Redlining on Track

[Lennym1984]

What is the general consensus about revving all the way to redline on track (ie. doing it repeatedly)? Usually on track days I tend to shift up at around 6k RPM in order to preserve the engine. I'm doing track days for fun and so (historically) my logic has been that I am prepared to forego a few seconds per lap in return for treating the engine with a little sympathy.

 

Now that my times are getting better (I don't do live timing before anybody complains) and I'm able to carry more speed through the corners, I'm left looking at my acceleration phase as a way to improve. The obvious solution here is to accelerate harder and forego the short shifting.

 

The car is a Gen 1 2.7 with ~106k on the clock.

 

Finally, if the person on here with the Silver Cayman S at Bedford on Monday wants a shoddy video of their car going round the track (I followed you for about 3/4s of the circuit), I have one!

 

 

[wtaite01]

Gen 2, 2.9, 48K on the clock - watching my videos back I'm generally shifting in the 6.6k to 7k range.

 

I know that these engines have been run in race series with 8k redlines, so I'm pretty confident it can take it.

 

A 5th to 2nd money shift on the other hand is what I worry about most on track!

[extanker]

With 106 k i would not hit the red line or limiter unless you are prepared for the consequences imho 

[Lennym1984]

Perhaps I should have been clearer, I dont actually mean bouncing it off the limiter, I mean more, revving into the 6.5-7.2k range. Obviously the limiter is set to prevent the engine exploding (on rising revs) but the forces acting on a piston at the upper rev ranges can obviously accelerate wear/encourage failure.

 

[jcm987]

On a typical track day, I generally shift at 6K for the morning, then when I feel like a quick lap in there afternoon, shift at 6.5K max. This approach seems to be working in terms of engine wear. 

 

Considering the car has such little power, but great handling. I have more fun focusing on late braking and fast cornering. 

 

 

[Lennym1984]

5 minutes ago, jcm987 said:

On a typical track day, I generally shift at 6K for the morning, then when I feel like a quick lap in there afternoon, shift at 6.5K max. This approach seems to be working in terms of engine wear. 

 

Considering the car has such little power, but great handling. I have more fun focusing on late braking and fast cornering. 

 

 

Thanks. That is the approach and philosophy (brake later, carry more speed) that I tend to follow. I just wanted to check that I wasn't missing out by up shifting early

[Aaron]

7k is the max RPM worth hitting as the engine gives up on power over that RPM.

 

You're already WOT and in high RPM - saving it a few hundred RPM isn't going to do a lot in terms of engine wear.  Piston speeds at 6500 are 17m/s and at 7000 they are 20m/s.  Both are relatively conservative as far as piston speeds go and well within specs for an average sports car piston.

 

It is more the constant heat degrading the oil that, if degraded too far, causes excessive wear, less than how the car itself is driven.

 

The cars are designed to be tracked and driven as such; shift at 7k.  No need to go past there, though, as you will be better off shifting up.

 

Regular oil changes (especially before and after track days) would be much wiser than holding off a few hundred RPM.  Oil is also much cheaper than a reconditioned engine.  Track the car at ~6k max with 18 month old oil, versus track the car at ~7k with brand new oil, and you can quite easily deduct which is going to wear less.

 

No need to go out and buy crazily priced oil - buy cheap and change it often.

[zcacogp]

I can't add much to what Aaron said (other than to say that those piston speeds are quite low - where does that data come from?) Good oil, changed often, while keeping an eye on temperatures is by far your best option. 

 

Whoever said "At 107k I'd not hit the limiter unless I'm happy to have the consequences" doesn't seem to have much experience of the 2.7 987.1 engine. 

[Aaron]

1 hour ago, zcacogp said:

I can't add much to what Aaron said (other than to say that those piston speeds are quite low - where does that data come from?) Good oil, changed often, while keeping an eye on temperatures is by far your best option. 

 

Whoever said "At 107k I'd not hit the limiter unless I'm happy to have the consequences" doesn't seem to have much experience of the 2.7 987.1 engine. 

 

Piston speed is calculated with stroke and RPM.  Pistons are generally rated for specific maximum and mean piston speeds.

 

Maximum and mean piston speed tolerances are a good indicator of an engine's general build quality and bulletproofing.