Blower Cam recommendation from Comp...
#13
Originally Posted by BenKey
Right now I have a Comp custom grind, 214/220 .559/.564 116+4. Switching to a FMS cam very soon. Going just a little bigger.
What are the charateristics of the cam you have now? Is there a noticeable bleed off of boost? Do you lose low end and gain it up top?
Wondering when you got the 2.75 pulley....and how your cam reacted to it.
#14
I don't think there was any "bleed off" in boost. Not sure why blown chevy used that term with the LS6 thread, but I don't see it happening. If anything, there would be lower boost in the low rpms because of the increased duration. I don't mean to answer for you Ben, but I think it actually picked up boost from his previous cam on the same pulley size.
#15
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Yeah, 3rd one.
The cam I have now is a good cam. Builds boost extremely fast. I'm not sure what bleed off looks like, but may have a slight bleed off in the upper RPMs just before the shift. My boost peaks before the shift does, then declines some just before the shift -about 3/4 of a pound. I have a digital gauge.
Saw no differences with the 2.75" pulley for the cam. I have gone up a size now in pulleys to a 2.9". Trying to find the optimum setup for the Radix. Think I may have been spinning it past it's optimum operating point. I seem to have picked up power, although have not confirmed. Lost a pound and a half of boost (8.6lbs peak), but have been able to bump my timing up 3 degrees so far to 22 degrees. Still tuning it.
The cam I have now is a good cam. Builds boost extremely fast. I'm not sure what bleed off looks like, but may have a slight bleed off in the upper RPMs just before the shift. My boost peaks before the shift does, then declines some just before the shift -about 3/4 of a pound. I have a digital gauge.
Saw no differences with the 2.75" pulley for the cam. I have gone up a size now in pulleys to a 2.9". Trying to find the optimum setup for the Radix. Think I may have been spinning it past it's optimum operating point. I seem to have picked up power, although have not confirmed. Lost a pound and a half of boost (8.6lbs peak), but have been able to bump my timing up 3 degrees so far to 22 degrees. Still tuning it.
#17
Originally Posted by BigTex
I don't think there was any "bleed off" in boost. Not sure why blown chevy used that term with the LS6 thread, but I don't see it happening. If anything, there would be lower boost in the low rpms because of the increased duration. I don't mean to answer for you Ben, but I think it actually picked up boost from his previous cam on the same pulley size.
Simply relaying information I recieved from the engine builder @ magna charger. When they tested the supercharger kit on the Z06 (LS6) they noticed boost dropping off in the upper RPM range, i.e. "bleeding off boost"
#18
Interesting. I'm going to have to do some research on that.
Whitt1 - thats a big'un. Should make some power. Let us know how 7000 rpms feels in a 5.3 tahoe.
Ben, I'd think that losing a pound of boost and gaining 3* timing is a good trade off. If you can get it up another degree without KR, you are doing something.
Whitt1 - thats a big'un. Should make some power. Let us know how 7000 rpms feels in a 5.3 tahoe.
Ben, I'd think that losing a pound of boost and gaining 3* timing is a good trade off. If you can get it up another degree without KR, you are doing something.
#20
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BigTex - I think I have picked up power with the 2.9" over the 2.75", with being able to add the 3* of timing. Hoping to get more out of it. Funny thing is on my gm/s readings, still maxing them out just as easily.



