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Hi I just got a 03 si. Want to know what should I do to if I want to go allmotor. Because everybody is talking about K20a2. Want to see what I can do to a K20a3. Don't want to go turbo. Thx a lot. :)
 

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Cams will be coming out soon also a good header like DTR or Hytech or equivalent...ITB's might have to be modded to fit not sure on the whole K20a3 K20a2 fitment. Hondata without question.....Just a few little ideas to get your thread moving...
 

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11sec CR-X said:
Cams will be coming out soon also a good header like DTR or Hytech or equivalent...ITB's might have to be modded to fit not sure on the whole K20a3 K20a2 fitment. Hondata without question.....Just a few little ideas to get your thread moving...
Defnitely all of those, you might also want to look into pistons and rods. port and polish maybe. A good exhaust and intake will never hurt.
 

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To my knowledge, hytech and DTR don;t make headers for the Ep3. In all motor, the k20a3 is just not good enough. Not only it doesn;t have the I-vtec cams but the torque is low too. For the same amount of money you are going to spend on the A3, you might as well got a2 or a4.

The cams will help for sure but if I were to invest money and time at a non type S head style motor,, I would go with the k24a.. More tq. more displacement and a stock crank that is strong.

Good luck,

Nikos
 

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k20a2 for $3500, k20a for $5500 but you can actually keep the transmission so you only need a longblock. That is why I like the k24a. Once cams hit the market for the k24a, you can reach 190-200 whp with it with k pro.

The tsx is a cool motor but there are a some issues that I really do not know the answer too. For example the manifold... You cannot bolt on a type S or type r manifold. Some rewiring has to take place. Again, I do not know much about this. K20a.org user hotwheels has a TSX in his RSX and he knows a lot of this. I will message him to come here and post about it.

One more thing, in the june/july issue of honda tuning, there is going to be some info how to make your 5 speed tranny into a 6 speed. :)
 

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drhonda said:
Defnitely all of those, you might also want to look into pistons and rods. port and polish maybe. A good exhaust and intake will never hurt.
Rods, pistons and a port and polish would be pointless on the K20A3. Even a port and polish on an A2 without cams would be pointless.


nikos said:
To my knowledge, hytech and DTR don;t make headers for the Ep3. In all motor, the k20a3 is just not good enough. Not only it doesn;t have the I-vtec cams but the torque is low too. For the same amount of money you are going to spend on the A3, you might as well got a2 or a4.

The cams will help for sure but if I were to invest money and time at a non type S head style motor,, I would go with the k24a.. More tq. more displacement and a stock crank that is strong.

Good luck,

Nikos
Where to start.

Any header made for the DC5 will fit the EP3. The front sway bar might need to be changed to the samller 22mm DC5 one, and an aftermartket Type S exhaust will be needed.

All K series engines have I-VTEC, so I have no idea why you are saying the A3 doesn't have the cams? It just doesn't have the proper 3 lobe cams the A2 has. The torque is lower, but comes in at a lower point in the RPM range compared to the A2.

There have been numerous threads about the Base RSX vs. the Type S at ClubRSX. The general sensus is that the Base is able to run with the Type S until the S hits 3rd gear.
 

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Sorry, I should have typed " true I-vtec"

Please read the following


-Originally posted by Targa250R-



The K20A3 does not have a standard DOHC VTEC valvetrain as we know it from the B-series engines - the K20A3 should actually be called a "DOHC i-VTEC-E" engine, because it uses a VTEC-E cam setup. The K20A2 is the "real" DOHC i-VTEC engine, utilizing the standard DOHC VTEC cam setup we're all familiar with. To help you understand the differences between the K20A2 and K20A3 engines, I've included the following information from a post I made elsewhere:

Allow me to evaluate. Let's start out by defining some terms:

VTEC - Variable valve Timing and lift Electronic Control. At low RPM, a VTEC engine uses a normal cam profile to retain a smooth idle, good fuel economy, and good low-end power delivery. The VTEC mechanism engages a high-lift, long-duration "race" cam profile at a set RPM value (i.e., ~5500RPM on the B16A) to increase high-end power delivery.

VTEC-E - Variable valve Timing and lift Electronic Control for Efficiency. This system isn't really VTEC as we know it. At low RPM, the VTEC-E mechanism effectively forces the engine to operate as a 12-valve engine - one of the intake valves does not open fully, thus decreasing fuel consumption. At a set RPM value (i.e., ~2500RPM in the D16Y5), the VTEC-E mechanism engages the 2nd intake valve, effectively resuming operation as a normal 16-valve engine. Note: in a VTEC-E engine, there are no high-RPM performance cam profiles; this engine is supposed to be tuned for fuel economy, right?

