Does anyone here like ,timed dyno runs? : V-Twin Forum: Harley Davidson Forums

Krash_Kinkade · 10-04-2009, 04:38 AM

hi all, i like to have my dyno runs timed, what do you think?
like i drag race and i've found if i just do a RPM in say 4th gear and just look at making the most HP & TQ then go to the track, if i gained in HP i might not see a quicker time ticket but will see a faster trap speed.
then i started having it timed and not worrying about just trying to make more HP i just went with the tune that made the most TQ & HP in less than 5 seconds WOT and i found i see a quicker time. so i just put that down to quality of the HP.
what do others think?
cheers

Hillside · 10-05-2009, 06:12 AM

We provide the dyno chart, AND the data chart, with all info regarding weather, length of time of pull, and hi-lite important areas with yellow marker. ALWAYS have done this, since the mid-nineties.

Scott

FXDRYDR · 10-05-2009, 08:06 AM

John,

I think of this as "time to power." I think it's important as it indicates the ability of a build as as you noted. It seems you've just hit on a way of looking at it that lets you optimize your tune for the riding you do - and the proof of its effectiveness is the improvement you see.

I think it also underscores the "long black dyno" as being the bottom line indicator of performance. Think I've heard that before... LOL!

All that said, when launching at 4500 or so and slipping the clutch -that light comes on pretty damn fast. When I was launching at lower RPM, I thought it might be more important but launching at higher RPM gets me there quicker. Interestingly, trap speed is about the same.

Hillside · 10-05-2009, 09:17 AM

Prime example of this is the same build, and then lighten the flywheels.
May not make ANY more power, but it'll rpm quicker, and the data, printed out at 100, or 50 rpm increments will be spell out the tell-tale info.

Scott

**rosascycle** · 10-05-2009, 11:10 AM

Any and All Dyno info is good and a must have for all types of motor sports but nothing beats tuning at the track on a given day to match weather conditions, wind speed, at sea level or above .Isn't that what all the top crewcheifs get the big bucks for doing so well!! taking information from sensors and computers then going faster

Hillside · 10-05-2009, 03:04 PM

Andrew,
Very good point indeed.

Scott

oh1deuce · 10-05-2009, 06:48 PM

Ahhh, the timing of the subject of timed runs popping up here..... Funny chit!

Krash_Kinkade · 10-06-2009, 04:06 AM

Good to read your replys.
you always give good advice Scott, with a wealth of knowledge.

Gordon getting out the hole quick is the hard part, so is shifting quick.

Thanks for your reply RosaCycles, so true!

With me i'm just a bracket racer, so consistency is important. but if uneaven entry a top qualifier gets the bye.
if it don't rain we are racing this sunday, all harley street bikes, love racing in this but it's hard.
do you think the CV is good to adust to elivation?
Cheers

oh1deuce · 10-09-2009, 09:10 AM

Is there an A to B rpm standard for timed runs?

Knighty-Knight · 10-09-2009, 09:32 AM

http://www.rbracing-rsr.com/orcadyno.htm

If you can ignore the tone of the above site you might find the information interesting.

Hillside · 10-09-2009, 12:19 PM

Quote:

Originally Posted by oh1deuce

Is there an A to B rpm standard for timed runs?

Such as?????????????

oh1deuce · 10-09-2009, 12:36 PM

2,000 to 6,000?

Krash_Kinkade · 10-09-2009, 03:16 PM

Quote:

Originally Posted by oh1deuce

2,000 to 6,000?

I never worried about RPM just tried to make the most HP & TQ in say 4 or 5 seconds WOT with load.
the way i look at it is if i'm only going to take 11 something seconds in quater mile and i'll be in 4th gear at the end that means i'll **** gear three times i'll probably only use what i can make in say three seconds wide open. works for me as when i dynoed for all out power and did not time how long it took to make it. i did not see an improvement in my time just saw a mile per hour faster sometimes. then started timing the run and comparing tune, and see what tune could make the HP& TQ the quickest, go to the track and could see a few thenths gain as long as i did not make any mistakes. the best part was runing with the big inch twin cams that all have two into one's and all tell me how much power and Tq and all i got is an ol 95" carb with one piece cycle shacks no baffles my motor looks stock too no ignition cut out no two stage rev limiter stock wheels just normal avon road tires 150 16".
thats what i call fun.
i tell them when i do bring a big stick look out

but i know if i dropped in say a 124" or a 126" G2 i might not go faster i would have to learn the bike all over again, and also have to remember with bracket racing i would have to be consistent to win. but if it was easy i would not be doing it.
cheers

Krash_Kinkade · 10-09-2009, 04:02 PM

Quote:

Originally Posted by Knighty-Knight

http://www.rbracing-rsr.com/orcadyno.htm

If you can ignore the tone of the above site you might find the information interesting.

Thanks for the link, a friend of mine has an engine dyno good tool!
but can't bolt a harley motor up direct to it as the 45 degree common crank pin motor cracks everything, but did not crack his dyno wheel, he built the dyno bullit proof, but we put a harley on it and it was cracking everthing but the dyno, i think would have to mount a harley motor off the dyno and drive the dyno with a belt drive to isolate the they dyno from the impact wrench type vibration harleys just put out. my twin cam feels smooth but its rubber mounted.
cheers