Modifying the stock Throttle body for more air flow

Quote:

---

Originally Posted by Limbo

breeza, have you worried about the piece holding the plate in being too thin?
Thought of this but i'm not sure as i'm worried on a boosted car the plate may get pushed back and stuff my intake?

But anyway, great mod idea!

---

I worried about this too but seems to be working fine. If it came off the bolts would fly into the engine via the manifold and it's game over.

haha yeah,it's looks dodgy but I would be VERY suprised if it did,they bite/lock real good!

Quote:

---

Originally Posted by ekay1

Thing is, ive been reading alot about the tb spacer, and it made like a 4.5kw gain on the Si. Not sure about the fd1, but people saying that it feels better and sounds different too. Apparently, the Throttle body spacer, allows more air flow, much like your DIY, so i was assuming that if i combined that 2 then i would get a better result xD

---

I reckon so!

im not interested in the kw gain really, just hoping for a better "feel" of the car after these two.

It definately achieves that,that's exactly what it does.

Guys i would highly suggest the use of locktite on those screws because they can back themselves out and it will grenade your motor

Other than that good diy
Also for people wanting to use a dremal you can buy special bits for alloy they look like sandpaper they work real well I got some for my die grinder it bored out my intake manifold really easly

Hrm I was thining of doing a similar mod to this but I personally wouldnt touch the butterfly valve nor the screws etc. The gap shown in the DIY photos illustrates the potential leaks. PErsonally this would not beacceptable and I would not want to 'tune this out' with the IACV etc.

If you stomp on your throttle and your cable is a litle tight you might just snap the axle/rod that holds the butterfly plate so i definately wouldnt take it down that much.. you REALLY dont want to snap your butterfly plate (or the rod/axle) on the track or EVEN WORSE on the street.. imagine permanent WOT in daily traffic ???!!!

If you look at the science of this (and what spoon has done also) you see that it is increasing the potential air velocity (speed) but it wont actually increase the flow as there is no increase to the diameter of the actual 'valve' itself. I guess the faster moving air would increase the pressure and therefore squeeze more air through the TB.. Those changes to the Butterfly plate and rod/axle (and screws) could also create some turbulence (possibly) however I think the reduced restriction by doing this wouldnt be worth the sacrifice in reliability/durability etc.

The spoon TB's actually have the centre re-bored and a replacement butterfly plate with larger diameter to suit. doing this increases the velocity AND the flow and hence can give you a snappier response and power gain.

Quote:

---

Originally Posted by cotties

Guys i would highly suggest the use of locktite on those screws because they can back themselves out and it will grenade your motor

Other than that good diy
Also for people wanting to use a dremal you can buy special bits for alloy they look like sandpaper they work real well I got some for my die grinder it bored out my intake manifold really easly

---

Locktite wont do much,if anything cause there's no real thread that the screw grabs onto..it simply grabs it real good.

U can weld it if worried.

Got anypics of the work ya did on the IM?

Quote:

---

Originally Posted by VT3C

Hrm I was thining of doing a similar mod to this but I personally wouldnt touch the butterfly valve nor the screws etc. The gap shown in the DIY photos illustrates the potential leaks. PErsonally this would not beacceptable and I would not want to 'tune this out' with the IACV etc.

If you stomp on your throttle and your cable is a litle tight you might just snap the axle/rod that holds the butterfly plate so i definately wouldnt take it down that much.. you REALLY dont want to snap your butterfly plate (or the rod/axle) on the track or EVEN WORSE on the street.. imagine permanent WOT in daily traffic ???!!!

If you look at the science of this (and what spoon has done also) you see that it is increasing the potential air velocity (speed) but it wont actually increase the flow as there is no increase to the diameter of the actual 'valve' itself. I guess the faster moving air would increase the pressure and therefore squeeze more air through the TB.. Those changes to the Butterfly plate and rod/axle (and screws) could also create some turbulence (possibly) however I think the reduced restriction by doing this wouldnt be worth the sacrifice in reliability/durability etc.

The spoon TB's actually have the centre re-bored and a replacement butterfly plate with larger diameter to suit. doing this increases the velocity AND the flow and hence can give you a snappier response and power gain.

---

Are U saying this mod won't work?

Quote:

---

Originally Posted by beeza

Are U saying this mod won't work?

---

nope I am not saying this mod wont work, I am weighing up the reliability of this moving part that has a fair bit of pressure on it from the suction of the motor through to the air-velocity running through the TB and also the tension from the Throttle cable and your right foot stomping on it.

and also I think the potential vac leak issues wouldnt be worth the 'gain'.

would love to see flow-bench tests on this between stock IM and this modification !!

i agree that the air-horn style bored-out mouth of the TB would be beneficial, however modification of the throttle plate without increasing the actual bore the 'gain' might just be noise caused by increased turbulence.

awsome write up mate!

^^ Thanks Lyle,cheers brotha!

Quote:

---

Originally Posted by VT3C

nope I am not saying this mod wont work, I am weighing up the reliability of this moving part that has a fair bit of pressure on it from the suction of the motor through to the air-velocity running through the TB and also the tension from the Throttle cable and your right foot stomping on it.

and also I think the potential vac leak issues wouldnt be worth the 'gain'.

would love to see flow-bench tests on this between stock IM and this modification !!

i agree that the air-horn style bored-out mouth of the TB would be beneficial, however modification of the throttle plate without increasing the actual bore the 'gain' might just be noise caused by increased turbulence.

---

haha yeah,might be aye.