Throttle body diameter?

[SVXRide]

Originally Posted by oab_au

Yes but its only 50% of 90mm, till it gets to 4000, then its 100% of 60mm.X2.
Just thought I'd clear this up.

Harvey.

I was wondering when someone was going to throw the IRIS into this conversation
-Bill

[sicksubie]

So are there any significant advantages to trying to fab dual 90mm TB's?

[SVXRide]

Originally Posted by sicksubie

So are there any significant advantages to trying to fab dual 90mm TB's?

doubt it...I don't believe anyone has shown that airflow is an issue with the current TB.
-Bill

[Trevor]

Originally Posted by drivemusicnow

35% TPS reading does not mean that 35% of the surface area of the TB is open. It means that the TB plate is just over 1/3 of the way open. Technically you never have all of the surface area because of the shaft.

The larger the diameter, the faster the Airflow/%TPS ratio increases.

Please correct me if I'm wrong as I am definitely not positive about this, however experience has shown this to be true.

When one thinks on this and considers the effect/disturbance/obstruction of the plate as well as changes in angle, it makes sense that the larger the diameter the less the effect on the airway. One could expect a larger shaft for a larger plate, but possibly not in a ratio with plate size, so there could be also advantages in this area.

[Myxalplyx]

Originally Posted by Trevor

When one thinks on this and considers the effect/disturbance/obstruction of the plate as well as changes in angle, it makes sense that the larger the diameter the less the effect on the airway. One could expect a larger shaft for a larger plate, but possibly not in a ratio with plate size, so there could be also advantages in this area.

Back from Dead!!!!

Old 4 year old post.

Felt the SVX is perfect and didn't want to touch it BUT I may be sending my RAV4 throttle body out to be bored out. Sooo......

Anyone have their stock throttle body(s) bored out? Notice any difference in throttle response and/or performance? Someone had to have done this by now. Instead of starting a new thread, figured I tag along this one.

I'm BAAAAaaaaccckkkk!

[svxfiles]

Originally Posted by Myxalplyx

Back from Dead!!!!

Old 4 year old post.

Felt the SVX is perfect and didn't want to touch it BUT I may be sending my RAV4 throttle body out to be bored out. Sooo......

Anyone have their stock throttle body(s) bored out? Notice any difference in throttle response and/or performance? Someone had to have done this by now. Instead of starting a new thread, figured I tag along this one.

I'm BAAAAaaaaccckkkk!

Hi Kevin!
I know someone who port matched his,
and the manifold,
and the stacks,
and the heads.

[pile o' wrx]

Asking the same question regarding bored tb's after receiving my tb from Eric.

Seems to be ~5mm worth of meat to punch out, along with the little things. Could Subaru make that throttle shaft any thicker?!?

But if the exhaust runners are the bottleneck in the system, then aside from looking for something to do, it'd be pointless.

[Crazy_pilot]

Actually, I believe Grimmspeed sells a ported EG33 throttle body. They don't change the butterfly diameters (which I can report to be exactly 60.55 mm diameter at their widest point - they aren't completely round ), but they clean the casting marks and add more taper to the passages.

http://www.grimmspeed.com/catalog/pr...roducts_id=166

And if you've ever wondered what goes into our throttle bodies....

[pile o' wrx]

So Grimmspeed cleans up the tb taper with a flapwheel but doesn't touch the butterfly? Well there's a quick way to make $130. And what's up with the $50 bbq paint job?!?

If your information is correct, the butterfly is 60.5mm whereas the tb tapers in from a sand cast 64mm.

[Crazy_pilot]

After taking mine apart I can tell you it would be a ***** of a time porting the TB properly to take larger butterflies. The throttle shaft is staked in place and would be extremely difficult to remove and re-install properly, and with it in place it's not possible in any practical sense to open up the tunnel any more.

[dynomatt]

I can report that crudely made headers, and standard throttle bodies (unported) made a substantial difference to my car.

I think your focus should be on the headers, not the TB's.

Just my thoughts.

M

[svxfiles]

Originally Posted by dynomatt

I can report that crudely made headers, and standard throttle bodies (unported) made a substantial difference to my car.

I think your focus should be on the headers, not the TB's.

Just my thoughts.

M

I would agree that the exhaust will realize more gains than intake on our SVXi.
But, that improving over what Subaru has made for our SVX is hard to improve on...

[Jake@FAPFab]

Interesting discussion, I feel as if I should give some tender care to a spare TB..

I'll be back.

[pile o' wrx]

Regardless of the naysayers, I'm undaunted in my approach.

Of course cams and exhaust are greatly beneficial, certainly moreso in a stock configuration, but sooner or later the intake will require more.

My bridgeport is calling my name on this one. But first I'll get my hands on some other EJ2x tb's before hacking into the EG.

[svxfiles]

Originally Posted by pile o' wrx

Regardless of the naysayers, I'm undaunted in my approach.

Of course cams and exhaust are greatly beneficial, certainly more so in a stock configuration, but sooner or later the intake will require more.

My bridgeport is calling my name on this one. But first I'll get my hands on some other EJ2x tb's before hacking into the EG.

When I did my porting and port matching I did it because I could.
The engine I put it on is supercharged, so any;
increase in flow
decrease in turbulance
reduction of restriction
is/was more necessary/less frivilous.:o

Did it make a differance?
Don't really know and can't afford dyno time.
Would I reccommend this as a thing for others to do?
Not really but its YOUR car!
Its YOUR time!
Its YOUR money!
Go for it!
Strap a skateboard to your sissy bar, do the worlds longest wheelie down the worlds steepest hill!
Go for it!












BTW, the sissybar thing, it did not work out.
Would SOMEBODY get the damn phone!?