450 top speed?

[Colin Blue]

anyone know the top speed of the yfz 450 yet?

[86atc250r]

http://home.earthlink.net/~gellett/yfz450.htm

http://home.earthlink.net/~gellett/trx450r.htm

[Colin Blue]

thanks!!

[sweet300ex]

Originally posted by 86atc250r
http://home.earthlink.net/~gellett/yfz450.htm

http://home.earthlink.net/~gellett/trx450r.htm according to that the 450r will hit 75! amagin the acceleration if it was geared lower, cause it was already pullin holeshots:devil:

Those two links are totally dumb. They say the trx450r goes 75 when the thing isnt even out yet. Also it says the top speed of the yfz is 69 when i was hitting 76 stock. Those things are totally off..baaad.

[86atc250r]

"totally dumb" eh? "totally off"?

Let me guess - you are 13 years old.

Pay attention in math a little more - then maybe you'll like totally understand what's going on at those links.

[Guy400]

Originally posted by 86atc250r
"totally dumb" eh? "totally off"?

Let me guess - you are 13 years old.

Pay attention in math a little more - then maybe you'll like totally understand what's going on at those links. LMFAO...Gabe, sorry, you're wrong. When you're under 15 and you ride a quad it's able to defy all laws of mathematics and physics:D

Originally posted by Guy400
LMFAO...Gabe, sorry, you're wrong. When you're under 15 and you ride a quad it's able to defy all laws of mathematics and physics:D

LMFAO


He's absolutely 100% correct...:D

[kfxrcer]

he!! yea those are off bs bs bs

[chucked]

will you actually be able to hit the rev limiter on the bike though???

[86atc250r]

Please resist the urge to respond to this thread if your IQ is in the single digits or hovering low in the double digits...

Thanks.

PS - if you're unsure, a simple check would be if you are thinking about posting something like this: "those are totally like way off dude" or "he!! yea those are off bs bs bs".

This is because if you do not comprehend the simple mathmatics behind those webpages (or you are unaware that there are even mathematics involved), it's very likely your IQ and/or maturity level will not support any further constructive discussion on the topic - in fact, it may be hazardous to attempt to allocate resources that should be keeping you breathing (or keeping you from soiling your trousers) to responding on this messageboard...

[exrider360]

do they have on for the 300ex

[chucked]

why dont we ban kfxrcer while were still ahead? ;)

[86atc250r]

do they have on for the 300ex

No, but if you can get me stock sprocket sizes, primary reduction and either gear teeth or ratios, I'll build one for the 300EX.

will you actually be able to hit the rev limiter on the bike though???

Who knows, that's why the RPM range is adjustable.

[quadrcr161]

:confused:

i tried the 250R and it seemed a little off. im running a 14/38 with 18x10x10 slicks on my oval 250r. this past summer i went to a local kart tri oval and raced. while we were there they wanted to see what kind of times we were running so they put the kart transponders on our quads. i won and turned a lap time of 10.46 i think and 2nd was 10.6x i think. the transponder calculated out the time of about 85mph. the outside groove of the track in right under a 1/4 mile. Dealing with racetracks everyday i ran across this web site lap/track times (http://midwesttracks.tripod.com/misc/quarter.html) and the times listed for around 10.4X is right about what the transponders calculated. i was going to get a print out that night at the track, but i will try to call them and see if i can get one faxed over from that night.

[86atc250r]

Keep in mind that real world testing introduces many more variables - with a transponder if they're calculating by using the track length, your line around the track will significantly impact the accuracy.

Also remember that tire stretch at high speeds will alter the numbers. You will need to also make sure you get a very accurate measurement of your rear tire size (i.e. don't just punch in 18" for 18" tires, because their actual height will vary).

The math used is very simple & accurate, until you introduce factors like tire stretch in that are very hard to determine... However, you have to ask yourself, does it really matter what the absolute number is - or is some of the other data you're being presented with more important.

[quadrcr161]

true about the different variables, and i know about calculating the gearing, and sprockets. i just thought it was a little lower then expected.

[86atc250r]

Remember to factor in the actual RPM you can spin in top gear - makes a big difference.

