I dont know but .4 sec is a lot.

 

Tommyboy,
As a general rule of thumb, I think you are about 1 quad length faster for each 0.1 second that you are faster in 300'. So that would mean that you gained 4 quad lengths with the Dyna cdi...not bad IMO.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I have great results, also. I have no numbers to share, except my 2 MPH gain to 71 MPH(speedo), but after I retimed my cams, I could not wheelie in high gear, at any speed. After the CDI, I can wheelie in high from idle to about 12 mph. Midrange acceleration is also much improved. That's a fantastic improvement, IMO.

 

I guess some guys are getting cdis that work and some are not.

 

Just a note ...at the speed/acceleration approximately of a prairie 4x4,..about 1.3 tenths is 1 quad length, for those who may be interested.Dale
PS 9.0 secs,you must have been going farther than 300ft,but ot doesnt matter,I know you were just using a said distance. I would expect you are about 2-3 lengths faster with you on it in the approx 475 ft you were going.

 

HELIX..... im gonna take a tape mesure up there and mark off 300ft exactly.. What speed should i be seeing on my speedo when i cross this mark?? I was only getting 51-52 mph at the caculated 475ft or so.. thanx.

 

Tommyboy,
On pavement, I can usually hit about 50 mph in 300', but I'm not sure how fast I'm going at 300' when on dirt/sand. For what its worth, I would have to say that going 50ish at 475 feet sounds a little slow on pavement or grass/dirt. I would guess that you should be going faster than that at 475 feet.

Happy trials...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Ok, somebody check my math:

Assumptions:
1. distance is 475 ft
2. Stock CDI 9.43 sec
3. Dyna CDI 9.0 ft

Avg. Velocity for Dyna
475ft/9.0 sec. = 52.78 ft/sec average

Avg. Velocity for Stock
475ft/9.43 sec. = 50.37 ft/sec average

Therefore after 9.0 seconds the Stock CDI machine traveled:
9.0sec. * 50.37 ft/sec = 453.34 ft.

So the Dyna CDI machine traveled 21.66 ft farther in 9.0 seconds.

I'm not sure if you have a Prairie or V-Force so lets assume Prairie 700.
Length = 82.6 in or 6.88 ft.

21.66ft/6.88ft/quad length = 3.15 quad lengths

OR

((52.78 ft/sec - 50.37 ft/sec) * 9.0)/6.88ft/quad length = 3.15 quad lengths

Hope this helps.
Mark

 

markdf

Your calculations seems good

 

well, i just got back from doing timed runs at exactly 300ft, i also mesures yesterdays runs and they were about 460ft.... today i did the runs on black top and very lose dirt... on the dirt my bast time with the stock cdi was 6.84 and my best time with the dyna was 6.56..... on blacktop my best time with stock cdi was 6.77 and my best time with dyna was 6.61.. im not a math person so ill let one of u tell me what thes new numbers mean... all runs today were at exactly 300ft.. P.S on one of my runs when i let off WOT it sounded like a gun went off behind me what causes that? P.S agian... my speed at 300ft was 48mph.... would a twin air nappa hose 142 145 jest and nyrocs mod help my 300ft time any?