SWAMPY56 Posted October 15, 2008 Share Posted October 15, 2008 Can anyone help just had new 20s fitted and now the slip light is on, after driving for about ten miles. The company that i brought them from assure me the tyre size is correct ie: 245/35/20 front rear 275/30/20 Thanks paul Quote Link to comment Share on other sites More sharing options...
Ekona Posted October 15, 2008 Share Posted October 15, 2008 Clicky Should sort it out for you bud. There's loads of guides on here, always worth a quick search first. Quote Link to comment Share on other sites More sharing options...
Andy Posted October 15, 2008 Share Posted October 15, 2008 Thr fronts ideally want to be a 30 profile to get as close to the stock rolling radius as possible. However, I have run 35's on the front of mine in the past so I am surprised you are having problems straight away. What wheels are they? Quote Link to comment Share on other sites More sharing options...
SWAMPY56 Posted October 15, 2008 Author Share Posted October 15, 2008 Thanks for the quick reply buddy. Reading the link, no one says it worked. will give it a try, nothing to loose Quote Link to comment Share on other sites More sharing options...
marzman Posted October 15, 2008 Share Posted October 15, 2008 Clicky Should sort it out for you bud. There's loads of guides on here, always worth a quick search first. Does that really work? There was no confirmation in the thread... I'd be worried bud, i'd say the tyre sizes are wrong... i would have thought you'd need a 30 profile on the front too. By chance, you didnt get these wheels from DP motorsport in scotland did you...? I got mine from them in July, and they were trying to force me to get the same tyres as you have, but in 19's, until i demanded they give me the same profile all round after reading about the rolling radium issues you're experiencing... Chris. Quote Link to comment Share on other sites More sharing options...
SWAMPY56 Posted October 15, 2008 Author Share Posted October 15, 2008 Thr fronts ideally want to be a 30 profile to get as close to the stock rolling radius as possible. However, I have run 35's on the front of mine in the past so I am surprised you are having problems straight away. What wheels are they? They are RS_FUTURA When i put the tyre size in a tyre calculator. the ones that are fitted are closer in diameter than a 30 profile front would be! confused Quote Link to comment Share on other sites More sharing options...
marzman Posted October 15, 2008 Share Posted October 15, 2008 They look very very nice pal The issue is caused by the change in rolling radius from the front to the back... i.e. the rear diameter may have been larger than the front before, but it may be the other way round now - which is what throws out the traction control. Quote Link to comment Share on other sites More sharing options...
Chris`I Posted October 15, 2008 Share Posted October 15, 2008 They look very very nice pal The issue is caused by the change in rolling radius from the front to the back... i.e. the rear diameter may have been larger than the front before, but it may be the other way round now - which is what throws out the traction control. Yup F R Dia. Diff OEM Rays - 225/45/18 245/45/18 2.73% My Rotas - 245/35/18 265/35/18 2.23% 20s - 245/35/20 275/30/20 -0.88 Now my Rotas arent the OEM spec rolling radius, but they keep the front to back stagger. Thats where yours goes wrong I think. As Andy says, you need 30 profile on the front. That puts it back at 2.75% stagger which would be fine. Sure Phil/Kev/Adam will correct this if I'm wrong! Quote Link to comment Share on other sites More sharing options...
RobD7 Posted October 15, 2008 Share Posted October 15, 2008 Liking them Quote Link to comment Share on other sites More sharing options...
YHTM Posted October 15, 2008 Share Posted October 15, 2008 This sorted out my TC cutting in - I had to change the tyres to the ones recommended below. Stock 225/40R18 (25.1) 235/40R18 (25.4) .3 inches 18" opt 245/40R18 (25.7) 285/35R18 (25.9) .2 inches 19" opt 1 245/35R19 (25.8) 275/35R19 (26.6) .8 inches 19" opt 2 245/35R19 (25.8) 295/35R19 (27.1) 1.3 inches 20" opt 245/35R20 (26.8) 285/30R20 (26.7) .1 inch First and foremost, you can go very, very wide on the car if you follow a few guidelines. First and most importantly there's the traction control issue. Putting the wrong size tires on the 350Z results in the traction control cutting in and disabling power to one or more cylinders. All but one model of the Nissan 350Z comes standard with traction control that is not easily disabled. The easiest way involves disconnecting several connectors, one of which includes the brake lights. We won't even go into how to do it since it is outright dangerous to drive a car with no brake lights! That being said, it is easy to get the tire size right front to rear, and here's how you do it. The traction control looks at the rate the front and rear tires are spinning and compare them to each other. The stock tires have slightly different overall diameters, and the computer knows this and calculates the rate with this in mind. The stock 225/40r18 has an overall diameter of 25.1 inches, the rear 235/40R18 has an overall diameter of 25.4 inches, so the stock tire is a little over a quarter inch larger than the rear. When changing to differently sized tires, you MUST keep the front and rear over-all diameter within 1/4" to 1/2", or the traction control light will cut on and the computer will cut power to the cylinders of the engine. Since the rear is not actually spinning the car will never stop cutting power, and the VQ35 will act like a 4 cylinder rather than a 6, if not worse. Quote Link to comment Share on other sites More sharing options...
Sarnie Posted October 15, 2008 Share Posted October 15, 2008 Thr fronts ideally want to be a 30 profile to get as close to the stock rolling radius as possible. However, I have run 35's on the front of mine in the past so I am surprised you are having problems straight away. What wheels are they? They are RS_FUTURA When i put the tyre size in a tyre calculator. the ones that are fitted are closer in diameter than a 30 profile front would be! confused I'm sorry but you can visually see the difference in the front to rear tyre aspect ratio...........also the rears look too skinny without lowering, imo......... Quote Link to comment Share on other sites More sharing options...
SWAMPY56 Posted October 17, 2008 Author Share Posted October 17, 2008 Thanks for the replies lads. will have to see if they will change the fronts. (there not going to like that) will sort the spacers and the drop, when tyres are sorted. Paul Quote Link to comment Share on other sites More sharing options...
theman Posted October 25, 2008 Share Posted October 25, 2008 Nightmare, just bought my car privately and it is doing the same. My fronts are 245/35/20 and rears 275/30/20. Is this the cause of the slip control cutting in? Not going to be too chuffed if I have to change them. The rears are slightly worn, the fronts brand new(all Bridgestone). Can I change the rears to correct the problem? Quote Link to comment Share on other sites More sharing options...
M350ZB Posted October 25, 2008 Share Posted October 25, 2008 20"'s from what i know the correct tyre size is > Front>245/30/20 Rear>275/30/20 If it was 19"'s then yes you could as these are> Front>245/35/19 Rear>275/35/19 hope this helps, what wheels you got on it anyway ? Quote Link to comment Share on other sites More sharing options...
theman Posted October 25, 2008 Share Posted October 25, 2008 These! Quote Link to comment Share on other sites More sharing options...
M350ZB Posted October 25, 2008 Share Posted October 25, 2008 These! ????????????????? Quote Link to comment Share on other sites More sharing options...
theman Posted October 25, 2008 Share Posted October 25, 2008 I know mate!! Can't remember the make-DOHHHHH? Been driving for 10 hours, will make more sense after some proper zeds! By the way, thanks for the advice. Looks like more money! Quote Link to comment Share on other sites More sharing options...
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