Raptor & Hill Climbs
#21
08-08-2001, 11:02 PM
What I can tell you from my experience is that the gear ratio change to a 43 will help you for trail riding, clearing obstacles, etc but not necessarily for the steep intricate hill climbs you mention unless you make engine mods. The problem with just changing the gearing is that you will probably still want to be in 1st except now you can't even go as fast as before in 1st with the 13/40 gearing. 2nd gear will probably still be a touch too high. Truth be told is that you would be better off with a 14, 15 or 16 in the front and just keeping it in first gear. This would work great because you would have the power and the speed range you want; however, this would su?k for all the other riding besides steep hill climbing and long flat sections like a highway. Yea, I know this isn't an option so I shouldn't talk about it...
If you think about it, the true final drive ratio is a combination of the transmission gearing plus the sprocket gearing. It is next to impossible to overcome the 1st-2nd gap via sprocket changes alone. You could verify this mathematically but I am guessing that you would need about a 12 tooth on the front and a 52 on the rear to give you the same final ratio for 2nd that you now have for 1st running 13/40 sprockets. Needless to say this isn't going to happen. Your 1st gear would be for rock crawling only but you wouldn't have any clearance left so they better be really small rocks. Your only real solution is to look to the engine for an answer. You need more torque!
The first thing to try is modifications outside the engine. You are probably safe with the e-series if you tune it for low end power. The advantage to the GYTR tip is that it is plug and play - no fuss and no headpipe change since it works better with the GYTR tip (Yamaha would have been better off with a smaller diameter headpipe for the stock exhaust pipe). I know you plan to open the air box up, a new filter, and rejetting. Hopefully this is enough to make the 13/43 gearing work for you. Oh yea before buying another pipe, try to get a torque chart comparing it to a GYTR tip and stock headpipe. You will most likely save yourself some bucks since you don't need a new headpipe and Yamaha can't complain about the extended warranty. You could try the 12/43 gearing too but realize that it isn't the best configuration to run - a little harder on the engine, chain, and front sprocket.
Your next big steps is to go into the engine. You can increase the compression by getting a new higher compression piston from JE or Ross (You shouldn't need to get an oversized piston since your quad is so new). This will add power all the way across the powerband. You will have more low end power and top end speed. I've been told not to go higher than 10:1 on the compression ratio just to be safe. Apparently the design of the head prevents a good burn in the cylinder. Perhaps RapTech or a few others could confirm this for you. The other change you can make is to the cam. Get a cam designed to make power in the lower RPM ranges. The stock cam is designed for mid to upper end HP.
If some of this sounds like familiar advice, it could be. Some of this is from my experience and some of it is repeated from trusted sources.
Good luck.
If you think about it, the true final drive ratio is a combination of the transmission gearing plus the sprocket gearing. It is next to impossible to overcome the 1st-2nd gap via sprocket changes alone. You could verify this mathematically but I am guessing that you would need about a 12 tooth on the front and a 52 on the rear to give you the same final ratio for 2nd that you now have for 1st running 13/40 sprockets. Needless to say this isn't going to happen. Your 1st gear would be for rock crawling only but you wouldn't have any clearance left so they better be really small rocks. Your only real solution is to look to the engine for an answer. You need more torque!
The first thing to try is modifications outside the engine. You are probably safe with the e-series if you tune it for low end power. The advantage to the GYTR tip is that it is plug and play - no fuss and no headpipe change since it works better with the GYTR tip (Yamaha would have been better off with a smaller diameter headpipe for the stock exhaust pipe). I know you plan to open the air box up, a new filter, and rejetting. Hopefully this is enough to make the 13/43 gearing work for you. Oh yea before buying another pipe, try to get a torque chart comparing it to a GYTR tip and stock headpipe. You will most likely save yourself some bucks since you don't need a new headpipe and Yamaha can't complain about the extended warranty. You could try the 12/43 gearing too but realize that it isn't the best configuration to run - a little harder on the engine, chain, and front sprocket.
Your next big steps is to go into the engine. You can increase the compression by getting a new higher compression piston from JE or Ross (You shouldn't need to get an oversized piston since your quad is so new). This will add power all the way across the powerband. You will have more low end power and top end speed. I've been told not to go higher than 10:1 on the compression ratio just to be safe. Apparently the design of the head prevents a good burn in the cylinder. Perhaps RapTech or a few others could confirm this for you. The other change you can make is to the cam. Get a cam designed to make power in the lower RPM ranges. The stock cam is designed for mid to upper end HP.
If some of this sounds like familiar advice, it could be. Some of this is from my experience and some of it is repeated from trusted sources.
Good luck.
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