Engine throttle body mods

throttle body mods

what would the engine do if you eliminated the throttle butter fly but left the spring actionso the engine still knew that air was going in but released the appropriate amount of fuel but wasw actually getting more air in.

and how would you control the rpms? now the engine will be in a feeding frenzy, unless you retro fit a valvematic top to the 4a-fe~

Give it a try and find out. Actually is an old school mod with carburators that couldn't get enough air in (drilled holes in throttle plate to clean up idle quality). Same with sport bikes that have two sets of throttle plates (one with holes, one without). Also a mod for diesel vehicles - many times, the vehicles will act no different, unless you have a runaway problem (uncontrolled fuel source).

Not 100% sure what will happen on an EFI engine with EGR, depends on how the ECM is programmed - as in how it responds to the reduced pumping losses (ECM might be totally confused). Lots of newer cars are starting to run without throttle plates, as they are equipped with direct injection, more powerful ECMs, revised timing, valve overlap, etc.

As SaberJ2X alluded to - the throttle plate is used for load control. If you can find another way to control loading (ie. variable valve timing), and run an EMS system, run forced induction to affect load control (in conjunction with valve timing), then you could run without a throttle plate.

cause if you left the throttle tensioner on that would create the load sequence but the engine would merely sux more air in. I mean say a 4afe doesn't need alot of air to work its not like the throttle is fully open all the time while our cruising at 60km/h or on the hwy at 110km/h.



see keep the tensioner on the left but remove the plates.

I agree with fishexpo101, this sounds interesting, and i know for sure that there is some problem that will occur that no one is thinking of right now, 1zzfes are queer like that, but we won't know until someone tries it right?

You plan on leaving the cross-bar in place? Might be tough to get that plate off to begin with - I'd highly recommend getting another TB, just to mod and keep this one as is.

Most of the throttle butterflys have the screws peened over - they purposely flatten the threads to keep it from backing off and smooth the flow around them. Sometimes you can get lucky and be able to back them off, YMMV.

Like mentioned above - the throttle plate is just a means to control load. If you remove it - you have to find another way to control the engine. Diesels (which this mod is commonly done) are a different beast all together.

If you remove the plate - you have to find a way to adjust/account for the signals that return engine speed, load, vehicle speed, engine, ambient temperatures, etc. to the ECM. Pulling the plate off without making adjustments would be similar to a misadjusted or damaged TPS sensor. Symtoms would range anywhere from stalling to poor throttle response, to idle surging, etc.

By leaving the "spring" on the side and retaining the TPS, you will have values to pump to the ECM, but they would be incorrect due to the missing plate.

so instead of doing that what if you were to drill some holes in the plate ... or maybe cut a lil off the plate ? what would happen then?

this is what i mean you could just cut the plates off as the rest of the throttle body is unchanged ill have a go at it hopefully before the next dyno day so i can see what difference it made. Thanks for all the replies

have a backup up plate just in case (most probably) you won't get what you want or uncontrollable idle