So I've got a trick-flow trackMAX stage 1 cam, like some of you guys, and I'm wondering what your idle is like. Mine is somewhat rough and a little lopey. I'm trying to decide if it's a characteristic of the cam, or if I've got some sort of problem.
Totally normal...
It won't be happy till you bring up the in gear idle to around 850-900 RPMs...
Yeah you're going to want to up the idle in the 850rpm range in drive. Any idea how much vacuum the engine has? The cam specs out as follows:
Duration at 050 inch Lift: 221 int./225 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.499 int./0.510 exh
I would think it should make around 14" or so of vacuum at hot idle. For example here are the specs on the cam in my Thunderbird:
Duration at 050 inch Lift: 210 int./215 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.533 int./0.533 exh.
About 10* less duration on the intake/exhaust side but much more lift. Idles great with a slight lope at 650rpm in drive and 700rpm in park. It has 17" of vacuum at hot idle.
I'll get my laptop out and try that tomorrow. The duration will have a noticeable effect on vacuum. When I get the chance, I'll measure it.
Raised the idle a couple weeks ago, God I really love tuning with a Quarterhorse and TunerproRT. Idle is smoother, I lowered back down some and settled on a target RPM of 825. Raising the idle actually increased my vacuum to about 14 inches, which among other things, has my brake booster somewhat happier. Thanks for the help, I still have to get on a dyno for tuning, but my street tuning is good enough to wait for next summer.
Glad to hear it worked out!
I still have to tune mine. I know there is probably 10-20hp that can be unlocked with a tune. The thing just runs so well that I really haven't been in a hurry to spend the cash to tune it.