Why the Slower FPS?

[Mitten_archery13]

Hey there.
I am fairly new to bow tuning and learning ot as I go.
My current setup lost FPS compared to a month ago and I am confused as to why.

Here is a little background as to what was going on with my bow.
Ordered new 70 pound limbs last summer and installed two months ago.

I was practicing the other night for TAC and the bow string came apart. Not sure how old string was as I bought the bow used.
Called around and had a custom string made, from my understanding a reputable builder, since no shops around had one in stock.
Installed the string, increased draw weight to 74 pounds by technician twisting the cables.
Paper tuned.
Shot 12-18 arrows while tuning

Shooting same arrows as other month but lost 5fps.

Specs:
2015 Hoyt Carbon Spyder ZT Turbo
Cam # 3. 29 1/2” DL
70 pounds limbs, pulling 74 on scale.
580 gn arrow.

Old FPS was 265@ 70 pounds
New FPS is 260 @ 74 pounds

Am I understanding this correctly, twisting cable = increase in draw weight and length, which should increase FPS?

What would the reasoning be for decreased velocity? I was hoping the velocity would increase after everything was done.

 

[Joe Holden]

Have you verified if specs are correct? ATA/Brace?

 

[BillNye]

String, knock, or peep weight going up could slow you down pretty easily

 

[sndmn11]

Did you switch chronographs?

 

[Stache Attack]

Different string material maybe, stiffer like 452x will be slower compared to some of the stretchy blends some of the new makers are using. Ie. that’s why system x gas strings are faster but you can feel the stretch in the back wall compared to ghost. I would check your specs though