the weather was warmer but I dont remember doing any pulls from stand still; plus with the Colder weather we will have more Power But I am sure even though it is dry out , the road temperature will play a part. Maybe Chris has some insignt to Track Temps and the adverse effects/ Tyre pressure in cold weather Quote Link to comment Share on other sites More sharing options...
bodilx6 Posted November 25, 2010 Share Posted November 25, 2010 Well you can just measure the tyre pressure on your tyres? And there are no question that your tyres will have worse grip in the cold. Much of a difference from a 3 degree tread to a 20 degree one. The performance summer tyres are definatly loosing a lot of grip in the cold weather. I would think you shouldn't go after optimizing a supras grip on summer tyres in the cold, if it works out for you in the warmer seasons. If you want grip, get some winter tyres on there. They have completely different rubber characteristics. Alternativly, you can just do a burn out every time you run you car in the cold ;-) Quote Link to comment Share on other sites More sharing options...
Jellybean Posted November 25, 2010 Author Share Posted November 25, 2010 Burn out Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 25, 2010 Share Posted November 25, 2010 My rear springs have a fairly aggressive progression, but even at their stiffest progression they are not much more than half that. The rear rate is more suitable for the front end of a road going Supra where you want a car with progressive feedback and some ride compliance. Quote Link to comment Share on other sites More sharing options...
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