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compression ratio?
- Thread starter wqcode
- Start date
ontGetIt:
TURBO1
Super Cool Member
It will to point, but there's many factors, that contribute to this as fuel octane, boost, timing,etc. I believe this LC2 engines are 8:1 stock at least for the TTA.
(please correct me if I'm wrong on any thing) I've also read on the LC2 engines, GN,GNX,TTA,etc. For every 15psi of boost, its equal to double the engines displacement. I.E. 231cu.in.+15psi= 462cu.in (Big Block power out of a 6cyl). Imagine with 20+psi & alky w/race fuel. No wonder these cars kick !@#$% on the track. Its all power to weight ratio.
(please correct me if I'm wrong on any thing) I've also read on the LC2 engines, GN,GNX,TTA,etc. For every 15psi of boost, its equal to double the engines displacement. I.E. 231cu.in.+15psi= 462cu.in (Big Block power out of a 6cyl). Imagine with 20+psi & alky w/race fuel. No wonder these cars kick !@#$% on the track. Its all power to weight ratio.
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jarredsoon
Gold Member
Is that the way to go,.... alky AND race gas??? I always run pump gas in my car with alky..... would I have to get a new chip for running alky and race gas ( c16) or could I just turn up the boost and go??
WHat do you guys think???
Jarred.
WHat do you guys think???
Jarred.
TTA976
Silver Member
If you have a TT chip or a Commander chip you can increase the timing. But be careful... Erics alky chip run 23* and 21* of timing. But, he does a little someting xtra w/ his alky chip as far as when the alcohol is sprayed at lower boost. I'd would just send it back for a reburn.
Never had an alky kit but Quiky ran 11.1XXX w/ 91 octane and alky.:cheers:
If it were me, I'd run C16 or Q16... and have the alky on for extra insurance. Anyway, with that being said, I will never be as fast as Jason.
With C/Q16 no Alky is required IMO......26 degree's of timing in all gears and lots-O-boost you'll have all the octain you'll need.....I think the factor will be between race gas and pump gas w/alky will be the burn rate of the fuel. The street gas (aka camel pee) has a higher or better burn rate..the alky will give the cooling effect of the AIT and will suppress detonation very well (allowing the extra timing and boost)..but if i was going to run big timing and boost in all gears at the track i would shut the alky off and run C16 now.....I had good luck also with C12 back in the day also (TE45A stock motored 26 degree timing and 28lb's of boost):cheers:
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El Dee Bee
Active Member
You mentioned CR, but what we are really talking about here is cylinder pressure, and it's simple arithmetic. Our Engines take a given amount of cylinder volume at the bottom of the stroke, essentially at atmospheric pressure, and compress it to 1/8 the volume. This is about the same as increasing the pressure by a factor of 8. When U have forced induction (Turbo or SC), U increase the pressure of what's coming in - it's no longer at atmospheric pressure - and then U increase that pressure by a factor of 8.
Atmospheric pressure @ sea level is ~ 15 Psig. If U boost 15 more #, now U have doubled the inlet pressure and also the outlet pressure. U have also ~ doubled the Lbs of Air + Fuel, which will roughly double your power. It will be kinda like doubling the CR, except for the fact that when U compress the Air/Fuel mixture U do heat it up a little bit, which will take away some of your increased mass of power mixture. That's why U add an Intercooler to try to limit this takeaway.
This is simplified, because whole books have been written on the precise details of this subject, but hopefully it explains the principle of what's going on.
Atmospheric pressure @ sea level is ~ 15 Psig. If U boost 15 more #, now U have doubled the inlet pressure and also the outlet pressure. U have also ~ doubled the Lbs of Air + Fuel, which will roughly double your power. It will be kinda like doubling the CR, except for the fact that when U compress the Air/Fuel mixture U do heat it up a little bit, which will take away some of your increased mass of power mixture. That's why U add an Intercooler to try to limit this takeaway.
This is simplified, because whole books have been written on the precise details of this subject, but hopefully it explains the principle of what's going on.
Thanx. that makes sense, my question came from a gas issue so all the post have helped.
