[Ashander]

Originally Posted by F87source

Ok I was actually messaged asking for advice about this topic a couple of times and I wanted to ask a few questions since I am genuinely curious and also wanted to properly explain this topic because there is alot of misinformation about it:

1) 1st gear and its gate, synchromesh etc is the same as all the other gears, there are no mechanical lockouts or anything to prevent you from down shifting into first. The only difference is the amount of teeth on the input side vs. the output shaft (first gear has the fewest teeth on the input and the most on the output shafts). Also when people say first is engineered only for starts and implying it is weaker than all other gears that is untrue. If that was the case launching it in first or using the full rpm band in first would destroy it.

2) The reason why it is difficult to down shift into first gear while moving is because it places alot of stress on the fist gear synchromesh to match the shaft speeds due to the large first gear ratio of our transmissions.

If I am not mistaken 1st gear is 4.110, and 2nd is 2.315.


3) and a few more additional tid bits of information, the manual gear box in the m2 is a modern style sychromesh gear box so double clutching is not a requirement, and the phrase "not double clutching like you're supposed to..." does not apply to this gear box - it is an old antiquated phrase for non synchromesed gear boxes from older cars. But there is still a use case for this technique which will be elaborated later on.




So I have been asked about this alot privately on IG - and I don't blame people because the forum isn't a nice place to ask questions at times due to the bashing that goes on.


So is it safe to down shift to first?

Yes and no. So if you are talking about cruising around in second and you want to drop into 1st to increase the rpm and get into a better spot in the power band like you would do from 4th to 3rd for example, then this is a really bad idea and habit. With the gear ratio of 2nd to first being nearly 2x, you are increasing the rpm almost 2X and putting a huge load on the first gear synchromesh to match shaft speeds causing excessive wear. You will feel that first gear will not even want to engage at high rpms or speeds because of the load it must do to match the shaft speeds - however if you wanted to you could force it in. But like I said before this circumstance should be avoided at all costs as it is extremely bad for your synchros - not your gear itself but your synchros.


Now when is this situation safe or acceptable? At extremely low rpms in second gear or during extremely low speeds of <10 km/hr when you need to get going again - in the situation of slowing down for a red light that suddenly turns green and you do not want to lug the engine slipping the clutch in second. Or you are pulling into a parking tight parking lot where continual slipping of the clutch and lugging the engine in second is not feasible. At this point you may want to shift into first, at this point the rpm increase from going into first from second is quite small, generally you will be at ~600rpm and down shfting into first will cause the rpms to jump to ~1100 rpm. This increase is around 500 rpm compared to at high speeds (2000 rpm in second will be almost 4000 rpm in 1st) where the rpm delta is in the thousands of rpm range and increases with rpm. So what you notice is at low rpms shifting from second into first gear doesn't have a lock out and will shift into it will very little effort due to the low rpm delta putting very little load on the synchros (load increases with rpm in this case). So it is safe to slot into first gear at this situation, and wear on the synchromesh will not be any greater than going from 4th to 3rd for instance.



Now what can you do to even further improve the safety of shifting into 1st gear? Double clutching it's not needed on any other down shift since the gear ratio difference is not as drastic but downshifting from second to first this technique can really aid your synchros. This technique was used with non synchromeshed manual gear boxes to match shaft speeds. So when you use this technique it eliminates the need for the first gear synchro to match shaft speeds as you are doing it manually and thus eliminates any concern of excessive wear on the first gear's synchro. What you do is shift from second into neutral, release the clutch, blip the throttle, and clutch in and shift into first. This technique should remove the lockout even at high rpm downshifts shifts into first gear and is used by alot of high gear ratio auto X guys who rely on first and second gears alot. This technique is not required at low speed low rpm scenarios going into first because the load is so small, but you can do it anyways to relieve some strain on your first gear synchro.

So this is what you can do to aid downshifting into first if you need to, although it is not recommended to do so at high rpms or speed (make sure your rpms aren't so high you money shift) unless you are racing in tight auto x circuits. It is more so to help aide those that are going so slow they need to shift into first to avoid stalling or lugging/excessively slipping second gear.





So no my question for you guys is: who shifts into first when going into tight low speed parking lots? Or do you guys just lug/slip second gear?


I myself shift into first frequently when going from a main road and up an incline into a parking lot. Second gear would require alot of slipping and lugging so I never use it as the strain on the throw out bearing and engine would not be great. In this scenario my speed is always below 10 km/hr since it is a 90 degree turn onto a pretty steep hill, and I will generally double clutch to help out first gear's synchro despite not needing to.







Anyways take my advice with caution, I will not be responsible for damages caused to your car or injuries caused to yourself or others. - Had to throw this in there for anyone who wants to shift into first for the sound and messes up.

If you're in bumper to bumper traffic is it safe to stay in 2nd and not lug the engine? Or is downshifting to 1st acceptable in this scenario?