I'm not concerned with power above 9K RPM, really. I'm more concerned with how quickly it revs to it's stock limit of 9K. I know gearing it down will decrease that time, but I'm looking at mods like lightening the flywheel to make the dramatic differences.

Chris

 

id try sprokets, that will help because it doesnt have to wind out a real long gear, but you wont go to fast top end if u gear it too low, im sure u knew that. flywheel probbably. im not sure tho. sorry

 

I would pick a Raptor over a 450 any day. The broad powerband is perfect, and its not even funny what kind of hell it is riding the YFZ in the trails. Its a great bike, but far far from what I like in a quad.

 

The raptor has a 9.2:1 piston and a sohc, vs the yfz's 11.9:1 piston and dohc much like those from the dirtbike.
Some people have lightened the flywheel with decent results. The problem that arises with lighter flywheels is that you change the powerband. The engine will lose power if you dont keep it at higher rpm's than you did before the lightening. kind of like a banshee, and more like a yfz.
the yfz has more hp due to the comp, dual cams, more aggressive cam timings, a lower weight, and yes, higher rpms. When you talk about power in low revs, you are talking about torque. when the engine is at high rpms, the torque lessens and hp increases. The raptor has more torque, but because it revs faster, the yfz can get into its hp faster and therefore out accellerate the raptor.

 

If you are looking at lot's of trail riding, get the Raptor. Put a good pipe on it, full skids, and you will be set for trail riding. If it comes down to getting a ton more hp, and kicking some 450 ****, there is plenty of builders that can hook you up. Mine is at Craycraft right now, getting the works. Needless to say I'll be hunt'in the 450's on the trails in about 2 weeks.

 

[quote]
Originally posted by: maddog56
So, is it possible just to buy a 11.9:1 piston for the raptor without having to change anything else?
So, are you saying that the low end power will be less with a lighter flywheel, but more in the higher RPM's? If it does change the powerband, where does the power shift to?
Gotcha! So, for $1000, what would be the best options for me to get the most low-mid range power for the buck strictly for trail use?

Chris

 

[quote]
Originally posted by: ravencr
Yes, you can buy a higher compression piston for the raptor. But to see any real hp gains you would need to install an aftermarket cam as well.Yes, thats what I am saying. The powerband shifts to higher rpms.For 1k i would get an aftermarket pipe, K&N air filter, jets, a 11:1 piston and stage 1 cam. That would give you lots of low and mid range and a peak hp of 50-55 while still running on premium pump gas.

 

I'm a lil bias just because I own a yfz... but I want to add a few more things to this.

1. at 230lbs, you are almost too big for the yfz.
2. the lighter yfz makes for getting out of the mud easier, and for just getting off and needing to toss it around a bit.
3. I'm assuming when you say trail riding, you include tight hill climbs, creek beds and other navigation obsticles in which you will definately want to mod the shocks on the raptor for. (IMO the yfz's shocks expand much better to give you a more thorough grip on uneven terrain.)
4. toss an exhaust kit on the yfz and you won't need to worry about lowend at all.
5. reverse rocks
6. the raptor is a heavy SOB.
7. try out both if you can... and see what you like more.

 

1. weight isnt the concern, height is. A big guy can still ride a yfz, just not if he's too tall. Not to say he wont be more comfortable on the rappy.
2. most of us dont get into too deep of mud. and the yfz has to be lighter and easier to move because it doesnt have reverse
3. the stock shocks on the raptor are good shocks. they will do a fine job for trail riding. aftermarket is better, but it is for every bike. the stockers are more than sufficient, but if you want to you can bolt on a set of front shocks off of a yfz onto the raptor.
4. The yfz doesnt lack lowend, it just doesnt have as much as a raptor. Most yfz pipes are geared towards high rpm curves for max hp, actually making the low end worse.
5. Reverse does rock, too bad the yfz doesnt have it
6. The raptor is heavy, yes. But when you weigh 230 and you have reverse, suddenly it isnt that heavy anymore. besides, its not like 350lbs is exactly a sack of potatoes anyway (yfz)
7. I agree totally.

 

I thought providing 25% more HP on the lowend would make it more responsive... this is not the case?