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Discussion Starter #1 (Edited)
I know this may not be time/effort best upgrade to do, but since I had some extra time, and while I am collecting parts for my high comp d16 project, I wanted to improve as much as possible the ones that I do have.

Why would you want to port and polish throttle body?
Here are some rough made illustrations.

First you have stock throttle body with almost straight walls (in my case 62mm at the entrance, and 60mm at the flap)


THen there is simulation of airflow with silicone reducer (which I will use for whale intake , but no matter if you use CAI yu have the same problem.
Problem is very thick edge of throttle body which could cause air hitting and turning before entrance and it worsens the airflow.


Then you should measure how much space you have to work with, or how much you can take of. The throttle body I used had 62mm entrance and 4.5mm thick wall all around.



I decided to port it to 65 at the entrance and polish it to have the airflow as smooth as possible


This is desirable airflow that I wanted to gain by porting it.


I don't expect some massive power or torque gains by this project, but as I said. I had some free time and wanted to do something that could at least improve work of engine a tiny tiny tiny bit.

Depending on how much porting you desire, you will decide how rough tool you want to use for start. Since I took of 1.5mm of metal all around, I started with very rough grinding tool, as seen on pictures which took of firs layer like butter.

As you don't want it to leave that rough inside which could decrease your airflow, you would want to make it as smooth as possible so that is why you use from rough to very fine sandpaper. You don't need to use exact sandpapers like I did but one sandpaper at my place costs like 0.80$ so it is easier to make smooth finish with smaller difference between gradations.

Although this may not be as time consuming project as possible, my laziness made me use my imagination to improvise instead of hand sanding which is very slow, and pain in the as* (fingers)

Used auger as axle and cut 4 same dimension pieces of sand paper.
I tried to stick them with scotch tape in cross, so when I start drill machine, the edges of sandpaper will stick and sand the inside of the throttle body. Please note that overall diameter of the sum of sandpaper pieces + auger must be larger than the desirable finish diameter -> How much larger diameter is that much sandpaper will stick and grill the inside surface while rotating.

Since you don't want to mess with flap, and you better leave it stock size (in my case 60mm) result you will get will not be straight but a bit cone. That is the reason why I cut with Scissors sandpaper pieces in lines so there is better - equal surface porting on each part. (please see the pictures)

Sandpapers from 40 to 240 are regular ones, and you should use them dry, but when you get to 500 and so on you should use water. (even better with oil or polish paste but at the moment I didn't have it-too lazy to go to store and spend 2$ on polish paste- will do after I clean outside of tb)






What you need for this project:

1. Throttle body
2. Some kind of grinding tool
3. Sandpaper in gradations of (40, 80, 120, 240, 500, 1000, 1200, 2000)
4. Auger (easier with larger diameter)
5. Scotch tape or duct tape
6. Some kind of drilling machine
7. Scissors
8. Safety glasses
9. Free time

If you consider this DIY worthless please delete it :bigok:

any comments hate or love are welcome :)

p.s. sorry for small thumbnail pictures, didn't know how to post them other way
 

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Hmmph.. Not a bad DIY

Im sure smoothing out that little lip would be benificial for racing engines to try to extract the most out of the engine. For a typical street/DD vehicle, i doubt the little bit of turbulence will effect much.
 

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Discussion Starter #5
thank you

Yup, I Know that it may not be that beneficial for street/dd car but as I said, had some free time and of I can make there any improvement, why not :)
 

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del Sol si '94
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Ive done it simpler with a dremel, I was bored lol Felt some throttle response improvement, motor was completely stock.
 

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Aztec Green EJ2
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Very good job!
I've heard of people thinning out the rod that holds the butterfly so that it does not disrupt flow. I'm sure you could do it.
As for the port job, every little bit helps.

Keep it up :)



Some people here in Quebec have developped couplers that serve the same purpose as your project:

Laminar Flow coupler
Basically what the site says is that the ridge between the intake and TB may account for 13% of the surface, they have had gains up to 3whp on built engines.
*Dynosheets included
 

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ministry of mayhem!
93 honda integra
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great job and nice diy :TU:
 

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Any improved flow on an air pump is always worth something. Especially one that is making our vehicles move about. Nice work hommie, and good write up too boot.

I have always wondered about port matching every spot on my engine when I rebuild just to improve the air flow throughout.

This adds to my thoughts and rekindles the idea. Even though many have done it before, I like you want to do it to a stock daily.
 

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You want to have some edges going backwards. So over bore the manifold so there is a lip behind the tb. This helps with reversion. I may want to do this just cuz on my f22.
 

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Discussion Starter #12
thanx guys

2 royboy - yup that is also plan to thin that rod and get some ultra slim bolts for it also polish the rod and butterfly :) I will update this diy with pics as I finish that part too, only problem is it allows only 8 pics per post so I have to make it in separate post. Hope some moderator could fix that afterwards.
That laminar coupler is nice though, but since whale intake goes from 114mm front and 80mm at the end, I wanted to overbore tb enterance to make that flow as smooth as possible.

2 whoshot - tnx, that was just about what I was thinking of, any improovement is a good one, no matter the time and effort. I had some time so why not. I will not put that tb to this stock d15z6 I use right now. It is ment to be used on other engine that I will rebuild.
D16z6 engine, p29 pistons, d16z6 ported and polished head, stage 2 camshaft, springs and retainers (Still looking for them if somebody has some to sell), custom intake and custom exhaust manifold, but yeah, it will be daily but sure not stock :).
Goal is around 170hp and about the same nm.

2 the hoove - tnx for the hint, as I will make custom made carbon fiber intake manifold I will keep that in mind :)
 

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The stock part - I meant more my thought of the stock thing, went with yours on the TB alone. Yeah I dig, I will most likely rebuild, stock internals, maybe a cam and tune, to make use of some of the mods I want to try, probably gunna break it, so I will buy a second y8. Deff not looking for 170 na, in for moar, sorry to put so much on your thread.
 
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