when i'm pulling out from pits i struggle to find 1st gear whilst sat there idling.
Starting in N i'm pushing Nbutton/left paddle to downshift to 1st, sometimes it works, sometimes i get nothing. So then i upshift without pressing N, sometimes that does nothing, other times it then engages 2nd. I roll the car forward in 2nd which seems to help, then Then N+downshift gets me back to 1st and i'm good to go.
Someitmes i'll do a combination of the above and its still stuck in N, i start panicking and try N+downshift or downshift then N+downshift or whatever else, and eventually i'll find 1st.
(all of the above with clutch engaged)
When i eventually find first and pull away, everything is fine. Clutch feels progressive and there's no issues.
When i come back to the pits the car is always fine, i drop it to 1st, clutch in, stop, N+upshift to Neutral and turn engine off.
whilst running the car's shifting is faultless, although i don't think i've ever used 1st whilst on track..
HOw do i diagnose GDU 1st gear selection issues or at least any advise on what to check? Or is this normal?
From my experience in my own SR3XX and around several other Radicals, they all behave exactly as you describe. For me, it is frustrating some times the number of sequences required to get into 1st while on the grid, etc.
I was told by a Radical tech to be quick when pressing the neutral button to shift in and out of first, and my experience has been that if I do not get to the clutch and then downshift paddle sufficiently quick, nothing happens.
Good info, thanks! I don't own an SR3, but I've got one that comes through the shop for maintenance, and I found the Neutral/first struggle quite confusing.
What you have described is normal, but here is some details to help yourself out.
Do not sit on the clutch for a while before selecting 1st gear. This is for two reasons. You want to spend the least amount of time on the clutch as possible. Other reason is because everything needs to be all in sync. Put the clutch in and the millisecond the clutch is fully in hit the Neutral button and down paddle to grab 1st gear. If it does not engage the first time re do the entire second again quickly.
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@grouparacing interesting thanks so much and to @davidf. There's no mention of this in the manual, i've definitely been engaging the clutch for whole seconds, not milliseconds!
What's the technical reason behind it then? What's the moving part or movement of the system that means if you hold the clutch in for a relatively long time it's difficult to engage 1st?
As mentioned this is normal, due to the design of the gearbox.
The gears all have 'dogs' on which engage with each other as you shift gear. This all works well as the gears and shafts are all spinning when under load on track.
When you put your foot on the clutch at idle the gearbox shafts stop turning, they can stop at a point with these dogs line up with each other and they it causes a 'dog on dog' situation where they hit each other. No matter how many times you try the gear will not engage. If you take your foot off the clutch peddle the gears all turn and if your try again it should be out of this and go into gear.
This never happens on track due to the speed the gearbox is turning out and even if you do get this situation with everything spinning the ECU is clever enough to try again and get the gear.
Going back into Neutral is fine as you are disengaging dogs and nothing should mesh.
This is why it has been mentioned to try quickly when getting on the clutch, as the gearbox will be spinning. If you end up a situation where it will not go into first the best thing to do is release the clutch, have a breath and wait for a second, then depress the pedal and try again - it should more than likely go in.
I do know of a place in the UK that offers a selector drum that moves neutral below 1st which make things nicer and means you do not need the button for neutral when below 2000rpm but unfortunately you need access to the ECU to change the gear voltages and make this work.
