Mean1,

I am in the same situation, but I have made my decision about which pipe to go with. It's CT Racing's. I called and spoke to Allen last night. He's a straight shooter. He will tell you that the gain from using his kit is not just from the pipe. He said he probably just beats the other pipes by a little bit. But, the rest of the power comes from the other parts of the kit.

The reason I am going with CT is the fact that he was the first guy to post Dyno readings on his pipe kit, and they haven't changed. Also, he has spent a huge amount of time trying setups, and components to make the most HP. In this forum, there are many guys who are trying to figure out how to get there different parts to work together.

CT has provided a kit which has been tested and proven. You will spend more time riding than trying to figure out how to get a pipe from one guy, and filters from another, and how many holes in the lid to drill, to get it to work properly.

In my decision making, I want to make the purchase, put the parts on, and ride it. CT has posted the expected gains, and moving from 34 HP to 49 HP is exactly what I am after. CT has solved the puzzle and I want the pieces which they used.

Just adding a pipe will only get you 4-7 HP. It's the other stuff (Lid, jetting, filter, discs) which will make the huge difference along with the pipe. The stock pipe is too restrictive when you start opening up the airways.

I will order mine in the next couple of days.

One other note, CT's pipe is supposed to be pretty loud, like over 100db. So that is a consideration also.

 

Maybe, could be. But CT advertises gains across the range. i would also add, with the 12t CT he should have taken Blubyu at the line. but, that was not the case. They rode neck and neck until they both hit 4th and the stock Raptor started to pull away.

 

my point is...use the same gearing in both quads so you can accurately compare the engine intake/exhaust mods.

 

Raptor660RNH,

Funny, after I posted I went back and thought "I bet he was responding to the first post and didn't mean all the info listed in the other posts wouldn't make a difference." I don't think there is much difference in the various pipe/air filter combinations either. I also totally agree with making the mods as cheap as you can and spending money elsewhere where it can make a difference. The Elka shocks have increased the "joy" factor more than the engine mods.

I do think the mods are worth it though. For my riding, the stock engine didn't have quite enough low end grunt (or I am not skilled enough to keep it in the powerband while climbing some pretty steep hills). I climb some hills that require more momentum than 1st yet in stock form the bike didn't have enough torque to keep the tires turning in 2nd unless you were in the powerband which made them spin too much and lifted the front end off the ground. In some ways, I wish I had tested just opening the airbox up and rejetting. I may not have needed the extra hp from the GYTR tip. Now that I have it though I wouldn't give it up.

BlueLeader and Raptor660RNH,

You both could be right and wrong about 12t versus 13t on the front. The only thing you know for sure when switching from a 13t to a 12t is that you have lowered your gearing and thus lowered your tire rotation for a given rpm factor. Truth is that sometimes lower gearing helps increase off-the-line speed and sometimes it hurts it. Testing on a given surface is the only true way to know (meaning the best gearing on one surface genrally isn't even the best on another). It takes drag racers (cars) years of experience to guess what is going to be the best combination of tires, gearing, jetting, etc to get a car down a given track the fastest (this is why the same car doesn't win week after week at the various tracks).

Generally speaking, as long as an engine has the power to turn the tires over and keep them turning (meaning wheel spin) then higher gearing almost always results in faster launches and acceleration. This is why many racers start in 2nd gear (their bikes easily have the power to keep the tire(s) spinning. Obviously there is a balance between wheel spin and traction - you can have too much spin and essentially loose traction. If the engine bogs at all from getting too much traction on a given surface then it effectively slows you down until the engine gets into the powerband again. In this case, lower gearing helps. You never want too much traction that the engine can't spin the tires.

I have argued with a friend about this many times to the point we have agreed not to talk about it anymore. He seems to think lower gearing always results in a faster launch. I try to explain that it only guarantees that it could pull more weight. In order to understand a theory like this, sometimes you have to exagerate the scenario. Imagine a 2 tooth sprocket on the front and a 200 on the rear. You aren't going to lauch very hard because the top speed the tires could turn at 8000 rpm in 1st gear is just under 1 mph. Pretty easy to tell that a quad with 13/40 gearing at 8000 rpm with tires spinning at 30+ mph in 1st gear will launch quicker.

