pneumatic air regulators and bottle filling.

[mellink]

Hi all,
I'm currently working to develop a pneumatic shifting system. However have some concerns over the regulator refresh rate and how to charge the bottle.

If you are using a pneumatic system are you filling our tanks for a bigger tank at the event? Is that allowed I know it's not suggested by BOC?

Where in the UK can I get a reg? At the moment I've gone a for a paint ball one but reckon the flow rate is far too low to be useful during rapid down shifts. At the moment I've included a accumulator, but is there a better regulator out there?

Thank You
Rob

[EPMPaul]

https://www.youtube.com/watch?v=oRNXEQp_ldI

I think it has the flow rate. Some of the paintball guns have full auto and shoot at pretty high rates. Don't have any uppfront data but as far as I can tell unless you're shifting 50 times a second I'd be very surprised if a paintball tank/regulator setup didn't work for you

[Menisk]

Coming from a team that ran a pneumatic shifter on paintball gear for a few years, yes a paintball bottle and reg work just fine. We'd run about 6-8 atmospheres in the shifting circuit and that allowed us to do 20ms cuts at part throttle and 45ms cuts under full load. You'll need to add a delay from valve opening to cut though as you'll need to allow the pressure to build in the cylinder. Ultimately it comes down to testing. You can have it working sweet in half an hour if you know what you're doing.

Things you'll love about pneumatic shifting:
- Don't have to reach off the wheel for shifting
- Feel like a baws F1 driver

Things you'll hate about pneumatic shifting:
- Air leaks, all the f***ing time
- No feel on downshifts, takes practise to rev match
- Air leaks, all the f***ing time
- Bottle needs refilling often, is a pain to get filled somewhere or keep a scuba tank on hand
- Air leaks, all the f***ing time
- You can't find neutral
- Seriously, our air leaked all the f***ing time

Ultimately we spent majority of our year testing without a working shifting system. We'd just put the car in second and slip the clutch a good amount on takeoff. There is no reason you can't do shifts just as fast with a stick shifter as a pneumatic. Just need to get the shift cuts working right. The only good thing that the pneumatic shifting taught us was that with a 600 inline-4 we don't even need gears. Our second gear tops out at 110km/h and it's still got enough power to spin you in a minimum radius (4.5m) hairpin. This year we've moved back to a stick shifter, none of us ever want to see that stupid paintball bottle ever again.

[mellink]

Thanks for the reply.
Filling is turning into an issue.
Leaks are something I'm paranoid about.
And we have a clutch that should improve our downshift. Sounds like you didn't run one?

While true they do allot of shot that's not at 6-8bar that's at a much higher pressure. Dropping from 200 to 8 is what I'm worried aviut . we start testing next week so hopefully should be great .

If bit we have a mechanical back up ready to roll out. Be prepared. We can't just use ibe gear as were running a single with very short ratios.

Thanks for the advise and good luck to you

[Menisk]

Yeah, no clutch on the downshift. Just hit the button to apply pressure with the ram and blip the throttle to unload the box.