Fx Impact best setting

It would be nice if everyone share there best setting or a base setting that work. It doesn’t matter which caliber. I have my impact for a week and just starting to tinker. It’s not easy. My best setting shooting hole in hole ad 45 yards is : barrel .22 , length 600mm, valve stop is max open (4 line visible), reg 92 a 93 bar, hammer spring gap 22,0mm and power wheel max, JSB 18,13 gr, 858 fps. 
 
Ivc, you can do much better, I think. For my Impact X .25 700mm. Reg is approx. 120, guessing because the gauge is not accurate. Hammer is 17mm and the Valve is on the 3rd line or a little less. I can get approx. 905-915 fps on Max. No power plenum, but I usually shoot at setting 4 which amounts to about 865-875 fps. Shooting JSB MKII's 33.9g

Have fun with your settings.

Stay safe.
 
My impact mk2 25cal 700mm with a slug liner likes nsa 36.2 slugs. The regulator setting if accurate is set @160 bar hammer spring is almost maxed out shoots the slugs @910 FPS but here lately I have the power wheel on #4 and @820 FPS shoots very accurately and I git a lot more shots at the #4 setting. I have been waiting on a power plenum but until then I’m liking this setting a lot, the gun seems to be not over worked and more of a calm overall behavior. The one thing I forgot is that the valve is just a little past the third setting mark. Hope that helps 
 
And, little changes in one setting effect all the other settings, so it’s really not as simple as that. Here are my settings anyway...

.25, 700mm Superior liner, external plenum, power tune parts, 115bar, hammer spring pre-load one full turn from max., power wheel max. valve adjuster 3.25 lines, 33.95 MKI @920fps. 84 shots per fill. 3/8” 5 shot groups at 50yds.
Stoti
 
.25 caliber 600mm STX Impact with PP, 6mm x 7mm dual TP, modified probe to match. The FX PP is custom as I didn't go with the full PP kit set up. A mix of old and new parts there. So, mine is not going to help much, but I'll give it anyways. Reg@ 135 bar. Valve spacing at 9.55mm, spring gap at 18.5mm. With JSB 34gr MKIIs and PW on max 950 fps, PW 5 928, PW 4 900, PW 3 850. The rest are reserved for the lighter JSB 25.4 Kings.

The power plenum is setup with old valve spring inside plenum tube. I'm also using the old hammer spring and the old rubber ball valve cap. I am using the new hammer, but not the added hammer weight.
 
I am in the same boat as the OP having recently acquired a new Mark 2 in 25cal with pp and 700mm. The gun is shooting kings at 900ftps but I know it is capable of a lot more and want to tune it for the heavies. I appreciate with all the variables going on it can seem a bit meaningless to explain your set up but it is useful to us newbies, even if it is just as a bench mark for our own results. 
 
It would be nice if everyone share there best setting or a base setting that work. It doesn’t matter which caliber. I have my impact for a week and just starting to tinker. It’s not easy. My best setting shooting hole in hole ad 45 yards is : barrel .22 , length 600mm, valve stop is max open (4 line visible), reg 92 a 93 bar, hammer spring gap 22,0mm and power wheel max, JSB 18,13 gr, 858 fps.

I’ve found another good tune. Shooting the mk2 pp 600mm Pellet liner ad 94 bar. I wanted more speed from 858 fps. Started upping the speed and the group fell apart. 880 900 920 al not good. Suddenly at 945 fps the group became super tight. Hole in hole ad 45 yards. Hammer spring gap 19 mm, power wheel A, valve max open, jsb 18,13. To be continued....
 
Good stuff Ivc, I decided to jump in and tune my Impact as well. Keeping the regulator at 110bar I am now getting 850ftps with jsb heavies (was 770ftps) and 925ftps with the hybrids, both lights out accurate at 50 yards (have pushed them further yet). The Kings now shoot a bit hot so just need to turn the hs down to 4 and they pop out at 890ftps. All in all very happy with how it is now shooting. I turned the hammer spring screw probably about 1 full turn to get these numbers but I appreciate this is meaningless as each gun is different. Pushed the valve back in to reduce the speed once around 15ftps over my desired speed and it all shoots well. I am very impressed with this bit of kit having shot it now for two weeks, rimefires and other fac airguns have remained firmly in the cabinet and are likely to do so for some time yet.....