I have a '96 2.5 V6, and I want to bore out the throttle body to 58mm or so. I saw this on cardomain.com, it was done to a 420A Avenger. I want to know who can help me do this. It is perfectly logical that you would get more air and it would be more than any CAI: I already have one of those. I view the throttle body as the one biggest restrictors in air flow. So if it can be bigger, why not? and who can do this for me?
i just bored mine out...i could do it for you, i have the tools. thing is..i dunno how much it actually does..since where the tb opens, there's still a tight spot air would be a bit compressed i guess, as it enters. also, i bored the manifold a bit as this would definitely have more pull. im thinking of redoing the manifold so as to get more pull, then the tb boring would be at a better advantage. and i wont be able to get any track times for a while as i need to fix my exhaust...if u want i can take pics of my tb and send it to u.
i just bored mine out...i could do it for you, i have the tools. thing is..i dunno how much it actually does..since where the tb opens, there's still a tight spot air would be a bit compressed i guess, as it enters. also, i bored the manifold a bit as this would definitely have more pull. im thinking of redoing the manifold so as to get more pull, then the tb boring would be at a better advantage. and i wont be able to get any track times for a while as i need to fix my exhaust...if u want i can take pics of my tb and send it to u.
Let me know more, I want all research done before I do this. What 'bout the butterfly? Is that replaced with a bigger one? Can you do that too? I was also going to do the plenum too, but I was going to have that done locally. I've tried to have Exile Racing do this for me, but they won't respond to my e-mails. I checked out your car on cardomain... -nice.
thanks red, I tried..its gonna get better though. but the tricky part of the whole thing is the butterfly. I bought a used tb from ebay for a diff. car. I'll have to shave it as it's pretty big. w/o getting a new butterfly it creates a bottleneck obviously. I havent installed the new butterfly, but I'll let u know the difficulty minust the shaving. i wasnt sure how much i wanted it bored, so i got a bigger one just in case. you might just wanna get the 58 mm butterfly plate like u planned. i would buy a plate off ebay...w/ a used tb and that should be good enough..if anything i can drill my own holes and stick my own screws in..not a bad job at all. ill measure and see what's the most ideal.
59mm is as big as you can go without hitting the bearings for the rod ...it must be PERFECTLY centered to do this ...Off one way or the other and you'll nick the bearings .... Just cut a new butterfly out of aluminum sheet takes two minutes ....Drill holes to match up to the stocker
thanks red, I tried..its gonna get better though. but the tricky part of the whole thing is the butterfly. I bought a used tb from ebay for a diff. car. I'll have to shave it as it's pretty big. w/o getting a new butterfly it creates a bottleneck obviously. I havent installed the new butterfly, but I'll let u know the difficulty minust the shaving. i wasnt sure how much i wanted it bored, so i got a bigger one just in case. you might just wanna get the 58 mm butterfly plate like u planned. i would buy a plate off ebay...w/ a used tb and that should be good enough..if anything i can drill my own holes and stick my own screws in..not a bad job at all. ill measure and see what's the most ideal.
you cant bore the throttlebody and not put a new plate on right away. You would have a huge amount of air bypassing the plate....
