I will provide a video link that showcases the notes outlined here, though some of these might be somewhat outdated and not necessarily the best option. (Gnade 1 has a perfect gear 3 change for example, but it's an extremely short window which I didn't tap into before getting it in a RTA run myself.)
It's worth to note that these are recorded on the PAL version, so input speed is different if you are running NTSC-U or NTSC-J. I also use a standard Dualshock controller in form of a 3rd party PS3 controller, so I got double inputs on gearing with R1 and R2 for upgearing, unlike neGcon users that only have one shoulder button each. Do experiment to find the perfect timing to make it work for your setup and circumstances.
Gnade 1 - Hold Square and X during countdown for Rev. Gear up ASAP to gear 3, whilst letting go of Square right after gearing to 3rd. Perfect achievement of this will give you a rolling start in 3rd gear at around 3-4k RPM. (You will see if your car kinda "dips", the you haven't achieved the perfect start.)
A more consistent strat is jumping off at gear 2, as you will get higher rev into gear 3. Both are almost as quick, and this is more useful for RTA runs like GPAny%
Gnade 2 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 4 whilst holding square to get rev up to 6/7k and release.
Gnade 3 - Timed "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up to gear 3 ASAP, then "rhythmically" gear up to 4 and 5 gear whilst holding square. (Rhythmically means giving each gear a bit more time to rev, rather then ASAP gearing)
Perfect execution of this, will get you out of the gate at 5k rev in gear 5.
More Reliable / Somewhat "Rocket Strats" ~ Hold Square and X for full rev whilst it counting down, gear up ASAP to gear 4 whilst holding square to get rev up to 6/7k and release.
Gnade 4 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 5 whilst holding square to get rev up to 6k and release before you start rolling.
Gnade 5 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 5 whilst holding square to get full rev and release before rolling.
Erriso 2 - Hold Square and X for full rev whilst it counting down, gear up to gear 3 "rhytmically" and release square to get a rolling start at 5k. (Rhythmically means release from gear 2 when you have reved a bit, rather then ASAP gearing)
Erriso 3 - Hold Square and X for full rev whilst it counting down, gear up to gear 4 "rhytmically" / ASAP , release square at 6-7k rev before car starts rolling.
Erriso 4 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 5 whilst holding square to get full rev and release before rolling.
Erriso 5 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 5 whilst holding square to get full rev and release before rolling.
Acceron / Instinct 2 - "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 4, and release Square This will get you out at full rev.
Acceron / Instinct 3 - Gear Down "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, then quickly gear down to 4. This will get you out at full rev. NOTE: Rocket Strats are possible, but are somewhat finnicky. For RTA runs, doing a gear 4 out is more consistent then trying to get to 5th gear as you can end up with low rev (3-5k)
Acceron / Instinct 4 - "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, and release Square This will get you out at full rev.
Acceron / Instinct 5 - "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, and release Square This will get you out at full rev. (Perfect start comes down to Square here, if you get the timing correct, you won't burn for another 0.5 seconds or so)
Abielle 3 - Hold Square and X for full rev whilst it counting down, gear up to gear 4 rhytmically, release square at 5k rev before car starts rolling
Abielle 4 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 5 whilst holding square to get rev up to 6k and release before you start rolling. (TIP: To avoid burnout and get a quicker rolling start, rhythmically tap your way to gear 5, rather then ASAP gearing.)
Abielle 5 - "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up ASAP to gear 5 whilst holding square to get rev up to 6k and release before you start rolling. (TIP: To avoid burnout and get a quicker rolling start, rhythmically tap your way to gear 5, rather then ASAP gearing.)
Bayonet 3 - Gear Down "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, then quickly gear down to 4. This will get you out at full rev. NOTE: Rocket Strats are possible, but are somewhat finnicky. For RTA runs, doing a gear 4 out is more consistent then trying to get to 5th gear as you can end up with low rev (3-5k)
Bayonet 4 - "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, and release Square This will get you out at full rev.
Bayonet 5 - "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, and release Square This will get you out at full rev. (Perfect start comes down to Square here, if you get the timing correct, you won't burn for another 0.5 seconds or so)
Fatalita 3 - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 3, and release square ASAP. It's possibly to do a 4th gear strat, but it's inconsistent and slower if not executed perfectly. "BONK STRATS": Bonk strats use the rev capacity to it's advantage. Repeat the first steps to gear 3, ride out towards your right, and bonk the wall whilst gearing up to 4th gear. This will get you into 4th gear with higher rev and doing it manually.
