Hey gang! I'm working on my project engine right now, and I have a few questions. First being, I need a new computer for the engine, I don't want to use my old one, I want to keep that computer with it's original engine. Any ideas of where or what to look for? I wouldn't mind using another ecotec brain, I'd actually prefer to, but if not, where to go? Will HP Tuners do the trick? My other big question is this, would it make sense to deck my head a little bit to actually raise my compression up to around 11.0:1? I'm going supercharged, but I thought that maybe a little more natural power would help things along. Just looking for some feedback, thanks!



"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-

So you want to replace your computer?

If you try to use a computer that wasn't for your vehicle/application, you will lose some controls (if not most) like air bags for example. Also, you can't just go and get a computer from some random car to use on your car, the computers have a certain capatability with certain systems.

You could get a standalone computer system that you could have 100% control over but depending on the computer and what the computer features allow and the capatability level (as far as what sensors you can hook up to it) it would only do so much outside of fuel and ignition control.

This is also not a plug and play project unless a certain company made one for your application (which there aren't any for your car that are plug and play...), so you have to wire everything into the new computer.

Your best bet is to keep your computer (cause honestly there is no need to change it) and use HP Tuners.


www.kronosperformance.com / 732-742-8837

cool beans, thanks!



"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-

Matt Dalin wrote:cool beans, thanks!

You're welcome


www.kronosperformance.com / 732-742-8837

one more, any ideas where I can get my hands on a stock CPU? My big thing is that I want the factory engine to stay as it is, everything together and what not. Thanks again!



"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-

Matt Dalin wrote:one more, any ideas where I can get my hands on a stock CPU? My big thing is that I want the factory engine to stay as it is, everything together and what not. Thanks again!

Ok, I'm just slightly confussed and not trying to pick apart what you're saying but just trying to understand...

1. You currently have a vehicle with a ECOTEC (stock) in it.
2. You have a spare ECOTEC motor that you are building up
3. You want another computer (stock) to go with this new motor
4. When you're done with the build up, you're going to swap the new motor and computer in

is this all correct? If so, then I'll make a comment.


www.kronosperformance.com / 732-742-8837

keep in mind if you mill the deck to raise the compression ratio you make the distance from your crank gear to the intake timing gear shorter maybe 1-3 degree off actually causing you too loose power to compensate you would have to buy adjustable timming gears for a VERY VERY slight increase in compression its not worth the trade off

floyd noack wrote:keep in mind if you mill the deck to raise the compression ratio you make the distance from your crank gear to the intake timing gear shorter maybe 1-3 degree off actually causing you too loose power to compensate you would have to buy adjustable timming gears for a VERY VERY slight increase in compression its not worth the trade off

Good point.


www.kronosperformance.com / 732-742-8837

Why would you wanna run 11 to 1 compression on a boosted application. I thought the rule of thumb was nothing higher than 10 to 1. Unless you dont plan on running huge boost.
~Adam

Adam Bruder wrote:Why would you wanna run 11 to 1 compression on a boosted application. I thought the rule of thumb was nothing higher than 10 to 1. Unless you dont plan on running huge boost.
~Adam

This is from the misconceptions sticky:

NJHK wrote:4. You shouldn't or can't boost a high compression (static) engine

This isn't true and there is nothing wrong with doing so if you of course know what you are doing from the beginning.

The reason people say this is because naturally, higher compressioned pistons (taller), experience higher combustion chamber temperatures than lower compressioned pistons (shorter). If you were to "boost" a naturally aspirated engine that is (for example sake) 10.5:1 compression, nothing different will occur than if you had 8.5:1 compression pistons.

The pros of boosting a higher compressioned engine is that less air is required from your compressor to yield X HP/TQ than if you had a lower compressioned engine. Why? High compressioned engines compress the air/fuel mixture tighter which also allows for a better air/fuel mixture burn which would yield a stronger ignition on the top of the piston, which creates force to turn the crankshaft and create more power.

With less boost pressure required, it is also more likely that you will be staying in the efficiency range of your compressor, which means a less likely of you creating excess heat and raising your IATs (Intake Air Temperature).

The con: Excessively High Combustion Chamber Temperatures

Yes, that is bad but it's all about countermeasuring it and doing things to a degree. There are many of ways to counteract excess heat:

1. Running a richer fuel mixture
2. "Colder" spark plugs
3. Retarding ignition timing
4. Running Higher Octane
5. Running Meth/Water Injection
6. Better (more efficient) Intercooling

These are the more general ways of doing so.

#4 is usually a big concern because of course, not everyone has access to Octane Fuel higher than 93 Rating but to also run into another misconception that you will NEED higher octane fuel...that's also incorrect because the other 5 options I listed can help to achieve the same goal.

www.kronosperformance.com / 732-742-8837

Correct, I want a completely different ecotec in the car when I'm done, computer and all. I'm anal like that, sorry. As far as the compression issues go, my thought was that if I can get a little more "natural" power from the engine, it'll stay stronger as I would loose the boost power. My big thing is that I want to make this a bit of an experiment engine and try and find out the best ways to make massive power at the "junk yard" level. The supercharger I pulled is off of a Nissan Xterra, they run almost the exact same set-up as the Cobalt SS, it's the same model supercharger and the openings match almost perfectly. The plus side to it is that it'll handle a larger Throttle Body with less monkey work, but the off-chute is at an odd angle for a transverse engine. Anyway, long story short, I need a new factory computer for the new engine because I don't want to lose any of the old programming I've got on my current one. (If anyone else here is confused, allow me to join that line, I'm just as confused! lol) Anyway, I thank everybody who's been helping me along the way, you guys rock!


"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-

I know you're saying you're being anal but there is nothing that you'll be losing if you're putting a new engine in with the same computer BUT are you trying to go from a L61 to another type of ECOTEC engine? If you are, you're going to need more than the computer cause it's a totally different wiring system as well as computer system (example: Deltas vs Jbodies).


www.kronosperformance.com / 732-742-8837

Nope, just stickin' with another JBody 2.2. It's out of another 04 Cav LS Sport 2 dr. Only had 8k on it before the car got wrecked.


"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-

Matt Dalin wrote:Nope, just stickin' with another JBody 2.2. It's out of another 04 Cav LS Sport 2 dr. Only had 8k on it before the car got wrecked.

Yeah, than there is absolutely no need to change the computers. You won't lose anything.


www.kronosperformance.com / 732-742-8837

Cool beans. I'll let you know when I get her fired up and dyno'd. Shouldn't be too long


"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-

Good Luck


www.kronosperformance.com / 732-742-8837

Getting a Nissan SC to work on an Eco is going to be fun.

So far it hasn't been too tough, a little fab work on the manifold and the port on the SC. The last thing that'll need to be done is the holding bracket but I think that should be easy, I figure I'll just use the radiator support.


"it's only a cavalier, right?...I mean it's not fast or anything, is it?" -famous last words-