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They have massive issues shipping things to existing customers and fulfilling existing orders, I wouldn’t count on getting one of these intakes anytime in the next 5 years
I would just say that just because something is shiny and billet, does not mean it has any engineering/science put into the whether it actually increases flow materially.
"just because something is shiny and billet, does not mean it has any engineering/science put into the whether it actually increases flow materially."
how true. sometimes.
i have always speculated that our OE UIMs may be better than most think. not shiny, not billet.
however as to the "engineering/science" maybe sneaky good.
consider our (2 rotor) engine as a two piston engine. when one piston is at TDC the other is at BDC. (when front rotor is at TDC the rear rotor is at BDC) especially on 2 cycle motors such as our 13BREWs there is a huge pressure wave formed as our ports close much more abruptly than a valved motor. this pressure wave bounces off the front closed intake port and heads back up the runner towards the just opening rear intake port.
take a good look at how the charge is guided around the "U" shaped runners and into the opposite just opening intake port.
Mazda chose to take advantage Newton's 3rd Law... for every action there is an opposite and equal reaction. one rotor helps to charge the other. nice theory, but does it actually work? unfortunately i have firsthand knowledge. i broke a ceramic apex seal in my front rotor. of course total carnage ensued in the front rotor but almost equal damage ocurred in the rear rotor. the ceramic grinding powder traveled around the runner. if you are not busy destroying your motor like i was, this dynamic inter rotor charging, seems like a win.
Mazda thought so... just take another look at how the runners are designed to loop charge air back and forth... with a small plenum to add help.
the Cosmo manifold doesn't have this.... just a plenum. no back and forth.
apparently this dynamic impressed a drag racer in Kansas... note the manifold. i am sorry i didn't record his name when i happened upon the picture. i do remember that at the time he was running in the 7s.
i do of course realise that most drag racers just run a plenum or throttle body w runners and i admit i have no idea which setup is better... and of course better for what? i am a dual purpose guy. i do know that Mazda liked the back and forth with the FD.
being a curious guy, i am interested in the JDLMFG manifolding. i already have evaluated the Cosmo plenum setup and the aftermarket version. a bit more over 9000 and a bit less under. not my preference.
Howard, the manifold you pictured from the drag racer guy is a Pro-Jay Typhoon manifold. Projay makes some seriously nice stuff!! Traditionally they've been limited to the drag racing crowd though.
it seems more likely that higher differential exhaust pressure suddenly recirculating around past the blown out apex seals blew the debris back through the intake over into the other rotor. The harmonics instantly stop when the organ bellows let go is a colloquial way of stating it. Except it’s two bellows with the good one blowing in the opposite direction. In reality it was just all rotary hell breaking loose … feeling exceptionally colloquial this evening.
Turblown - it’s been 8 months since you provided an update, enlighten us with the latest please. I know I saw one in a Rob Dahm YouTube video a little while back.
why are most aftermarket upper manifolds "all-open" and do not separate primary and secondary runners like oem? doesn't this affect low-end tq and drivebility ?
I don’t recall seeing it on their website several months ago.
**edit: surprisingly less cost than the “standard” price Turbosource has listed for their yet-to-be-available cast UIM.
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Originally Posted by TwinCharged RX7
I would just say that just because something is shiny and billet, does not mean it has any engineering/science put into the whether it actually increases flow materially.
in no way was I intending to promote it. I just stumbled across it and posted it up. I’ve spoken out many times against what is basically is some -same ol’- version of the OE manifold. Funny enough, had I posted up a Pro-Jay manifold my bet is nobody would have commented the same.
which they have been punching out more of the same ol’ with now some new ITB and Weber variations too
04-24-22, 01:10 PM
