Here is one of the SRX780 Dyno sheets

my dyno sheet below. no flat spot.
bob

SRX with Bender 835 big bore
EngSpd STPTrq STPPwr BSFC B Fuel B AirTmp STPCor BaroP
RPM Clb-ft CHp lb/hph lb/hr degF Factor in/Hg
7000 107.3 143.0 0.783 111.5 46 1.004 29.66
7100 106.5 144.0 0.779 111.9 44 1.002 29.66
7200 106.5 146.0 0.782 114.4 41 0.999 29.66
7300 107.5 149.4 0.777 116.4 40 0.998 29.66
7400 108.6 153.0 0.751 115.2 40 0.998 29.66
7500 111.1 158.6 0.725 115.4 39 0.997 29.66
7600 111.1 160.7 0.726 117.2 39 0.997 29.66
7700 115.2 168.8 0.705 119.4 39 0.997 29.66
7800 114.7 170.3 0.691 118.2 39 0.997 29.66
7900 116.5 175.3 0.664 117.0 38 0.996 29.66
8000 120.1 182.9 0.643 118.3 37 0.995 29.66
8100 119.8 184.7 0.646 120.1 37 0.995 29.66
8200 119.1 185.9 0.644 120.5 37 0.995 29.66
8300 121.1 191.3 0.618 119.0 37 0.995 29.66
8400 121.4 194.1 0.622 121.4 37 0.995 29.66
8500 119.8 193.8 0.627 122.3 37 0.995 29.66
8600 118.1 193.3 0.615 119.7 36 0.994 29.66
8700 115.7 191.7 0.615 118.9 35 0.993 29.66
8800 113.8 190.6 0.619 118.8 36 0.994 29.66
8900 110.3 187.0 0.627 117.9 37 0.995 29.66
9000 106.8 183.1 0.634 116.7 37 0.995 29.66
 

bufalobob said:
my dyno sheet below. no flat spot.
bob

SRX with Bender 835 big bore
EngSpd STPTrq STPPwr BSFC B Fuel B AirTmp STPCor BaroP
RPM Clb-ft CHp lb/hph lb/hr degF Factor in/Hg
7000 107.3 143.0 0.783 111.5 46 1.004 29.66
7100 106.5 144.0 0.779 111.9 44 1.002 29.66
7200 106.5 146.0 0.782 114.4 41 0.999 29.66
7300 107.5 149.4 0.777 116.4 40 0.998 29.66
7400 108.6 153.0 0.751 115.2 40 0.998 29.66
7500 111.1 158.6 0.725 115.4 39 0.997 29.66
7600 111.1 160.7 0.726 117.2 39 0.997 29.66
7700 115.2 168.8 0.705 119.4 39 0.997 29.66
7800 114.7 170.3 0.691 118.2 39 0.997 29.66
7900 116.5 175.3 0.664 117.0 38 0.996 29.66
8000 120.1 182.9 0.643 118.3 37 0.995 29.66
8100 119.8 184.7 0.646 120.1 37 0.995 29.66
8200 119.1 185.9 0.644 120.5 37 0.995 29.66
8300 121.1 191.3 0.618 119.0 37 0.995 29.66
8400 121.4 194.1 0.622 121.4 37 0.995 29.66
8500 119.8 193.8 0.627 122.3 37 0.995 29.66
8600 118.1 193.3 0.615 119.7 36 0.994 29.66
8700 115.7 191.7 0.615 118.9 35 0.993 29.66
8800 113.8 190.6 0.619 118.8 36 0.994 29.66
8900 110.3 187.0 0.627 117.9 37 0.995 29.66
9000 106.8 183.1 0.634 116.7 37 0.995 29.66
Click to expand...
Nice powercurve there bob ;)! Did you ever check if yours messures
the same as a new set of pipes?
 
I don't think the pipes are the issue here! I think port timing is the culprit. I have been out with Ryan many times and seen this sled run as well. It pulls through that flat spot really well. I have never seen Ryan stuck on a clutch set up for this engine. This package really flies!!
 
i was @ the dyno session w/ valin & jabber. i agree w/ jabber, more than likely porting. bender has been making those pipes for 10+ years & they work well.
bob
 
Bob I have my dyno back up and running! Shafts finally came in. I started a little project with my 835 that I want to test on it. I moddified my 38mm carbs to mount a yamaha throttle position sensor on them. Hoping to see if this does anything for the bigbores low to midrange power. Not that they need anymore power there, but any gain is good!!!
 
jabber800 said:
Bob I have my dyno back up and running! Shafts finally came in. I started a little project with my 835 that I want to test on it. I moddified my 38mm carbs to mount a yamaha throttle position sensor on them. Hoping to see if this does anything for the bigbores low to midrange power. Not that they need anymore power there, but any gain is good!!!
Click to expand...

hey dan.
I'd be curiouse about the results with the tps too.
 
jabber800 said:
Bob I have my dyno back up and running! Shafts finally came in. I started a little project with my 835 that I want to test on it. I moddified my 38mm carbs to mount a yamaha throttle position sensor on them. Hoping to see if this does anything for the bigbores low to midrange power. Not that they need anymore power there, but any gain is good!!!
Click to expand...
Nice! Care to share how you got the tps on there? Just got my tors. switch
on the 38's,was a tight fit but it works!
And it would be nice to have the tps on there aswell.
Cant wait to se your result on this!
 
bufalobob said:
i was @ the dyno session w/ valin & jabber. i agree w/ jabber, more than likely porting. bender has been making those pipes for 10+ years & they work well.
bob
Click to expand...
Well i just orderd them pipes.. Cant wait to try them out!
 
Installing the TPS was pretty tricky. I removed the main throttle control shaft from a stock yamaha carb rack and installed it in the 38 rack. Had to modify the carb slide machine screw holes as well as the throttle pivot hole. I then made a custom billet mount for the tps to mount on. It took an afternoon of cursing and about a 1/2 bottle of the captains finest but its working now. If there shows to be any gains to make this worth while doing I will snap off some pics and give a bit more details so others can do it.

And I'm sure you will not be disapointed with these pipes on a trail big bore! This is my 4th big bore and all of them got the pipes!!!
 
Ha,ha Sounds like me getting the tors.switch on there,alot of cursing! But now i can
let the gf. ride it to without worries. The labor with the tps seems to be about what i
found out when looking at it,more cursing.. Gonna wait until i se your results.

If you make a gain with it i guess i will look up a spare carbrack and get started. They
are real cheap here (Sweden) anyway. I dont have a bigbore now,had an 780 before
and had Don build me a 700 lakerace engine with a raceported case this year.
So i dont know how much i will gain with them?

But me and a freind who has my old 780 are planning a dynorun
together later this season.
Gonna run the pipes on both engines and se what happens?
 
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