Violent spinning when downshifting (with clutch)

  • Thread starter Thread starter The_Rpg_Moogle
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The_Rpg_Moogle

The_Rpg_Moogle

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I've got a little problem with what I guess is my own driving. Whenever I downshift using the clutch and H-shifter on my G25, the car I'm driving is very prone to some violent spinning.

I guess this has something to do with my way of downshifting being wrong (I've never driven a car in real life, so).

I experience this a lot more with more powerful cars, especially with ABS set to off (NSX 97 comes to mind immediately, as does the RUF Yellowbird, but the last one is known for it's tendency to spin).

What could I be doing wrong? Am I downshifting too fast? Or do I slam the brakes too hard? Both?

Even when I'm in a straight line I tend to spin out, though like I said before, this happens a lot more with ABS off on older, powerful cars like the aforementioned NSX.

In fact, could anyone just tell me how to use a clutch AT ALL since I've got no one around with experience in using the clutch in GT. I usually let go of the gas, slam the clutch, change gears, get my foot off the clutch and press the gas again. This takes a fraction of a second, but I'm thinking I'm doing this too violently.
 
Sounds like you are doing the right thing to upshift.

When down shifting are you allowing the engine speed to drop enough to allow for the raised engine speed in the lower gear?
One suggestion could be to try 'block shifting', for example you are approaching a 2nd gear corner after a straight where you are in 5th gear, pick your braking point as usual but press the brake only, until you are at a speed applicable to 2nd gear (40mph for example), then clutch doen and shift straight from 5th to 2nd skipping 3rd and 4th.

Technically the solution would be to use heal and toe where you use your left foot on the clutch, brake with the ball of your right foot and blip the throttle with the heal of your right foot on downshifts, this gives a less violent transition of drive in the new gear and unsettles the car less.

Type heal and toe into youtube and no doubt there is a video or two explaining it better than me!!
 
If you are in too high reves for your engine your car will spin as well. The engine is then trying to slow down so much that your wheels will lock.
 
jimantonic
When down shifting are you allowing the engine speed to drop enough to allow for the raised engine speed in the lower gear?
One suggestion could be to try 'block shifting', for example you are approaching a 2nd gear corner after a straight where you are in 5th gear, pick your braking point as usual but press the brake only, until you are at a speed applicable to 2nd gear (40mph for example), then clutch doen and shift straight from 5th to 2nd skipping 3rd and 4th
Click to expand...

This. Slow the car down first with the brakes then once at the correct speed, turn in, hit the apex, downshift and power out. As my instructor on track day told me: brakes slow the car not the transmission. I made the mistake twice of downshifting without rev matching - the results both times... The rear end stepped out, thankfully traction control saved me. Sounds like GT is modeling real life pretty much spot on in this case.
 
Another way to go is instead of from 5th to 2nd down shift through the gears. So say you need to get to 2nd from 5th go 5th, 4th, 3rd, then 2nd. Once you have a feel for your car and what it will tolerate then you can skip a gear or two on the down shift. Say go from 5th to 3rd to 2nd or what ever your good with. This will give you a good feel for where your car is on the power band during breaking and the engine will help slow the car also. I have had many manual transmission cars, it's a skill you can apply to real cars as well. Rev matching is for down shifting in a turn while the car is under lateral G's so you don't loose the rear in a turn.
 
When using the clutch with ABS set to 0 the Auto Blip is turned off as well, this means you have to heel & toe to stop the rear wheels locking up & spinning out. It won't happen if you set ABS to 1, but you will still hear the rear wheels chirping.
 
It's likely rev matching, as you dump the clutch into a lower gear, the engine should be going, say, 7000RPM, but because you coasted in neutral for a second while braking/downshifting, the engine is at 3000rpm. As they noted, blipping the throttle before releasing the clutch should resolve this.

The rear wheels take the added force of spinning the motor up to speed, if this added force (plus braking/turning forces) is outside of their grip, they'll slide and cause a spin.

Staying in gear a bit longer, and downshifting at a lower RPM during the straight is also a solution. Engines exert less force through the drivetrain if they're shifted lower in the RPM range. Instead of shifting 1000RPM off redline (as soon as you hit the brakes, basically), try waiting an extra half a second for the RPM's to drop about halfway down the range before changing gear.

And, avoid downshifting mid-turn, it will always shock the tires and upset the car.

Remember, slow is smooth and smooth is fast.
 

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