Shift points for maximum acceleration?
09-14-2011, 09:55 AM
#16
I also have a Q7 2009 TDi - and yes if would be faster to redline line it in every gear - but I don't like to abuse my 5500# family cruiser. RSR racer is correct about your Porsche shift lights - it even makes sense if you don't know the answer to this common HP vs TQ debate. Anyone that has been on a track in a manual knows that 2nd gear goes by quicker than 3rd, that goes by quicker than 4th, etc. So, Porsche set the light so that when you see it in 2nd, the rpms are climbing so fast that by the time you shift you should be approaching 8200rpms (your maximum wheel HP at that speed).
You can choose to believe that 7600rpms maximizes your acceleration, but you are going to have to post data showing this is correct - I will place a 1$ bet that shifting in every gear just befor the limiter will win the race.
For some real world evidence, I will offer up that a friend that I know that races a cup in a well known series against well known race car drivers has actually shown me the data. I hung out with him at Mosport during a race for his 3 days up here and the team deliberately during qualifying kept redline 300rpms below raceday as they were trying to hide some speed and argue that certain car's had too much advantage so they might get equalized at future races - this is all standard stuff that pro teams do all the time. Those 300rpms in gears 2-6 for 1 lap was almost 3/4qtrs of a second per lap. This is on a 3.8L Porsche engine from a Porsche Cup car - that is hard data from a racetrack under qualifying conditions.
You can choose to believe that 7600rpms maximizes your acceleration, but you are going to have to post data showing this is correct - I will place a 1$ bet that shifting in every gear just befor the limiter will win the race.
For some real world evidence, I will offer up that a friend that I know that races a cup in a well known series against well known race car drivers has actually shown me the data. I hung out with him at Mosport during a race for his 3 days up here and the team deliberately during qualifying kept redline 300rpms below raceday as they were trying to hide some speed and argue that certain car's had too much advantage so they might get equalized at future races - this is all standard stuff that pro teams do all the time. Those 300rpms in gears 2-6 for 1 lap was almost 3/4qtrs of a second per lap. This is on a 3.8L Porsche engine from a Porsche Cup car - that is hard data from a racetrack under qualifying conditions.
Last edited by 997gt3north; 09-15-2011 at 02:26 PM.
09-14-2011, 10:11 AM
#18
Until I post the data it isn't real - and I wasn't really there, and he and the team didn't really do this - but it did give the Vettes a little bit of a surprise - especially the guy holding the radar speed gun on the back straight that was taking notes during practice of all the top speeds coming into the braking zone in #8 at Mosport. I stood next to him with my son for 20 minutes and watched the data - on practice day, the Vettes were 9mph faster than anyone else - not so on raceday.
09-14-2011, 10:56 AM
#19
2 classic threads on this subject... if you like dyno curves and technical explanations !
https://rennlist.com/forums/racing-a...onal-best.html
https://rennlist.com/forums/racing-a...you-shift.html
https://rennlist.com/forums/racing-a...onal-best.html
https://rennlist.com/forums/racing-a...you-shift.html