Just posted this to provoke some thought...I actually enjoy the physics of quads almost as much as riding them.

 

I agree with you. There are subtle differences with all mods. But I would get a stop watch and race both quads with the 12 tooth and again with the 13. This way you can evaluate more accurately. Try taking off in 1st vs. 2nd, etc... Post your findings here!! Now get to it. I need to know!!! [img]i/expressions/face-icon-small-smile.gif[/img]

 

By the way, this is a really cool calculator for figuring out some of the figures used in a previous post.

http://home.earthlink.net/~gellett/mph.htm

You have to enter the Primary Reduction Ratio which is 2.088 on a Raptor (listed on 10-3 in the owner's manual) and the tranmission reduction ratios one at a time (listed on 10-4 in the Raptor owner's manual as gear ratios).

1st - 2.428
2nd - 1.526
3rd - 1.238
4th - 1.047
5th - .904

Stock tire size is 20"

If you enter all this information, it will compute the mph for a given gear at a given RPM.

For example, a Raptor with 13/40 gearing with 20" tires at 7000 RPM would be traveling at 71.77 mph.


Later, gotta go rejet the girlfriends 400ex.

 

NotuRaptor, I have to agree with you on the fact that there should not be a "major" diference between the different pipe set-ups. Lets take HMF and Big Gun for instance. They both look alike, seem to have a 2" direct-flow core(muffler) with two-to-one head pipes. Shape, interior diameter, bend and other variables seem to be almost the same therefore they should produce similar power gains. On the other hand take the DMC which has two seperate headpipes all the way back. That would infact decrease low end grunt but maybe give some more on top because of increased flow. Then there is the disc system which I have not really looked into...

I think it all comes down to a couple "categories" of pipes and it's the airbox(or lack of) and jetting that makes the difference. I ride with my airbox lid on and removed it the other day for a quick ride. I lost tons of low end power but it fealt stronger on top. It seems to depend on the "air-flow setup" that is chosen.

Just my humble opinion...

 

Xplor,

If you take your airbox lid off, rejet, and readjust the carb, you should not loose bottom end. You will definately loose bottom end if you increase air flow without increasing gas flow. I made the mistake of cutting the snorkle flaps out and not taking the time to rejet. Talk about a sick puppy on the low end.

I guess the real synopsis is that no setup has a staggering advantage over another on a stock Raptor engine that rider weight, skill, tires, suspension, etc. couldn't overcome. If you start getting into cam changes, increased bore and/or compression, then there would be an advantage to having a larger pipe.

If you want a pretty pipe then spending the bucks is the only option. The stock headpipe certainly isn't the prettiest one available.

 

1st my post(s) address the subject regarding pipes. And i repeat...i find no significant diffrences. After pondering this futher. i decided to reverse myself. as i recall when i removed the stock muffler it weighed considerably more than my FMF. There it is. theres your benefits.

2nd regarding gearing. NotuRaptor, i love the formula. as far as i can tell your math works. However, i'd be curious to hear what your friend has to say on this matter. Just to satisfy my OCD.

3rd i hate dragging, too many factors can alter an outcome. and you need to repeatedily produce the same outcome over and over before the loser conceeds. Even then, under their breath they will swear they were ripped because of a head wind or one tire had lower pressure than the other. Whatever. I'll stick to moto trail riding and jumping.

Blueleader,
We've done that. matching the same setup quads was the first thing we did. you seem really interested in the CT, so i'll leave you with this. I raced the CT full exhaust against my fmf full exhaust. Both have airbox mods both used pro flo. My jetting is at 150/145 his was something ridiculous like 170/165. BOTH had 12T sprockets ( this confused me because this guy was a dragger, and i would have expected his gearing to be hirer. i keep my gearing for moto.) anyways we did two runs on a dirt road and i beat him by 3ft both times.

We tried to repeat on the grass by i couldn't keep my front end down. He beat me twice as i rode a wheely ( it was the best i could do, it was the end of the day and i was getting exhausted. he was also the more experienced rider and had more control in sliiping the clutch.) there is no timing with stop watches here. we make our mark and race to it. Hope this helps. i'm done with this subject. thanks guys.

 

Raptor660RNH, it took all these posts to get to the point. The CT pipe is too fat for a stock motor!!