MODIFICATION , THROTTLE BODY ( 4G Accord / Ford 65mm + B16 Manifold / TB Spacer )

[1988starter]

PORTING STOCK TB / OVERBORE 4G TB

Well I gave it a shot and bored out the TB I felt some defante gains and will probably experiment with another soon to see the max I can go. Right now this brings the mods list to (not including appearance)

Bomz /AEM custom CAI K&N Filter
MSD 6Al
Accel 14001 Super Coil
Magnecor Wires
NGK Irridium IX Plugs
Colt Cams Triflow Cam
(Specs)
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Duration/lift:
Intake 1 260/384
Intake 2 270/384
Exhaust 274/402
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DC Sports Headers 4-2-1
Highflow cat
2.25 Dynomax mandrel exhaust
Cosmo Racing FPR
High Flow Fuel injectors.
Bored Throttle Body
Centerforce Dual Friction Clutch
Hyper ground made with monster XL wire.
92 Civic strut bar custom fitted

[Mike's89AccordLX]

Sweet I can't wait to get my custom intake manifold done for my Weber. I've been working on it every now and then at school with their spendy alluminum de-burring bits

[Elijah]

Have u ever ran it?Do u know how much hp ur putting down.

[Mike's89AccordLX]

Who are you talking to?

[A20A1]

Starter I believe.

[1988starter]

no I have never ran it or dynoed it I would love to. All I know is every one who rides in it is very impressed with it's ability

and A20A1 I love the tequila kitty avitar

[Sabz5150]

I'll agree, it definitely helps. Not an extreme amount, but you can feel the increase after the bore/polish is done.

[Justin86]

So what do you guys use to polish it. I have mine pretty smooth but not with the polished finish.

[Sabz5150]

Originally posted by Justin86
So what do you guys use to polish it. I have mine pretty smooth but not with the polished finish.

Dremel. Got all kinds of attachments for it

[mugenprelude86]

and the bore, do you do it before and after the butterfly?i did mine but i think i can go bigger yet.... what size did you go to?

[1988starter]

yes before and after I stopped around 63mm It was a bit of an experiment I am probably going to try more after the intersesion

[Justin86]

Well I used the dremel bits on my dril press but I can't find any bits that will produce the polished look. I'm pretty close with using fine sadpaper but you can still see little scratches all over it.

[Sabz5150]

Originally posted by Justin86
Well I used the dremel bits on my dril press but I can't find any bits that will produce the polished look. I'm pretty close with using fine sadpaper but you can still see little scratches all over it.

You need a wire brush, polishing stone, felt polish discs, the polish compound and a lot of elbow grease.

[Justin86]

If I can just find that stuff.

[1988starter]

look in almost any hardware store

[Justin86]

That is where I looked and they just had the bacis bits, I should check to see if they can order me the bits

[bobafett]

hey u bored it out to 63mm on the intake side on the manifold side or what?

that reply seemed like u did both sides, but what did u do with the butterfly then? or did it look like >-<

[1988starter]

currently the butterfly is the same I am waiting untill I have more time to get a new one

[Immeraufdemhund]

i tried doing something similar to that. I dont see how you measured it... how did you any way did you have a micrometer? Also my throttle has been sticking after i took it off any clues?

[foobari]

Boring the throttle body on a stock or almost stock Honda engine seems to be a wasted time.

Here's a quote from "How To Build Honda Horsepower, Dyno-Verified Results" by Richard Holdener.
---
"The stock throttle body from a B16A motor flows almost 600 cfm. To give you an idea how good the stock throttle body is, that amount of airflow will support right near 400hp.
...
Sometimes, bigger throttle bodies do add power, but the increase is generally small and the motor in question needs to be really healthy. Your stock D16Z, or even a high-winding B16A, will not likely benefit from the installation of a larger throttle body. How do I know? Dyno tests were run on both motors comparing stock and over-sized (64.5 mm) throttle bodies with no measurable change in power."

[shepherd79]

Boring the throttle body on a stock or almost stock Honda engine seems to be a wasted time.

Here's a quote from "How To Build Honda Horsepower, Dyno-Verified Results" by Richard Holdener.
---
"The stock throttle body from a B16A motor flows almost 600 cfm. To give you an idea how good the stock throttle body is, that amount of airflow will support right near 400hp.
...
Sometimes, bigger throttle bodies do add power, but the increase is generally small and the motor in question needs to be really healthy. Your stock D16Z, or even a high-winding B16A, will not likely benefit from the installation of a larger throttle body. How do I know? Dyno tests were run on both motors comparing stock and over-sized (64.5 mm) throttle bodies with no measurable change in power."

i think you are wrong. i don't know how you do your dyno runs around there, but here in the US. even slight overbore will give you increase in power.
if you read sport compact, import tunner, turbo & high performance or honda tunning they all recomend bigger throttle body for stock engine as one of the easiest way to pick up a few HP at middle and upper RPM range. i agree the power gains are small but they are there.
i think the last time sport compact magazine did dyno run with bigger TB they gained about 3-4 hp at upper band on B16 motor.

[foobari]

i think you are wrong. i don't know how you do your dyno runs around there, but here in the US. even slight overbore will give you increase in power.

I'm not saying that boring the TB does nothing, I was just quoting the book By Richard Holdener, who BTW does all his dynoing on DynoJet machines in the US.



In the book he states on several occasion, that according to his dyno tests, boring the TB on stock motor yielded no (significant) power gains. The best numbers seem to be on a B20/B16A Hybrid (200hp to the wheels), where he got max +2.8hp with a bigger RC Engineeing throttle body, and a Supercharged D16Z 1.6 VTEC (153hp to the wheels) where the bigger Holley Throttle Body gave out huge 6.1hp.

So ok, I guess I was too prompt with my "waste of time" comment. If you have en engine with mods on it, at least it won't hurt you to bore the TB out.

[stolenracer]

ok here is the deal if you bore out your throttle body you will see gains of around 2 to 15 hp nothing to big but for a 3gee every hp helps i dosent matter if it is 1 hp or 20 its not a old street rod its a frickin honda so we need all we can get the only thing you will see is a bit more accel thats about it and yes you will get 2 to 15 hp i live 5min. from a race shop they have a dyno we bored a civic si no mods only the thottle body and thats what we got but you should doo it little by little and take your time

[foobari]

thats about it and yes you will get 2 to 15 hp i live 5min. from a race shop they have a dyno we bored a civic si no mods only the thottle body and thats what we got but you should doo it little by little and take your time

Ok, sounds really interesting! What do you mean by "2 to 15hp", is this increase measured in one run (like +2hp@3000rpm and +15hp@6000rpm), or do you mean 2 to 15 hp depending on the bore? How did you bore the TB? Did you just bore it (with a sort of venturi), or did you also re-blade it?

[3rd GEN]

hey sweet!!
so did ya get that idea from me?? did I inspire you to do soo...haha
i'm glad you like it..i love mine