I'm busy on stuff.
I'm no engine designer but I do a good job assembling them.
My mate Derrick is 72 years old and I follow his advice. He's my go to
guy but turbo isn't his thing.
I have two options on my new plenum design. I can go with or without
trumpets. I'm thinking they might not be necessary with the turbo application
but I have the molds and the means to do them.
I've attached two pics, one is more complicated and I need the experts to advise
on what route I should take?.
Thanks in advance.
Mike,
Adding the trumpets might increase airflow a "bit", BUT, they will definitely change the intake runner length. If the "plain" plenum has "generous" radii at the entry to the runners, the flow difference might be "minimal".
What I think you should do is:
Measure the total intake runner length for both scenarios, accurately. You want to measure it at the port centerline. Calculate which length is a "better" match for the rpm range you intend to use for your engine. And yes, engine geometry is a factor here as well.
VERY generally: Longer length, better at lower rpm. Shorter length, better for higher rpm. Unless the lengths are DRASTICALLY different, there is probably only a modest difference here.
From a practical standpoint, the plain plenum is easier & simpler. I would use it if it was close on tuned length. And I suspect Dynoroom would agree with me, but it wouldn't hurt if he would chime in with his thoughts.
Fordboy