Intake design/shape debate, end-feed vs center feed
08-26-2018, 12:33 PM
#31
Rainman
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eaton supercharger with a 16v head. No way the original manifold fits, the SC is huge and takes up all the space of the OE plenum. You'll see soon..
08-26-2018, 02:47 PM
#32
Drifting
I’m going to use this SFR regular 16V intake manifold I picked up from a fellow rennlister at a great deal and make an adapter flange. I have an issue with a bent frame I have to address before I get my engine together. I might have to visit Luis if I can’t get it fixed. But there is a Porsche frame specialist in Lakeport, Ca but he usually deals with 356’s and old 911’s. I hear he’s really good thou.
08-26-2018, 09:30 PM
#33
Rainman
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That'll be interesting to see, the port shapes are really different. I made a simple gasket adapter plate just to work for running NA like for smog testing, probably not great for pure airflow.
the manifold im putting together has a waterjet flange made specifically for the 928S3 head and 1-7/8" runners, perfect fit.
the manifold im putting together has a waterjet flange made specifically for the 928S3 head and 1-7/8" runners, perfect fit.
03-15-2019, 12:38 PM
#34
Three Wheelin'
I'm going with end feed. I really thought long and hard about the double plenum. I bought a s2 intake from Spencer, a plenum from mazworx and velocity stacks from Ross machine racing. Waiting on my new tig welder to show up
03-15-2019, 01:07 PM
#35
Rainman
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is that your discussion on FB (yesterday) about the intake?
it's a 3D stop sign
looks like a huge volume inside, very interesting.
BTW for this thread, i wanted center feed but it wouldn't fit in my space envelope so i went with end-feed, with a 2.5->3 elbow tapering up to slow/expand the air and turn it before it actually enters the "plenum" in front of the runners..
it's a 3D stop sign
looks like a huge volume inside, very interesting.
BTW for this thread, i wanted center feed but it wouldn't fit in my space envelope so i went with end-feed, with a 2.5->3 elbow tapering up to slow/expand the air and turn it before it actually enters the "plenum" in front of the runners..
03-15-2019, 01:25 PM
#37
Rainman
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to summarize from the TB threads from years ago, basically match it as best you can to your IC pipes/IC outlet size.
the Ford engineer's thoughts were in essence, "if the TB is smaller than your pipes you'll probably find a gain by going bigger. if the TB is bigger than the pipes, probably not."
IE a 2.5" 16ga pipe has about 2.38" ID = ~4.5 sqin.
a 65mm TB (like Ford 4.6) is about 5.14 sqin before you subtract the throttle shaft from flow area, about 8mmx65mm brings flow area of 65mm TB to around 4.34 sqin. close enough.
using that 65mm TB refresh951 picked up like 30 hp vs the stock 951 55mm unit and it smoothed out the power curve nicely up top too.
the Ford engineer's thoughts were in essence, "if the TB is smaller than your pipes you'll probably find a gain by going bigger. if the TB is bigger than the pipes, probably not."
IE a 2.5" 16ga pipe has about 2.38" ID = ~4.5 sqin.
a 65mm TB (like Ford 4.6) is about 5.14 sqin before you subtract the throttle shaft from flow area, about 8mmx65mm brings flow area of 65mm TB to around 4.34 sqin. close enough.
using that 65mm TB refresh951 picked up like 30 hp vs the stock 951 55mm unit and it smoothed out the power curve nicely up top too.