Revs / Power Bands, Etc
Posted Sep 01 2015 - 02:41 PM
Did all 60s era F1 cars use the synchro'd sequential ZF?
No. Lotus were the first team to adopt the ZF box with the Lotus 25, keeping it for the 33. The 43 used a BRM box but the 49 reverted to ZF. However, in 68 Lotus switched to the Hewland box for the 49B. Cooper used a ZF box for the T-81, but went to Hewland for the T-86.
Posted Sep 01 2015 - 02:43 PM
Posted Sep 01 2015 - 04:26 PM
You short shift in order to either eliminate wheel spin in a low gear, or if it makes the next corner more comfortable, or if going downhill.
Where in Setup Manager does it give these bhp/rev limit figures? There are two graphs but I've never been able to make head nor tail of them apart from using one of them to get an idea of gear spread.
Posted Sep 01 2015 - 04:58 PM
Posted Sep 02 2015 - 10:47 AM
This is a graph illustrating what is meant by "marginal returns." Often referred to as "diminishing returns" or "maginal utility."
(Its from economicconcepts.com).
A marginal return is apparent in the change in output between any two points along the line topping out at point C.
Easy to notice this coincides very nicely with a torque and horsepower graphs in Set Manager and Race Engineer.
There are lots of ways to apply marginal returns analysis to motorsport.
Validity of the marginal returns graph is proven by direct evidence of the torque and horsepower curves for an engine.
An easy way to think of it is if fuel or throttle is the variable factor, (or input).
Unit of fuel equals horsepower, torque, speed, (whatever).
The chart is divided into three stages.
Stage I yields the most output for a given unit of input.
So speed is increased the most per unit of fuel input during this stage.
Stage II continues to yield more output than input, but the amount of gain is less for each unit of input added.
So the car is still accelerating, up to maximum cumulative marginal returns at point C.
However, easy to see the rate of acceleration slows a bunch during Stage II, so maybe best to get back into the next gear's Stage I condition as quickly as possible, maybe somewhere a little past point B? But don't get back too far, maybe just down a bit before point A?
Thus my earlier posts about shifting into the next gear's bottom of 90 percent output lines.
Edited by John Woods, Sep 02 2015 - 11:05 AM.
Posted Sep 02 2015 - 12:12 PM
Posted Sep 02 2015 - 07:51 PM
Typical definitive keywords found: "set RPM," "recommended," "safe."
It refers to the maximum appropriate RPM the engine is capable of running continuously under load without blowing up.
It refers to some point well before catastrophic disaster...not an engineering/theoretical maximum ideal output like Point C at the top of a curve.
This isn't economics...its real racing and the car that first finishes wins.
Redline refers to a point before C, as determined by an engineer using mechanics, physics, machine science, and math to lock in the exact safe RPM that if set as the redline, with a given set of gears, would yield an appropriate rate of acceleration and run as close to flat out as necessary for the duration of a single race.
Redline is what an expert says it is. But we have ShiftR!
And we are, of necessity, our own experts.
Not really happy with definitions like "safe" and "recommended" decided to make an interpretation of a racer's redline, (GPL Lotus49 diagram below).
Edited by John Woods, Sep 02 2015 - 08:07 PM.
Posted Sep 02 2015 - 07:56 PM
Posted Sep 02 2015 - 08:55 PM
Posted Sep 02 2015 - 10:02 PM
Posted Sep 03 2015 - 07:24 AM
Been criticised in the past for speedshifting there.
Posted Sep 03 2015 - 08:04 AM
As I said already. At the end of a race if the red needle is on 9000rpm. You did good. Anything past it you screwed up. Watch what papy has in mind by looking at where the AI shift everytime. They never short shift, or go past 9000rpm. They also never ever downshift too early. If anything they downshift very late, and don't use the engine for braking.
As cole said. Holding it at 9000rpm too long will blow it too. Gear the car so it hits 9000rpm at the very end of the longest straight. Gearing too low will hold top rpm too long. You can also hold it too long in the lower gears by hold a gear too long to get to the next turn. Choose your gearing so that doesn't happen.
Another way to blow is to have it geared for the longest straight by yourself to reach 9000rpm at the end of the straight, and then in the race you draft someone, and go past 9000rpm. better to be geared a bit higher in the race, so you can draft.
Proper gearing is critical in the Lotus. Along with common sense in rpm control.
Edited by Pete Gaimari, Sep 03 2015 - 08:10 AM.
Posted Sep 03 2015 - 08:23 AM
Edited by John Woods, Sep 03 2015 - 05:07 PM.
Posted Mar 03 2018 - 10:01 AM
Mr. Fangio commenting on the proper shift point.
(found in Fangio A Pirelli Album by Sterling Moss, c1991 Pavillion Books).
"Whenever I was given a fresh car I would ask the mechanics, where is the maximum torque in the engine, at what revs? Then I would drive precisely to those revs and change up around that point to have the engine's maximum torque working constantly. There was no point in revving higher towards the red line; the power would only fall away and you would be risking the life of the engine."
Edited by John Woods, Mar 03 2018 - 10:04 AM.
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