Cruise timing...
#1
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Join Date: May 2006
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Car: 1990 Corvette
Engine: 415
Transmission: six speed
Axle/Gears: Dana44 3.73
Cruise timing...
hi all
i have done some searching, but didnt find a mathcing answer, maybe there isnīt one...
anyways, now that everythign is working, i want to give my cruising a last finish...
what is interesting, my blms are very good, except in the cruising area where i read always very lean, only at around 2000rpm and 40-60kpa, although Wbo2 shows good numbers...below and above this rpm and kpa, everything is ok.. (accoding to DM histogram)
i run around 40° timing, in this area, i have some bucking too under these light loads, maybe thats too much SA..
also noticed, another .bin with less timing seems to be easier to drive
should i go down with timing?
is there a sweet spot for cruising with AFR 195compport heads, 11:1 comp and single plane, 236/240° 110 cam?
thank you
i have done some searching, but didnt find a mathcing answer, maybe there isnīt one...
anyways, now that everythign is working, i want to give my cruising a last finish...
what is interesting, my blms are very good, except in the cruising area where i read always very lean, only at around 2000rpm and 40-60kpa, although Wbo2 shows good numbers...below and above this rpm and kpa, everything is ok.. (accoding to DM histogram)
i run around 40° timing, in this area, i have some bucking too under these light loads, maybe thats too much SA..
also noticed, another .bin with less timing seems to be easier to drive
should i go down with timing?
is there a sweet spot for cruising with AFR 195compport heads, 11:1 comp and single plane, 236/240° 110 cam?
thank you
#2
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Re: Cruise timing...
My afr combos never like that much timing. I only ran 35-37 deg in spots like that. May have abit to much timing.
Also that could be a bad rpm for cruise with that cam. It may be reversion issue as overlap is high. Cam is starting to move into powerband but struggling at that point. It may want more fuel, but likely less timing. My current big cam car also did not like 1900-2000 rpm
Also that could be a bad rpm for cruise with that cam. It may be reversion issue as overlap is high. Cam is starting to move into powerband but struggling at that point. It may want more fuel, but likely less timing. My current big cam car also did not like 1900-2000 rpm
#3
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Join Date: May 2006
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Car: 1990 Corvette
Engine: 415
Transmission: six speed
Axle/Gears: Dana44 3.73
Re: Cruise timing...
My afr combos never like that much timing. I only ran 35-37 deg in spots like that. May have abit to much timing.
Also that could be a bad rpm for cruise with that cam. It may be reversion issue as overlap is high. Cam is starting to move into powerband but struggling at that point. It may want more fuel, but likely less timing. My current big cam car also did not like 1900-2000 rpm
Also that could be a bad rpm for cruise with that cam. It may be reversion issue as overlap is high. Cam is starting to move into powerband but struggling at that point. It may want more fuel, but likely less timing. My current big cam car also did not like 1900-2000 rpm
hi and thank you!
its indeed not a good rpm for cruising, above 2200 it works ok...
maybe i was not exact im my first post, i run about 38° in this area, the 40° come at higher rpms...
anyways, lowered the timing a bit, the car drives a lot smoother now, also reduced the prop gains to 75% or the stock values...
BLMīs are tolerable, most of the time 122 to 132, only sometimes when coasting down, they go up to 150, but comes back immediately when hitting the throttle...
engine takes gas nicely, also consumes a good bit,...
what gives me a bit concern is, how long will the cats last...they are spun metallic type, and get very hot...i have heat reflectors and insulation, so no trouble here, but still, the get very hot...
i also dont see any chance to change sth here, i think, this is due cam overlap...
greatings...
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