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#404's Dad
07-03-2007, 10:00 PM
Just thought I would toss this up, this is a few runs from late in the session and this is where it liked to be with the jetting, any fatter and it lost power and torque.

I ended up getting consistent runs of 3.80 and 2.40 within 1-2 thousandths early the next day with good fuel and a slightly different tune.

When playing with small quads on the dyno you are playing with 100ths and 1,000ths of a point at a time and it can get a bit frustrating at times lol, nothing like their bigger bros and workign with whole points at a time :)~

We have two nights of racing on this tune which is 4 practices and 4 motos which he grabbed the wins and took all the holeshots in.

Bike runs very very well at this point and is bone stock with the 21 OKO carb.

http://img.photobucket.com/albums/v337/sidewaze79z/DRR50CC6-2007.jpg

dblacks
07-04-2007, 07:40 AM
obviously the oko21 is working for some

drr wizard
07-04-2007, 08:03 AM
great info , thanks
do you have a graph of the power curve from 7000 rpm and up , or did you note the peak power point rpm? what jetting did you use for this pull main and pilot ? is the carb stock or have you done the recommended mods.thanks again for info
drr wizard

#404's Dad
07-04-2007, 08:45 AM
These pulls are from a "Dead Stop" on the drum, with being a CVT clutch setup it does not seem to be a simple to pull a sample from where ever I want to like if it were a normal trans/clutch setup.

I have a run here from the next morning that is in "MPH" rather than "RPM" and that is prolly the way the CVT runs should be posted imho, it is from 0-25 MPH which is the speed I ran every pull, starting the sample from any other speed gave it an unstable looking pull imo and running it up to a higher speed seemed to be useless and just added where and tare to the bike.

I have to fly up to the shop and tune a pair of TT quads for a local guy, when I get back i will try and post up the other graph in MPH for ya.


Corey

kenjolly
07-04-2007, 09:40 AM
Im with DRR wizard what jetting are you running, my dyno consist of my 6yr old and the street in front of the house. My 70cc runs good but after looking at this i think it could be better. I drilled both holes the same .032 , what did you do to your 21 oko.

#404's Dad
07-04-2007, 06:23 PM
The jetting was at 45 Pilot, 2.75 turns out on AF screw, Needle 3rd clip down and a 128 Main and it all works great with this furl and my altitude.

I plan to try some other things later on like Fuels and Additives to see what can be gained, another thing with these lil boogers is the chain being well lubed releases allot of power compared to a dry one.

Small changes = small increases but they all add up lol.

I want to break 4/3 with this thing stock and feel it is there just waiting to be released, maybe timing or a good fuel additive will do it, Cant wait to find it lol.


Corey

riding4fun
07-04-2007, 07:24 PM
Wow Corey,
I wish I was your neighbor.
You have lots of goodies.

OK which one of you shop owners are gonna let me come down for a few days and learn how to work on these things.

Darrell

#404's Dad
07-04-2007, 07:53 PM
Here is a few runs of a brand new 2007 Apex 90cc quad that one of our sponsored riders picked up today, thought I would get some runs while it was stock cuz lord knows the mods are hitting it right about now lol.

Thought I'd post this up just for a comparison against the DRX50cc, Quite a difference huh?

http://img.photobucket.com/albums/v337/sidewaze79z/Apex90CC4thofJuly.jpg


Corey

kenjolly
07-04-2007, 08:07 PM
How did your 50 run with a smaller jet, my 70 likes the 95m and 42p my 50 is 100 and stock main.

#404's Dad
07-04-2007, 09:13 PM
Originally posted by kenjolly
How did your 50 run with a smaller jet, my 70 likes the 95m and 42p my 50 is 100 and stock main.

Any leaner than shown above may show more power but much more than above and you start seeing the kind of heat that melts parts :(

dirttrack86
07-04-2007, 09:19 PM
What are these fuel additives you keep talking about ? :)

bulldogfallon
07-04-2007, 09:53 PM
There are some good fuel additives, but you may need to check with local rules before using them...


Great info on the grpahs, but if your air screw is turned out more than 2 turns it should indicate a need for a smaller pilot jet?

