08 CamShaft question


2 replies to this topic
  • Ga426owner

Posted August 13, 2007 - 05:25 AM

#1

I was reading several mags and some other sites over the weekend on the lack of power a lot of people are discussing on the 08
It seems that the new Cam Shaft may be to blame for this. Apparently the 06/07 have the same cam shaft. The lobe produces a 106 degree of cam timing. On the 08 the lobe produces a 100 degree of timing to increase throttle response but it also tames the hit/bark. I would think the owners would want to consider a aftermkt camshaft from Crower/RHC/HotCams etc...to get the hit back. :thumbsup:

thoughts??

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  • Mutu

Posted August 13, 2007 - 06:44 AM

#2

I think it is the muffler, not the cams.....

  • grayracer513

Posted August 13, 2007 - 02:45 PM

#3

The muffler contributes, I'm sure, but a lot of it is cams.

The '06 and '07 do not have the same cams, however. The '03-'05 all used the 5TA-12170-00-00 and 5TA-12180-00-00. The '06 used 5TA-12170-10-00 and 5TA-12180-10-00, and the '07, 5TA-12170-20-00 and 5TA-12180-20-00. In all cases, given the part numbers, I would guess that the lobe profile is the same or nearly so, and the main difference is in the timing.

GA, the numbers you are quoting would likely be lobe center measurements. That's the distance in degrees of crankshaft rotation between point where the centers of the lobes on the intakes and the exhausts are over the valves. For a read on the effect of changing this, check this out:

http://www.muzzys.co...be_centers.html

Upshot: replace the cams with ones from an earlier model and change the character of the beast, OR, have competent engine shop re-index your existing cams, OR, go aftermarket.

You might also find that you get something out of modifying the ignition map (say, Vortex)





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