# Groves Spitfire vs Pittsley Predator speed test w/2nd Test Corrections



## returntoarchery (Jul 21, 2009)

An unscientific speed test. I audio recorded the 2 shots each. 
I used Audacity to determine the time of flight. I measured the elapsed time using the spectrum graph from start of release to start of target impact.

Distance: 15 yards
Arrow: 670 grain
Mic distance from target: 7.5 yards (half way).
release: finger

Pittsley Predator 51#: 180 fps (arrow flight time .25sec)

Groves Spitfire Mag 46#: 155 fps (arrow flight time .29 sec)

All in all given the Groves is down 5# and using arrows that are not optimum weight for it, it did pretty well.

BTW: The arrows for the Predator had a decidedly louder more pronounced wack on target than the Groves.


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## robert carter (Jul 22, 2009)

The Predator is one of the fastest recurves made. The one Chris has smokes and arrow.RC


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## returntoarchery (Jul 22, 2009)

I didn't know how fast until someone on Leatherwall posted they chrono'd a 52#@28 Predator with a 468 grain arrow at 28 inch draw and got 193, 194, 199.7, 199.7, 199.7, 199.7 for six shots. 

A bowyer I shot with at the Howard Hill shoot keep commenting how my bow smoked them and wanted to know what bow it was. I was using 540 grain arrows. He guessimated it was shooting 190 fps.

I beleive Chris is shooting a higher draw weight and I bet it really smokes them.


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## fountain (Jul 22, 2009)

my predator shoots fast too--its only 54 lbs--i am shooting a 540 gr 55/75 out of it now and it seems to push it pretty well.  i will chrono it very soon.  i have a good friend that seenms to think his royal hunter is faster, but will prove him wrong.  my dad also thinks his quillian canebreak is as fast.  
the predator hits hard as well.  as soon as i get my bow from jim, i am sending my limds back for re-finishing and prolly going to set/trade them for some 60+ lbs limbs for a little extra


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## returntoarchery (Jul 22, 2009)

I believe Ron said the 62" limbs are more efficient and store more energy, i.e. faster arrow speed for same weight.


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## returntoarchery (Jul 22, 2009)

fountain said:


> my dad also thinks his quillian canebreak is as fast.



I remember reading some eulogies about Dan. I recall one story was about him mouthing off at an archery trade show about how fast his Canebreak recurve was and it was as fast as a training wheel bow. Finally a training wheel bow rep took bait and challenged him to a chrono shoot off. Their compound against his recurve. The story goes as the time of the show down was near Dan kept saying how fast his bow was the closer the time can the louder he got. By the time they got to the shoot off a crowd had gathered. Another rep from  a different vendor agreed to be the independent shooter.  The result? The Canebreak won by a few fps. All the training bow rep could say was "At least we have the letoff.".


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## ChrisSpikes (Jul 22, 2009)

I'm shooting 480 grain arrows out of mine at 64# and 67#.  I've never chronoed it, but it seems pretty quick.


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## robert carter (Jul 22, 2009)

I`ve owned a Canebreak and several Royal Hunters.The Canebreak was the faster of the two but I seemed to shoot the Jeffery better.A Martin Dreamcatcher is a more forgiving version of the Canebreak.RC


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## returntoarchery (Jul 22, 2009)

robert carter said:


> A Martin Dreamcatcher is a more forgiving version of the Canebreak.RC



That's good to know. I shot a Canebreak at a hunting/outdoor fair in '87-88. Dan was there showing off his bows. I remember him telling me how fast it was. It was fast but I didn't like the laminated riser. I'm a purty wood kind of guy. Wish I had bought one though.


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## fountain (Jul 22, 2009)

the canebreak was built to get all the pounds at once--and tha was at almost full draw, where others were smooth in "building" up to max pound and the same draw.  the canebreak's pounds seem to come in all at once.  they are good bows.  i have one for years in the upper 60's and my dad has a 53# now.

i have the 62" limbs on my predator and they are smooth on the draw and seem to shoot good to me, not as hard as chris's obviously, but pretty good.  if i can get off my lazy butt i will tell you how they do on a hog, but im too lazy.


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## returntoarchery (Jul 22, 2009)

more fun:

'61/62 vintage Ben Pearson Javelina 66" 50#

Arrow: 670 gr Speed: 160 fps (.28 sec)

Arrow: 500 gr Speed: 173 fps (.26 sec)

Predator:

Arrow: 500 gr Speed: 187 fps (.24 sec)

Groves Spitfire

Arrow: 500 gr Speed: 173 fps (.26 sec)

Looks like the Groves a 60" 46# shoots like a 66" 50# bow.

Once again unscientific test but interesting and fun just the same.


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## returntoarchery (Jul 23, 2009)

Correction: The 670 gr arrow should be 645 gr.


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## returntoarchery (Jul 23, 2009)

I ran the test again tonight as I discovered I can measure the elapsed time better, down to .000001 if I wanted to but only gonna use .0001, and after recalculating my first test I found my fps calculations were too fast.

I'll try and post the new results later tonight. Got to finish watching today's Tour de France stage. Got to have my priorities straight you know.


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## returntoarchery (Jul 24, 2009)

how unscientific? Very but good nuff for gov't work.  

Audacity's waveform  scale measures in down to the .000001 sec. I magnify the waveform graft until I can see exactly where the string release starts. I then select the waveform from that point to the point of impact. That gives me the elapsed time. Same thing a chronograph does except a chrono uses  light sensors  to measure the elapsed time for the tip of the arrow travel between the rear and front sensor. Also since light travels a kzillion miles a second I doubt the chrono allows for any delay. But sound travels at only 1100 fps (dependent on air temp and some also say density; although air temp affects density). I did a second set of calculations to account for the sound time delay between the bow and mic and the target and mic.


```
Distance in feet	45 ft

Predator 51#@28
Groves 46#@28
Javelina 50#@28
Draw 28"-28.5"
Shots: 2 per bow

	           Predator     Grove Spitfire	Pearson Javelina 
              ---------------  --------------- ----------------
Arrow 645 gr
time in sec	0.2692	0.2704	0.2887	0.2864	0.2929	0.2882	
fps            167.16	166.42	155.87	157.12	153.64	156.14	
avg fps	        166.79		156.5		154.89	
							
Arrow 485 gr								
time in sec	0.2430	0.2387	0.2536	0.2532	0.2521	0.2579	
fps            185.19	188.52	177.44	177.73	178.5	174.49	
avg fps	        186.85		177.58		176.49	
							
												
calculated with time delay subtracted from elapsed time.							
Arrow 645 gr								
time in sec	0.2494	0.2506	0.2689	0.2666	0.2731	0.2684	
fps            180.43	179.56	167.34	168.79	164.77	167.65	
avg fps	        179.99		168.06		166.21	
							
Arrow 486 gr							
time in sec	0.2232	0.2189	0.2338	0.2334	0.2323	0.2381	
fps            201.6	205.56	192.46	192.79	193.71	188.99
avg fps	        203.58		192.63          191.35	

speed of sound at 78 deg F	1137 fps
  (http://www.sengpielaudio.com/calculator-speedsound.htm)					
time delay for 22.5 feet 0.0198 sec	
(mic is 22.5 feet from bow and target at half way point)
```

I'm not a scientist, engineer, or physicist but I did stay in a Holiday Inn Express last night.  


Also if the results relative to each other is correct, then the Groves reputation for being a fast bow is well deserved as it shoots with a bow 4# heavier.


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