This is my understanding at least....but I am not an expert either.


Is this OKO carb modified at all?

This large of a main jet on a stock OKO just doesn't seem like it would work and I have many hours logged jetting them (In FL)


Am I missing something that you have done that is yielding such a different result?

Our bone stock quads w/o carb mods like:

DRX50 38-40 Pilot 90-95MJ Air Screw 1/2-3/4
DRX70 40-42 Pilot 95-98MJ Air Screw 1-1 3/4
DRX90 42-45 Pilot 98-100MJ Air Screw 1- 1 3/4

I am willing to try anything if it will work, but there still is no way the OKO will outperform the Keihin carbs in stock form

Not possible......


Also--I am not challenging your info and I am grateful for your support and sharing of info....I just need some help to see why our results "seem" to be so different

bulldogfallon
07-04-2007, 09:54 PM
Originally posted by dirttrack86
What are these fuel additives you keep talking about ? :)



Klotz makes a few nice additives....

Ask me about them next time we talk

#404's Dad
07-04-2007, 10:41 PM
Originally posted by bulldogfallon There are some good fuel additives, but you may need to check with local rules before using them...
Yes there are many additives available and some work and some not so good and rules "should" be checked prior to using, also if you are not real decent at knowing what the bike wants when it comes to jetting and plug temps you should prolly not play with them as major engine damage can occur.



Great info on the grpahs, but if your air screw is turned out more than 2 turns it should indicate a need for a smaller pilot jet?

This is my understanding at least....but I am not an expert either.

This is where the bike ran where "I" and the "AF Meter" liked it, Idled Perfectly and has awesome response for an OKO.

Change the Pilot and changes everything I just listed above lol.



Is this OKO carb modified at all?


Yes, as mentioned in a few other posts it has the recommended mods done to it like most others have done.



This large of a main jet on a stock OKO just doesn't seem like it would work and I have many hours logged jetting them (In FL)

Am I missing something that you have done that is yielding such a different result?

Our bone stock quads w/o carb mods like:

DRX50 38-40 Pilot 90-95MJ Air Screw 1/2-3/4
DRX70 40-42 Pilot 95-98MJ Air Screw 1-1 3/4
DRX90 42-45 Pilot 98-100MJ Air Screw 1- 1 3/4


Again Gary we are at different elevations and much different climates, both which play a huge roll in jetting as you would already know i am sure.



I am willing to try anything if it will work, but there still is no way the OKO will outperform the Keihin carbs in stock form

Not possible......

I for one "never" said the OKO would out perform anything or vice versa, I am the one that asked you for the info on the Keihin brutha, I am a Keihin kinda guy lol.

I am just worried that others will complain/whine about it being changed even though it is a "Dealer Option" but I will be asking the track officials this weekend :)



Also--I am not challenging your info and I am grateful for your support and sharing of info....I just need some help to see why our results "seem" to be so different

Not sure Gary, all bikes run differently and different locations with different elevations and climates add to the mess man, your guess is as good as mine lol.

No offense taken Gary, we are all here to learn and asking questions is all a part of the learning process, Although if I am stepping on any toes here by sharing what I learn then please say the word bro and I will pack up and split, just thought this was a good place to offer up some goods and take a few with me :)

bulldogfallon
07-04-2007, 10:49 PM
By the way I also have a tweaked TRX450R...Much easier to get power out of them :)



The Keihin part of my post wasn't meant for anyone...Just a general statement I threw in there...

This carb thing really causes an uproar.... OKO vs Keihin



With the carb mod your numbers make a lot more sense to me

I may give it a try tomorrow to see how it works

I found the plug very hard to read with the carb mods......so we mod ours at .029 on both sides instead of the huge air screw hole.

The quickest fix is to bolt on the Keihin and enjoy the rest of the day :) :) :)

#404's Dad
07-04-2007, 10:58 PM
If somebody would like to see a test between the OKO and the Keihin just mail me the Kiehin and any part I need to make it function and I will test it and return it to you ASAP.

All results would be posted on here.


