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Split Durations

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Old Dec 27, 2009 | 11:39 AM
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Default Split Durations

While conversing with my tuner on Saturday, I mentioned TR 590g and TR-625g cams. He stated they are split duration and as a result, they are tough to tune in?????? especially with the PCIII i have my 103 UC. He claimed if installed, my bike may have decel popping issues, that will be tough to work out. Normally he's done a good job tuning but with his comments about the two cams, I am a little curious about his knowelge. I have a Woods 8 standing bye, but with that, as Scott suggested I need to jump my compresssion of to 10:8.


Just for learning purposes, All comments are welcomed.
 
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Old Dec 27, 2009 | 12:53 PM
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Bad

to me split duration cams are for known issues with the intake or exhause designes or systems. Mostly for the exhause.

Goes back. For instance the old Ford v-8's liked them for longer exhaust duration cause the exhaust ports for those old engines were restricted some. Helped there.

Lots of other examples. Chevy never had to use them really.

Time you get the porting done for these TC's and a good exhaust system I don't think they are needed. For most normal street use up to pretty wild.

Just me.
 

Last edited by Old Gunny; Dec 27, 2009 at 12:55 PM.
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Old Dec 27, 2009 | 01:44 PM
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Default Split Durations

Interesting,

Thanks Old Gunny.
 
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Old Dec 27, 2009 | 03:05 PM
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your talking 2degrees of duration being split . from talking to dave and dave tunes a lot of TR stuff he never once stated they were hard to tune ads a matter of fact they tune up real nice . send me your e-mail and i will send you a few dyno sheets. you can print them out and show them to your tuner. and then maybe have him call dave or Joe from joes cycle repire in Ny as he has no problem tuning them either. its not the arrow its the indian.
 
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Old Dec 27, 2009 | 03:36 PM
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Default Split Durations

I love it!

Thanks George, the address is comming Via PM.

Phil
 
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Old Dec 28, 2009 | 06:04 AM
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I do know that some of the cams out there with split lifts/durations are a real bear to tune, especially with a D&D Fatcat. Doc, and I spoke about this recently. No names mentioned, but it was not TR's cams.
Scott
 
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Old Dec 28, 2009 | 08:17 AM
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I argree wih both George & Scott on this.

My tuner likes tuning TMan setups Because they are NOT as "finiky" as some other configs which makes them "easy" to tune.... Not to mention it's easier for him to ensure a happy customer when he sends them out the door with great results and the infamous dyno sheet.
 
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Old Dec 28, 2009 | 09:04 AM
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Default Split Durations

I'll interview a different tuner, it's kinda of a drag as their are only three or four tuners here in SND, two have already been ruled out. If anyone that may be reading this post, knows of a top notch tuner in Southern California, either in Orange County or south of it, please PM me.

Thanks to all, as always I appriciate the info.

BD
 
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Old Dec 28, 2009 | 11:26 AM
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Don't know how far you are from Hayward, but Bob Lobenburg, that tunes out of RC Cycles, is absolutely top-notch.
Scott
 
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Old Dec 28, 2009 | 03:12 PM
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Thanks Scott,

He's by San Fran. A little TOOOOOOOOOOooooooooo far for me at the moment, that's a cold ride, this time of year.

Phil
 
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