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CPI vs Shearer


kshoulde35

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No pipe dyno thread will ever get followed through...it can't be.

Different pipes like different motor characteristics...

We could take 20 motors, dyno them all side by side.  Half might like one pipe, the other half might like another.

 

Pipes are a very, very small part of an overall winning package.

 

But they're the firestarter for pretty much any thread on here.

 

Pipe A. vs. Pipe B, it's all you need for 100 pages of chest thumping, and about 80% of them have never been down a drag strip or organized race to where the last nth of HP is important.

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I have a pic of two slips from last season comparing the 2. Their in my gallery under drag bike. The runs were about 20 minutes apart.<br /><br />Sent from my SGH-T679 using Tapatalk 2<br /><br />

 

 

thanks for that info nightmare.. could you share more details on the overall setup... fuel, carbs, motor, port timings ?

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Stock stroke/stock Cyl, 35mm pwk's, 91 pump gas, +4 timing, backyard port job lol, stock frame on struts +6 swinger, lockout/mmatv hd clutch. It put out 86 on the dyno at sea level but I'm at 5000ft now. I was also 245lbs when I made those runs and made NO jetting changes, pipe swap and go. I'll be comparing cpi and shearers along with another unknown name set of pipes this Friday. <br /><br />Sent from my SGH-T679 using Tapatalk 2<br /><br />

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I just called my motor guy and I'm just waiting for him to call me back but I want to say it was shearer. We're at a different track this year and its about 500ft higher than the old one, I'm sure that will have some affect?<br /><br />Sent from my SGH-T679 using Tapatalk 2<br /><br />

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Ok, it was shearer that he talked to but used 35mm carbs instead of using 33's like Mat suggested. With the changes he's making now (port timings and domes) it SHOULD run better with the shearers.<br /><br />Sent from my SGH-T679 using Tapatalk 2<br /><br />

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Who has some actual time slips to compare the two? not dyno sheets... with the cpi's liking more exhaust duration and reportedly having a front side curve what kind of et's are they laying down against the shearers who seem to be dyno queens.

 

FFS

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Ok, I'll post the slips when I get home tonight but it was the cpi's all day long over the shearers. I know that all motors are different of course but this one likes the cpi's. So for the hell of it we compared them on a bike that's stock other than 28mm carbs and pods and it liked the cpi's also. So there:D<br /><br />Sent from my SGH-T679 using Tapatalk 2<br /><br />

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Ok, I'll post the slips when I get home tonight but it was the cpi's all day long over the shearers. I know that all motors are different of course but this one likes the cpi's. So for the hell of it we compared them on a bike that's stock other than 28mm carbs and pods and it liked the cpi's also. So there:D<br /><br />Sent from my SGH-T679 using Tapatalk 2<br /><br />

Just a suggestion, but, um, if your builder built your motor specifically to run with shearers, and it runs better with CPI's, I'd say it's time to find a new motor builder.

 

 

 

just saying

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