sick421 Posted October 17, 2014 Report Posted October 17, 2014 I need some help deciding whether to trade my sb inframe cpis for some sb inframe shearers . I was at the dyno here at D&M racing testing both pipes with my cpis I got 92hp with my ported 421 , with the shearers I got 97 peak hp. The problems is that the cpis had a more broad power curve but less peak hp , the shearers were a little dead in the mid but revved to the moon. On my Seat of pants dyno I really felt the difference the bike felt faster at WOT and the gearing felt longer with the shearers but it lacked in the mid. With my cpis it hit hard from mid to top but the power fell off a little sooner , but it also would get up and go sooner in the band. Would it be a good idea to trade , and have max peak power , im sure in a drag race it would be faster with the shearers , but with the cpis I feel i would get out the hole quicker. Sent from my iPhone using Tapatalk Quote
bluebanshee98 Posted October 17, 2014 Report Posted October 17, 2014 What kind of riding do you do? Quote
dave5.0 Posted October 17, 2014 Report Posted October 17, 2014 Know anybody with a set of snipers? Quote
sick421 Posted October 17, 2014 Author Report Posted October 17, 2014 60% dune 40% drag , no I dont non of the local shees here have snipers i could borrow Sent from my iPhone using Tapatalk Quote
dave5.0 Posted October 17, 2014 Report Posted October 17, 2014 Testing we did on a cub showed the snipers having same of not tad more torque up the face than CPIs and lil more top end than the shearers. Might be a good pipe for what you're wanting. Quote
bluebanshee98 Posted October 17, 2014 Report Posted October 17, 2014 ^ this! Also if your not in a rush there might be some other pipes coming out soon. Could be worth the wait to see Quote
trickedcarbine Posted October 17, 2014 Report Posted October 17, 2014 The CPI's will definitely have more usable power, however they do sign off earlier. The shearers usually rev out further. When I first messed with the shearers, I've found that they liked a very rich needle. Also, does the current set up already have more timing and compression? Quote
sick421 Posted October 17, 2014 Author Report Posted October 17, 2014 Its a 165 psi and +7 timing, yeah i guess il wait to see if i come across some snipers or if new pipes are being made that would be even better Sent from my iPhone using Tapatalk Quote
trickedcarbine Posted October 17, 2014 Report Posted October 17, 2014 Can you post both graphs? Quote
sheerider11 Posted October 17, 2014 Report Posted October 17, 2014 Fir where I ride I prefer the tq. that CPI offer. While it would be nice to have more topend. It's not useful. I don't drag race. I trail with a dune port. So that's why I have the CPI. Style and environment are the deciding factor. Quote
sick421 Posted October 17, 2014 Author Report Posted October 17, 2014 Il get the graph this weekend and post them Sent from my iPhone using Tapatalk Quote
Deadbeat Posted October 18, 2014 Report Posted October 18, 2014 if the cpi got a bit more mid and a bit less legs, why not go up a couple of teeth on the front sprocket post the torque curves too Quote
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