Well, I'm going to have my TB ported, polished and bored out sometime very soon. I believe it's a 60mm stock and I'm concidering increasing to about 62 or 63mm, if anyone has any experience or ideas as to what might be a good amount to bore out, please let me know. Thanks
S|Lv3rBu||et
The limiting factor will probably be either the engine side of the intake manifold, or definitely the MAFS mount. The MAFS mount is 2.5" in diameter, so widening the throttle body any more won't do anything. You're only getting so much air into the engine, so widening anything beyond the smallest diameter in the intake system is pointless.
Well, if you've got two throttle bodies, you can just swap them out in between runs.Originally posted by S|Lv3rBu||et
Well, I'd love to post some dyno results, but I dont think I have the time or the money to hit up the dyno twice... but we'll see
But I'm not sure what you mean about 'milling the arm that holds the plate flat'....care to elaborate?
If you look into the throttle body, the part that holds the throttle plate is basically a cylinder with a slit in the middle to hold the plate. If you flatten this cylinder out a bit, you'll gain a bit more airflow through the throttle body.
Well, you can only gain so much from porting the throttle body. After that, the intake runners and/or head would be the final bottleneck. If anyone knows the total volume of air the intake runners can handle, matching the the throttle body to that would give you the most airflow. Not sure if you can safely port the GT intake manifold, though, since it's plastic.
Yeah, I'm gonna take it one step at a time. However, depending on how easy it is to remove the intake manifold, I might give it a good cleaning before final re-assembly.
But thats a good call about the airflow capacity of the intake manifold.... if nobody on here knows it, any ideas of where I can get that info from? Maybe directly from toyota (thats assuming I can get someone from toyota to talk to me).
Boring it out 10mm is way to much IMO. If you take off your throttle body and compare it with your intake manifold, you'll see that there's a slight gain to be had by a mild boring to match it to the manifold. That is unless you're planning to port a plastic manifold also.
Then if you remove the intake manifold, you'll see that there's another restriction. The ports of the runners don't match up with the head. Then there's the head...just look at it. :bang: The 1ZZ was definitely not made to be a clean NA motor.
Okay, I thought boring 10mm seemed like a lot... but if you concider the 1.8l out of the integra (I know, a very different engine) companies sell TBs for that engine with a diameter of 65mm!! Thats the only thing that makes me think boring out to 63.5mm would be okay. But now I'm really not sure.
So if the stock size is 53mm, and MAFS housing is 63.5mm... maybe I should go for 58mm? 60mm?
So if the stock size is 53mm, and MAFS housing is 63.5mm... maybe I should go for 58mm? 60mm?
I'm going to be putting a slightly used '03 1zz in my car within a month or so. The head will be ported and polished so I believe it will be a good application for a larger throttle body, so I am saving this project for that application. Unfortunatly, the results will not be applicable to stock 1zz heads but... eh....
In any case, so long as the walls of the TB are thick enough, I plan on going with 60-63mm to match the MAFS.
In any case, so long as the walls of the TB are thick enough, I plan on going with 60-63mm to match the MAFS.
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