jevansio Posted September 3, 2008 Share Posted September 3, 2008 When pulling away or accellerating in the wet the wheels light up & start to judder, is this wheel hop? I run 34 PSI in the rears (295/30/19 R888's). I am right in thinkng the following will help illimenate it: 1) New TRD engine mounts 2) New TRD gearbox mounts 3) New solid rear subframe mounts 4) The Ian C FAQ full suspension arm replacement 5) New wheel bearings 6) Full geometry setup & corner balancing Is there anything I have missed, or anything there that is unecessary. I know the 19's aren't helping but I just cannot bear to get rid of the wheels as I love them so much Quote Link to comment Share on other sites More sharing options...
SteveR Posted September 3, 2008 Share Posted September 3, 2008 How would engine/gearbox mounts affect the rear wheels? Quote Link to comment Share on other sites More sharing options...
jevansio Posted September 3, 2008 Author Share Posted September 3, 2008 How would engine/gearbox mounts affect the rear wheels? Not sure , I sort of went through some previous posts & pulled together as many of the solutions as I could Quote Link to comment Share on other sites More sharing options...
CarlT67 Posted September 3, 2008 Share Posted September 3, 2008 How bad is the judder...? You will get a small amount of tramping if the wheels are moving that much faster than the road. But as its enough for you to mention then I suppose its not a low amount.. Quote Link to comment Share on other sites More sharing options...
jevansio Posted September 3, 2008 Author Share Posted September 3, 2008 It's quite loud & you can feel it in the cabin, it feels quite voilent. I've just tried my suspension on full soft then hard & although slightly better on soft it is still present. It does this in the dry too on hard launches (when I was practicing them for TOTB), in the wet you just have to push the loud pedal in 2nd & the wheels light up then start hopping. It seems worse when the wheels have just broke traction too & when you're just past the edge of traction, keep the accelerator down (as long as I can keep the car straight) & it goes. Also it's not really noticable in 1st, more so in 2nd & 3rd. Quote Link to comment Share on other sites More sharing options...
supradibbs Posted September 3, 2008 Share Posted September 3, 2008 Might be well off here mate but are you sure its the rear wheels and not coming up through the clutch i get the same in first sometimes if i dont balance the revs and clutch just right Quote Link to comment Share on other sites More sharing options...
jevansio Posted September 3, 2008 Author Share Posted September 3, 2008 Might be well off here mate but are you sure its the rear wheels and not coming up through the clutch i get the same in first sometimes if i dont balance the revs and clutch just right No I'm not sure at all Wayne but I don't think so. Thing is it happens when the clutch is fully engaged ie I'm in 2nd gear cruising, I squeeze the accelerator, power builds to the point it breaks traction, then the noise/vibration occur at that exact moment. It also sounds/feels as if it's coming from the rear Quote Link to comment Share on other sites More sharing options...
GazB Posted September 3, 2008 Share Posted September 3, 2008 Jay When horsepower is suddenly delivered to the differential, whether from a clutch or a torque converter, the pinion attempts to "climb" the ring gear. This sudden shock of torque causes the entire rear axle housing to rotate backwards in a counter-clockwise direction. This causes the springs to distort, resulting in severe driveshaft/U-joint misalignment. This link may help explain 'Wheel Hop' http://www.competitionengineering.com/articles/chassis2.asp When i got wheel hop at pod i dropped wheel pressure which seemed to work my thinking was the tyre wall would absorb some of the pressure that's being delivered on launch not the diff. don't know if it's right but did the trick that day. Didn't have same problem at York may be because of different surface, did you get it at TOTB? Only running 8 bar pressure may not be good on road though Quote Link to comment Share on other sites More sharing options...
Homer Posted September 3, 2008 Share Posted September 3, 2008 I had the same on my old car. Super grippy tyre's help, but thats no real solution for a road car used in all weathers I replaced all the dampers, springs and some of the suspension but it made little difference, the only item that came out was that the diff had too much back lash, which Mark @ Pheonix thought could have been one of the issues. Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted September 3, 2008 Share Posted September 3, 2008 What condition are your diff bushes in? (The two that mount the rear of the diff to the subframe) If these are badly worn it would certainly contribute to wheel hop. Quote Link to comment Share on other sites More sharing options...
jevansio Posted September 3, 2008 Author Share Posted September 3, 2008 Jay When horsepower is suddenly delivered to the differential, whether from a clutch or a torque converter, the pinion attempts to "climb" the ring gear. This sudden shock of torque causes the entire rear axle housing to rotate backwards in a counter-clockwise direction. This causes the springs to distort, resulting in severe driveshaft/U-joint misalignment. This link may help explain 'Wheel Hop' http://www.competitionengineering.com/articles/chassis2.asp When i got wheel hop at pod i dropped wheel pressure which seemed to work my thinking was the tyre wall would absorb some of the pressure that's being delivered on launch not the diff. don't know if it's right but did the trick that day. Didn't have same problem at York may be because of different surface, did you get it at TOTB? Only running 8 bar pressure may not be good on road though Cheers Gaz, will read that at work tomorrow. Funnily I didn't get it at TOTB, I only seem to get it on normal roads (at TOTB I was running 27 PSI as opposed to my usual 34 PSI though) I had the same on my old car. Super grippy tyre's help, but thats no real solution for a road car used in all weathers I replaced all the dampers, springs and some of the suspension but it made little difference, the only item that came out was that the diff had too much back lash, which Mark @ Pheonix thought could have been one of the issues. So will a TRD diff help? What condition are your diff bushes in? (The two that mount the rear of the diff to the subframe) If these are badly worn it would certainly contribute to wheel hop. I've no idea, they'll be on the car from new so 11 year old wear I guess. I'll add them to my list Quote Link to comment Share on other sites More sharing options...
Nic Posted September 4, 2008 Share Posted September 4, 2008 What condition are your diff bushes in? (The two that mount the rear of the diff to the subframe) If these are badly worn it would certainly contribute to wheel hop. Worn diff bushes are usually a big contributing factor, if you're getting wheel hop then this will only wear the bushes even more. New OEM diff bushes should help as would replacing any tired rear suspension components. Give me a shout Jay if I can help with anything. Quote Link to comment Share on other sites More sharing options...
jevansio Posted September 4, 2008 Author Share Posted September 4, 2008 Worn diff bushes are usually a big contributing factor, if you're getting wheel hop then this will only wear the bushes even more. New OEM diff bushes should help as would replacing any tired rear suspension components. Give me a shout Jay if I can help with anything. You know I will bud Quote Link to comment Share on other sites More sharing options...
Mr. Fish Posted September 4, 2008 Share Posted September 4, 2008 cant you get anti lift kits for supra's? Quote Link to comment Share on other sites More sharing options...
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