I'm in the position at the moment to pick up a Mustang Cobra twin 57mm throttle body (big deal you ask, but i can't get them here in australia) quite cheap. Exactly like this:
Has anyone contemplated using such a tb in an all motor application? It would be using a standard plenum for now, attached to the tb by a custom fibreglass section. As it stands, the car has a custom reground cam (262 inlet and 264 exh duration) and PnP'd heads, headers and a 2" mandrel bent exhaust (which will be upgraded to 2.25" mandrel bent soon). A piggyback ecu will also be thrown into the mix shortly.Opinions/Criticisms?
Twin 57mm throttle body?
I will be doing something about the plenum/runners soonish...-
Open4Cycle
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Open4Cycle
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Actually I wasn't camparing it to anything. It was a nice thought of something he may have overlooked for his application.(OVERKILL) If its for a 2.4 litre then you can at most only draw 350CFM at 8000RPM's. It would be nice to have some flow bench data from each. Working on testing the KA body very soon. The idea of higher velocity from the twin is good but your not going to have the air flow of a 114mm single TB from the twin 52mm. Don't forget there is more tubing surface drag. Where are you planning to mount the throttle body on your custom plenum? Inbetween primaries tubes 2&3 or on the end close to number 1? That could be an interesting design.Goodluck
Does anyone else think this is a waste of time on an NA engine? I mean, with lots of work I can see the benefit to upgrading the throttle body but that is crazy, I don't think you could ever flow enough air to take advantage of the larger size unless you had forced induction.
? Would be VERY interesting to see though with a custom intake manifold, please prove me wrong!!
Timhttp://www.projectaspec.com
? Would be VERY interesting to see though with a custom intake manifold, please prove me wrong!!
Timhttp://www.projectaspec.com
It may seem a waste of time, but when you compare the openings on the twin 57mm Cobra TB compared to the std KA, the intake velocity of the Cobra TB ideally would be higher, thus improving cylinder filling, hence torque. If i don't get this Cobra TB, i'll be having a twin tb setup fabricated with no smaller than 45mm openings.
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Scott McLellan
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Twin 57 mm throttle body has 5,100 square mm of opening vs the single 63.5 mm throttle body's 3,165 square mm of opening. That's not 114 mm of flow (10,200 square mm of opening). Remember pi times radius squared? As the cobra throttle body was designed for a 4.6 L V8, I am kind of questioning the need for that much air flow on a 2.4 L 4 cylinder with basically the same rpm's range. Sure it would be cool to say you have a cobra throttle body, but it doesn't seem to be very smart. I agree with Rownan, "The greater area allows more air to pass but at a lower velocity." This means less torque. Bigger isn't always better... If this were true, why not go with a 5 inch exhaust? I'm sure you could pick up the piping from the sewer company for "dirt cheap." I can maybe see upping the throttle body dia. 5 mm tops, but after that, it is forced induction territory. Hey Aries, you have messed around with the LT1 V8. Stock throttle body dia. is like 48 mm (twin). After market ones are offered in 52 mm and 58 mm and all the companies recommend 52 unless you have forced induction or a very radical race engine. The 58 loses so much low end it isn't even streetable on a NA engine. Back to the KA. There are restrictions in the engine, but don't expect the throttle body to be the only one as an engine needs all of its parts to be balanced to each other to perform well.
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Nismo_Freak
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