Possible bernouli effect in plenum ?

[Fastrotor]

Hi All,
I made up a plenum thats sits atop of a twin 50mm IDA throttle body. Inside the plenum is two 50mm ram tubes / bellmouths ... now this is on a turbo charged rotary, and i have a 3" inlet coming in the firewall side of the plenum perpendicular to the ramtubes...

My concern is that because the ramtubes finish about 3/4 of the height of the incoming 3" tube , effectively allowing the incoming charge to blow across the top of the tubes , could this cause a bernouli effect ??

Im not sure since the plenum is sealed and all air entering will be forced into the ramtubes and into the motor... but can a slight bernouli effect partly counteract the flow into the tubes and lower the effeciency ?? As in kill off the top end or something...

it been something that has worried me since i built it .. figured i'd thro it out the for some experts... as its abit over my head.

Thanks

Gary.

 

[Tmoose]

There are many tales of extreme tuning woes including extreme rich-ness and lean-ness at certain boost levesl on the various turbocharging and supercharging Yahoo and Usenet groups. Many seem to be related to inlet "bonnet" conditions fouling thihgs up, whether bulk inlet flow, or local pressure problems in the vicinity of the bowl vents. Corrections, when found, sometimes involve flow straighteners or grosser measures in the form of perforated plates in the inlet. It sounds like it is NOT all good.

 

[Viper488]

I'd say if there are any problems, they might be more related to the size of your plenum and how that larger size slows down air after it's entered the plenum. If you're question is concerning WOT then your engine is sucking it all in anyway. Not much time for incoming air to rocket past the bellmouths is there?

If you're accessing supposed high pressure air from windshield base,it's not enough to charge your 3" inlet anyway I'd guess

.. I'd get rid of the ram tubes anyway. Why do you need ram tuning with a turbo? Turn up the boost man!