Author Topic: Custom Intake Plenum (Read 32308 times)

Danny707 · « **Reply #15 on:** March 09, 2009, 09:48:07 PM »

The throttle body goes before it?

rob_e30 · « **Reply #16 on:** March 09, 2009, 09:52:03 PM »

Quote from: Danny707;68003

The throttle body goes before it?

Yes. There is a bit more work to do with the charge pipe to the throttle body but there should be room for everything. We are running a much wider radiator than a stock M42 so the top radiator hose needs to be changed a bit.

Appletree IS supercharged · « **Reply #17 on:** March 10, 2009, 02:34:49 PM »

What rad do you use rob? might be worth considering in mine

bmwman91 · « **Reply #18 on:** March 10, 2009, 03:45:32 PM »

Looks like fun! Any plans for velocity stacks in there? What design guidelines did you use for sizing the plenum with the runner length & diameter?

tjts1 · « **Reply #19 on:** March 10, 2009, 03:59:51 PM »

Really impressive work.

rob_e30 · « **Reply #20 on:** March 10, 2009, 04:03:55 PM »

Quote from: Appletree IS supercharged;68061

What rad do you use rob? might be worth considering in mine

The E30 Competition Radiator from Zionsville. It's the same design as the M20 radiator but with 35% greater capacity.

kowalski · « **Reply #21 on:** March 10, 2009, 05:05:11 PM »

Hey Rob, YGPM

rob_e30 · « **Reply #22 on:** March 10, 2009, 10:09:23 PM »

Quote from: bmwman91;68064

Looks like fun! Any plans for velocity stacks in there? What design guidelines did you use for sizing the plenum with the runner length & diameter?

There are a number of variables that I tried to take into account based on the details in Forced Induction Performance Tuning by A. Graham Bell. Runner diameter, runner length, throttle plate size, plenum volume, and plenum wall distance were all factored in. It's tough to explain the interaction of them all here, and like everything else it all involves a series of trade-offs.

Given the curved lip at the entrance to the runners and the fact that it's FI, I do not plan to introduce velocity stacks.

e30guydownunder · « **Reply #23 on:** March 18, 2009, 05:20:12 PM »

it seems like quite a small plenum? i take your book would have given you direction on plenum vloume, whats the general theory behind plenum volume with FI?

apart from that looks good, its a nice simple (relative anyway) design that maintians nice airflow and distribution. Will be interesting to see any wheel horsepower differences...i will assume you'll be dynoing after the install?

rob_e30 · « **Reply #24 on:** March 19, 2009, 09:16:17 AM »

I don't have the details on the calculations and recommendations with me, but plenum size varies with displacement as well as the type of FI that you're running. I do recall the recommendation for turbo 4 cylinder was 1 to 1.5X displacement which would make this a 3L plenum, and is about the calculated size. I've not measured the actual volume. Other FI applications (roots blower for example) require a larger plenum in order to smooth out the pulses from the blower itself. At least according to the book.

I think if you look at other plenums from companies with a large R&D budget you'll see that the size and shape conforms nicely.

e30guydownunder · « **Reply #25 on:** March 19, 2009, 06:05:00 PM »

thanks rob, 1.5 was the figure i had in mind for FI, didn't know about the differences for supercharging thou, might be worth while finding myself some literature.

95m3032679 · « **Reply #26 on:** March 21, 2009, 09:45:46 AM »

Impressive work indeed

rob_e30 · « **Reply #27 on:** July 25, 2009, 02:41:52 PM »

Got the plenum powdercoated and installed, along with the re-routed charge plumbing and coolant hoses.

And this one...

kevins08 · « **Reply #28 on:** July 25, 2009, 03:29:33 PM »

i might have to buy one of these from you. interested in knowing how much power gained for sure though! and does the price include powdercoating?

psyyambmw · « **Reply #29 on:** July 27, 2009, 01:53:26 AM »

Quote from: rob_e30;75856

Got the plenum powdercoated and installed, along with the re-routed charge plumbing and coolant hoses.

]

Omg!!!!!!!!!!! :eek: What a beauuuutiful M42 turbo I've ever seen.

Quote from: rob_e30;75856

And this one...

What throttle body is that??? and what's the oil filter cap you got, Rob???

Cheers,

George