CAMARO6 - View Single Post

baron95 · 04-10-2018, 06:47 PM

Believe it or not it is all connected.

You are starting the downshift at the end of the straight already above redline. (I understand why you did it - I have other posts saying that it seams the shift from 4th to the very long 5th is death for the Camaro SS in acceleration).

If you were in 5th gear, you'd be below 5,000 RPM, and would either do 5-4-3 or 5-3 (which is a slower move than 4-3). People tend to develop these timing cues on track. You can't really watch the speedo on your downshift. It is moving too fast under heavy brake. Most people do it based on timing. Some (very few) use reference markers to clutch out.

You get used to the time it takes to do 5-4-3 or slow 5-3 at the end of a typical track straight ~140-145MPH. Now all of a sudden you start stretching 4th, perform the fastest downshift 4->3 and clutch out with the same timing. Now you are still too fast for 3rd.

It feels good. You are less busy at the end of straight. Instead of 4-5-4-3, you now only need to do 4-3. You can devote more brain cells to watch the markers. You start braking later, downshifting faster.

The little over revving becomes a larger overrevving. 7200 on a 6,600 redline is a serious ˜10% over rev.

Boom.

I probably have corrected over a dozen students who were over revving on downshift. Most let the clutch out very slowly, so there is little to no shock to the engine - but I still remind them that they were starting clutch out at too high a speed.

This scenario, that contributed to your engine failure, is much more common than you think. Every time you stretch 4th you need to be very, very vigilant.

Don't beat yourself up. It happens to the best drivers. I too raised the redline of my Coyote Mustang GT to 7,350 (˜5%) RPM with a tune that made it develop meaningful power to deal with the very short Mustang gears. Luckily I never blew my engine, but I did have an early clutch failure - possibly the slight over-revving contributed to it.

04-10-2018, 06:47 PM	#78
baron95 2018 1LE, NASA Instructor Drives: 2018 Camaro SS 1LE Join Date: Jan 2018 Location: New England Posts: 235	Believe it or not it is all connected. You are starting the downshift at the end of the straight already above redline. (I understand why you did it - I have other posts saying that it seams the shift from 4th to the very long 5th is death for the Camaro SS in acceleration). If you were in 5th gear, you'd be below 5,000 RPM, and would either do 5-4-3 or 5-3 (which is a slower move than 4-3). People tend to develop these timing cues on track. You can't really watch the speedo on your downshift. It is moving too fast under heavy brake. Most people do it based on timing. Some (very few) use reference markers to clutch out. You get used to the time it takes to do 5-4-3 or slow 5-3 at the end of a typical track straight ~140-145MPH. Now all of a sudden you start stretching 4th, perform the fastest downshift 4->3 and clutch out with the same timing. Now you are still too fast for 3rd. It feels good. You are less busy at the end of straight. Instead of 4-5-4-3, you now only need to do 4-3. You can devote more brain cells to watch the markers. You start braking later, downshifting faster. The little over revving becomes a larger overrevving. 7200 on a 6,600 redline is a serious ˜10% over rev. Boom. I probably have corrected over a dozen students who were over revving on downshift. Most let the clutch out very slowly, so there is little to no shock to the engine - but I still remind them that they were starting clutch out at too high a speed. This scenario, that contributed to your engine failure, is much more common than you think. Every time you stretch 4th you need to be very, very vigilant. Don't beat yourself up. It happens to the best drivers. I too raised the redline of my Coyote Mustang GT to 7,350 (˜5%) RPM with a tune that made it develop meaningful power to deal with the very short Mustang gears. Luckily I never blew my engine, but I did have an early clutch failure - possibly the slight over-revving contributed to it.