oqjoi

So i was talking to a friend and he recommended shaving my head. I told him how i want to swap my a3 had for a2, and he said it was too much work. Why would i or would i not want to shave my head? I mean aside from that girls look funny bald what are the pros and cons of each. He mentioned boosting and such but i want more opinions.

ezone

In repair, milling or machining might be called shaving a head, but in this case it's to remove unwanted warp from the head gasket surface, to restore a truly flat sealing surface.

In a performance application, shaving a head is done to raise the static (calculated) compression ratio by reducing the volume of the combustion chambers........but at the same time this action alters the cam timing (on OHC engines) because the cam centerline is now moved closer to the crankshaft centerline..... so fancy adjustable cam gears may need to be used to restore proper valve timing.

Raising compression ratio is generally only done to naturally aspirated hi-po engines.

In the olden days (carburetors and points distributors) it used to be said, "The quickest and cheapest way to gain power is to raise compression." But nowadays it may not be quite that simple.


If going to a forced induction setup, most engine builders want a LOWER static compression ratio. (Forced induction essentially amounts to artificial compression once boost kicks in.) Lower static compression allows a lot more ignition timing advance before reaching the dreaded detonation point under boost.

Detonation is always the enemy!

On a turbo engine running on pump gas, more power may be obtained through increased ignition timing advance with lower static compression than the other way around (high comp/less advance).

On factory turbo engines I dealt with in the past, the turbo versions had about 1-1.5 compression points lower than the naturally aspirated version. The turbo engines generally used "dished" pistons to lower the compression ratio instead of altering or using a different cylinder head.


This stuff may all change once you start going far higher than 14 PSI boost, or using alternative fuels.

An engine designed to use strictly E-85 can be built with a much higher static compression ratio than an equivalent engine designed to run E-10 or lower fuel, thus one can consider a similar build for a turbo E-85 application as long as that fuel is always used.


Can this person build real power from an engine?
Does this person have any real wins to his name, or is he just bench racing?

If there is no proven performance, then we're just talking smack!




I know an awful lot of women that seem to get jealous of a guy that has longer hair than they do. Most guys wouldn't care, we'd still be staring at *****.

oqjoi

Thanks ezone, you answered everything so well. But i have a few more questions then. If i go NA and get an intake and such, would it then increase the pressure or heart in the cylinder right? If i go that way, i need pistons and rods and valves that can handle it. Or would the ones sock on the a3 handles it?

ezone

External bolt-ons can't raise the static compression ratio.

The best you can hope for is better performance through better breathing (more efficient cylinder filling and more efficient exhausting). Same deal if you wanted to go with different cams.
The next step IMO would be tuning, to take better advantage of any bolt-ons.



----


I read 9th gen forums too, the right tune on a stock 2.4K SI can unlock quite a bit of power without engine modification.

Check out this thread: http://www.9thgencivic.com/forum/vittuned/76706-bone-stock-si-vittuned-vs-stock-tune-comparison.html

Stock internals should be able to handle any NA bolt ons without a problem. (Excluding N2O.)

This isn't my area of expertise, but from what I understood in the past, Hondas stock bottom ends can generally withstand about a 50% power increase without sacrificing (much) reliability. So if you somehow manage to bump your 160HP up to 240HP with bolt-ons, it probably wouldn't be a problem.



JMHO. YMMV. HTH

oqjoi

Could you just come kick it in my garage? Where do you learn all this stuff. I've been searching forums and I've learned a lot but you have an answer for everything. Some of the forums are hard to understand though. Like they use toooo many acronyms. What does kpro do? It's an ecu or an ecu modification?

ezone

Sure! Got groceries?


It took most of a lifetime! Started at about age 3 when I picked up screwdrivers and tried to take apart all my toys.

Then on to reading old service manuals for fun. Yeah, I did LOL.


I've already forgotten more about cars than many people will ever know LOL


This should explain more gooder than I can:

http://www.hondata.com/kpro.html <--clickylink

oqjoi

Yes I keep food around. I like eating.

