How to drive on the track?
05-09-2002, 11:36 AM
#1
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How to drive on the track?
I just bought my '86 951 and will be taking it out to the track soon. I have been testing it out on some back roads and here's the behavior:
1. I show good boost at around 2500 (1.4) with full coming on around 3000 (1.8 - 1.9). However, the power doesn't seem to really kick in until 4000+. Is this typical?
2. Going around corners, I'm afraid to really nail it due to the above 4000rpm issue. It kicks in extremely strong and I can see spinning very easily. Is there a way to feather the power through a turn and then nail it coming out?
Thanks
Jim
1. I show good boost at around 2500 (1.4) with full coming on around 3000 (1.8 - 1.9). However, the power doesn't seem to really kick in until 4000+. Is this typical?
2. Going around corners, I'm afraid to really nail it due to the above 4000rpm issue. It kicks in extremely strong and I can see spinning very easily. Is there a way to feather the power through a turn and then nail it coming out?
Thanks
Jim
05-09-2002, 02:40 PM
#3
Race Director
"1. I show good boost at around 2500 (1.4) with full coming on around 3000 (1.8 - 1.9). However, the power doesn't seem to really kick in until 4000+. Is this typical?"
Yes, what you are feeling is the torque-curve of the car. It peaks at around 4000rpm and is where the biggest push comes from the engine. Boost really just raises the entire torque curve up and down, but doesn't change its shape too much (torque-peak remains in same place).
2. Going around corners, I'm afraid to really nail it due to the above 4000rpm issue. It kicks in extremely strong and I can see spinning very easily. Is there a way to feather the power through a turn and then nail it coming out?"
Yes, it's called the throttle! You only want the throttle open to produce only as much power as the traction limits of the tire allows. The more powerful the car, the less time you can be at full-throttle. Sometimes, only when the car is pointed down a straightaway, can you fully open the throttle.
I like Mark Donohues comment on when you have enough power. It's goes something like, "when you can lay down tire tracks from the exit of one corner all the way down the straight to the entrance of the next corner all around the track, then you have enough power"!
Yes, what you are feeling is the torque-curve of the car. It peaks at around 4000rpm and is where the biggest push comes from the engine. Boost really just raises the entire torque curve up and down, but doesn't change its shape too much (torque-peak remains in same place).
2. Going around corners, I'm afraid to really nail it due to the above 4000rpm issue. It kicks in extremely strong and I can see spinning very easily. Is there a way to feather the power through a turn and then nail it coming out?"
Yes, it's called the throttle! You only want the throttle open to produce only as much power as the traction limits of the tire allows. The more powerful the car, the less time you can be at full-throttle. Sometimes, only when the car is pointed down a straightaway, can you fully open the throttle.
I like Mark Donohues comment on when you have enough power. It's goes something like, "when you can lay down tire tracks from the exit of one corner all the way down the straight to the entrance of the next corner all around the track, then you have enough power"!
05-10-2002, 04:27 AM
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[quote] I like Mark Donohues comment on when you have enough power. It's goes something like, "when you can lay down tire tracks from the exit of one corner all the way down the straight to the entrance of the next corner all around the track, then you have enough power"! <hr></blockquote>
I've always been fond of that one too, although I heard it as "When at the end of the longest straight, at the fastest track, I can still spin the tires, THEN I will have enough power."
Regarding boost coming on abruptly in corners, there aren't too many track corners that are slower than 40 MPH, and the issue that you raise is lessened in the higher gears. I don't think that you'll find it as scary as you think.
Perhaps someone with more turbo track experience will speak up on the following topics.
1. Plan ahead. You may find that you can ease the throttle on earlier than in a NA car. By the time the boost comes up, you'll be past the apex and ready for more power if you've done it correctly.
2. Short shift. I've really enjoyed combination turns that allow for some acceleration, but not all of what the turbo can do. I'm thinking of a double corner leading onto a long straight. If I were to stay in 3rd, I'd come onto the straight well above 5k RPM.Instead, I upshift going INTO the 2nd corner and feed in the throttle. I go by the apex @ ~3.5k RPM and by the exit of the corner I'm at full boost and nearing 4k RPM, really launching down the straight. If I had stayed in third, I'd be near 4.5k RPM at the second apex, and probably would need to be very light on the throttle, and I'd never get much boost back before it was time to shift. By short shifting, I can keep more throttle going and the turbo spinning a little better. This is somewhat different than the way I drive the same combination in my NA race car. In that I would go by the 2nd apex @ 8k RPM (torque peak), full throttle and upshift @ 10k RPM (HP peak) before the exit of the turn. Again, I hope someone with more turbo experience chimes in on this one.
Enjoy your track time
Gary
I've always been fond of that one too, although I heard it as "When at the end of the longest straight, at the fastest track, I can still spin the tires, THEN I will have enough power."
Regarding boost coming on abruptly in corners, there aren't too many track corners that are slower than 40 MPH, and the issue that you raise is lessened in the higher gears. I don't think that you'll find it as scary as you think.
Perhaps someone with more turbo track experience will speak up on the following topics.
1. Plan ahead. You may find that you can ease the throttle on earlier than in a NA car. By the time the boost comes up, you'll be past the apex and ready for more power if you've done it correctly.
2. Short shift. I've really enjoyed combination turns that allow for some acceleration, but not all of what the turbo can do. I'm thinking of a double corner leading onto a long straight. If I were to stay in 3rd, I'd come onto the straight well above 5k RPM.Instead, I upshift going INTO the 2nd corner and feed in the throttle. I go by the apex @ ~3.5k RPM and by the exit of the corner I'm at full boost and nearing 4k RPM, really launching down the straight. If I had stayed in third, I'd be near 4.5k RPM at the second apex, and probably would need to be very light on the throttle, and I'd never get much boost back before it was time to shift. By short shifting, I can keep more throttle going and the turbo spinning a little better. This is somewhat different than the way I drive the same combination in my NA race car. In that I would go by the 2nd apex @ 8k RPM (torque peak), full throttle and upshift @ 10k RPM (HP peak) before the exit of the turn. Again, I hope someone with more turbo experience chimes in on this one.
Enjoy your track time
Gary
05-10-2002, 12:13 PM
#7
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[quote]Originally posted by 951Gary:
<strong>
Perhaps someone with more turbo track experience will speak up on the following topics.
1. Plan ahead. You may find that you can ease the throttle on earlier than in a NA car. By the time the boost comes up, you'll be past the apex and ready for more power if you've done it correctly.
</strong><hr></blockquote>
That is how I handle it to keep from boosting myself into a spin. Of course a lot of that will depend on when your turbo starts to come on. Different cars... different techniques. YMMV
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />
<strong>
Perhaps someone with more turbo track experience will speak up on the following topics.
1. Plan ahead. You may find that you can ease the throttle on earlier than in a NA car. By the time the boost comes up, you'll be past the apex and ready for more power if you've done it correctly.
</strong><hr></blockquote>
That is how I handle it to keep from boosting myself into a spin. Of course a lot of that will depend on when your turbo starts to come on. Different cars... different techniques. YMMV
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />