I wrote a little program a while back that figures piston speed, displacement, gearing, and helps you figure & track valve shimming.

Sure, you may say "Why bother, there's a ton of gearing and displacement calculators out there on the innerweb" and you'd be right.

This one's a little different, it has data for most popular quads preloaded -- and I just updated it with 06 TRX and YFZ info

http://www.xcracing.com/gabe/quad_calc.exe

You can run more than one instance of the program for handy comparisons....

Dude you are the coolest!!!

well aren't you just the coolest thing!

If you have a quad you'd like to have added, I need the ratios for each gear and the primary reduction (stock sprocket sizes would also save me a little time) - this information is in most service manuals.

I've used the older version of this a begillion times.

Who's got the Raptor 700 info?

what is the correct rpm level on the trx...9500,9800 or 9850

9850

Gabe!!your freakin awesome

sweet gabe, another useful desktop item. lol

wow im impressed nice job man!

Nice Gabe, you are the man!

what would make this complete is.......if it could tell you the difference in accelaration with diff. gearing.......

Wow, my 04 has more displacement than the 06's.... I feel so much better...

hye gabe how about one for a cvt? complete with spring specifications and differences in gram of weights? lol just j/k it would be nice though

The program has been updated with Raptor 700 information. Download from the link at the top of this page.

Hey Gabe, I was wondering how you calculated the piston speed and at what position the piston is at in the cylinder when you determine the speed. Cause at TDC and BDC the piston speed would be 0. I was just curious, so I can impress my friends with it later.

Good question. It is average piston speed in feet per minute, since that is the most commonly used number.

i found that changing the tire size is not the same as sprocket change
according to the gearing calculator 13/39 on 20"tires is the same as 14/38 on 18"tires but when i actually rode it the 14/38 setup felt like taller gearing than 13/39 on 20".......so i guess theres something different about changing the gearing using tires over sprockets...

tires have different rotational mass added to the equation...sprockets don't

Also, if you took 5 different 20" tires, from 5 different manufacturers and measured them all..........you'd get 5 different heights. Then throw into that different sideway deflection once they are on the quad with a load, and the actual diameter will be quite different among them.

so if i measure them they'll probably read 19" instead of 18"........i had some 20"maxxis raz and when i measured them they was almost 21" tall and they were heavy thats why i sold them.

The most acurate measurement for tires is SLR,static loaded radius.You can get a true reading this way.

THE DISPLACMENT FOR THE 06 IS WRONG IT'S ACTUALLY FROM THE BOOK IT'S 449.4 THE BORE & STROKE IS 96.0 X 62.1.... JUST TO SET THE RECORD STRAIGHT... NOT TO FAR OFF THE 04 05 R

i measured them today and there alittle over 18-1/2" tall so i changed my gearing to 13/36 and it now feels almost as low as 13/39 on 20"tires.......i guess when you wanna change your gearing its best to do it with the sprockets not the tires.......i liked the feel of the 13/39 on 20" thats why i'm tring to get that same pull with the 18"tires.

Great Job Gabe!!!

Well said Danno...on the tires that is!

Well, according to Honda's website, it's 96.0x62.0 -- if you want to tear down, measure, and validate that the stroke is actually .1mm longer than 62 - I'll change the default in the software

http://powersports.honda.com/atvs/sport/sp...lStyle=TRX450R6

If calculated with 62.1 as the stroke you actually come up with 449.5, rounded to the nearest tenth.


You did catch me on one thing - I don't remember my reasoning at the time, but I used a historic approximation for calculating Pi - 22/7 which yeilds the value of 3.14285714 which is actually a bit greater than the actual value which should be closer to 3.14159265

In the latest version of the program, I changed Pi's value to the latter.

Rookie!




j/k, Gabe

well atleast i'm saving weight with smaller tires....smaller sprockets and if that gearing becomes to low i can save more weight and get a 35t for the rear...

for those who are looking for the correct gearing for there riding or racing....

Gabe lookslikean awsome program.
I made one similar but crude in excel I had rpm fallback points included to see what your rpm fell back to when shifting. Like 10000 rpm when shifted into 3rd would be 8300 rpm to match what power you have to deal with.

Hey Gabe...love the calculator...

BUT.. is there a calculator out there that will determine the RPM 'range' when shifting gears....??? for example....10,850 RPM max in first gear gets me to about 32mph (give or take)... when I shift using STOCK gearing.. what RPM does my engine rev down to? 8,000 9,000 ??? etc.. I know I could figure it out by simply determining the % difference in gear speed.. then subtract that RPM from the 10,850 and that would give me the RPM when shifting into 2nd.. then 3rd.. etc..