Fatalita 4: Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 4, and release square ASAP. It's possibly to do a 5th gear strat, but it's it's inconsistent and slower if not executed perfectly. Bonk strat not viable.
Fatalita 5 - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 4, and release square ASAP. It's possibly to do a 5th gear strat, but it's slower. "BONK STRATS": Bonk strats are possible for a tiny bit more, but do almost the same thing as gear 4 to 5 because of increased rev potential in Fatalita 5
Pegase 4 - Timed "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up to gear 3 ASAP (double tap if possible), then "rhythmically" gear up to 6th gear whilst holding square and release as soon as you start rolling. (Rhythmically means giving each gear a bit more time to rev, rather then ASAP gearing) This is still very finnicky and the margin for error is very low. If used in RTA, gearing this way to 5th gear is possible.
Pegase 5 - Timed "Rocket Strats" ~ Hold Square and X for full rev whilst it's counting down, gear up to gear 3 ASAP (double tap if possible), then "rhythmically" gear up to 6th gear whilst holding square and release as soon as you start rolling. (Rhythmically means giving each gear a bit more time to rev, rather then ASAP gearing) This is still very finnicky and the margin for error is very low. If used in RTA, gearing this way to 5th gear is possible.
PEGASE NOTE: Due to the dip in rev at 4-6k on Pegase, the timing for a perfect start is very finnicky. You might be doing it right, but timing might just be a tiny bit off!
Hijack 4 - Hold Square and X for full rev whilst it's counting down, gear up to gear 3 ASAP (double tap if possible). Going to gear 4 is possible, but you will have less rev and it is slower then gear 3.
Hijack 5 - Gear Down "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear to 5, then quickly gear down to 4. This will get you out at full rev.
HIJACK NOTE: There is no way to do Rocket Strats on Hijack like Acceron and Bayonet. Trying to do Rocket Strats will result in dead starts (Gear 5 no Rev)
Instante 4 - Hold X for full rev whilst it counting down, hold Square quickly whilst holding X, and gear up rhythmically to gear to 3, and release square ASAP. (*The rhythmically room here is very low, it's jus a tiny bit slower then ASAP Gearing)
NOTE: It's possible to go to 4th gear, but it's very finnicky with timing, but gives great reward if pulled off.
NOTE 2: Holding Square + X before Countdown is also doable, but I seem to get it more consistent with pressing square after the countdown or just right before it ends as a buffer input.
Instante 5 - Hold X for full rev whilst it counting down, hold Square quickly whilst holding X, and gear up rhythmically to gear to 4, and release square ASAP. (*The rhythmically room here is very low, it's jus a tiny bit slower then ASAP Gearing)
NOTE: You can also go to gear 3 like you do in Class 4, but it's easier to go to Gear 4 in Class 5, as coming out with 5k rev in 4th gear is still quicker then Gear 3 strats.
NOTE 2: Holding Square + X before Countdown is also doable, but I seem to get it more consistent with pressing square after the countdown or just right before as a buffer input.
Ghepardo 5 - Hold X for full rev whilst it counting down, hold Square quickly whilst holding X, and gear up rhytmatically* to gear to 4, and release square ASAP. (*The rhytmatically room here is very low, it's just a tiny bit slower then ASAP Gearing)
Devil Cars: These all have similar qualities to their car manufacturers, so I will quickly outline them, though this guide was made on an old setup before I was able to record these.
Age Vainqure: "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear 6, and keep holding square until the car releases from it's burnout. This comes down to timing, as letting it go before won't stop the burn, and will lower the rev of it and let you out of the gate at a lower speed. If done optimally, you should get about 210MPH out of the gate. I usually use Hurricane Hub whilst playing this car, as there is a nice sound cue that might help you achieve this optimally.
Lizard Bulldog: "Rocket Strats" - Hold Square and X for full rev whilst it counting down, gear up ASAP to gear 6, and release Square. The time room for this is very low, pretty much lower then Bayonet 3, so getting full rev is really finnicky.
Assoluto Squaldon: Hold X for full rev whilst it counting down, hold Square quickly whilst holding X, and gear up rhytmatically* to gear to 5, and release square ASAP. (*The rhytmatically room here is very low, it's just a tiny bit slower then ASAP Gearing)
Have discovered Rocket strats are easily available for this, just ASAP gear whilst holding break to gain 10k in 6th gear and release Square when the car gives. (Releasing earlier will lose rev just like Vainqure)
Video:
