Well im considering building up my spare engine i have here for a turbo and was looking around on some sites that showed the different set ups people have had. Like having 10:1 compression having 9:1 compression, etc... I was wondering if I were to install the 10:1 wiesco pistons if i would have to go even crazier on the octane level. My goal is 300-350 hp in my ecotec 5 spd. I know tuning will have a HUGE part in this all but if i could get away with premium let me know. im curiuse to know what people think of this all. I know the S/C guys use these... which is what made the idea pop into my mind.
well think about it this way, what is preium gas? or better yet, what does it mean when you run a higher octane gas.......... no really say it out loud.....done ......k.
in case you dont know running a higer octane gas is doing nothing more then putting gas that is harder to burn in your car. with crap compression raatings that get sunk into our econoboxes, our cars are meant to run on low octane gas. intersingly enough, by putting in Higer octane gas into your car, your essitanly doing more harm then good.
so ask your self well why is this. well it comes down to the fact that when you run a lower compression motor, the compressed gas in your cyl, is under a much lower stress point, and takes alot less to burn. where as with a high compression motor, you are going threw a boat load of squeezing begfore it actually sees spark. so if you run crappy easy burning gas on a high compression motor, theres a good chance that the motor is going to fire well before TDC. (top dead center or intially where it starts its way down on the power stroke) if this happens you get preignition of detionation. this will blow your motor, becuse it trying to be pushed down, while its still traveling up.......this sucks........however you do get to watch your piston blow threw your hood (if your lucky) and thats fing worth it.
so back to your question, what gas should you run? esstiantly, whatever gas you tune for.
with any forced induction application, it is critical to under stand that the mixture that is going into your cylinder, is MUCH more volital then if it were say NA. this means that combined with a cheezy gas, there is a very good chance that your mixture will blow, well before it gets to where it should be. however there are many combatants to this. Low comp pistons, proper ignition timinig, cool charge temps (ohhhh soo thats what an intercooler does,richer af gas mix, and yes a gas that can handle the mad crazy compression.
so what does this mean for you? this means that if you want to run 10:1(......ummm dont) then your are goning to have to use the meathods supplied in order to fight the pistonhood affect. although, if you succesfully combat preigntin, and your doing what needs to be done, your will actually make more HP with a higher comp pistons with much less boost, this means, fast spool time, more TQ. with lower comp pistons you can give your self a little leway, run lots of boost, and impress your freinds with your crazy loud BOV....
well Im done, Ijust filled my JBO Quota for the week, so if any one needs anymore help there going to have to PM me,
BTW, on a serious note, if you still dont get it hit me up and Ill break it down, I love this ish, and I want other people to also.
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Kick azz is my boost hero!!! 
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^^^Remember in Billy Madison when Adam Sandler makes his little speech and the teacher is like we are all dumber now for having listen to you talk....? I kinda feel like that after reading your post.
14.261@ 95.45
Check out my car....
http://members.cardomain.com/o4blackfire
i have the same feeling blackfire, i sware i throw "newbie" into a post title and i get dumbed down
im sorry but your little TDC breack down made me laugh.
Sorry Jcavi. I know that stuff. And to honestly say if i was a REAL newbie, i would say .. "well with that info your saying you are hurting your engine with boost! " Yes tecnically you are because your doing things the engine doesn't want to do. your putting the stress on all this spinning metal making about 150hp. So why do it? its fun, you want to, etc...
Another thing ... i feel kind of insulted by the coments ment in there ... "oh thats wht the IC is for !" most people who have DONE RESEARCH like i have know what a IC is. To show you im not a dumb A@@ an FMIC (front mounting intercooler) is used to cool down the compressied air. Hot air is less dense and is worht nothing when looking for high HP numbers. When running a FMIC, you cool down the compressed air making it more dense which means more air to fuel ratio ( you know gas needs air to burn fully) Some people use this wierd crazy thing called a N-ter cooler which is mounted in front of the FMIC. What does this do? lts say its like a water to air IC ( you use water to cool the air) The bar is chilled by shooting rather cold C02/Nitrous through the bar which then cools the air flowing through the IC even more.
