Modifying the stock Throttle body for more air flow

[beeza]

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!

Aim: To 'open up' the OEM Throttle body (TB) to promote more air flow.

Since the tps will be removed for this mod,U should calibrate it when U put it back on,U should anyways lol

So here's how to do it:

Calibrate the tps

Enjoy!

Required: A small round file
Sand paper (for metal)



Steps: Remove the TB from the car and take it apart,try to remember how it came apart so U can put it back together again.I have steps below on how to do this so don't worry to much.It's just that TB's vary,so your's may be different? Any TB can be adapted to this DIY and I believe all engines will benefit from this mod because U are not changing anything just removing the restrictions to promote more air flow into the engine.

All work was done on my d16y4.

If your tps is riveted on,U can hacksaw them off,dont need a grinder:



Replace with screws,the screws U need are in the tps thread:



Grab ya small round file and file that sucker out! Don't buy a cheap crap file,they dont work.



You will feel how much to file out.The main thing is to not file where the TB plate sits/seals and the rear,where it mounts up to the IM.It's very easy to file,I think the material is aliminium.

2 hours later,done! Make sure U polish that sucker up with say 3 stages of sand paper,finishing with a super fine paper to get it smooth/polished.Comparison pics:



No flash



Take ya stock TB plate and arm and do the same! U can use an electric sander if U have one to take off the majority,save time (I've done 6 now,so it's a good tool to have.)



Done!















Just looking at the inner 2 parts,not the TB









Next ya wanna get those 2 screws that hold the TB plate smaller,any way ya can!

The screw



The easiest way is with an electric sander,if not just file it!





Yes,it sanded the metal screws hehehe



Do the other side!



Put em' in and sand it to near flat (need a little sticking through to grab)

[beeza]

The finished product!









Next,check to see that your TB is opening 100%,most I've found are 96,97,98% If your's is like this,just file a bit off the throttle rotor until it is.Check regulary so you don't go too far

100%



If not file here





Putting it back together: Can be tricky at first..

Put the spring on the rotor to get it ready





Next put the other spring on the tps side like this



Then put the arm in,like this



Turn the arm clockwise 180 degrees and hold it there under tension.

Then fit the spring on like this.I didn't get a pic of it but there is a 2cm long metal tube thing that sits under the spring (oops..)



Hold it all there,dont let go! Now turn the rotor anti clockwise 180 degrees and push it on the arm,then put the washer and nut back on.



Will look like this on the other side now



Then put the tps on,like this



Then put the TB plate in there



Wiggle the plate around and get it to sit as closed as possible,then tighten the screws up.



Put it back in and Calibrate the tps and ya done!

Other comments:

Idle issues will only happen if U have filed too much off the TB plate and it is not sealing properly.

You can see mine isn't 100% sealed



Luckily I had a bit in my idle/air screw to play with,so I screwed that in and got it to idle perfectly.Now,no air goes through my idle/air screw and it idles from that small gap there,perfect.

On Tim's car the idle/air screw was turned right in,so we had to unscrew the throttle stop (TS) screw a bit so the plate would seal more.This put CT @ 0.43V and WOT remains @ 4.5V (The voltages U want are 0.48-.49V @ CT and 4.5V @ WOT) BUT that dosen't matter cause the car is running just awesome.

If the surging starts in the idle again we can still unscrew the TS screw to get it to seal more but if it throws the tps out too much ad/or it affects the running of the car,we will swap in another one I done.

Well! Time for a shower and a break!

Hello



Can U see the Great Cormorant?





He supported me,all day!



Oh,I guess ya wanna know the RESULTS?!?!

Yup! We have a winner! Kinda feels like after a Suburu upper engine clean,revs more freely now,accelerates quicker,smoother running.

I'm Loving it!

A 60mm TB is too much on a slightly modified d-series.U need to have done ECU or internal work for it to work.

This is what got me thinking,well,what can I do to my TB then?

Hope U liked it,

Brett.

[ekcoupe]

oh i loved it lol

beeza did this with my y4 tb i couldnt notice a difference because i changed it when i swap the intake manifold but im sure with how beez has described the difference i can aggree with that, very thoughtful of you to post it up here an very detailed diy good job bro

[beeza]

I'm a share-er

[DLO01]

Nice work Beeza! Could I suggest using a 'half round file' instead of the small round file. Will be much easier to use/control and easier to keep uniformity around the area to be filed.

[DEMON83]

awesome job, luv u work!

[SiReal]

i believe you are the new king of DIY. Good stuff Brett, those D engines go forever and are great to learn with.

[Aydin]

great write up! +1

[beeza]

Thanks guys!!

I did buy one of those files from the $2 shop Dean and it lasted 2 minutes lol but forsure that would make the job quicker forsure

Well,I got up at a birds fart this mornin',moon still shinin'



And got stuck into Chris's (gio's) TB



As the day came in



Finished filing



And polished up



3rd one down! Ready to be installed when U are Chris

[Premature Vtec]

Nice work, +1 for you how much mm you think its at now ?

[Gio]

Beez you are a glorious beacon of light in terms of your rep, how funny is that haha. Good work bro! Loving the morning.

[beeza]

Nice work, +1 for you how much mm you think its at now ?

Thanks mate,it's still 56mm,stock size,that's where the TB plate seals but I've opened it up at the front there.It does make a difference.

Thanks Chris,beautiful winters mornings now,so nice!