Onion Posted June 21, 2013 Share Posted June 21, 2013 Correcting Understeer Raise front tire pressure. Lower rear tire pressure. Soften front shocks. Soften front springs. Stiffen rear shocks. Stiffen rear springs. Stiffen bump. Lower front end. Raise rear end. Widen front track. Install shorter front tires. Install taller rear tires. Install wider front tires. Install narrower rear tires. Soften front anti-roll bar. Stiffen rear anti-roll bar. Increase front toe out. Decrease rear toe in. Increase negative front camber. Increase positive caster. Increase front suspension travel. Decrease front end weight. Increase rear end weight. Correcting Oversteer Lower front tire pressure. Raise rear tire pressure. Stiffen front shocks. Stiffen front springs. Soften rear shocks. Soften rear springs. Stiffen bump. Raiser front end. Lower rear end. Narrow rear track. Install taller front tires. Install shorter rear tires. Install wider rear tires. Install narrower front tires. Stiffen front anti-roll bar. Soften rear anti-roll bar. Increase front toe in. Increase rear toe in. Decrease negative front camber. Reduce positive caster. Increase rear suspension travel. Increase front end weight. Decrease rear end weight. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 21, 2013 Share Posted June 21, 2013 That list is correct, but who has time for all that? How to correct understeer: 1. Brake early and slow down entry speed into turns and accelerate out. 2. Camber plates (more camber in front). Quote Link to comment Share on other sites More sharing options...
gnosez Posted June 21, 2013 Share Posted June 21, 2013 Braking early in say the 2.5L and under vintage race groups and every little %^$#(& British and Italian sportscars will divebomb the inside of your apex. Having the car become unsettled at that point means you have more than likely lost the race. I watched the "lost" film done 42 years ago about Bob Sharp racing and Bob would do the same thing in C Production against the likes of Vettes, Mustangs and Camaros. His crew took the time to get the car to handle an early apex so he could get out in front of the pack. If you want to see the film and meet Bob come to ZCON 2013 (www.zccazconvention.com). Ask him how he did it yourself. Quote Link to comment Share on other sites More sharing options...
Sideways Posted June 21, 2013 Share Posted June 21, 2013 How to correct understeer: More loud pedal.How to correct oversteer: Less loud pedal.S'worked good for me so far. Quote Link to comment Share on other sites More sharing options...
duragg Posted June 21, 2013 Share Posted June 21, 2013 How to correct understeer: More loud pedal. How to correct oversteer: Less loud pedal. S'worked good for me so far. Funny, I use just the opposite... Lift for just enough weight transfer to get turn in, Keep that power on if it steps out! Differential breakaway Tq (or open / or welded) has a lot to do with it also Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 21, 2013 Share Posted June 21, 2013 Hey Onion, what's the background behind starting this thread? I should have asked before posting my thoughts. Quote Link to comment Share on other sites More sharing options...
Onion Posted June 21, 2013 Author Share Posted June 21, 2013 (edited) Hey Onion, what's the background behind starting this thread? I should have asked before posting my thoughts.My big thing is showing the arrogant miata drivers that a 40 year old car can lead the way around a track for them. The best way to do that, in my opinion, is to beat them at their own game and improve the way our cars corner. I've done a lot of reading about suspension etc lately, and since there wasn't a list of everything you can do to correct oversteer and understeer, I put one together to make it a bit easier for beginners like myself to find the info they need. I'm not saying you have to do all that to correct understeer or oversteer but it's handy to know if your front toe is too far in, then you should dial some out to correct the issue. Edited June 21, 2013 by Onion Quote Link to comment Share on other sites More sharing options...
roger280zx Posted June 21, 2013 Share Posted June 21, 2013 I think it is a good, comprehensive list. It is kind of like learning English in billiards, until you do it a few hundred times you really have to think about which way it will go when hit it over here or over there. After the practice it comes pretty naturally. If you really want to show the miatas something get to a track with some elevation change, that will level the playing field. Quote Link to comment Share on other sites More sharing options...
socorob Posted June 21, 2013 Share Posted June 21, 2013 My little british car would understeer in autox a lot. I picked up time by using trail braking.. waiting as long as possible and heavy on the brakes at the very last moment to shift as much weight as possible to the front tires. It cut down a lot on understeer and cut off a decent amount of time. Quote Link to comment Share on other sites More sharing options...
