vega Posted March 25, 2012 Share Posted March 25, 2012 So I've been reading, a friend mentioned understeer in his 350z. He went with bigger tires in front and solved his issue. Apparently the 280Z cars have a tendency to "Lift-off oversteer", what would you suggest I do for tires? Same all around? Smaller in front? Etc? Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 25, 2012 Share Posted March 25, 2012 (edited) Any car can have lift-off oversteer if it is at the limit of adhesion and you transfer all the weight off the tires. Don't drive fast in dangerous places. Save it for the track. Slow down prior to turns and accellerate thru them. If you are on a track and you over-do it, you'll go off in the flat runoff area and you will just pull back on and try it again. If you run off and hit something or someone, you'll be busy for a while sorting all that out, then fixing your car. Sorry about the soapbox, but the track just frees your conscience and really makes driving fun and guilt-free. On the street, look cool, make some noise and maybe scratch out a little, but don't speed (very much). Keep all your tires the same size. The Z is roughly a 50-50% weight distribution car. In stock form, it pushes (or understeers) pretty bad. If your suspension settings are stock, you REALLY need to get slowed down before tight turns to avoid pushing the front end like a steam shovel. Then you can hit the throttle pretty hard coming out and maybe you can even induce a little oversteer, but you kind of have to do it on purpose. Keeping all your tires the same makes it easier to rotate tires. You are much more likely to be spinning one or two tires when you are fooling around, and that one will go bald first, so if you rotate that tire around, you will get more miles out of a set. You will also tend to roll the outside of your front tires, so you'll want to move those around too. Folks like to put wider tires on the back of lots of cars, but on z-cars it is mostly just for looks (it does really look cool). Edited March 25, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 25, 2012 Share Posted March 25, 2012 Toe in the rear tires. Run 1/8 or 3/16 inch total, and then don't drop the throttle in the middle of corners. Quote Link to comment Share on other sites More sharing options...
vega Posted March 25, 2012 Author Share Posted March 25, 2012 Thank you for the advice guys that is exactly what I needed to know. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted March 25, 2012 Share Posted March 25, 2012 I used to run a lot of track days.I did my braking while the car was still rolling in a straight line .when I was done braking I turned the steering wheel for the corner and used a small amount of throttle to try to keep the weight even front to rear.My car handles well enough so that I really only turned the wheel and held the setting i turned it to-no sawing back and forth on the steering wheel mid corner.At the apex I would start to feed in power with the throttle.If you chop the throttle or brake mid corner you are shifting weight around and overloading the suspension . Quote Link to comment Share on other sites More sharing options...
johnc Posted March 26, 2012 Share Posted March 26, 2012 Lift off oversteer generally isn't. People confuse a transition from understeer to neutral as oversteer. If you're not counter steering then the car is not oversteering. A good handling car will transition from understeer to neutral or even oversteer if you lift off the throttle in a corner. This is a car with lift throttle oversteer: Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted March 26, 2012 Share Posted March 26, 2012 **** that sideways (pun). Dave Quote Link to comment Share on other sites More sharing options...
jt1 Posted March 27, 2012 Share Posted March 27, 2012 Wow. That is an ill handling beast for sure. I can't decide if that guy is real good or real dumb. jt Quote Link to comment Share on other sites More sharing options...
luseboy Posted March 27, 2012 Share Posted March 27, 2012 That's a pretty cool video haha. That guy looks like he's an adrenaline junky... In the sticky, it said to use from 1/8" to 1/16" rear toe in for a street car... If you're not experiencing lift off oversteer but you want to avoid it and make your car handle the "best", is 3/16" better? Quote Link to comment Share on other sites More sharing options...
johnc Posted March 27, 2012 Share Posted March 27, 2012 More is not always better. You can start breaking stub axle flanges if you run too much rear toe-in and autox or track the car. Quote Link to comment Share on other sites More sharing options...
luseboy Posted March 27, 2012 Share Posted March 27, 2012 More is not always better. You can start breaking stub axle flanges if you run too much rear toe-in and autox or track the car. Good to know lol. I was planning on starting off with 1/16" when I get my Z on the road... But maybe 1/8" is better? Does front toe have any affect? I've heard toe in in the front makes it a little more predictable and "safe" and 0 toe makes it rotate better... Quote Link to comment Share on other sites More sharing options...
