Dropped plenum question - ZR-1 Net Registry Forums

LGAFF · 10-12-2013

While we have some hood restrictions...would it not make more sense to have a topped vs dropped plenum to get the plenum runner further from the ceiling/wall? As in adding the volume to the top of the plenum?

Any thoughts?

LGAFF · 10-12-2013

Kevin · 10-12-2013

big runners and dropped is so sexy....that's about as helpful as I can be

Coupe89 · 10-13-2013

Isn't the TB the restriction on air flow into the plenum ?

Bob Eyres · 10-13-2013

Quote:

Originally Posted by Coupe89

Isn't the TB the restriction on air flow into the plenum ?

Yes, but you can get a bigger one of those.

Didn't Lingenfelter use the dropped plenum on some early (or all?) 415's?
I would think that with a dropped plenum, and siamesed runners, you would need a BIG stroker sucking on it to keep the port velocity up.

If you did anything to the top of the plenum, you would need a high rise hood. Mine's banging on the hood now, with just those phenolic plenum spacers.

Kevin · 10-13-2013

LPE used the dropped plenum on some cars. Mark Horner's 385 has one, i know others have it also but i can't think of them off hand.

Blownrunner · 10-13-2013

Quote:

Originally Posted by LGAFF

I have seen pictures of this on cars. What is it and what does it do? Where does the DIS module get mounted?

Kevin · 10-13-2013

Quote:

Originally Posted by Blownrunner

I have seen pictures of this on cars. What is it and what does it do? Where does the DIS module get mounted?

adds volume and the dis box gets relocated to the firewall

Vette Guy · 10-13-2013

I have not pulled the plenum on the 385 Z since I've owned it, however Bob Hall tells me that it is a work of art! The DIS has been relocated.... I'll take plenty of photos when the time comes to remove it. I understand that the dropped plenum added quite a bit of torque throughout the rpm range.

I always wondered what happened with Bill Kirchoffer's prototype carbon fiber plenum. Anyone remember seeing it at BG in 2003? I recall it having more space up top and direct ports to the IHs.

Mark

FU · 10-14-2013

Geez Mark , that entire car is a work of art ! Talk about one well sorted out car.

10-12-2013	#1
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Dropped plenum question While we have some hood restrictions...would it not make more sense to have a topped vs dropped plenum to get the plenum runner further from the ceiling/wall? As in adding the volume to the top of the plenum? Any thoughts? __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

10-12-2013	#2
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Dropped plenum question __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

10-12-2013	#3
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,624	Re: Dropped plenum question big runners and dropped is so sexy....that's about as helpful as I can be __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

10-13-2013	#4
Coupe89 Join Date: Aug 2009 Location: Livermore, Ca Posts: 193	Re: Dropped plenum question Isn't the TB the restriction on air flow into the plenum ? __________________ 1990 ZR-1 #642

10-13-2013	#6
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,624	Re: Dropped plenum question LPE used the dropped plenum on some cars. Mark Horner's 385 has one, i know others have it also but i can't think of them off hand. __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

10-13-2013	#9
Vette Guy Join Date: Jul 2005 Location: San Antonio, TX Posts: 658	Re: Dropped plenum question I have not pulled the plenum on the 385 Z since I've owned it, however Bob Hall tells me that it is a work of art! The DIS has been relocated.... I'll take plenty of photos when the time comes to remove it. I understand that the dropped plenum added quite a bit of torque throughout the rpm range. I always wondered what happened with Bill Kirchoffer's prototype carbon fiber plenum. Anyone remember seeing it at BG in 2003? I recall it having more space up top and direct ports to the IHs. Mark __________________ Mark Horner President, ZR-1 Net Registry 91 ZR-1 #2016 95 ZR-1 #21 DRM-600, LPE 385

10-14-2013	#10
FU Join Date: Mar 2004 Location: Found Member Posts: 4,327	Re: Dropped plenum question Geez Mark , that entire car is a work of art ! Talk about one well sorted out car.