The higher octane ... thing did the same thing ... and to say it load and clearly for you to understand (idk if you do or not) Higher octane is used to slow down the preignitions stage which is made by higher compression, less dense air ( like in some peoples brains)
The reason i ask is because i know for a fact that if you make a higher hp N/A engine, and throw boost at it, it will be a higher performance engine. Thats why you can take your pnp head, different cams, over sized valves, etc... for turbos, S/C, and N/A versions.
So why do i ask about the 10:1 compression? because i want to know if i would be pissing my money away in race gas or if i would still be able to tune the car for premium. If i need race gas then i got my answer ... it would be a no go.
Man now i got all jumpy over being dumbed down on a rather simple question. Maybe from now on I will leave the "newbie" out of the title.
Well, JCavi made quite a few errors, but we expect it from him, so it's all good
Higher compression=more pressure in the cylinder=more heat generation...the octane rating is resemblant of the fuel's resistance to igniting via this heat (like a diesel).
So, how do you sucessfully run a higher static compression ratio on your boosted motor? Simple, you run a longer intake duration (closes later) or retarded cam timing to bleed off cylinder pressure, lowering the temps back down. This lowering of your dynamic compression ratio is often accompanied by a new powerband due to the new cam profile.
There are many other steps you can go through to prevent detonation:
1) Polish, polish, polish. Your combustion chambers, piston faces, valve faces.
2) Thermal barrier coatings, they keep heat from being soaked into the metal.
3) Lower temp thermostats. They will hurt your gas milage, but a cool engine is a happy engine.
4) Lower your quench distance. This speeds flame propogation keeping even heat distribution and eliminates 'hot spots'
5) Alcohol injection. Windshield washer fluid is cheap, and very effective.
Also of note, your car sparks the fuel before TDC normally, due to the flame having to progress through the chamber (it's not instantaneous), so don't think it shouldn't be sparking while on the compression stroke.
Also, pre-ignition or detonation will not "blow your piston through your hood", nothing will cause that. Valve stems go through hoods, rods go through blocks, pistons may melt or jamb things up.
fortune cookie say:
better a delay than a disaster.
all I am going to say to make it easy for all of us is
lower your compression if your going turbo and are building your engine... period...
get some cams and a head and 300 will be cake to surpass
LE61T PTE6262 Powered
SpeedRacerZ wrote:Notec = smart 
Muchas gracias senor. I try my best.
And I'm going to disagree with QBE there, that's the easy way out
Of course, if all you want is 300, then leave all your internals stock, and focus on tuning, since the engine will hold it.
fortune cookie say:
better a delay than a disaster.
I didnt mean to offend you, It was more of a way to help anyone reading,
I dont know what I wrote that was wrong?
Well, JCavi made quite a few errors, but we expect it from him, so it's all good
, im not that bad.
Higher compression=more pressure in the cylinder=more heat generation...the octane rating is resemblant of the fuel's resistance to igniting via this heat (like a diesel).
i said that
So, how do you sucessfully run a higher static compression ratio on your boosted motor? Simple, you run a longer intake duration (closes later) or retarded cam timing to bleed off cylinder pressure, lowering the temps back down. This lowering of your dynamic compression ratio is often accompanied by a new powerband due to the newd cam profile.
I dont think he was going to run new cams. thats why I didnt mention that.
Also of note, your car sparks the fuel before TDC normally, due to the flame having to progress through the chamber (it's not instantaneous), so don't think it shouldn't be sparking while on the compression stroke.
I guess what I should of said, is that your attempting to avoid having the burn create power and work agaisnt the piston.
Also, pre-ignition or detonation will not "blow your piston through your hood", nothing will cause that. Valve stems go through hoods, rods go through blocks, pistons may melt or jamb things up.
comone man I was joking.
"
Kick azz is my boost hero!!! "
higher compression will give you more hp on lower boost however it will increase combustion temps, and be harder to tune..
however 10:1 is not all that higher compression...
Higher octane fuel is harder to burn and will help with knock or pre detonation.
Things will be easier with the lower compression, However if we wanted easy we would own civics right???
horsepower is how hard you hit the wall, Torque is how far you push the wall with you
I really should of just said that
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Kick azz is my boost hero!!! "