Corey

#404's Dad
07-07-2007, 03:29 AM
She pulled a 3.98 / 2.57 tonight lol :) , Getting closer to the 4 HP mark .

hotquads1
07-07-2007, 07:26 AM
what changes brought the increased power ?

hotquads1
07-07-2007, 07:55 AM
8trx450r,
first of all thanks for this info , I've not had dyno access for about 7 years , and would love to try these mini's on the dyno. You mentioned you could not get clean pulls below what appears to be 8500 rpm I believe that is due to the cvt shifting .But since the pull shown seems to peak at the beginning of the pull it could possibly be past the peak point . If the cvt finished its shifting by 8000 rpm then you could pull from about 500 less rpm and we could see the exact peak rpm which is key to the cvt tuning. the shift point can be easily lowered by changing roller weights ( maybe increase 1 gr per roller ) total 6 grms should move shift point 500 - 700 rpm less. Realizing this would not be the best set-up for racing just for dyno purposes. RPM is more beneficial to me than MPH, I dont know about the other guys . Your stock drx 50 should have 3.5 rollers , I can supply you 4.5 rollers if you need to test. Let me know if this makes since to you , and again thanks from all of us who wish we had a dyno that doesn't go to bed at 8:30 pm

Nichols Atvs
07-07-2007, 09:26 AM
OK so are you using the stock rollers, small springs and large torsion spring to do the test or have you changed them out because i have a lot of different people saying to use all kinds of different set ups what i want to know is which set up works best on a plain stock engine . thanks for the help

#404's Dad
07-07-2007, 10:48 AM
Originally posted by hotquads1
8trx450r,
first of all thanks for this info , I've not had dyno access for about 7 years , and would love to try these mini's on the dyno. You mentioned you could not get clean pulls below what appears to be 8500 rpm I believe that is due to the cvt shifting .But since the pull shown seems to peak at the beginning of the pull it could possibly be past the peak point . If the cvt finished its shifting by 8000 rpm then you could pull from about 500 less rpm and we could see the exact peak rpm which is key to the cvt tuning. the shift point can be easily lowered by changing roller weights ( maybe increase 1 gr per roller ) total 6 grms should move shift point 500 - 700 rpm less. Realizing this would not be the best set-up for racing just for dyno purposes. RPM is more beneficial to me than MPH, I dont know about the other guys . Your stock drx 50 should have 3.5 rollers , I can supply you 4.5 rollers if you need to test. Let me know if this makes since to you , and again thanks from all of us who wish we had a dyno that doesn't go to bed at 8:30 pm

Keep in mind here that these runs are pulled from a " Dead Stop ", I hit the sample button at the same exact time as the thumb throttle.

What i mentioned earlier about clean runs was that pulling a sample from over zero mph or past 25 showed what i would call unstable, not easily comparable to other runs as is was harder to get consistent samples.

Not sure how else we can pull these samples on the CVT bikes but this seems to work the best so far " Dead Stop - 25mph " now on the 90cc bike they seem to like "0-45mph".

I am open to any info I can get as far as getting this ironed out if it in deeed needs ironing out I guess.


Off to the races, Corey

#404's Dad
07-07-2007, 10:52 AM
Originally posted by Nichols Atvs
OK so are you using the stock rollers, small springs and large torsion spring to do the test or have you changed them out because i have a lot of different people saying to use all kinds of different set ups what i want to know is which set up works best on a plain stock engine . thanks for the help

This particular bike does have all stock componets on it right now, I have tried a different weight roller and rear sho springs and seen good " Riding Increases " but NOT " Dyno Increases ".

Peace

hotquads1
07-07-2007, 11:26 AM
I guess my concern is, what if the stock engine makes peak power at 8300 rpm / it would not be reflected on the sheet you have displayed. how else can we check power output from 8000-8500 rpm range? in our testing most stock drx 50cc seem to shift in that range making it hard for the dyno to differintiate power curve, I think we have to take the shifting out of the equation .Either disable the cvt from shifting (start with frnt variator in fixed high position) or put enough roller weight so shift occurs before power band comes in, For cvt tuning it is not the amount of power or accuracy of that amount that is crucial it is the rpm peak at which it occurs . And I agree that the cvt tuning will not affect engine power output so springs are not an issue in dyno tuning. If the cvt tuner can find out the rpm of the peak power output and the rpm of the peak torque output he can then tune quite easily. thanks again 8trx450r

#404's Dad
07-08-2007, 12:10 PM
Originally posted by hotquads1
I guess my concern is, what if the stock engine makes peak power at 8300 rpm / it would not be reflected on the sheet you have displayed. how else can we check power output from 8000-8500 rpm range? in our testing most stock drx 50cc seem to shift in that range making it hard for the dyno to differintiate power curve, I think we have to take the shifting out of the equation .Either disable the cvt from shifting (start with frnt variator in fixed high position) or put enough roller weight so shift occurs before power band comes in, For cvt tuning it is not the amount of power or accuracy of that amount that is crucial it is the rpm peak at which it occurs . And I agree that the cvt tuning will not affect engine power output so springs are not an issue in dyno tuning. If the cvt tuner can find out the rpm of the peak power output and the rpm of the peak torque output he can then tune quite easily. thanks again 8trx450r

At this point in time the testing being done on these DRR's and Apex's are for "Tuning" purposes mainly on Sponsored riders bikes and if a good number is achieved it is just simply a bonus imho.

Both the Graphs I have shared were "Tuned" perfectly from no throttle to wot no matter where the bike is shifting which is exactly what i wanted to achieve, as for the clutching that can be done with track testing whether it be Holeshots, Top Speed or Shift Points that are desired to be altered, none of which affect the state of Air Fuel Tune.

After the season ends and Winter sets in things will slow down in the shop and I will have tons of spare time on my hands and be more than willing to experiment around with other testing like I do on all the big bikes everyday but right now time is tight with the mini's, Hell by son destroyed a frame, swing arm, steering stem and lord knows what else last night on his 2 month old 07 DRX50 when he tried to get around a bike that was operated by a child that was not even signed up to race a quad but a dirt bike yet was still on the track on a Raptor 80 shifter bike and stopped and then jolted right into by boys line at the last second causing a huge crash with also broke my sons Helmet and Goggles !!

So you see how my time is lol, work on it all weekend then race it two days in a row then work on it again on the weekend which is generally started on Friday but this time I am sure I will be working on this bike all week to be ready for Friday.

Anyways I am willing to do all the testing and experimenting with these lil bikes but only as time permits so be patient and we should be able to master the art of the CVT engine and its trans.


Later, Corey

riding4fun
07-08-2007, 06:34 PM
Corey,

I am new to this and don't understand everything you are saying but I can really appreciate the time you are spending that will help all of us. So keep up the ggod work.

I hope you boy is ok from the crash.

Thanks,
Darrell

dirttrack86
07-08-2007, 06:39 PM
Hey Corey,
Sorry to hear about your son. Same thing happened to us in the Nationals last year and she received a broken collar bone. So its not just the local tracks that pull bone head moves sometimes. And I would also like to say thank you for all the work and info your doing. Some us don't have the access or the money for dyno service, so I would like to personally say thanks a ton. :)

#404's Dad
03-20-2008, 02:44 PM
Testing on the 08 Water Cooled bikes will start soon. Just waiting on parts to return from here and there.

I will start a new thread when it continues.


Corey

Nichols Atvs
03-20-2008, 03:01 PM
Awesome cant wait

Thanks for posting this up

Heath

machwon
03-20-2008, 05:17 PM
#8trx450R, I've done the dynos the same way you have but I usually graph it over mph so its smoother. I've had no luck with changing the carb to the larger oko's, but porting and head work make a difference. :D

#404's Dad
03-20-2008, 07:00 PM
Originally posted by machwon
#8trx450R, I've done the dynos the same way you have but I usually graph it over mph so its smoother. I've had no luck with changing the carb to the larger oko's, but porting and head work make a difference. :D

I 100% agree, I started doing all my CVT bikes in MPH too and it makes them much better imo too.

I have never been impressed with the OKO 21's, the PE 20"s ROCK!!!!