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[Para Bellum]

Hoping some of the professionals will weigh in here.  Do you need to have the cam's specs to do a dyno tune?

Edit:  For most cams, if the tuner knows which cam it is, they can get the specs.  This question is for situations where they can not get specs.

[Ridgerunr]

Not a tuner. Since 2004 I've been through more than a few cam changes (7 to be exact, 2 bikes) tuners never asked for spec's.

[Para Bellum]

Not a tuner. Since 2004 I've been through more than a few cam changes (7 to be exact, 2 bikes) tuners never asked for spec's.

Did they know which cam was in the bike?  If they did, for most cams they can get the specs.  I'll edit my first post's question to cover this aspect.

[Fullsac Performance]

Hoping some of the professionals will weigh in here.  Do you need to have the cam's specs to do a dyno tune?

Edit:  For most cams, if the tuner knows which cam it is, they can get the specs.  This question is for situations where they can not get specs.

An experienced tuner will always want to know what the cam specs are before the dyno. A lot of dyno time can be saved by prepping the base map properly for the predicted power output. An example would be a stage I 110" stock cam dyno tune VS Stage II with mild cams. The stock cams will tune with the displacement set at 110". Most stage II cams will require the displacement to be increased to about 115" to have enough fuel. Finding out your VE numbers are maxed out at full throttle after you have VTuned for an hour can get real frustrating. Once you increase the displacement you start all over again. VTune 3 actually increases the VEs for you if they get maxed out. It can still set you back time wise.

SG

[Para Bellum]

An experienced tuner will always want to know what the cam specs are before the dyno. A lot of dyno time can be saved by prepping the base map properly for the predicted power output. An example would be a stage I 110" stock cam dyno tune VS Stage II with mild cams. The stock cams will tune with the displacement set at 110". Most stage II cams will require the displacement to be increased to about 115" to have enough fuel. Finding out your VE numbers are maxed out at full throttle after you have VTuned for an hour can get real frustrating. Once you increase the displacement you start all over again. VTune 3 actually increases the VEs for you if they get maxed out. It can still set you back time wise.

SG

Thanks for the explanation.  Exactly what I needed to understand why the tuner needs cam specs up front.

[Ridgerunr]

I always gave specifics of my build to the tuner, displacement, cam make and lift, squish (.030" for example), compression ratio, throttle body size, but never was asked for intake/ exh. opening/closing, lift @ TDC, lobe separation, Lobe center, duration or overlap, which are what I consider cam "specs". Maybe the tuners looked all of that up themselves.

[hrdtail78]

My reason for wanting them is compression.  You can tell me 10.5:1, but is that 10.5:1 with a cam that closed in the 50's or 30's?  More info you can give to the tuner the better.