400ex speed calculator

[DementeD]

Ok..basically what im tryin to do here is gain a lil more bottom end while still keeping top speed close to what it is now..


so i used the speed calculator..and i just want to make sure its..right?..

does the 400ex really rev to 8250??....

if so ..i have like an 18" tire stock sprockets..

i was thinkin that using a 14t front sprocket to gain more bottom end and getting a cdi box to increase my rev 1000...

so overall if the calculator is correct i should actually gain 3mph
from 61.- to 64.-
but i wanna make sure thats correct before i do this..

i also plan to get a stage 2 cam to help a lil more bottom but definitely more top end overall..since itll rev higher id prefer the stage 2 cam that has more top end then stage 1..

i already have sparks advance key and that definitely improved power..but..of course i want more but simple power not rebuild power :D hehe

so..i guess let me know if this sounds right or just crazy before i buy..

I dont think that is the rev limiter I think its just before 9100RPM. I could be wrong but i'm pretty sure is 9100 or just before

[AZ440ex]

Not sure what the rev limit is. Anbody have the hour meter with the tach?

Also keep in mind power tappers off as you get to the high RPM's. Look at a Dyno chart and you will see HP dropping fast after the peak.

Just because you get more RPM's you may not get more speed.

Could always go high compression or BIG BORE/ Stoker

[DementeD]

^ i definitely understand that...thats the reason for the stage 2 cam..to extend the power curve of the bike..

[matt1106]

your top speed seems a little low, i gps'd mine on flat ground at around 72mph with a pipe filter and jett kit and stock gearing with 20'' rear tires. And gps is actually the most accurate way to get your speed, its within .5-.75mph to your true speed. and i remember a magazine clocking a stock 400ex at 67 with gps a couple of years ago

[DementeD]

well 18" rears make it a lil slower...
and im just basing this off the calculator..
if the stock rev limit is 9100 like some people have said then it would be a lil faster then what the calculator is stating..

[hornetgod13]

The rev limiter my be that high but the motor will have a hard time reaching it in 5th lugging a person around. You might hit the limiter in 5th if you were going down a hill or had one hell of a tail wind.

[DementeD]

ok...so um..

are we just going of what people think here??


i mean does anyone actually try these things out maybe on a dyno or something when they build...or does everyone go off the "feel" factor..
if it feels faster it is..??

not tryin to be a dick but it seems like almost every ? i ask has no evidence to back it up...

does anyone know the actual rev limiter??
and where power falls off at?
and where power falls off at on a stage 2 hot cam??

anyone stock internal 400ex's that have been dyno'd so i can view the power curve??

[skidoome]

I don't know what rpm the limiter is at but I only hit it at the dunes

don't really care what my mph is...

[DementeD]

yea i think imma just get the 14t and a stage 2 cam and see what i think..
i just dont wanna waste money at all..i want things to work out

like for cars..so many people owned honda cars and know so much with proof so when i built my car i knew the exact components to use to keep the build cheap but very powerful..

im tryin to do the same thing here..

[drew416ex]

the stock rev limiter is 9100. A stock motor has a hard time reaching it. When mine was a built 416 with stock gearing and 18in tires with the stock rev box it had a top speed of 67.5mph according to the drag strip. That was wide open on the rev limit with no wind. I say put the cam in and try it before you drop your front sprocket since you already have 18's which lower the gearing.

[DementeD]

yea i guess i could do that..i just figured doing the sprocket is easy n cheap..

i dont drag the quad but i dont want it to top out to fast

i do love it as of right now but of course i want more :D

every since the sparks key when i hit 2nd n the 3rd it easily pulls the wheels off the ground...and i definitely like how fast it feels now

but like said i always want more but i dont want to sacrifice any top end..


any reports of the difference of a basically stock motor with a stage 2 cam? any dynos?