cam for high elevation
I had a 94 Caprice wagon LT1 4l60e 2.56 in the 8.5" 10bolt, particularly when I got to hilly areas it got better milage in drive than OD. OD was only useful dead level 65+mph. Car NEEDED 3.42 but was a rusty turd so I didn't bother.
Enough gear to keep an engine from lugging benefits not only performance but milage. Another thing to consider is when looking at a cam a 210/216 cam on 110 might have less overlap than a 228/234 cam on 113.
Overlap can help power and shouldn't be feared except when sniffer testing is a worry, when staying mild on displacement and looking at custom cams be prepared to hear a tighter LSA than you typically see guys discuss when going more duration.
Enough gear to keep an engine from lugging benefits not only performance but milage. Another thing to consider is when looking at a cam a 210/216 cam on 110 might have less overlap than a 228/234 cam on 113.
Overlap can help power and shouldn't be feared except when sniffer testing is a worry, when staying mild on displacement and looking at custom cams be prepared to hear a tighter LSA than you typically see guys discuss when going more duration.
Formerly 2001c3driver-7/31/10
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From: Santa Fe New Mexico
Cool- I'm still doing the camshaft study. We don't have emissions testing here- at least not yet; honestly, if I can get on the bubble more easily I'd be a lot happier. Tuning(HP Tuners) has made a good difference but can only go so far. When I got my 96 Impala SS when I lived in Chicago it ripped, shifts where crisp and it put my 2001 Sierra to shame and I swore I was gonna swap valve bodies from truck to Impala. But tuning changed all that.
After moving back here to 7000 ft everything is decimated; The Lady(Impala) doesn't have that big edge over my 2006 Sierra as it seemed to have over the 2001.
Well- anyhow, 3.90's are first on the menu; I don't think this will be a real big compromise as doing the math bears out 2.40;1 with 3.42's O.D. to 2.73;1 with 3.90 O.D. That and the spacing of the gears should be tightened up as well...................
After moving back here to 7000 ft everything is decimated; The Lady(Impala) doesn't have that big edge over my 2006 Sierra as it seemed to have over the 2001.
Well- anyhow, 3.90's are first on the menu; I don't think this will be a real big compromise as doing the math bears out 2.40;1 with 3.42's O.D. to 2.73;1 with 3.90 O.D. That and the spacing of the gears should be tightened up as well...................
Formerly 2001c3driver-7/31/10
iTrader: (1)
Joined: Mar 2007
Posts: 901
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From: Santa Fe New Mexico
I heard about the servo ad nauseum and concluded it's not necessary right now(actually just never got to it), but with tuning the shorter shift times and dialing down the TM have really livened things up. I never did get to tuning my 2001 until waaaaay later which made quite a SOTP difference...............
Last edited by 2001 Sierra; Dec 25, 2014 at 08:13 AM. Reason: Truth
