We're all in search of more "gitty-up" for our machines. The concept is simple; the more you flow, the more you go. The better you can move air and fuel through the motor, the more power you will produce. We do this with exhausts, air filters, porting, valves, and on and on. The downside to this equation is that with every modification you do to your ATV, the more risk you run of losing reliability. Every once in a while a modification will come along that will get you gains you are after without increasing that risk. The following is one of them. We found out about this guy called Kenny, from KDS Racing. He bores out stock throttle bodies on the Raptor 700R by 2 millimeters, and claims noticeable gains from doing so. That's all we needed to hear, and our throttle body was on its way to his shop.
After cleaning and disassembly of the throttle body, Kenny mounts it on a flat table that has a centering pin and a wear sleeve, where he aligns the casting with a centering cone. He does not align the throttle body with the factory bore, as he has found that some are offset from the factory. Once location is correct he uses two different custom counter-bore cutters, one for the initial overbore, and the other for the new inlet angle. It is optimized by using a vacuum, a smoke wand, and ultra-violet lights to see what's happening with the airflow.
The throttle shaft gets machined, then drilled and tapped for button head screws, and coated with a dry film lubricant. The throttle plate is thinner (.047") and stainless compared to the OEM .060" brass plate. The plates are first laser cut, and then 12 at a time are cut to final size in an arbor designed to hold them at a 3.5 degree angle. This gives an optimal oval shape for good idle control.
The throttle housing also gets drilled and tapped for a throttle stop. Kenny has found that the stock throttle body allows the throttle plate to go 2-4 degrees past wide-open throttle, thus hurting flow. He then uses a fixture to hold the plate at 90 degrees while the set screw is adjusted. Finally, the throat gets "swirl-polished".
What is produced by all this? Horsepower gains up top without losing torque and power down low. An added bonus is that with the +2mm throttle body, the horsepower and torque is held longer in a usable range. When we initially threw our 700R on the dynometer, it had a serious power loss down low compared to our “before” dyno run. We started adding fuel and it got even worse, so we went the other way and leaned out the fuel by 4%, and found that to do the trick. Now it was running very comparable to our "before" results down low (5500-4500 RPM, and below). Up top (5500+ RPM) we found it quite lean. We upped the PCII between 4-8% at various points along the RPM range until enough fuel was added. Click HERE for our dyno plot.
There you have it, a safe and affordable modification for your Raptor 700R. At a cost of $159 and an increase in a couple of horsepower, this is a modification that makes sense and is easy on the wallet. At $100 per HP, that's a real value! We feel Kenny at KDS Racing has a real winner on his hands here, and not just in the 700R market. He has mentioned to us that the Suzuki guys are catching on as well. Let's try not to help them too much yet; we can let them know after we beat them! You can contact KDS Racing by giving them a call at 540-392-4929.
Quality: 5/5
Performance: 4/5
Installation: 5/5
Value: 5/5
Overall: 4.75/5
|
Our 700R's stock throttle body, before Kenny from KDS Racing gets his hands on it.
After boring two full millimeters. The throttle body's size increase is very visible
The new thinner, stainless throttle plates are cut to an oval shape, for good idle control.
At less than $100 per HP, the KDS Racing throttle body boring is well worth the money.
|
REVIEWS
