I have 70hp on my 730 and run 14/38 top of 3rd gear up the face of sand mountain (UT). I know gearing is critical in the dunes to get your peak rpm that you can pull on the biggest hill to get the most MPH. What I am wondering is, on dirt and flat ground, is there a benefit to going with higher gearing? The reason I ask is I have ALWAYS been a fan of gearing everything I have to get that quick shifting and what seems like the quickest accelerating setup (Going on the basis of, I dont need to top out at 110, so why not gear for 70-80 so I can get there quicker).

I was doing some reading in the raptor 700 forums and it seems a lot of people jump up a tooth (front) to reduce tire spin which translates to faster acceleration. Would this be beneficial? I have some 50% worn razr's in 22" and I spin up to fourth in dry grass/dirt. I plan on getting new tires soon which will help, but should I gear up so that the power is actually being used in each gear?

First gear is totally worthless right now. I still have my dune gears on... 14/38 which works perfect for 9 paddle hauler extremes in 23x10.5x12 but its pretty low for 22 dirt tires. I am putting on a new rear sprocket this week (I think I have a 39...maybe its a 40) but I have 14/15/16/17 fronts so was thinking 15/40?? And instead of just going with a "good" gearing (15/40 or what not) should I over gear to extend the MPH in each gear thus reducing spin? Maybe 17/40?


I will admit im addicted to tire spin (makes for fun donuts/burnouts/powerslides and its a rush snapping through the gears!) but its embarrassing when I do try to race, and I just spin!

Any help is appreciated!

 

Roost,
For dirt I would gear for 1st gear. For trail riding there is nothing worse than a bad first gear.

Are the Rappy guys talking about dirt or sand?

Most of my riding is trail riding and for dirt I like having a first gear that is low enough you can get though technical areas without a lot of clutch slipping. For sand I like to gear it so I can launch in 2nd gear when hill shooting.

I was at 15x40, but am very happy with the 15x42 I'm using now for all my riding and will be sticking with the 15x 42 from now on. Even with my mild build in dirt I can just break the rear loose through 4th gear by rolling on the throttle and even 5th if I'm not straight,

To go any higher than a 15x40 for me would make my first gear too tall for some of the tight place I ride.

I do not see you ever really hooking up that much power in the dirt no matter what gearing you use, I think you will always have to be playing with the throttle to keep your tires hooking.

Scott

 

Dragging is only about 1% of what I do but its nice to have every advantage you can especially if the power is there to use. I may go 14/40 just so I can continue the non-stop shifting to 5th for the fun of it [img]i/expressions/face-icon-small-smile.gif[/img]

 

)roost.. i had pretty much the same motor as you(exsept for the head porting,i have race/drag porting with 1mm over valves and 13 to 1 comp) and ran stock
gearing(16/40) this summer and 1st gear was way to low, but i think its because
1st in the trans is low comp. to 2nd, even 3rd and 4th are closer together, but in
5th it would omly pull about 7800 RPM on a strait road.. im building a 800 for next year, and trying to choose a sproket set is drivin me flippin nuts....[img]i/expressions/face-icon-small-confused.gif[/img]

 

did you dyno your setup? I have always wondered what bumping compression would put me at. Im right at 70 hp now (moving the peak hp/tq down a bit with the cam combo eric/randall and i figured out, instead of having a ton of power at the top end it moved some more down to mid range).

They were saying I could probably be at 75 or more hp with 13:1 compression... I would just hate to run race gas all the time [img]i/expressions/face-icon-small-sad.gif[/img]

 

never dynoed mine, but eric said thay built someone else the same motor and it
got 74 HP with bad rear end bearings... ya, mines a low/mid motor to, i love power, the trottle is like a torque swich.... i love the smell of race gas[img]i/expressions/face-icon-small-happy.gif[/img]

another ???.. im sure you have HPRs shim under kit... do you have problems
with the buckets spider webing (little cracks) on the top of them on the intake side??? not sure whats causing this, but this will be my 3 set in about 20 hours
of riding....

 

Ya I do have the shim unders but have not noted any problems. Actually the last time the valve cover was off was when eric randall and myself were testing cams which was 30-40 riding hours ago. Might be something I go take a gander at!

What did eric/randall have to say about the issue??

 

Yes flux my buckets have the same spider webbs had them checked by "the preacher" and he said its not a problem just thing that happens to the bucket on this tipe of serfice, I dont no but I do trust him not to use a bad part sence its my money he would be spending to replace them.

 

eric dosnt know what it is????? maybe just a bad bach of buckets....
i hope....... he said hes seen others do the same thing...

 

<div class="FTQUOTE"><begin quote>Originally posted by: pipelayer

Yes flux my buckets have the same spider webbs had them checked by "the preacher" and he said its not a problem just thing that happens to the bucket on this tipe of serfice, I dont no but I do trust him not to use a bad part sence its my money he would be spending to replace them.</end quote></div>

thanx .....
ill let eric know... maybe its just a flaking thing.....sence the buckets are very hard.... whos the preacher?????