What I am looking for is this....since a DYNO can pretty much tell us where our powerband is.....is there a calculator out there that can tell me the RPM range when shifting? for example..if I have stock gearing... 1st gear starts out at 0 RPM...and if shifting at Limiter of 10,850 RPM, what RPM would 2nd gear start out at...? then 3rd.. and so forth... this way we could gear our quads to the exact powerband we are creating on a dyno...

i mean...if you have a WIDE powerband....of 5,000 to 10,000 RPM.. no sense in short shifting like a 2-stroke from 9,000 to 10,000 RPM.. and if you have a very short powerband.. like 9,000 to 11,000, no sense in gearing too high.. causing you to drop below the powerband when shifting into the next higher gear....

anyways......ive been working too many long hours...and my head hurts.. so I doubt much of that made any sense..... just curious

That can be done fairly easily -- I'll look into incorporating that into the next version

Hey thanx....I am amazed you figured out what I was trying to say... im still asleep....hehe

Where's the Mac version.....

ningún habla la manzana -- LOL

Pero la manzana es buena.

Yo quero Taco Bell

Program has been updated with "shift drop" or fallback, keep in mind that it doesn't tell you how long it takes the engine to pull through the gear, only how much RPMs will drop in a perfect world when you shift without figuring in inertia, horsepower, load, etc...

Thanks for the input Dan & 450RRR

AWESOME!
Thanks !

Hey Thanx a ton Gabe...

And...one more thing....... we all know your the SHIIIIIT... but,... one LITTLE itty bitty error.....the 06 T-rex is 96.0 x 62.1 mm bore/stroke.. according to my Honda service manual.... (3.78 in X 2.44 in).. according to Honda... 449.26 CC's.... (27.40 Cubic Inches) Dang...that aint much compared to a 454......hehe...

Oh....and a little insight as to why Tires and tire sizes never agree with gearing...other than the other wisdom you all noted that tire sizes are not all the same..... there is one more thing tires do....they Expand.... not only from various tire pressures going up/down due to temp/barometric pressure/altitude.... but they will stretch and grow as you turn them...the faster you turn them...the larger they grow...... its actually a good thing... but you can see how this would throw off a mechanical calculation of time/speed/rpm... etc... Just My Humble Opinion......

Im gonna go try your new updated calculator now... thanx again Gabe

super cool gabeborg!!

the update will tell you how far down the rpm scale you will drop with each shift....

great way to campare your shift point power with your point in the power curve immediately after the shift

so lets see...if i shift booster with the hrc cam @ 10grand (~55HP) it will drop me back to 8,200 rpm (average) where i will be at....why looky there... 55HP, again..... good to know!!

thanks again gabe

Honda's website lists the stroke as 62.0 -- so that's what I used when building the calculator -- if someone wants to validate what is actually correct (DynoDn?), I'll change it in the program.

dang, i thought it was 62.0000004837627282994875763482921, guess I was wrong.....









Don't you love sarcasm...

I was thinking Pie R Squared....

Except the last one I ate...which was round.. go figure...

Hey Gabe...I pulled up my calculator..and nothing had changed.. .so just when I was going to give ya a PM...i remembered.....Snap!....i was using the old one I D/L'd on my computer...so of COURSE you werent able to change THAT one.....like....duh...

anyways...this calc works great...thx

Dang it...I forgot to ask....

I know you dont have the Exact figures.. .but ROUGHLY....

what is the 'powerband' of the 06 Trex... with HRC cam and full pipe...

just a ruff estimate.... please.. Mix...Tice....Gabe....Killer..... anyone???

at what RPM do I start losing too much power....both top and bottom...??

if i knew..i'd be happy to tell you


but i don't have any runs on an '06 yet..sorry

look on the rossier thread about the 06 dyno results it may help you.

Thanx guys...I looked up the Dyno chart that CCrider posted a while back... 06 stock vs HRC installed... peaks at about 8,700 RPMwith just HRC installed............probably a bit higher RPM with my ESR pipe tho....and less down low I would assume....will look in to it.......thanx...

can anyone tell me what the average shop charges for a dyno run?? or time on the dyno?? however they calculate it....

are local shop is $35 per session. a session consists of several runs, maybe 4 or 5, and maybe more if they're not busy. if you "know" them, you can often get "hookups". Typically 20 to 30 dollars.