VTC - Variable Timing Control. This is a mechanism attached to the end of the intake camshaft only which acts as a continuously variable cam gear - it automatically adjusts the overlap between the intake and exhaust cams, effectively allowing the engine to have the most ideal amount of valve overlap in all RPM ranges. VTC is active at all RPMs.

i-VTEC - intelligent Variable valve Timing and lift Electronic Control. This is a combination of both the VTEC and the VTC technologies - in other words, i-VTEC = VTEC + VTC. Currently, the only engines that use the i-VTEC system are the DOHC K-series engines.

Now this is where things get tricky - Honda uses the term "DOHC i-VTEC" for two different systems: The first system is used in the K20A2 engine of the RSX Type-S. The second system is used in the K20A3 engine of the Civic Si.

The First System (K20A2):

This system is pretty close to the older DOHC VTEC engines. At low RPM, the K20A2 uses a normal cam profile to retain a smooth idle, good fuel economy, and good low-end power delivery. At 5800RPM, its VTEC mechanism engages a high-lift, long-duration "race" cam profile to increase high-end power delivery. The only difference between this i-VTEC engine and the older VTEC engines is the addition of the VTC system. The intake camshaft has the automatic self-adjusting cam gear which continuously optimizes valve overlap for all RPM ranges.

Here we see an image of the intake cam lobes of the K20A2. Notice there are 3 lobes; the two side lobes are the low-RPM profiles, and the center lobe is the high-lift, long-duration profile which engages at 5800RPM. Basically the same setup as the old VTEC engines we are familiar with.



Now here we see the VTC mechanism - the gear on the end of the intake cam that adjusts valve timing (overlap) automatically on the fly.



This system is used in engines powering the JDM Honda Integra Type-R, Civic Type-R, Accord Euro-R, and the USDM Acura RSX Type-S and TSX.

The Second System (K20A3):

This system does not really conform to the "DOHC i-VTEC" nomenclature, as Honda would like us to believe. As I mentioned in my previous post, it actually should be called "i-VTEC-E," because it uses a VTEC-E mechanism rather than a standard VTEC mechanism. At low RPM, the VTEC-E system effectively forces the engine to operate as a 12-valve engine - one of the intake valves does not open fully, thus decreasing fuel consumption. At 2200RPM, the VTEC-E system engages the 2nd intake valve, effectively resuming operation as a normal 16-valve engine. There are no high-RPM performance cam profiles; this engine is tuned to balance fuel economy and power, rather than provide pure performance. On the intake cam, there is the VTC mechanism which basically is an automatic self-adjusting cam gear used to continuously optimize the valve overlap for all RPM ranges. This being a VTEC-E system - and not a true DOHC VTEC system - is the reason the K20A3 redlines at a measly 6800RPM, while the K20A2 is able to rev all the way to 7900RPM.

Here we see an image of the intake cam lobes of the K20A3. Notice there are only 2 lobes - there is a nearly round one used only for the low-RPM disabled intake valve, and then there is the regular lobe used by the other valve at low-RPM and by both valves at high-RPM:



This system is used in engines powering the USDM Acura RSX base, Honda Civic Si, Accord 4-cylinder, CRV, and Element.

Special note: The K20A3 engine used in the Acura RSX base has a slightly different intake manifold design from the K20A3 engine used in the Civic Si. The RSX engine uses a dual-stage manifold, similar in concept to the manifold of the B18C1 in the old Integra GSR. It uses long intake runners at low-RPM to retain low end power, and switches at 4700RPM to a set of shorter intake runners to enhance high-end torque. This accounts for the extra 9 ft-lb of torque in the RSX (141 ft-lb, vs. 132 ft-lb in the Civic Si).

Here is an image showing just how this dual-stage manifold works. On the top, you can see the low-RPM (long) runners are in use, and on the bottom, you can see the high-RPM (short) runners in use.



Myths:

1. The i-VTEC engine engages VTEC gradually, and not suddenly like in the old VTEC engines.

Wrong. The i-VTEC engine "engages VTEC" at a single set RPM, like always. Whoever started this rumor is a fucktard. Read the definitions above.

2. VTC engages at a set RPM.

Wrong. VTC is always activated. Read under "VTC" above.

3. The K20A3 engages VTEC at 5000+ RPM.

Wrong. Technically, there is no "VTEC" (as we think of it) in the K20A3 engine - it uses a VTEC-E technology, which engages at 2200RPM. Read under "The Second Sytem" above.

 

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nikos said:
Sorry, I should have typed " true I-vtec"

Please read the following
I've read it plenty of times over the past few years. Not sure why you gave me the article, since I obviously pointed out that I already knew the difference between the cams in my post. Thanks for trying to make me look stupid ;)

And yes, you should have typed it that way, no need to give new people false information.
 
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