ok so the previous owner of my lude had rebuilt the motor to get it ready for F/I which means i have lower compression pistons (9:1 to be exact) and i dont want to go F/I since this is my daily driver.my car has been dyno tuned and i was wondering if I invested in getting higher compression pistons (12:1) how much power could I expect to gain?I would get the car retuned at the same place i took it to before.any info would be helpful.
well i dont think you will want a high compression n/a engine for your dd man, the turbo may be a better way to keep your dd, just make sure you have a good tune. If you use the 12:1 compression pistion then you are always gonna need high octane fuel to prevent detonation(this is the only limitng factor of goin high compression, what happens if you are not near a premium fuel staion).
^ yes, and or water methanol injection of course....however what i guess i was meaning to imply is that if you are not sure of what kind of piston you need for your setup, then perhaps it is the wrong setup for what you reallyneed out of the car. It sounds like this guy needs a reliable DD to get him to and from work. A high compression high revving engine is not what you would desire in such situation. Truthfully, a turbo'd setup isnt what is required either but in my opionion would be the better of the two choices. (plus his block is already built for a boosted setup)
.....octane boost away OP.....
Last edited by bouckarooo; 05-08-2010 at 11:54 PM.
well i appreciate it bouck and indy but really dont have the cash to boost it and there are just more parts that could lead to more problems.I just want a little more power out of the car and i think it would be fine day to day since the block has already been properly resleeved and all.plus i know a guy who has a high compression civic SI that he has been running for 2 years now w/o a problem.i just dont know a guestimate as to how much power i will be gaining by doing this.
I think what gain you will see can only be estimated if we have more information about the current setup. How much power is it making currently to the wheels? What other modifications have been done?
With a stock engine and simple bolt ons you might expect to see ~ 170 HP to the wheels after adding 11:1 compression ratio pistons. I personally wouldn't go up to 12:1 for a daily driver.
So lets say you are making 155 to the wheels right now. You might see a gain of 15 whp after adding some higher compression pistons.
well its not just the comression of the pistons that i am concerned with, i mean if you have high compression pistons then you should upgrade your valvetrain also, possibly run a na cam, get high lift, it depends how serious you want to go, usually a high comression engine revs quite high and produces power aimed at the higher rpm range. The thing about high compressions setup is the decreased buffer zone before failure. All depending on the tune of coarse. What ecm are you going to be utilyzing? I would recomned the aem series 2, this is the best ecm standalone i could find, although its expensive.(plius its the only one that you can use with the immobilizer without issue) Either way you are gonna need to have a good tune for it to be reliable.
ya i have a skunk2 valvetrain and a flashed ECU that the tuner provided.and after my tune i had 164whp but all the guys there said it would actually be a little more because the tuning took about 4 hrs so the engine was pretty heat soaked also that was a dyno dynamics number,dynojet is more.
Your problem is its gonna cost more money to swap out the pistons than what it will probably cost you to go turbo. If you buy dependable parts and don't go crazy on the boost your engine will last just as long, especially since the whole set up is set up around a turbo application.
Your problem is its gonna cost more money to swap out the pistons than what it will probably cost you to go turbo. If you buy dependable parts and don't go crazy on the boost your engine will last just as long, especially since the whole set up is set up around a turbo application.
well its about 1k total for new pistons and install or 4k for turbo hmmmmm...doesnt seem like the same price to me.dont get me wrong guys i would love nothing more than to turbo the car but i really cant justify spending the money
You can probably piece together a turbo system for cheaper than that.
But if you found someone to take apart your block and reinstall high comp pistons for 1k parts included. I would go for it. My n/a build is over 2k already but they did have to resleeve the block.
The OP already has a complete built engine so I don't think he would have to change anything other than the pistons and tune. He already has the resleeve, valvetrain upgrade, and stronger internals. Lots of parts to add to go turbo....
The OP already has a complete built engine so I don't think he would have to change anything other than the pistons and tune. He already has the resleeve, valvetrain upgrade, and stronger internals. Lots of parts to add to go turbo....
not really, i mean if you just want a little boost, go with an internal wastegate and then maybe if you like you could get an air to air intercooler(kinda like the non intercooled 300zx tubo setup). N/A h22s are sexy as hell also but i mean if you got your block builkt for boost then i say boost it tillt eh cows come home......just take some time to gather up the funds.
i dont know maybe ill keep my lower compression pistons and just go nitrous or just slowly aquire the turbo parts over time but i would also have to buy a new fuel pump and bigger injectors along with all the turbo stuff.what would be a safe and reliable amount of boost?remember this is my DD
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or just slowly aquire the turbo parts over time but i would also have to buy a new fuel pump and bigger injectors along with all the turbo stuff.what would be a safe and reliable amount of boost?remember this is my DD
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