johnc Posted March 27, 2012 Share Posted March 27, 2012 Wow. That is an ill handling beast for sure. I can't decide if that guy is real good or real dumb. jt Its actually handling pretty well given that its a 1964 short wheelbase 911 running on 5" wide bias ply vintage racing slicks. Car is very predictable and just requires large slip angles to get around the track quickly. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 27, 2012 Share Posted March 27, 2012 More is not always better. You can start breaking stub axle flanges if you run too much rear toe-in and autox or track the car. I never broke a stub axle, and I autoxed every month for 8 years and almost never ran less than 3/16" toe in. I also did ~10 track days in that time. Once I had a "bad zero" on the alignment rack and ran closer to 1/2" toe in on the back for a couple weeks, including an autocross. Figured it out when my brand new tires were corded. On the other hand, there was a guy just the other day on www.classiczcars.com who broke a stub axle just tightening the nut after changing bearings. With a 40 year old car and suspect axles, you really never can tell. If you're putting a lot of power down, replace them. Toe in will drive the loaded outside rear tire back towards the centerline. It helps a lot with lift throttle oversteer. Quote Link to comment Share on other sites More sharing options...
zack_280 Posted March 28, 2012 Share Posted March 28, 2012 John, that is the exact video I thought of when I read the first post. What a great driver! Quote Link to comment Share on other sites More sharing options...
jt1 Posted March 28, 2012 Share Posted March 28, 2012 Its actually handling pretty well given that its a 1964 short wheelbase 911 running on 5" wide bias ply vintage racing slicks. Ahh... I understand. That explains all that wheel he's having to get into it, and the quick transitions. he's doing a good job no doubt. Is this a vintage event he's running at? Any pics or links? jt Quote Link to comment Share on other sites More sharing options...
johnc Posted March 28, 2012 Share Posted March 28, 2012 There's a discussion about this video on Jalopnik. http://jalopnik.com/5894294/ride-along-on-a-wild-lap-of-circuit-de-spa Quote Link to comment Share on other sites More sharing options...
luseboy Posted March 28, 2012 Share Posted March 28, 2012 There's a discussion about this video on Jalopnik. http://jalopnik.com/5894294/ride-along-on-a-wild-lap-of-circuit-de-spa I re-watched that video... amazing haha. I laughed though, the windshield wiper is like halfway up the windshield lol. That's some impressive driving... He gets pretty sideways at one point there. Quote Link to comment Share on other sites More sharing options...
vega Posted March 29, 2012 Author Share Posted March 29, 2012 (edited) Porsche 911s are terrible to drive hard, fun, but terrible cars. They have just perfected a turd really. Rear engine rear wheel drive is just a bad design in general. Compare that to say a NSX or MR2. An MR2 turbo in 1990 can out brake most performance vehicles that are 20 years newer. Its where the weight bias is. Mid-engine rear wheel drive makes the best handling cars. I would say next would be a front midship design like a z with a v8. Although I have been told that a s30 still (even with a v8) has a bit of rear bias, which I would attribute to the transmission location. Either way this is not really the discussion here. I like the way my z handles as is right now on modern tires taller in the rear shorter in the front. I don't remember what they are in the front I would have to go look at them. When the butt end does start to slide it kicks out just enough oversteer to go around a corner BUT as soon as it does it gets to a point where it stops sliding and on its own accord hooks and goes. The z is a very very easy car to drive. I have yet to put my v8 in. I just spent 1800 dollars on heads so it might be awhile. I was thinking about running sticky 245/50r16s all around. The availability of rims for these cars sucks for race use. The bigger problem is the lack of tires in the size of rims available. I don't know if any of you have driven a cayman s, but I guess that would be a good way to describe how the z I have handles at its limit in its current form. Its gives a good amount of confidence to the driver to what its going to do. I can actually feel what the car is going to do before it does it. I know what its going to do when I step on the gas etc. I am just concerned that changing where the weight is with the v8, and changing tires (larger and stickier) to compensate for the extra 380hp to the wheels it will be making. Also I don't want to end up like peter brock with my car wrapped around a tree and die. I am a bit concerned about my stub axles. I am running a r200 and want to stay with that even though its not "even" side to side per se. The thing is I am sure as hell not going to spend 1000k on a set of axles. I have yet to find a solution for it that is 500 or less. If you guys know of anything that would be awesome. Lastly, I am also looking for subframe connectors, if I can purchase them pre-made that would be to my liking. Otherwise I can just bolt on some angle iron I suppose. Does this make sense? Edited March 29, 2012 by vega Quote Link to comment Share on other sites More sharing options...
johnc Posted March 29, 2012 Share Posted March 29, 2012 Porsche 911s are terrible to drive hard, fun, but terrible cars. They have just perfected a turd really. Rear engine rear wheel drive is just a bad design in general. Really? A bad design? The most successful race car IN HISTORY... I would argue that its the most successful race car design in history. Quote Link to comment Share on other sites More sharing options...
vega Posted March 29, 2012 Author Share Posted March 29, 2012 .... it is successful because of the people who drive them. Not because the car. Why are f1 cars not rr then? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.