Dropping fps

[ProPain]

Got my gun chrono'd yesterday and its shooting 370fps.

The gun is an ics m4 with a m120 spring short stroked 2 teeth on a 13:1 shs gear set

I'm quite happy with the rate of fire and worried about getting pre engagement issues if I drop the spring to a 110

Should I take another 1 or 2 teeth off, clip the m120 or put in the m110?

Cheers

Rich

[Pezza]

Re: Dropping fps

Another tooth should bring it down fine.
My two short stroked setups come in at about 345 on a m120 short stoked by 3 teeth. That's with a 6.03 tightbore at 455mm mind.

[dave38x]

Re: Dropping fps

Depends entirely what battery your running it on. On a 7.4 lipo you shouldn't get pre-engagement on an m110 with that setup (having built a couple of these myself), but if your cylinder volume can handle it I'd definitely say take a tooth off and see what it gets it down to. Gives you more space to make it run even faster :D

[ProPain]

Re: Dropping fps

It's at 21rps on a 7.4 and 35rps on an 11.1

Nice and snappy on both. Do you think I'd get PE on the 11.1 with the m110?

[dave38x]

Yes, I've had pre-engagement with an m120 at 30rps on two teeth before.

Sent from outer space

[ProPain]

Re: Dropping fps

Yes, I've had pre-engagement with an m120 at 30rps on two teeth before.

Sent from outer space

So you think I should take out another tooth to run the 11.1?

Although I don't mind only using 7.4 batteries and dropping the spring but I don't want to compromise reliability as its running sweet at the min (just too high fps)

[dave38x]

Re: Dropping fps

Drop another tooth, you wont do any harm

Doing a 30rps build myself at the mo