J-Spec didn't want this over in the SR20DET forum, but I was actually enjoying the discussion. And since it was about KA-T's in a way, I figured that the thread might have a better chance of maturing into something good over here. So...
http://www.nissaninfiniticlub....72527
The last 2 posts are where it gets into the KA vs SR. What I'm mostly interested in is the cfm flow potential of the KA head, at what RPMs. I'd like to know how they compare to the SR flow numbers, which I also haven't seen.
Do any of you guys have any idea if one flows significantly better than the other?
KA-T Boost Potential
Actually, I think it's more that the SR forum is not the place to be having ANOTHER sr vs. ka argument...it's almost all been heard. I say almost because Phax has a good question that I'd like to know the answer to as well 
I know the KA exhaust side of the head sucks a bit, but after some dremel work mine looks a lot better. The intake side probably couldn't be designed much better, it's allready a very direct path and quite open. I think the KA head with a bit of work on the exhaust side can probably flow quite well, especially with some oversized valves and worked over ports.
I know the KA exhaust side of the head sucks a bit, but after some dremel work mine looks a lot better. The intake side probably couldn't be designed much better, it's allready a very direct path and quite open. I think the KA head with a bit of work on the exhaust side can probably flow quite well, especially with some oversized valves and worked over ports.
J- Spec is just doing his job as a mod. He has nothing against the KAT. In fact he is willing to help me install and tune mine if I decide to take the plunge. The fact of the matter is, pretty much any motor when properly built will hold boost and make good power. I just dont see the point in swapping in an illegal engine, when you have one with just as much potential already in the car.
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TrunkMonkey
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and neither is the KA forum. J-spec is doing the same thing i'm going to do. the sr vs. ka debate has been used, abused, beaten up, and dragged through the mud so many times until it's just ridiculous.Nathan wrote:Actually, I think it's more that the SR forum is not the place to be having ANOTHER sr vs. ka argument...
you can discuss the KA's head flow potential (or lack of) all day long, but i will lock this one if it turn into another sr vs. ka debate.
-demetrius
*edit*
toki, i deleted your post because it was uncalled for. if you have any questions or comments, email me.
[email protected]
nope...i dont hink so.What I do know about the sr head is this:
The red-top head has a hig-port design that flows really well from the factory, but has a higher potential fro flow when thoroughly worked. This is found on a the s13 sr20det, and the sr20 blacktop motor.The s14 vtc sr20det has a low port head that flows well from the factory as well, but is supposed to be lacking slightly where the red-top can flow in high cfm's.I have seen, and read studies where both heads were compared on a flow-bench and on a car. Neither of them made more power given the same setup and upgrades over the other. This applies for both worked and non worked platforms. By worked i mean valves, springs, retainers, P&P, etc, etc..The KA ports are larger than the sr's ports by physical comparison. But that doesnt mean much when you are talking about the physics of flowing air through a head. The ka should flow the same cfms if not more. Seeing as how the sr benefits much more from a p&P than the KA does.
The red-top head has a hig-port design that flows really well from the factory, but has a higher potential fro flow when thoroughly worked. This is found on a the s13 sr20det, and the sr20 blacktop motor.The s14 vtc sr20det has a low port head that flows well from the factory as well, but is supposed to be lacking slightly where the red-top can flow in high cfm's.I have seen, and read studies where both heads were compared on a flow-bench and on a car. Neither of them made more power given the same setup and upgrades over the other. This applies for both worked and non worked platforms. By worked i mean valves, springs, retainers, P&P, etc, etc..The KA ports are larger than the sr's ports by physical comparison. But that doesnt mean much when you are talking about the physics of flowing air through a head. The ka should flow the same cfms if not more. Seeing as how the sr benefits much more from a p&P than the KA does.
Well naturally, a KA head will flow more than an SR because it does have 2.4L to fill. The valves on the KA head are huge (~31mm Ex/36.6mm Int), combine this with a fairly straight high intake port tract and you will have no problems to get this head to flow. The exhaust ports could use some work for better flow.Here is a link to Modified mag's S13 project. If anyone has some SR flow bench results, please post so we can compare.
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WDRacing
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Another thing to consider, all heads from GM to Nissan are flowing less now then they did say 10 years ago. The air velocity is higher and the head design is better. So more CFM isn't always a good thing. The head has to be built with the valve size, cam turbo and rpm range all put into the equation. I hogged the hell out of my RB20 ports and killed all my low end torque. The motor responded great at high rpm under alot of boost, but the daily driver benefits went down the crapper.
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