iRacing Transmission How To: Synchromesh h-pattern

Jack B

For those trying to learn manual shifting, I thought it might be good to isolate the instructions for each transmission type and start a thread for discussion. iRacing has modeled each type of transmission and even each type has subtleties for each car.

Good luck to all of those trying to learn a new skill. I'm having a blast! I'm slower, but in some ways more in control.


Synchromesh h-pattern:

- Mustang FR500S
- Solstice
- Spec Racer Ford

For the Solstice, Mustang FR500S and Spec Racer Ford with synchromesh gears, the synchros do all the work when the revs are mismatched. You won't hear a grind when you select the next gear while the synchros are doing their thing, so the neutral timing isn't the same as a crash box. You don't absolutely have to use a clutch for a synchro box - but the synchros are not even remotely close to being strong enough to overcome the entire motor when trying to rev match so you have to get the entire motor to match the correct rpms for the next gear yourself, but if you use a clutch pedal then the synchros can easily match the transmission input shaft for you and make shifting a much faster and reliable experience.
When shifting with a real synchromesh gearbox, you engage the next gear's synchros by lightly pulling the stick against the next gear, until the gear clicks into place. Unfortunately, the sim has no ability to know that you're trying to select the next gear until you actually select the next gear, and only then can the sim start working the simulated synchros. With sequential controls, the sim knows you are trying for the next gear up or down, so you just need to press and hold the shift button until the gear engages. With an h-pattern you need to actually click your next gear into place quite quickly so the sim can start pushing it's simulated shifter against that gear's synchro. The timing of the shifting process feels a little different to a real car. You'll have to get used to the timing of your shift request but continuing to hold the clutch in until the gear finally engages before letting the clutch out, unlike in a real car where you can feel the shifter clicking into place as the gear finally engages.

- Upshifts you typically want to do as fast as possible, but it's not as fast as a dog-box transmission can do it: press and hold your upshift a moment before you lift to preload the shifter, then lift the throttle while pushing in the clutch. As the next gear engages, you can push the throttle down again and release the clutch. You could also choose to not lift, and just push in the clutch pedal until the next gear engages. This method of power shifting will not make your clutch want to be friends with you for very long. Or you could not use the clutch at all, but you have to lift off the throttle and wait for what will feel like forever and ever until the engine drops enough rpm for the next gear to engage. Remember to hold the shift button until the gear shift completes.

- Downshifts you will also want to shift as quickly as you can, to start working the next gear's synchro. Press and hold your downshift a moment before you blip to preload the shifter while braking with your right foot, then press the clutch pedal in with your left foot and roll your right foot somehow to blip the throttle while maintaining smooth brake pressure at the same time, and when the next gear catches, release the clutch pedal smoothly. This is called heel-toe downshifting, and it's very hard to get a good feel for in the sim due to not being able to physically feel the response of the car and the shift lever. It is possible to left foot brake and not use the clutch on downshifts, but it's hard work on the synchros and you must make sure to blip the engine rpm well enough to match revs or you'll be stuck in neutral fishing for a gear. Remember to hold the shift button until the gear shift completes.
Sometimes if you mis-time your synchromesh gear shifts (particular if you don't use a clutch) you can clear the synchro but still miss the gear engagement, and you will hear nasty grinding sounds from your gearbox.
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