Re: My 2000 M Coupe hops when i try to smoke the t (archive)

This happens on a lot of cars, especially those with short control arms and rubber supsension bushings. It's a function of energy being stored and released in the various suspension components at some natural frequency. So many components have flex built into them, like the busings, shocks, tires...If the shocks are good (assumed here), and the suspension busings are all perfect (also assumed here), tires are probably the leading cause here. The M coupe has been gine through by a ton of journalists, if the hop was indemic to the car, we'd have heard about it. I'm running the stock setup (Dunlop 8080E) and haven't had the problem, running 32lbs on all four corners.

I'd try different tire pressures. Sometimes less pressure helps, as it slows the sidewall's reaction, seldom does more pressure work. The Michelins may want a touch more or less, only experimenting will discover where they are most happy.

On other cars I've had that exhibited the problem, I found launch technique contributes to the problem as well. I had an IROC Camaro that required a very specific technique to wheelspin, or it would shake and rattle like an LA earthquake (could knock your molars out on some road surfaces). At the drag strip, on a tacky surface, it got really violent. Once I figured out what it wanted, however, I could make smooth runs one after another. Then found that same technique worked on the street as well.

Try this: Instead of hammering the throttle and dumping the clutch, which tends to wind everything up, then rebound, then rewind...etc. Try launching at a lower RPM, let the clutch out quickly, but allow it to slip a touch, while you feed in more gas. This is also easier on drivetrain parts. The M motor makes peak torque at 3800 rpm. From a dead stop, you can get the tires to let loose at 3500 RPM, then spin up to readline! Banging the tires at 5500 will most certainly present an impact the rear suspension has a hard time dealing with.

At the drag strip, with street tires, by the way, it's best to skip the water box and launch dry and cold. Street tires get greasy very fast when they are over-heated and a smoky burn-out will do just that in a hurry. Drag slicks are made to be heated up. They have special oils inside the rubber,that are released when heated, that are like glue, adding real bite on launch.

Street meat has no such feature, and heating them up just makes them slick. Over time, it also makes the tread harder and less pliable, which means they have less grip, so be cautious. Too many spinning launches, and you may find the car ground-loops more easily in hard corners.

From what I've read, mods that can help elliminate the problem include harder businings in the suspension, and shocks with more rebound dampening than compression damping.

: I have a 2000 M Coupe that has 3000 miles on it and im facing a problem. When I turn of the traction and hit on the gas the car losses traction. usualy a normal car would spin the tires than move. my car tends to hop from behind as if the deffrential would break. i have the new michlen sport on. do u think that the problem would be from the tires, should i change them to the dunlop. please some one help me. i like to have fun with the car but also when the road is wet the car hops....

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Thank U very much guys White M Coupe 01:05 4/16/2000 (0)

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