heh, I bored mine out with a dremel, but talked to a machinist who does this for a living, he said not to dremel the metal where the butterfly flap touches the inside wall, to just bore it out, leave the hump there, but smooth the wall going up to the flap, but don't touch 2mm where it hits the walls. I also thinned out the center piece that holds the flap in there (you'll shave some of the screws off). But the most important thing: THIS DOESN'T DO SQUAT UNLESS YOU PORT MATCH THE OPENING OF THE INTAKE PLENUM TO THE NEWLY SIZED OPENING OF THE BACKSIDE OF THE THROTTLEBODY! You will be surprised how much material you'll have to remove, but that part is really easy. I HIGHLY recommend removing your plenum while doing this, or even better, buy a used one online (I paid 20 bucks for one on ebay). or junkyard. Also go to a garage and have them wash the parts (when you're done grinding at it) in a parts washer a couple times (remove any electronics: TPS,MAP before you wash). Because You DO NOT want metal flakes going into your engine! Oil her up bolt her up (might as well put a manifold and tb spacer on while it's off) And you are good to go. Make sure you reset your computer (disconnect battery wires, hold down brake lights for 20 seconds, wait ten minutes, reconnect). When your computers (ecu and tcu) retrain in a week you'll notice a big difference in acceleration as long as you have a nice exhaust to go with your mod. You can dremel to 60mm at the outside lips, and taper off to 59mm inside. If you take a couple extra hours, you can fine polish the inside until it is almost a chrome polish, which I assume would create better suction since it has less surface resistance.
heh, I bored mine out with a dremel, but talked to a machinist who does this for a living, he said not to dremel the metal where the butterfly flap touches the inside wall, to just bore it out, leave the hump there, but smooth the wall going up to the flap, but don't touch 2mm where it hits the walls. I also thinned out the center piece that holds the flap in there (you'll shave some of the screws off). But the most important thing: THIS DOESN'T DO SQUAT UNLESS YOU PORT MATCH THE OPENING OF THE INTAKE PLENUM TO THE NEWLY SIZED OPENING OF THE BACKSIDE OF THE THROTTLEBODY! You will be surprised how much material you'll have to remove, but that part is really easy. I HIGHLY recommend removing your plenum while doing this, or even better, buy a used one online (I paid 20 bucks for one on ebay). or junkyard. Also go to a garage and have them wash the parts (when you're done grinding at it) in a parts washer a couple times (remove any electronics: TPS,MAP before you wash). Because You DO NOT want metal flakes going into your engine! Oil her up bolt her up (might as well put a manifold and tb spacer on while it's off) And you are good to go. Make sure you reset your computer (disconnect battery wires, hold down brake lights for 20 seconds, wait ten minutes, reconnect). When your computers (ecu and tcu) retrain in a week you'll notice a big difference in acceleration as long as you have a nice exhaust to go with your mod. You can dremel to 60mm at the outside lips, and taper off to 59mm inside. If you take a couple extra hours, you can fine polish the inside until it is almost a chrome polish, which I assume would create better suction since it has less surface resistance.
exactly what i did...but i had a change of mind and working on something else.-
Makes like a funnel right? I was going to do that after I get it bored out to 58mm. I e-mailed throttlebodys.com, but I haven't recieved their recieving info e-mail in a few days. All I need is conformation that they will be expecting it and their address.
correct red, if you want to go a step further, you can port-match the lower intake manifold to the upper intake manifold. there's a process called "extrude hone" out there that's really expensive, but basically it makes the inside of your engine look like a polished mirror, but it's not recommended for the inside of the upper intake plenum because the coarsness of the inside walls is there intentionally to create turbulence so the engine has time to suck in the intake charge.
correct red, if you want to go a step further, you can port-match the lower intake manifold to the upper intake manifold. there's a process called "extrude hone" out there that's really expensive, but basically it makes the inside of your engine look like a polished mirror, but it's not recommended for the inside of the upper intake plenum because the coarsness of the inside walls is there intentionally to create turbulence so the engine has time to suck in the intake charge.
....so..y do ppl spend time trying to get air FASTER?....Ill do some serious measurements..and if it seems possible w/o a doubt..ill port match them myself...but wouldnt that just create turbulence???I mean...the suction area expands and then contracts.
i dont think anything expands or contracts. the manifold is metal the intake is metal or rubber. the only thing that could possibly expand or contract is the vacuum hose. i dont understand. the inside walls of the upper intake plenum is coarse like sand paper. you can enlarge the openings that connect to the tb and the lower manifold, but dont touch the inside walls, just the hole diameter. extrude hone is used for exhaust manifolds, headers, cylinder walls, etc.
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