What are everyone's thoughts on big cams and loss of low end?
#13
Resident Retard
iTrader: (31)
Here is the several setups i have run on my 4.8
First was 220/220 .56x/.56x 114+4. I could only cut a 2.0 60ft with this cam, best time was 8.7. Dyno graph showed it pulled to 5800.
Next i added a 222/224 .56x/.56x 112+2. I could only cut a 2.0 60ft with the heads in my sig, best time was a 8.5, this cam peaked at 6000 before heads and 6300 after... I don't have the after graph, i lost it...
Next i switched to the cam in my sig. 214/220 .600/.597 108+2, my best 60ft with this cam was a 1.8, my best time with this cam was a 8.3, this cam peaked at 6600-6700...
So with all that, the amount of overlap really plays into where the rpm band lands and how it performs, also the DCR of the cam also helps with bottom end... And lastly, tuning, mainly spark tuning, is the key to keeping bottom end...
First was 220/220 .56x/.56x 114+4. I could only cut a 2.0 60ft with this cam, best time was 8.7. Dyno graph showed it pulled to 5800.
Next i added a 222/224 .56x/.56x 112+2. I could only cut a 2.0 60ft with the heads in my sig, best time was a 8.5, this cam peaked at 6000 before heads and 6300 after... I don't have the after graph, i lost it...
Next i switched to the cam in my sig. 214/220 .600/.597 108+2, my best 60ft with this cam was a 1.8, my best time with this cam was a 8.3, this cam peaked at 6600-6700...
So with all that, the amount of overlap really plays into where the rpm band lands and how it performs, also the DCR of the cam also helps with bottom end... And lastly, tuning, mainly spark tuning, is the key to keeping bottom end...
#20
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here is a graph of the cam i am looking at getting, the cam is the comp xfi261 http://www.compcams.com/Cam_Specs/Ca...csid=1097&sb=2
the graph is from dezert1500 on gmfs.
here is a thread he made in case you were wondering how it ran and what else he has in it. http://www.gmfullsize.com/forum/showthread.php?t=151586
"Here is my dyno graph. Compare my torque @ 3000 rpm to other dyno graphs out there with larger cams. Remember to add approx 15% to my numbers if your comparing to a Dynojet or Mustang dyno. So 305rwtq corrected at 3000rpm."-dezert1500
the graph is from dezert1500 on gmfs.
here is a thread he made in case you were wondering how it ran and what else he has in it. http://www.gmfullsize.com/forum/showthread.php?t=151586
"Here is my dyno graph. Compare my torque @ 3000 rpm to other dyno graphs out there with larger cams. Remember to add approx 15% to my numbers if your comparing to a Dynojet or Mustang dyno. So 305rwtq corrected at 3000rpm."-dezert1500