I'm going to have to race my CRF 450R (2004) for another season and I want to get more low end power out of it. I'm trying to come up with the right set-up. I was looking at just putting a cam in it, ( Hot Cam Stage 1 or 2 ) or a high compression piston and a cam. Maby a pipe? I'm thinking I would like to stay away from a big bore. Any suggestions?
More low end power for my CRF 450R
- Thread starter Woods428
- Start date
The best low end combination we've seen on the 04 CRF is the high compression Wiseco piston and the Thunder Alley slip on pipe. The Stage 1 Hot Cam works really well but I would suggest trying the piston and pipe first to see if you get the results you want and if not, it takes less than an hour to pop a Hot Cam in .
We aim to please. :)
- Thread starter
- #5
I do have another question. Do I need to run race fuel with a high compression piston? Some people at the track say yes and some say no. Some say change the ignition and or timing. (not thrilled about either one of those). What do you think?
Thanks,
Thanks,
Race fuel isn't necessary on the Honda. The combustion chamber is efficient enough and the intake valve closes late enough to bleed off plenty of compression pressure to run on pump premium. The exception would be extremely hot +100F days with very low humidity. In those cases running at least 50/50 pump to race fuel would be a good idea just to give yourself some margin for error on your jetting.
Take a look at the following thread for a little more info :
http://www.dirtrider.net/forums3/showthread.php?p=839213#post839213
Take a look at the following thread for a little more info :
http://www.dirtrider.net/forums3/showthread.php?p=839213#post839213
Maybe I'm imagining things, but my 04 CRF 450 gets a noticible boost in low-end when I run 110 octane race gas. It might be because pump gas is 10% alcohol here in the big city. I also went one tooth larger on the rear sprocket and it eliminated all of the flat spots between gears. Alot of racers go two teeth larger on the 04 because stock gearing is really high for MX.
Shig said:
I didn't say the CRF wouldn't run better on the proper race fuel. They always have better response and make more high rpm power with the proper race fuel so you probably aren't imagining it.
If someone is looking to save money and is willing to accept the trade offs running pump premium is SAFE, just not the optimal setup. ;)
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- Thread starter
- #9
Shig,
Thank you for your input. I have never tried race fuel, maby I should. If you dont mind me asking, what kind of race fuel did you use. I did gear it down and that did help. But I think a person can only gear it down so far untill you hit a point of diminishing returns.
I think I'm at the point of just wanting more power. Or at least a change in power. I did call the guy at Thunder Alley. That pipe sounds like the best bang for your buck. He made it sound as if I would not see a loss of mid and top end power and still get the low end boast I'm looking for. I think I will also go with a high compression piston.
Thank you for your input. I have never tried race fuel, maby I should. If you dont mind me asking, what kind of race fuel did you use. I did gear it down and that did help. But I think a person can only gear it down so far untill you hit a point of diminishing returns.
I think I'm at the point of just wanting more power. Or at least a change in power. I did call the guy at Thunder Alley. That pipe sounds like the best bang for your buck. He made it sound as if I would not see a loss of mid and top end power and still get the low end boast I'm looking for. I think I will also go with a high compression piston.
Hey Woods,
I've been getting 110 octane race gas at my local Shell station. One of the local tracks sells another brand, Phillips 66 I think, that works great too. It costs about $5.50 per gallon, but I often mix it with pump premium for practice sessions. As Rich just said, the bike runs better and is more responsive with the race sauce. It seems to start easier too.
I hear you loud and clear about gearing. I made the mistake of going too low on my 02 CRF. I was shifting way too much. I'm keeping my 04 through the 05 season, so I'm interested to hear how any uprades work for you.
I've been getting 110 octane race gas at my local Shell station. One of the local tracks sells another brand, Phillips 66 I think, that works great too. It costs about $5.50 per gallon, but I often mix it with pump premium for practice sessions. As Rich just said, the bike runs better and is more responsive with the race sauce. It seems to start easier too.
I hear you loud and clear about gearing. I made the mistake of going too low on my 02 CRF. I was shifting way too much. I'm keeping my 04 through the 05 season, so I'm interested to hear how any uprades work for you.
Woods428 said:
Definitely. The Honda headpipe is an excellent design and complements the Thunder Alley slip-on really well. My guess is that Bob Murray from Thunder Alley would probably say the same thing. He's a real honest guy who has a reputation for only selling people what they need even if he makes less money as a result. :cool:
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