Injector Plate Bore / TB Bore

[NWINNIE34]

Hey when i purchased my TSX IM... the guy sent me the OEM injector plate for the TSX (exact same part are we have in our I4 accords)
i would only assume that boring this out would benefit me but would this cause issues with the seal between the TSX IM and the injector plate?

I have the P2R IM gasket....
would this require me to also bore out the TSX IM to match the bore diameter of the injector plate?
what kinda increases could i expect from this?

also interested in the boring of the TB.
havent seen much literature of boring these parts out, but logistically would benefit in getting more air SLAMMED into the engine

any info would be appreciated,
anyone work at a machine shop that car bore ? haha

Nick

[NWINNIE34]

and if i were to bored the injector plate... i would then also have to bore the TSX IM ports to be the same diameter?
then essentially i would have to bore out my P2R gasket to have all 3 matching port diameters?

[thisaznboi88]

if you want to bore out your tb check out maxbore.com I also have an extra accord tb if you need one. That should reduce your down time on your car. PM if you are really interested.

its 100 to bore the tb and another 80 i believe to port match the manifold.

[NWINNIE34]

pretty sure this was never dyno tested to get actual preformance results... but do you think this is really worth doing ?
i would think faster throttle responce and more air being sucked into the engine....
might make MPG go down even more but also making more power at the same time

i'll check out that site

[thisaznboi88]

I really don't know. Some people say better throttle response, other say it does nothing, I seen on k20a.org that up to a 65mm throttle body it will make power. anything after that you have to have massive head work and crazy hardcore cams.

[BliNx197]

As for Injector plate I assume you are talking about the injector base, the 2nd part of the manifold touching the cylinder head.

In the case for my 06-07 I installed the TSXs Injector Base and had problems. They are different part #s. The difference is that the TSXs EGR valve is located in a different place than the Accords. If you open up the top piece bolted onto the Injector Base the plate there should be holes leading to the runners of the Accord Injector Base and no holes inside the TSX Injector Base.

Long explanation short this will make you throw EGR CELs

[timot_one]

You're talking about two different things here. Boring the TB, and port matching the IM.  Will it make a difference if you do both?  Yes.  Will that difference be significant?  It all adds up, so it's something worth looking into.  As thisaznboi88 pointed out, check out maxbore and ask for prices.  One more thing, this work doesn't "slam" air in any way.  The purpose of this modification is so that more air can flow easier into your cylinder head with less restriction.

[BliNx197]

Honestly, I think a bored TB is a waste of time for beginning mods. I just think you could spend your $$$ on more bang for your buck mods at first. Then again IDK about your mods list at the moment and most people have big plans for their CM.

So if you plan to actually go through with them then this will be something that I believe will add power in the longterm. But if you dont mind having your car down for some time, Id send Maxbore your TB and TSX IM and get the TB port matched. I dont think they bore IM to Injector Bases normally but hell. Ask em or you could of course look locally!! But as for the TB specifically Id go with Maxbore.

[thisaznboi88]

I was just thinking if you open up the yes there will be more air flow but the air will have a slower velocity. And since we all know that the accord is not the world best k head I would believe that we would see some improvement but not as much as a true vtec head since the cams are wilder and can open up more to make use of the extra air. I read on k20a.org that a 65mm rsx-s tb gain like 3hp over stock bore but once again we are taking about a performance vtec vs or econo vtak.

[NWINNIE34]

interesting stuff, something to look into...

my mods list is in my signature, i have a lot of bolt ons.... just something i was pondering
i'll check out maxbore and see whats up over there

[timot_one]

I'm going to side with Bryan on this one.  I think there are other mods that you can do first that would make a more significant difference.  What are your plans anyway?

[BliNx197]

Im just theorizing about this more. Lets look at some of the Ks with Larger TBs than the k24a4/8 and look at the differences. Ok youve got the k20a2/z1/(possibly z3) k24a2. Im only including USDM because Im not too familiar with JDM and Euro models. Ok so the differences in those 4 I mentioned. The obvious one is the 3 lobe Vtec valvetrain. The Ability to pull in more air than an a4/8, I would say this is a large reason for it but when looking at the a4/8s they are in vtec for a over 60% of their powerbands. Which is equivalent to only running low lobe on performance vtec heads. So Im not 100% convinced that this is the only reason for it.

In addition the a4/8s reach max hp production below their 6500 rpm redlines. Only making me think theres more factors as well. Also when looking at the 4 other Ks mentioned their redlines are 7k rpms each. This makes me think there's a certain point rpm at which using a larger TB is more beneficial. Not to disclude the additional the use of the vtec lobe. Obviously you've got the differences in Compression Ratios accross the entire line of Ks, Id have no idea where to begin with that one so if anyone has an idea please toss it out.

As I said before this is just me theorizing and Id like to keep this thread going because I know I ignore TB boring as a big performance gainer. Anyone have dynos BTW?

[Skippy]

Ok here are my thoughts...

First, Bryan, You are slightly incorrect about the injector base part numbers.  The injector base on 03 Accord models IS the same part number (17050-RAA-A00) as the 04 TSX until the 06 shift.  At the 2006 designation, the part number changes for the TSX but not for the Accord.  The Accord's injector base stays the same (17050-RAA-A00), while the TSX part changes to (17050-RBB-A00).  Your specific case is correct, but K24a4's share a common injector base with the TSX.  Also, TSX's do not currently have and have never had an EGR system, so something else must have been been giving you problems.

About Throttle body boring:  Yes it's a great modification.  In order to limit down-time on the vehicle, I would recommend purchasing a TSX intake manifold and a spare Accord throttle body, send them out to maxbore and let him work his magic.  Asian-sensation is correct, the throttle body boring service is $100 and it's $70 to port match the intake manifold to the throttle body.  Note that the port matching is to the throttle body opening, not to the runners.  This set of modifications should be done before the TSX intake manifold is installed.  By having the work done at the same time, you suffer no downtime in the process.  

The theory is that having a bigger TB opening allows more air into the engine with less restriction.  My analogy to this is a runner sprinting down a track.  If the runner has his mouth and nose taped shut and a straw inserted into the mouth area...the runner will sprint for a short distance, pass out, and expire.  If you instead tape the runner's nose shut, and insert a toilet paper tube into his mouth, the runner will be able to finish the race without expiring.  The same idea applies to your throttle body.  By enlarging the opening, more air is allowed past at all RPM levels and power is thereby increased.

For K24A4's, the TSX and Accord injector bases are exactly the same.  The runner openings are the same on the Accord and TSX, so there's no need to make anything bigger.  
 
Have I cleaned house sufficiently?

[BliNx197]

I wouldnt say all that.

Nowone is debating on the fact that using a larger TB is better, Im wondering is there a point where the extra effort to expand the runners and TB opening becomes ineffective on a Stock k24a4/8?

Actually Aznboi already stated the thread I was referring to on TB size on k20a, ( really dont wanna go fishing for it) but Im just wondering if anyone else has thoughts as to why Honda decided to equip a 2.4l w/ a smaller TB than a 2.0l? Im sure they have logical reasoning, just want some more insight, and honestly Ive never looked at k20a3 engine, much less TB. Maybe its just the addition of the Performance Vtec lobe!

I on the other hand will be looking into swapping to a TL or J-series DBW TB soon.

[thisaznboi88]

if you are serious about doing it I have a spare accord TB and intake manifold that I can hook you up with. That should reduce any down time. Takes about a week before maxbore can get it back to you sometime even longer