[kfxrcer]

ok so your tellin me through that my kfx will almost keep up with a yfz and a ex will keep up with me ahahahahha well i would rather stick to what i know than to trust that

[Guy400]

kfx, what you're not discerning is the difference between rate of acceleration and top speed.

[chad502ex]

Originally posted by 86atc250r
Remember to factor in the actual RPM you can spin in top gear - makes a big difference.

I would have thought by now you would have updated your 400ex gearing calculator to include 450r gearing top speeds.... Do you need tranny gear ratio info to update? I can certainly change the html, but its yours not mine,...

Let me know if you need that info
:)

chad502ex.com

[Guy400]

What is the countershaft sprocket RPM in 5th gear vs. the crank RPM? It's not 1:1 is it?

[86atc250r]

Chad, look at the beginning of this thread.

Guy - no, if you need the details I'll have to do a little math.

[chad502ex]

Originally posted by 86atc250r
Chad, look at the beginning of this thread.

Guy - no, if you need the details I'll have to do a little math.

sorry Gabe, my bad. I hadn't read the entire thread. I've looked at the source code and the gear ratio is on for the 450r. Why is the default "Engine RMP" only 9500 instead of the 9850 rev limit? Is this cause of the realistic rev limit you speak of?

Nice calculator tho!

chad502ex.com

[BigAl]

Guy, the crank turns the transmission the clutch Hub, the gear ratio between the clutch hub and the crankshaft gear is called the primary reduction.

It will probably be easier to let Gabe do the math, but I have the YFZ specs out of my service manual.

Transmission
Primary reduction system Spur gear
Primary reduction ratio 62/22 (2.818)
Secondary reduction system Chain drive
Secondary reduction ratio 38/14 (2.714)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio
1st gear 29/12 (2.416)
2nd gear 27/14 (1.928)
3rd gear 25/16 (1.562)
4th gear 23/18 (1.277)
5th gear 21/20 (1.050)



Gabe will be along to correct me soon I hope, but here is my best guess.

engine rpm=10,000 (easy figuring) /
primary reduction=2.818 = 3549 /
5th gear ratio = 1.050 = 3380

So at WFO 5th gear the YFZ C/S sprocket is spinning 3380rpm

secondary reduction (stock gearing)=2.714

3380/2.714 =1245

Rear axle is spinning 1245 rpms.

[86atc250r]

I didn't know the rev limit at the time - however, none of my calculators are set at the rev limit - but more of a guess of a realistic RPM that may be seen in top gear - I also try to make similar engine families the same RPM for easy comparisons. All are adjustable though if you don't like my defaults for whatever reason :)

[chad502ex]

Originally posted by 86atc250r
I didn't know the rev limit at the time - however, none of my calculators are set at the rev limit - but more of a guess of a realistic RPM that may be seen in top gear - I also try to make similar engine families the same RPM for easy comparisons. All are adjustable though if you don't like my defaults for whatever reason :)

certainly,..

:)

chad550R

[BigAl]

I went ahead with my formula to see if I was on the right track.

with a 20" tire, the top speed would be 74.043 or something like that.

10,000 rpm isn't realistic, but neither is a perfect 20" tire, but I'm backing Gabe all the way on this one.






Like HE needed help :D

[86atc250r]

How you liking your YFZ so far Big AL?

[BigAl]

I love it Gabe, no second thoughts yet, well not too many anyway.

The light weight and nimble handling are the things I like the best, but the motor is also very good.

I raised hte bars with some tag bar clamps and some spacers, then I custom fitted some pro-peg nerfs, to lower the pegs, and the ergos are now perfect.(did the same to my EX)

I haven't broken anything YET. Although I do have 1 complete tie rod with me at all times, so far that is the only weak link I can see.


Yamaha has truly fixed their air filter and ill handling legacy on this machine.

The chain adjustment while still more time consuming than a Honda, is a much more solid design than in the past also.


I have a buddy getting the first TRX locally, so maybe in the next few days I can ride one...I hope I don't regret it then :D

[TGW_400ex]

If that site is right that means a banshee has a lower top speed than a 400ex and a 250r that cant be right banshees definatly have a higher top speed than a EX