As I noted in an earlier blog post, I purchased the Blueprinted Clone Carb from ARC Racing, a moderately priced Honda Clone Performance Part. I was excited to install it but ended up waiting until we got to the track to put it on. The thoughts I had going into installing this carb was that I would see some small performance gains possibly on the bottom end and maybe even on the top end. I was not expecting a large gain, however I was expecting to notice a difference.
My clone motor is completely stock with the exception of a header pipe. I had not even changed the jet size in the carb. The install of the carb was easy. See my blog post on installing the ARC Racing Clone Blueprinted Carb.
The ARC Blueprinted carb has been machined to a larger bore which should allow more air flow. The carb has also been rejetted. I installed the carb and went out on the track. I noticed a small increase in bottom end out of the corners which probably had to do with the larger jet size. I noticed no difference on the top end. My measurements for this was peak RPM at the end of the straight away. I understand that this is not the best way of testing for performance increases but for a $55 carb that you can buy stock for $18 you should at least get a little something out of it.
I would understand not seeing any difference if I was running the AKRA legal header and weiner pipe, but I’m running a full header with RLV, so exhaust is not being restricted upon exit from the motor.
I want to give this carb the benefit of the doubt. There is not much you can do to the carb and still have it legal to race with. The venturi of the carb can not be increased that much. Some of these carbs come from the factory pretty close to the maximum allowed bore. However some carbs can come as much as “.010” under bore, which still is not that much of a difference.
What do I recommend? Check the bore of your carb with a pair of calipers. The max bore according to current 2010 rules is “.615”. On the two clone motors that I own, both carbs are stock bore at “.612”. I should not expect to see any difference out of “.003” change in the bore. However the carb being properly jetted to the pipe and cam I am using did help on the bottom end as noted before. Keep in mind that jet sizes will need to change depending on where you are located in the world. Different climates call for different jet settings. You may find yourself rejetting the blueprinted carb because your climate is must more humid or dry than average.
Is it worth $55? Only if you are racing and want to make sure everything on your motor is maxed out according to the rulebook. A carb bored to “.615” will assure that nobody else has a bigger carb. However if you are ok with jetting your own carb, I think you will be ok with doing it yourself.
Thoughts for the future: I will be leaving the blueprinted carb on that motor. I plan to install the CL1 cam from DynoCams in my clone which should work well with the blueprinted carb.
Product Link: ARCRacing Clone Blueprinted Carb Model #DJ-2225