So. I'm sure you might be getting a lot of these questions but I haven't be able to find much on this. I'm getting some cheese back from our gov't and after paying some bills i want to put it toward the car. I have a 04 3 2.0 ~125k miles now. Now I'm sure you guys would say take the money and put it toward a down payment on a speed 3 n such but I gotta say i LOVE not having a car payment. So with that in mind:

I've been looking at protege garage for some parts and i'm wondering with the forged pistons for the 2.3 work for the 2.0 the bore is the same on both engine but the stroke is different. hence, the hp and tq gain over the 2.0 engine. The thing I'm concerned about is obviously valve clearance. I want the higher compression and obviously i'd lose stroke because of this.

The 2.0's run 10.0:1 I think the pistons would push me up to a 12:1 or a 14:1 compression. i've noticed that going to 14:1 requires some serious octane that one, is not easily accessible for me. two, more expensive, three, not what i want to maintain for a DD. Is the higher compression enough concern to get a thicker head gasket? Would i lose compression because the added gap of the thicker head gasket? If I decided to go to 12:1, Is high compression concern for forged rods and bearings? Granted this is a better setup but is it a necessity? Basically am i going to throw a rod after driving 100 miles with 12:1 with better pistons and stock rods or is that really a complete waste? Go big or go home right lol?

Obviously if this WERE to work, tuning would be done. I'm looking at the split second a/f controller to work with the higher compression

I have heard but not seen people switching out the 2.0 3 head with the 2.0 miata head for the higher compression, is that something can be done? would it be cheaper?

I've also been contemplating going with a universal procharger kit and running about 5psi. Regrettably I have an auto-tragic and running too high of boost, even if i could get my engine to handle it, My transmission couldn't. The front differentials in these cars suck more dick than NPH lol (no offense to NPH fans lol).

 

don't worry about the higher compression thing. not enough gain there. just bolt up 5 psi and tune the car. you can run that on stock internals without destroying the engine. just be sure to keep the afr's in stoich.

 

Forced induction; now that is a mod that will pay dividends.

 

Let me start with this, im pretty sure ive heard of swapping the heads of a 2.0 from a miata but im 90% sure ive read they were talking about putting it on the protege. With that said no it wont work.

Pistons are not going to be your main concern, rods are the weakest link when it comes to "serious" performance these rods cannot handle much heat over stock esp on a DD.

If you decide to do all motor stay with 12:1 comp but your gonna have a lot more issues to deal with such as the bearings since the engine is gonna get alot hotter even though a proper tune will help with this the stock rods and bearings are simply not gonna put up with it.

As you said even if your able to get your engine to handle the power and whatnot your trans is really gonna kick you in the *****. To put it simply in order for these trans to even withstand "real" power its gonna take all of your tax money away.

I wouldnt get a spd3 either, sadly unless you want to dump a boat load of money for this car to perform as well as (lets say) a honda with 2.5k in it your gonna have to spend an absurd amount (depending)

 

Yeah I've heard of cosworth making a front diff for the tranny it can handle up to some odd 500 ft/lbs of tq but it cost like $2k. Even going that route the stock tq converter wouldn't be able to handle that kinda power.

 

Its not the diff that takes a crap, its the internals of the transmission i.e the clutches, gears and whatnot. The stock diff is not gonna go 1st. When your talking about upgrading the clutches and gears (which you have to do) thats well over 2k for an auto trans.

 

I only stated the front diff first because my front diff "turned to dust in my hand" (as the mazda dealer put) at 90k miles with pretty much no mods besides bolt ons.