Maybe you should write some of it down before you forget toooo much more lol.


What does the pbr, pnc, prc mean?

And finally, if i have all the information straight so far, NA= higher compression, retarded timing, better set of lungs for my car. Boost= lower compression, advanced timing, less work; a gas mask type setup.
So if i did as others say and swapped heads to an a2 head it breathes better, so I'd want freeer flowing exhaust. It would also make higher compression and i would not be able to boost it well. Assuming kpro is what i think it does, it adjusts the timing and such to work an a3 block with an a2 head or however it's programmed?

And the opposite with boosting. Advance the timing, Yeeeessss?

ezone

PBR is a beer. I bank at PNC.
I dunno. I'd have to stop and think about them, and read the context of the post.

Some people abbreviate their paint colors.

Ignore the timing aspect for now, that's all computer controlled.
Some might program to run ignition timing at the maximum possible, and use knock sensor controls to retard timing when detonation is detected. Others might have a max timing preset (in the map), then back off a little more when detonation is detected.
From what I understand, some of them can even self-learn all the fuel and timing and stuff as it gets driven.

Did you check out the differences in the specs of the two engine versions? Drop the whole thing in as a replacement?

Research thoroughly before you choose to do anything. There's a lot of info if you choose to find it, but you probably have to filter bad from good.

This isn't my area at all. I deal with mostly stock stuff.
I'm sure there are others that deal with this sort of stuff all day long and are good at it.

oqjoi

I was reading on the kpro link you posted, it listed different things to pay for as p?? Acronym or non p?? Acronym for $??? I was just curious. Usually google tells me, but i haven't found it yet, lol it pulled up pabst though... i much prefer kcco or lagunitas if I'm drinking beers. Lol

I'm not doing anything to my car right now, I'm just trying to learn enough to make good decisions. My papa and i work on building cars back from death and rust. I want to someday tune my honda, but i chose to be a taekwondo instructor. And taekwondo instructors don't make much money. Lol. It does keep ME well tuned though :-D. Thank you for directing me.

So tuning without extra stuff entails what kinds of things? I hadn't read much about that, nothing so far has popped up on Google. And my auto savvy friends give me so so information.

ezone

Ok now I see. They are referring to the middle section of the ECM part numbers.
I didn't see it, I dunno.
You have rust down there? We got real rust up here, chica!

Mechanics don't either ....
And the millionaire position is always already taken whenever I fill out the job applications LOL.

BTW: Congrats.
Mostly remapping fuel and spark and tweaking other things like VTEC engagement conditions (and VTC if equipped).

The factory engineers MUST adhere to strict emissions controls and meet federal emissions standards, and everything about the stock setup is designed to get the emissions as low as possible as soon as possible.
If you toss all that out the window and remap the ECM strictly for power, you can make gains.
(EDIT: Whatever the engineers come up with also must work for a zillion cars at a time. With custom tuning you only have to worry about one car and one engine.)


This may not fly if you have to pass an emissions test.



A factory trainer once told us to think of an engine and all of the computer controlled systems that run that engine as merely a life support system for the catalytic converter. EPA regulations have made that cat the most important thing in the engineers' lives, and everything in the car revolves around getting that cat working as soon as possible, and keeping that cat working for as long as possible.
Emissions first, performance second.

oqjoi

Thank you for the congratulations lol.

oqjoi

Yes we have rust. I live in a desert
But we still get rust. Only we get Sun rot too. My tires have blown out because of it. I was driving on the highway, and blam, tire busted. Like totally busted. So far it's happened three times. First time i was in socorro, i flipped my car. It was an 84 Toyota corolla, second on my way to Mexico, a 20 minute drive and bam, in the middle of el paso highway traffic jammed ness, i almost got run over changing my tire. Then with this car. Every time if you look at the rubber is like crispy. It gets so bad i have to wax my car with the "twelve month" stuff every Saturday..