DCR vs SCR vs Octane
#1
DCR vs SCR vs Octane
i am curious about this subject as many ppl are. i figured that i could gather some data from a sample group and plot the data to see what kinds of interesting things i get. i will post my finding here so that you can see them too. i will let collecting of data run for about two days, and once it's over i will process it and present my findings.
so to help me out i would like a few things from you
what is your DCR?
what is your SCR?
what temp does your engine operate at?
bore and stroke?
what octane you use without any issues?
so to help me out i would like a few things from you
what is your DCR?
what is your SCR?
what temp does your engine operate at?
bore and stroke?
what octane you use without any issues?
#5
Moderator
iTrader: (20)
Originally Posted by RomulusSmallBlock
i am curious about this subject as many ppl are. i figured that i could gather some data from a sample group and plot the data to see what kinds of interesting things i get. i will post my finding here so that you can see them too. i will let collecting of data run for about two days, and once it's over i will process it and present my findings.
so to help me out i would like a few things from you
what is your DCR?
what is your SCR?
what temp does your engine operate at?
bore and stroke?
what octane you use without any issues?
so to help me out i would like a few things from you
what is your DCR?
what is your SCR?
what temp does your engine operate at?
bore and stroke?
what octane you use without any issues?
#7
Originally Posted by jmm98LS1
Wow...8.97 DCR on pump gas .....awesome.
Last edited by RAACCR; 05-17-2007 at 12:29 PM.
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#8
Originally Posted by RAACCR
11.36:1 SCR
8.97:1 DCR
160's highway, 170's around town
Stock LS1 bore & stroke
93 octane (in hot & humid South Florida)
8.97:1 DCR
160's highway, 170's around town
Stock LS1 bore & stroke
93 octane (in hot & humid South Florida)
i have graphs if someone tells me how to post them it will be done. i made trend lines for both and as soon as i figure out how to do a trend surface for 3D plots i will post that data (i think is more promissing)
DCR vs Octane trend line: f(x)= -.0252x^2+3.915x+59.906
x is DCR and f(x) is octane
SCR vs Octane trend line: f(x)= -.0631x^2+3.3908x+62.85
x is SCR and f(x) is octane
what i found to be interesting are engines that when using the trend lines for both DCR vs Octane and SCR vs Octane that their Octane usage was the same.
example:
DCR= 7.68 and SCR= 9.11 its octane requirement is 88.5. RAACCR's engine is an other good example of this too. the LS1 the i built requires 91 for both as well (purely accidental). hower, i was doing this research to help a build on a old school 388 chevy for my friend. i purposely made the DCR and SCR requirements the same (89 octane).
what makes this interesting is that its DCR complements its SCR. it kind of begs the question: does this complementation improve HP and torque?
#13
The time limit i posted it up, so here are the findings.
The finding for DCR vs Octane
Aluminum and Iron combined
Iron only
Aluminum only
The findings for SCR vs Octane
Aluminum and Iron combined
Iron only
Aluminum only
The finding for DCR vs Octane
Aluminum and Iron combined
Iron only
Aluminum only
The findings for SCR vs Octane
Aluminum and Iron combined
Iron only
Aluminum only
Last edited by RomulusSmallBlock; 05-18-2007 at 01:43 AM.
#15
UNDER PRESSURE MOD
iTrader: (19)
Originally Posted by ProjecT 9
so does it tend to read high or low?
Back to the topic at hand, my SCR is 11.27, and DCR is 8.88 and can run 91 or 93 without a problem. I do run a lot of timing though, I max out at 27 degrees but mostly it's 24-26 degrees. Most tuners will tell you that too much timing will only hurt but doesn't help much. The difference between running 24 and 28 degrees might be 2-4hp, but as soon as you get knock, it will pull lots of timing anyway. So a safer tune of 24-26 degrees is better.
I ran a 160-tstat last year for the power tour because I was in stop and go traffic all week long and never saw temps above 175. I've since switched back to the stock t-stat and hover right around 190. Gotta realize that our motors like to run hotter because it helps to burn cleaner and make more power. I saw no difference in performance running 20 degrees colder temps and my mileage went down 2 mpg.