waxhead
wannabe backflipper
- Location
- gold coast
All good each to there own
Total Loss Timing Curve
- Thread starter springy
- Start date
masterblaster
X-H2
I wish,Ive heard kommander has one,but dont hear much about it,seems like after racing died out and factory teams were no more,so as went the dyno. now its just throw some parts at it and see what happens for the most part. Its like they "really dont wana know"
I can get access to a dyno over here but time for me is always a problem. The guy who started this thread....Springy had his set up on a dyno I will see if I can get hold of the printout. For the most part the dyno confirms what you can feel on the water however it is very useful for finding the torque peak of your engine, this is where you need to be off maximum advance although with most good freestyle engines you will go through max torque very quickly. The real danger is if you are propped too high and you have a "lazy" engine so that maximum throttle will hold you in the torqe peak causing detonation.
Masterblaster, I have an 8mm stroker that I run with 30* maximum advance backing off quickly at 5750rpm. If you are worried about this you can back it off a bit sooner.
Chris.
Masterblaster, I have an 8mm stroker that I run with 30* maximum advance backing off quickly at 5750rpm. If you are worried about this you can back it off a bit sooner.
Chris.
Someone must have one. Model aircraft have fantastic data loggers now which you can check with your computer after a flight and get all the airspeeds, G loads, GPS readings, etc etc
Maybe someone does one for a ski?
It would be nice to get exhaust gas analyising read outs.
Maybe someone does one for a ski?
It would be nice to get exhaust gas analyising read outs.
masterblaster
X-H2
chris...that would be nice to see the torque curve from his dyno run,with,carb,porting and timing adjstments a dyno is pricless in my book
I wasnt really concerned with the extra stroke as much as the longer rod config of more tdc dwell,not sure how much timing needs to be pulled for this at a given rpm
I wasnt really concerned with the extra stroke as much as the longer rod config of more tdc dwell,not sure how much timing needs to be pulled for this at a given rpm
masterblaster
X-H2
this is a curve im considering running with a 5 mil stroker start retard at 5000 rev lim 8750 with 15 deg retard.
I had charted this curve.this curve holds alot of timing
5750.....27
6000....26
6500....25
7000.....23
7500....21
8000...19
8500...16
rides out 15 deg from there on
I under everything on the tl exept for the switch 1 settings far right switch of s6 s7 s8,can you use these to effect just the final timing # and not effect the total curve to the rev lim set?
Wax how are you adding timing after 7000,the way this msd tl looks is its only capable of a flat fall off with no other adjustments?
I had charted this curve.this curve holds alot of timing
5750.....27
6000....26
6500....25
7000.....23
7500....21
8000...19
8500...16
rides out 15 deg from there on
I under everything on the tl exept for the switch 1 settings far right switch of s6 s7 s8,can you use these to effect just the final timing # and not effect the total curve to the rev lim set?
Wax how are you adding timing after 7000,the way this msd tl looks is its only capable of a flat fall off with no other adjustments?
masterblaster
X-H2
matt..thats the other thing that bugs me,Im sure its not doing more than 7500 if that in a straight line in flat water,but I dont want the rev lim coming on in whitewater or when bouncing in chop for the rare wot runs.
After reading the msd directions for the 2nd time,I see that the s6 s7 s8 switches must be used to retard static timing,rather than moving the stator itself,this still screws with the intire curve? So is there a way to set the curve to lower advance in the 6000 to 7000 range and still use 8750 as a rev lim? How is wax putting more timing back in after 7000?
After reading the msd directions for the 2nd time,I see that the s6 s7 s8 switches must be used to retard static timing,rather than moving the stator itself,this still screws with the intire curve? So is there a way to set the curve to lower advance in the 6000 to 7000 range and still use 8750 as a rev lim? How is wax putting more timing back in after 7000?
masterblaster
X-H2
ive not yet run it,but comp is 180 squish is .43 and was going to run 93 oct in surf and 50% 110 oct in flat
masterblaster
X-H2
?
OK, I have managed to get get a print out of two runs with Springy's ski. Problem is I can't post it because its done on a dot matrix printer and difficult to read. The other problem is I don't have any runs comparing different timing curves and I'm pretty sure the runs are with the curve set as he posted (I didn't do this curve). What is interesting is that the first run is with an original FP stinger and the second is with the stinger reduced to 40mm.
The first run shows 76.4 ft Lbs of torque @ 6398rpm and 93 bhp, and the second run with the stinger reduced shows 83.4 ft Lbs @ 6525 rpm and 103.7 bhp. If you need any more figures just ask.
Chris.
waxhead
wannabe backflipper
- Location
- gold coast
Thats a great gain from just reducing the stinger size
Worth while doing for sure
Worth while doing for sure
Superjetjim
X-
I rode Springys XFT many times - I can testify to the hit it had, you'd swear blind it had an 6 or 8mm stroker in it. Just 48's specs, ported 753cc 62T cylinders and ATP Ignition/timing as Chris mentioned above. Insane power..
He was pulling flat water rolls with no wake almost plate to plate.
Jim
masterblaster
X-H2
Chris can you post that curve like I did in post #27,on how fast it falls off after 5750...what was your rod length in the 8 mill,I have one stock rod 5 mill and one long rod 6 mill.
A dyno is a awesome thing,Id of never guessed the stinger reducer would bring on 7 extra lbs of torque at 6500. I suspect most of us see that rpm at the top of a decent size wave. I knew the stinger reducer got some extra rpms outa the motor,but 10 hp is significant.mod pipe or limited? what were the aprox water settings on the head pipe? id have to guess these runs were made with a a/m baffeless wb. Take a closeup pic of the dyno sheet in high res and post it here where we can blow it up,or please email it to me,Im interested to see how much more power it made in the early part of the curve.
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My 8mm is a long rod crank with Kwak flat tops, the curve in post 27 is the one I use.
Chris.
masterblaster
X-H2
i cant see that curve workin safe with a long rod setup even runnin 110 oct or more
It has been working like this for some time but I don't suggest anyone should just jump on someone elses timing curve, particularly from another country there are far too many variables. Our fuel, climate, cranking pressure, riding styles, riding conditions and pipes all make a difference. Best start with somethig safe and go from there.
Chris.
masterblaster
X-H2
I think my long rod motor is 133 length,it has a long tdc dwell time. That curve listed was running 23 deg at 7000.Maybe if NO wot runs at all were happening even for a short per and good race fuel.Ive seen a sim setup seize at 21 at 7000,with a few secs of wot.It was nasty as a freestyle setup though,ton of pop out of the hole
also you said in your pm that you guys use your freeflowing wb to test stinger restrictions.I assumed the test was done with a free flowing baffle less wb. The Fp was designed around the restriction the oem wb has with the baffles,at least for a somewhat close to stock cc motor. Prolly diff once you get over 850cc but I think you would get a more accurate power gain by dynoing the chamber with a oem wb first then the 40 mil restic and a/m waterbox.My guess is it would be near the same power.
also you said in your pm that you guys use your freeflowing wb to test stinger restrictions.I assumed the test was done with a free flowing baffle less wb. The Fp was designed around the restriction the oem wb has with the baffles,at least for a somewhat close to stock cc motor. Prolly diff once you get over 850cc but I think you would get a more accurate power gain by dynoing the chamber with a oem wb first then the 40 mil restic and a/m waterbox.My guess is it would be near the same power.
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