throttle body mods
09-13-2002, 07:50 PM
#1
Drifting
Thread Starter
throttle body mods
anyone know about this? i just picked up an old one with the intention of increasing the airflow, only i have absolutely zero experience with this. any pointers on how to procede, dimensions to aim for?
09-13-2002, 09:43 PM
#2
drnick,
Best I can offer is Guru in hiding
Ed Ruiz.
I believe he mentioned adding a throttle plate - spacer -.
I can reference extensive Mustang throttle body
inside diameter I.D. increases they run from around 65mm to 80mm. Dependig on C.I., heads, huffer, ignition system/ engine mapping. Flowing more air is a good thing when looking for HP but there is a lot more to it than hanging a big intake pipe on the engine.
Some things to consider:
Does your mass air sensor need to be recalibrated? The Brain might take up the slack.
Are you going to have a new lean condition?
Are the heads even going to flow any additional air without a huffer or turbo?
As long as you maintain a good seal I suppose you can ream that puppy out as far as you care to.
Any Machine Shop should be able to do the job in no time - the reaming that is -.
But, there has to be a butterfly/flappy valve involved there somewhere. If the valve doesn't get bigger you just have an increased 'volume' of air knocking at the door. Maybe, Ed, Abby- 6.4L worked heads, Sc, widebody, or perhaps even Pierre from South Africa - Fat Bully - can enlighten us with higer volume /denser air/fuel mixing tips.
I'm curious myself as to how much air (cfm) the 4.5L can flow and how much is actually getting to the combustion chamber.
Give it a shot!
Best I can offer is Guru in hiding
Ed Ruiz.
I believe he mentioned adding a throttle plate - spacer -.
I can reference extensive Mustang throttle body
inside diameter I.D. increases they run from around 65mm to 80mm. Dependig on C.I., heads, huffer, ignition system/ engine mapping. Flowing more air is a good thing when looking for HP but there is a lot more to it than hanging a big intake pipe on the engine.
Some things to consider:
Does your mass air sensor need to be recalibrated? The Brain might take up the slack.
Are you going to have a new lean condition?
Are the heads even going to flow any additional air without a huffer or turbo?
As long as you maintain a good seal I suppose you can ream that puppy out as far as you care to.
Any Machine Shop should be able to do the job in no time - the reaming that is -.
But, there has to be a butterfly/flappy valve involved there somewhere. If the valve doesn't get bigger you just have an increased 'volume' of air knocking at the door. Maybe, Ed, Abby- 6.4L worked heads, Sc, widebody, or perhaps even Pierre from South Africa - Fat Bully - can enlighten us with higer volume /denser air/fuel mixing tips.
I'm curious myself as to how much air (cfm) the 4.5L can flow and how much is actually getting to the combustion chamber.
Give it a shot!
09-14-2002, 05:04 AM
#3
Drifting
Thread Starter
i only want to tweak things, not too much! that way id hope the maf, brain, injectors etc will cope without as you say creating a lean condition. no plans to force feed though.
yes there is a large buttrfly that will need to be made even bigger! this seems to be the point of most restriction, ie where the butterfly sits has minimum diameter. also the throttle body side walls are quite thin and will limit the amount of machining possible.
i was curious to see if anyone knows whether an appreciable difference would develop if the diameter is increased say anywhere between 2-5mm.
also, the engine it will be feeding is an 'S2' ie 4.7 euro.
yes there is a large buttrfly that will need to be made even bigger! this seems to be the point of most restriction, ie where the butterfly sits has minimum diameter. also the throttle body side walls are quite thin and will limit the amount of machining possible.
i was curious to see if anyone knows whether an appreciable difference would develop if the diameter is increased say anywhere between 2-5mm.
also, the engine it will be feeding is an 'S2' ie 4.7 euro.
09-18-2002, 12:17 PM
#4
Drifting
Thread Starter
spoke to a carb specialist who does this all the time and he recommended no more than a 2mm increase, good for 20% more airflow he reckoned.
excellent!
excellent!