Outler limits of DCR?
05-06-2007, 04:34 PM
#1
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Outler limits of DCR? Ok everyone, I've been experimenting with DCR for a while, the last one built (L92 headed LS2) was the highest yet for a DD, @ 8.92:1. It had .040" head gaskets, and an 11:1 scr. Stock heat range plugs, stock hot-as-**** thermostat, stock mufflers, and stock CAI. ambient MAP was 97kpa, WOT low-rpm was 96 KPA and high-RPM MAP was 93-94 KPA.
I'm starting to get a little leary on increasing DCR even further, but so far this high compression stuff works deceivingly well. I'm considering doing another 92 octane pump gas motor and breaking into the low 9:1 territory but wanted to consult first.
1. Which is less prone to detonation, reaching a DCR goal with SCR or valve events?
2. Realizing there are many factors, which makes more power @ a given RPM? (assuming cylinder pressure is constant), is there even a difference?
I'm thinking if pressure is pressure (lets say @ x RPM), the larger combustion chamber would yield marginally greater results.
I'm starting to get a little leary on increasing DCR even further, but so far this high compression stuff works deceivingly well. I'm considering doing another 92 octane pump gas motor and breaking into the low 9:1 territory but wanted to consult first.
1. Which is less prone to detonation, reaching a DCR goal with SCR or valve events?
2. Realizing there are many factors, which makes more power @ a given RPM? (assuming cylinder pressure is constant), is there even a difference?
I'm thinking if pressure is pressure (lets say @ x RPM), the larger combustion chamber would yield marginally greater results.
05-06-2007, 07:26 PM
#2
You might get a better response to this thread in the Advanced Tech Forum. As far as your question I have heard of very few running that DCR on pump gas. From my understanding it is all in the tune. I would run the TR6 plugs with the 160 thermostat for starters.
05-06-2007, 07:43 PM
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The information about the thermostat and plugs was more to make the point that since this car didn't have any knock, maybe the DCR guidelines need to be revisited. There's nothing wrong with the car, it hauls ***!
05-06-2007, 08:02 PM
#5
Originally Posted by stevewix
The information about the thermostat and plugs was more to make the point that since this car didn't have any knock, maybe the DCR guidelines need to be revisited. There's nothing wrong with the car, it hauls ***!
That is not what I was implying. I meant for the new motor I would swap those things out for the cooler setup. Sounds like your current setup is spot on.
05-06-2007, 08:07 PM
#6
Originally Posted by stevewix
I'm thinking if pressure is pressure (lets say @ x RPM), the larger combustion chamber would yield marginally greater results.
05-06-2007, 11:35 PM
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Originally Posted by Beast96Z
Actually, the smallest, effective combustion chamber you can run is best. Hence the reason C5-R stuff is like 35cc's.....
Agreed, in this case by combustion chamber; I'm referring to the assembled engine (deck height, head CC and gasket thickness).