Onion Posted June 21, 2013 Author Share Posted June 21, 2013 I think it is a good, comprehensive list. It is kind of like learning English in billiards, until you do it a few hundred times you really have to think about which way it will go when hit it over here or over there. After the practice it comes pretty naturally. If you really want to show the miatas something get to a track with some elevation change, that will level the playing field. Thanks! Unfortunately, Florida is so flat you'd think it was man-made. That's why I'm looking at a motor swap - I'd end up with roughly the same weight (probably going RB and turbo) and a whole lot more power. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 21, 2013 Share Posted June 21, 2013 Onion-Are you road racing, autocrossing or just thinking about it? Quote Link to comment Share on other sites More sharing options...
johnc Posted June 21, 2013 Share Posted June 21, 2013 <soapbox.> Its important to know the following before even looking at the list above: TIRE TEMPS SECTOR TIMES/LAP TIMES </soapbox. Without data, you will waste time and money. Tire temps will tell you why the handling balance is off. Sector and lap times will tell you if the oversteering demon is setting lap records and the issue is more with the driver's perception then how the car is behaving. Trying to solve a driver problem with anything on the list above is fruitless. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 21, 2013 Share Posted June 21, 2013 Another suggestion is to put each adjustable part of your suspension at its extreme range of adjustment and run laps. Put all 4 shocks on full soft, run a few laps. Put the shocks at full hard and run a few laps. Put one shock at full soft and the others at the middle of the adjustment range, run a few laps. Put camber at 0 all around, run a few laps, put camber at -5 all around, run a few laps. Raise the front ride height 2" above the rear, run a few laps... The idea it to get a feel for the car at the extremes so you can notice a trend in that direction. Quote Link to comment Share on other sites More sharing options...
Onion Posted June 21, 2013 Author Share Posted June 21, 2013 Onion-Are you road racing, autocrossing or just thinking about it? Just thinking about autocross. I almost started racing with my previous car (2000 Mustang GT), but it wasn't suited for autocross at all, so I never did. Closest thing to racing that I've done in this car is driving like an idiot in empty parking lots. <soapbox.> Its important to know the following before even looking at the list above: TIRE TEMPS SECTOR TIMES/LAP TIMES </soapbox. Without data, you will waste time and money. Tire temps will tell you why the handling balance is off. Sector and lap times will tell you if the oversteering demon is setting lap records and the issue is more with the driver's perception then how the car is behaving. Trying to solve a driver problem with anything on the list above is fruitless. Another suggestion is to put each adjustable part of your suspension at its extreme range of adjustment and run laps. Put all 4 shocks on full soft, run a few laps. Put the shocks at full hard and run a few laps. Put one shock at full soft and the others at the middle of the adjustment range, run a few laps. Put camber at 0 all around, run a few laps, put camber at -5 all around, run a few laps. Raise the front ride height 2" above the rear, run a few laps... The idea it to get a feel for the car at the extremes so you can notice a trend in that direction. Good info right there. Quote Link to comment Share on other sites More sharing options...
ablesnead Posted June 21, 2013 Share Posted June 21, 2013 thats a lot of laps! Quote Link to comment Share on other sites More sharing options...
johnc Posted June 21, 2013 Share Posted June 21, 2013 Excuse me Mr. Shumacher, how do I get to Monte Carlo? Practice, practice, practice. Quote Link to comment Share on other sites More sharing options...
30 ounce Posted June 22, 2013 Share Posted June 22, 2013 If you want to correct understeer with tire pressures shouldn't you LOWER the fronts or RAISE the rear? Same thing with your oversteer pressures...? Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 22, 2013 Share Posted June 22, 2013 How much time and money do you want to spend? PM me if you want and we can have a low profile discussion out of public scrutiny. You are discussing a very open ended subject and you will get overloaded with suggestions. If your town (police) and autocross club are anything like mine, you will get somewhere between 3 and 6 minutes of practice and testing time a month: not a lot of opportunity for trial and error. Johnc's alignment recommendations have been spot on for me (he did the testing for us-thanks John!). Those specs have created a neutral car with even tire wear across each tire and from front to rear, left to right on both a road course and monthly autocross. I haven't graduated to tire temp testing (I have a probe pyrometer) but you really start needing a dedicated crew chief for all this because as the novice driver (that's me-and perhaps you) you will be mentally exhausted just trying to remember the course and figure out the fastest line, etc. if you are like me, you will be fully consumed just trying to keep the front of the car pointing forward-and that is with a neutral car! It is important to know that the driver can make a neutral car push (under steer) all day long if you screw up entry speed and weight transfer. I'm just getting to the point of sort of knowing what these terms mean. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 22, 2013 Share Posted June 22, 2013 Every term you listed above assumes that you are DRIVING correctly. Brake at the wrong time or stomp it (gas) at the wrong time and NONE of that stuff matters. At your next autocross, ask the guys in the timing trailer to point out the fastest driver in the club. Those guys are usually fast in ANY CAR. ( I hope you know the caps are for friendly emphasis-not yelling). Have the fastest drive drive your car a couple times on the track-heck, pay extra for him to be your co-driver-and you will probably find that your car is faster and more neutral than you think it is. All for tonight. Taking 15 year old daughter to a Tire Rack sponsored defensive driving school tomorrow with instruction given by the fast guys at the local SCCA. I'm gonna sit in and glean whatever I can. Dry and wet skid pads!! Yippee! Quote Link to comment Share on other sites More sharing options...
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