grumpyvette
Well-known member
Detonation vs power
some of the major factors in your engines potential power, is the volumetric efficiency (how efficiently you fill and empty the cylinders) and the octane of the fuel used, compression ratio and detonation limits,
With detonation, prevention the main factors are
Ignition timing
Quench
FUEL OCTANE
DCR
and cylinder heat level
you’ll be fairly safe if you stay under
8.5:1 dcr at 170f degrees
8.25 dcr at 180f degrees
7.8:1 dcr at 210f degrees
and keep the quench in the .036-.043 range
heres some differant calculators
http://www.kb-silvolite.com/calc.php?action=comp2
http://www.wallaceracing.com/dynamic-cr.php
http://www.smokemup.com/auto_math/compression_ratio.php
http://not2fast.wryday.com/turbo/compression/cranking_pressure.shtml
average the results
the numbers are for 92 octane premium gas run at a 14.7:1 a/f ratio
BTW heres a VERY SIMILAR GRAPH
richen up the mix to 12.5:1 for max power/tq vs low emmissions and you can cheat slightly as the cylinder temps go down slightly.
keep in mind ALUMINUM absorbs and allows the transfer of heat to the coolant at a much faster rate, so your less likely to have cylinder temps raise into the detonation range as quickly.
and it should be obvious that your igntion curve and spark strength will also effect results, personally Ive found the BETTER MSD multi strike ignitions keep the cylinders cleaner and less likely to detonate
btw, reading material
http://www.kennedysdynotune.com/Dynamic%20Compression%20Tech.htm
http://www.misterfixit.com/deton.htm
http://www.federal-mogul.com/cda/content/front/0,2194,2442_7359_7525,00.html
http://www.diabolicalperformance.com/hotrodoctane.html
http://www.sdsefi.com/meltdown.htm
http://www.procharger.com/intercooled.shtml
http://www.kb-silvolite.com/article.php?action=read&A_id=36
http://www.chevyhiperformance.com/techarticles/94138/
http://racingarticles.com/article_racing-10.html
http://www.popularhotrodding.com/tech/0311em_power_squeeze/index.html
1985,1992,1996 vettes
keep the rubber side down and the fiberglass off the guard rails
some of the major factors in your engines potential power, is the volumetric efficiency (how efficiently you fill and empty the cylinders) and the octane of the fuel used, compression ratio and detonation limits,
With detonation, prevention the main factors are
Ignition timing
Quench
FUEL OCTANE
DCR
and cylinder heat level
you’ll be fairly safe if you stay under
8.5:1 dcr at 170f degrees
8.25 dcr at 180f degrees
7.8:1 dcr at 210f degrees
and keep the quench in the .036-.043 range
heres some differant calculators
http://www.kb-silvolite.com/calc.php?action=comp2
http://www.wallaceracing.com/dynamic-cr.php
http://www.smokemup.com/auto_math/compression_ratio.php
http://not2fast.wryday.com/turbo/compression/cranking_pressure.shtml
average the results
the numbers are for 92 octane premium gas run at a 14.7:1 a/f ratio
BTW heres a VERY SIMILAR GRAPH
richen up the mix to 12.5:1 for max power/tq vs low emmissions and you can cheat slightly as the cylinder temps go down slightly.
keep in mind ALUMINUM absorbs and allows the transfer of heat to the coolant at a much faster rate, so your less likely to have cylinder temps raise into the detonation range as quickly.
and it should be obvious that your igntion curve and spark strength will also effect results, personally Ive found the BETTER MSD multi strike ignitions keep the cylinders cleaner and less likely to detonate
btw, reading material
http://www.kennedysdynotune.com/Dynamic%20Compression%20Tech.htm
http://www.misterfixit.com/deton.htm
http://www.federal-mogul.com/cda/content/front/0,2194,2442_7359_7525,00.html
http://www.diabolicalperformance.com/hotrodoctane.html
http://www.sdsefi.com/meltdown.htm
http://www.procharger.com/intercooled.shtml
http://www.kb-silvolite.com/article.php?action=read&A_id=36
http://www.chevyhiperformance.com/techarticles/94138/
http://racingarticles.com/article_racing-10.html
http://www.popularhotrodding.com/tech/0311em_power_squeeze/index.html
1985,1992,1996 vettes
keep the rubber side down and the fiberglass off the guard rails
