glamisaurus Posted December 19, 2009 Report Share Posted December 19, 2009 My setup: HJR dune port Pro Circuit pipes 33 PWKs Boyeson reeds Timing advance Lightened flywheel Modquad head 21cc domes I dune fast and don't worry to much about drag racing. It seems like the PCs hold the motor back a little on the top end. I did a search and some people say the Shearers have a good midrange while others say topend only. General agreement that the CPIs come on and sign off earlier. I pm'd Kevin to see what he has to say and wanted to get some other input. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted December 19, 2009 Report Share Posted December 19, 2009 pretty much any mid-top pipe will open her up, compared to a mid-low pipe Quote Link to comment Share on other sites More sharing options...
Wildcardracing Posted December 19, 2009 Report Share Posted December 19, 2009 I think you'd appreciate the CPI's over the Shearers for your described application. The Shearers would be a good pipe for a guy who drags most of the time and only dunes occasionally. Quote Link to comment Share on other sites More sharing options...
GNR101 Posted December 19, 2009 Report Share Posted December 19, 2009 ive got the same sorta mods as you.. ive got cpis they work well (i had fmfs b4) the power of the cpis will hit alot later than ur pipes now.. but last forever and is real smooth and controlable u will notice alot of power up in the mid to top of your power range but.. u will loose a lot of bottem i wasnt a fan of the loss of bottem at first but sort of changed my riding style a little.. and now wouldnt go back all in all cpis would be not a bad choice just remember u will loose the bottem Quote Link to comment Share on other sites More sharing options...
06specialedition Posted December 19, 2009 Report Share Posted December 19, 2009 CPI. Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted December 21, 2009 Report Share Posted December 21, 2009 Cpi's all the way. Quote Link to comment Share on other sites More sharing options...
wacko2000 Posted December 21, 2009 Report Share Posted December 21, 2009 You will loose some bottom, nothing to cry over especially if your doing alot of duning If you do loose more than you where whiling to sacrafice, you could always through some more compression and timing at it to make it up Just kno that the delivery is going to be way different than the pro circuits but it isnt anything that you can't get used too. Cpi's are a awesome pipe, I have them on my shee and i basically do alittle of everything. I have 35pwk airstrikers and my bottom end hits real hard Joey Quote Link to comment Share on other sites More sharing options...
glamisaurus Posted December 22, 2009 Author Report Share Posted December 22, 2009 Thanks for the input. I do not mind keeping the rpm up, I just don't want a lightswitch powerband. Anybody tried both pipes on their same bike? Quote Link to comment Share on other sites More sharing options...
AKheathen Posted December 22, 2009 Report Share Posted December 22, 2009 well, most people don't run those pipes and dune porting.......depending on who's definition of a dune port, i suppose.....but that is streatching the limits of the pipe. you can run boysen power reeds for a smoother transition, and keep it at +4 boysen pro would perform better, and crisper. that one mod alone made the huge difference in how the powerband came on... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted December 22, 2009 Report Share Posted December 22, 2009 Talk to your builder. He might tell you a lightened flywheel with his porting and CPI pipes is not a good thing for duning...(Make sure you mention all of that to him) You paid to have him port your motor. Kevin always answers the phone when I call, talk your motor and what you want to do over with him instead of most of us just guessing. And since Kevin's a California guy....he knows where you ride, too... Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted December 22, 2009 Report Share Posted December 22, 2009 Find out your exhaust duration as you could be set up for PCs Quote Link to comment Share on other sites More sharing options...
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