do you really need back pressure with a drag pipe--or can you just have some straits coming out and turning down to the ground

 

Drag pipes, can be a tricky thing. You really need to biuld a drag pipe after you have biult your motor. The drag pipe should be "taylor-made" to match your motors strenghts.


Most biulders will biuld thier own versions of drag pipes to suite thier particular engine parts( HPR, RWR, CRAYCRAFT, KENZ, etc etc.)




DSmike and I had custom drag pipes made by a gentlemen that made Headers for indy cars. and also biuld Nitro-Harley motors. DSmike went through several different configs before he found a couple that worked really well(one in-frame and one out-of-frame) . I still have one set, he sold his set.

If your ever up this way let me know, I would like to see if it works on other motor configs aswell as it worked on my motor.





Bigger.

 

You guys need to check with some folks that actually run them.

 

????



I have ran them, and did so with alot of success.



Bigger.

 

Thats cool. I just wish more people would chime in that actually use them. I think the differences are huge. I had people tell me that some of them produce 7hp on the bottom and a huge increase in speed on the top over the standard RWR exhaust. I think that specific user results in low, mid and high as well as top speed should be posted.

 

Im sure there will be different gains on different motor builds. But, I currently run a HPR drag pipe on a bone stock motor. I could definitely see the difference when running this pipe with the stock carb. I would say that back pressure plays a roll in the amount of horsepower that can be gained from any engine...from stock to modded.

 

I would also like to see the #'s. Drag pipe is my next step.

 

I was having my HMF rewelded, and decided to take a spin with just the header on...I figured since my hmf is pretty old with a LOT of hours on it (and fully open) it wouldnt get TOO much louder... O HOW WRONG I COULD BE! With a helmet on my ears hurt. I loved the sound (besides the loud part) and it gained about a bike length more than usual over my buddies yfz.

Seems like more builders would want to create a drag pipe that worked with their setup as it seems even if it isnt tailor made for your setup, they still produce more power.

 

You dont need back pressure at all. The trick is to control the speed at which exhaust goes out the pipe.

 

Drags pipes are loud, there is no doubt about it. When I decided to get one it came down to the two current pipes, and I wanted inframe. On my bike, that I have only ran it one day, and I havent got it fully dialed in, I gained, compared to stock exhaust with end cap, about the same that I lost from the ron woods pipe I use to run, its about the same gain you get in the low end with a end cap, then after that she starts flowing. In the mid she pulls hard and keeps going until you have no more rpms. Compared to the ron woods full pipe, this is an entirely different animal. My rwp sucked butt in the bottom, bad. I lost all ability to wheely. She flowed good on the top, but in comparison, My fastest hill time with the full pipe was 51.4 mph. With the drag pipe I now pulled a peak of 56, and a even pull of 54! THats a huge gain for just a pipe. You dont notice this as much on all motor, but with nitrous its a different ball game. The HPR 5 cams I run just couldnt breath because of the pipes, then I got this thing on and besides killing you ears, holy crap hold on. I think with some more tuning the 56 should be easy and going for the 60 mark. Oh thats on the fourstroke hill in Utah, which is comparable to sand mt. nevada. On our other bike with hpr 4 cams, it made all the difference in the world from having the stock with end cap. It just opens a whole new realm.