Im thinking about istalling a Holley throttle body on my slightly modified 1.6 vtec, and was wondering if a 68mm would work just as good if not better than a 62mm. I been told that a 68mm is really made for a turbo or a super charger, I have a naturally aspirated vtec. So can any one tell me from experience or knowldedge if a 68mm will work fine with out any problems of any sort? Any info would greatly be apprecciated.
I think 68 is bigger than the manifold, so it would be a little weird to put it on. but as for it only being for turbo, no way, NA will love the big TB. the throttle response will be outrageous. but if you do put it on, port match the manifold to the TB.
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Yes, there's a "Replacement for Displacement". Its called Volumetric Efficiency.
Ok, this is probly a dumb question, but how do you port match the manifold to the throttle body? I personally dont know. Do you drill new holes in the manifold, or the body? Or, can you just get a throttle body spacer and adapt it that way, is that even possible? Please let me know!
you use a dremel and reshape the manifold to the same size opening as the TB, with a nice gradual taper into it. if there is a lip going into the manifold from the TB, it will hurt the power a lot.
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Yes, there's a "Replacement for Displacement". Its called Volumetric Efficiency.
I went to the Holley site, and here's what they had to say if it would fit the stock manifold.
"Holley's 68mm Honda Civic throttle bodies fit the stock manifold plenum
flange and have provisions for the fast idle valve, MAP sensor, TPS, and
EAC valve"
The funny thing is, is that on some of the other sites that I have visited about the TB, they say that some port matching may be required. Well, who should I belive?
Does the manifold have to come off inorder to do this? So basically you're just matching the opening of the intake to the opening of the throttle body right?, where both openings are the same diameter. Can any mechanic or a shop do it?
a performance shop should know where to go. you can do it yourself, but if youre nervous, just take it off and take them both to a local machine shop. this would be a good time to step up to a Y8 manifold. or even an aftermarket piece like a skunk2.
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Yes, there's a "Replacement for Displacement". Its called Volumetric Efficiency.
Sounds good, as for the intake manifold will Y8 bolt right in, any machine work or any thing of that sort neccessary? How about the comression ratio? What gains could I expect? Also, here's a few manifolds that I looked at on Ebay, please take a look and let me know if you see any thing worth while.
I think I'll save up for Skunk2 manifold. That will just bolt right in to place instead of the stock one right? Also Im assuming that the manifold will need to be port matched to the 68mm Holley TB righ?
Holley throttle body, 68mm, would it work?
