New CDI and coil combo for racing available!

GoldenMotor.com
crmachineman

crmachineman

New Member
May 24, 2012
259
2
0
New Hampshire
Hi everybody.
I wanted to let you folks know about a new high performance CDI available.
Now, this CDI takes a very different approach to ignition timing than the Jaguar units.

The Jaguar units retard the ignition timing at high RPM's, essentially making it a rev limiting CDI.
This is not good for high performance use.
For optimal performance on this type of engine, the ignition timing should not retard, unless you want to shut the engine down.
Thanks to Huffydavidson, the maker of these CDI's, there is a true high performance alternative to the stock ignition CDI.
Here is a link to my ebay store for the single spark ignition units.

http://www.ebay.com/itm/Motorized-b...Parts_Accessories&vxp=mtr&hash=item20db0d002d

I also have twin ignition CDI's available too! I run one now, and I love it!!!!

Thanks everybody.
-Fred
laff
 
Scott.D.Lang

Scott.D.Lang

Member
Jan 1, 2013
406
2
16
Chicago
I have 3 of them and they work very well Huffy did one heck of a job on them. You do not want to get shocked by one of them it will knock you on your ass like a car's coil will lol.
 
MotorBicycleRacing

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
5,844
109
63
SoCal Baby!!!
www.facebook.com
2door said:
Any dyno reports from this?
Post them here.

Tom
Click to expand...
My buddy Ryan the mopedler has the only dyno I know of.

Ryan dynoed a stock China girl recently along with a lot of other motorized bikes at the last Oct 19th race.
We can get any mods made to a China girl tested on his dyno.

I will be getting one of my "balanced" 40 mm stroke 69cc motors dynoed but it may not be until the next big race in April 12th 2014.
 
darkhawk22

darkhawk22

New Member
Aug 17, 2010
733
8
0
Acworth, GA
Hey Great news Fred!

I tried one of the Jaguar CDI's once but ended up returning it. I didn't have any type of difference in performance. Maybe it was me, but I just couldn't justify the money for it as I didn't notice any difference over the stock one.

Ash
 
48ccbiker

48ccbiker

New Member
Apr 5, 2013
58
1
0
California
CRM said: "For optimal performance on this type of engine, the ignition timing should not retard"
Name one racing motorcycle anywhere in the world that doesnt use an ignition system that retards the ignition at high RPM. just one.
Here is why ignition needs to be retarded: As RPM increases so does turbulence. The turbulence causes the gasoline droplets to reduce in size. That causes the air/fuel mixture to combust more rapidly. So with more rapid combustion the ignition has to happen later for the peak cylinder pressure to happen around 15 degrees ATDC.
Another advantage to retarded high RPM ignition is that with an expansion chamber it extends the pipes pówerband. The later ignition causes the exhaust entering the pipe to be hotter which allows the sound waves in the pipe to travel faster to match the faster port periods of the engine at top RPMs.
The only possible exception that I can think of is less retardation needed due to extremely poor fuel atomization due to a very crappy carburetor, which the stock NT is. The larger the gas droplets, the more time it takes to burn them. So more advance is needed.
But heres the million dollar question: who in their right mind would modify their engine for racing but not throw away that crappy chinese carburetor and put a good one on like a Mikuni or Dellorto?
 
Scott.D.Lang

Scott.D.Lang

Member
Jan 1, 2013
406
2
16
Chicago
you are right but remember this we are dealing with 100 year old engine designs and they do not hit the rpms even when doing high rpms they are hitting at most 10k the modern engines hit 12k or more much more in some cases. so yes we man need a little retard but the racers dont want it on these HT engines so finely that is what there getting is what they have been asking for.
 
48ccbiker

48ccbiker

New Member
Apr 5, 2013
58
1
0
California
"the racers dont want it"?
You make it sound like you have talked to all of them and they all said that.
Slick advertising, inferring something that isnt actually true.

These engines can be made to rev to 10 or 12K but the power will be greatly lacking due to the fact that the transfer port size is too small for high RPM.

Making a high RPM CDI for these engines is a mut point since 8500 is the maximum anyone should port it for. The formula for engine power is directly affected by the RPM but that is only assuming the rest of the engine breathes (in, transfer, out) adequately for high RPM. I really doubt the power at 10K is any more than at 8500 due to the transfer limitation.
 
KCvale

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
crmachineman said:
Hi everybody.
Thanks to Huffydavidson, the maker of these CDI's, there is a true high performance alternative to the stock ignition CDI.
Click to expand...
Well done Huffy! So Ivan's initial design values as it evolved over this 12 page topic works well http://motorbicycling.com/showthread.php?t=50044

I just posted up my latest progress report in that thread with circuit pics so we'll see if my replacing all the jumpers with a precession pot and a couple of DIP switches makes it easier to use.

Can I send ya one Huffy to try out on your HP builds that test the limits?
 
crmachineman

crmachineman

New Member
May 24, 2012
259
2
0
New Hampshire
Hi 48cc biker;
That language you are using to rationalize the need for retarding the timing sounds familiar.
You are free to believe those theories.
On the other hand, I am in a more objective position than you because I have actually tested The HD Lightning vs the other CDI's and the difference clearly put the HD Lightning on the top.

Boy, I have seen more graphs and technical explanations about this stuff to last me a lifetime.

What really matters is the results, especially on those from the race track.

The data on other CDI's, gathered from the race track also supports my test results to a tee.

So, that's the data that we have, I think it would be foolish to argue with that.

Thanks
-Fred.xx.
 
Last edited:
KCvale

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Not to go off point but for $20 I couldn't resist buying one of these today if for nothing else but direct comparison even in just a stock bike.
http://www.ebay.com/itm/161152225948

Racing is out of my league (so far) but I am looking at everything to do with ignition that will help above what an Iridium plug and good wiring will do for a 'just over stock' build.
 
crassius

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
KCvale said:
Not to go off point but for $20 I couldn't resist buying one of these today if for nothing else but direct comparison even in just a stock bike.
http://www.ebay.com/itm/161152225948

Racing is out of my league (so far) but I am looking at everything to do with ignition that will help above what an Iridium plug and good wiring will do for a 'just over stock' build.
Click to expand...
is that the kind that needs a set of points for timing?
 
crassius

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
hmmm, I've got one CDI on the shelf that times 4degrees retarded compared to others on the shelf - someone said that it may be a 50cc CDI since they think those are diff from the 66cc CDIs - I don't even know of there is a diff between 50cc & 66cc, or if this one is just a bit off spec, or what

would be interesting to know if your new one times same as standard
 
Huffydavidson

Huffydavidson

STREETRACER/MANUFACTURER
Jan 29, 2012
1,076
4
38
st.louis,mo.
Not the same. They also run those on 4 stroke atv. Pure junk. Thats they so readily available and cheap as a bic lighter. Burns out regularly!
laff
 
You must log in or register to reply here.
Top Bottom