INLET PLENUMS - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

COSSYCam · 22nd August 2006, 07:13 AM

Would a tuned length inlet plenum with individual runners the same size (similar to an exhaust manifold in design) be a way to totally overcome the problem with number 6 cylinder running lean on an RB motor?
Here is a picture of a very serious quad GT47 blown V8 featuring such a plenum.

R32 Combat · 22nd August 2006, 07:46 AM

Yes it would. The runner length is very important for shock wave tuning. I'm not too sure the setup in that pic is very good. Some VTEC engines and motorcycle engines have variable length trumpets/hornh to get the optimum lenght as the engine revs up.

COSSYCam · 22nd August 2006, 08:07 AM

Quote:

Originally Posted by R32 Combat

Yes it would. The runner length is very important for shock wave tuning. I'm not too sure the setup in that pic is very good. Some VTEC engines and motorcycle engines have variable length trumpets/hornh to get the optimum lenght as the engine revs up.

I know how important tuned (and variable length) runners are on high revving N/A motors but a isn't a forced induction plenum more about equal and adequate flow charateristics to each cylinder? Would the "exhaust manifold in reverse" design not reduce each intake pulse interfering as much as on a regular "common tank" plenum design or would the shock waves have just as much or even more effect when they are further from the intake valve ?

The motor pictured dynoed at 3900bhp on 91 octane btw

tarmac terror · 22nd August 2006, 08:48 AM

COSSY, u got a link to an article on that engine?? Sounds MEGA. I assume its a marine engine??

TT

COSSYCam · 22nd August 2006, 08:55 AM

Quote:

Originally Posted by tarmac terror

COSSY, u got a link to an article on that engine?? Sounds MEGA. I assume its a marine engine??

TT

I dont have the link on my work laptop

The motor is fitted in a street driven Camaro belonging to Jay Leno

tarmac terror · 22nd August 2006, 09:02 AM

NO WAY !!!!!. How are you ever going to get that kind of power down on the tarmac. Mr Leno would be as well buying a few hundred new tyres, pouring petrol over them and setting light to them as they're all gonna go that way in the end.

Tut-tut........4K HP in a car.......eedjit

TT

Lamb · 22nd August 2006, 09:09 AM

Talking of plenums guys..........is the greddy plenum a good upgrade on the gtr???

Seen quite a few cars running them............

COSSYCam · 22nd August 2006, 09:13 AM

Quote:

Originally Posted by Lamb

Talking of plenums guys..........is the greddy plenum a good upgrade on the gtr???

Seen quite a few cars running them............

Hugh Keir runs one and posted pictures before and after gasflowing
Std Greddy plenum

After gasflowing

The Nismo plenum appears to be about the best for equal distribution but when I asked what power they are good for nobody could give me an answer.

ChristianR · 22nd August 2006, 09:16 AM

sorry for off topic, but more info on that Camaro please!!

COSSYCam · 22nd August 2006, 09:23 AM

Quote:

Originally Posted by ChristianR

sorry for off topic, but more info on that Camaro please!!

Its Jay Lenos toy, he has over 200 amazing cars in his collection. He drives the Camaro on the street but its a full on drag car.
There is a video torrent of his car and bike collection kicking about on the net inc his gas turbine powered 280mph bike and the above Camaro.

Now back to the pros and cons of tubular inlet manifolds/plenums......

Asim R32GTR · 22nd August 2006, 09:33 AM

http://www.popularhotrodding.com/eng...05em_turbo_bb/

i think the engine did about 2200hp, and is a dragcar ??

Asim...

COSSYCam · 22nd August 2006, 10:04 AM

Quote:

Originally Posted by Asim R32GTR

http://www.popularhotrodding.com/eng...05em_turbo_bb/

i think the engine did about 2200hp, and is a dragcar ??

Asim...

Leno bought it off Moran and had it wound up to the nuts so he could lay claim to owning the most powerful streetcar in the World

R32 Combat · 22nd August 2006, 10:25 AM

As far as I'm aware, the inlet design doesn't change massively for forced induction. You still get shock waves, you just don't get inertial ramming issues with N/A.

The problem with the GTR is the physical room around no6, hence no6 suffering from inertial ramming. Fitting a GTS inlet does seem a good way around this but its tuned for a different engine rpm.

Lamb · 22nd August 2006, 10:33 AM

Quote:

Originally Posted by R32 Combat

As far as I'm aware, the inlet design doesn't change massively for forced induction. You still get shock waves, you just don't get inertial ramming issues with N/A.

The problem with the GTR is the physical room around no6, hence no6 suffering from inertial ramming. Fitting a GTS inlet does seem a good way around this but its tuned for a different engine rpm.

What inlet do you run on your beast Andy?

R32 Combat · 22nd August 2006, 11:26 AM

I've got a STD GTR inlet with a single throttle at the mo.

I've started to make my own plenum, something along the JUN/Veilside design.

I ordered a book about inlet designs, but it's gone out of publication so I've ground to a halt. I might just bite the bullet and carry on anyway with my ideas.

22nd August 2006, 07:13 AM	#1 (permalink)
COSSYCam GTR Register Member Join Date: Nov 2004 Location: Derbyshire/Scotland Posts: 1,114	INLET PLENUMS Would a tuned length inlet plenum with individual runners the same size (similar to an exhaust manifold in design) be a way to totally overcome the problem with number 6 cylinder running lean on an RB motor? Here is a picture of a very serious quad GT47 blown V8 featuring such a plenum.

22nd August 2006, 09:09 AM	#7 (permalink)
Lamb GTROC Member Join Date: Sep 2003 Location: Herts Posts: 1,330	Talking of plenums guys..........is the greddy plenum a good upgrade on the gtr??? Seen quite a few cars running them............ __________________ Too often we lose sight of life's simple pleasures. remember, when someone annoys you it takes 42 muscles in your face to frown. but it only takes 4 muscles to extend your arm and bitch-slap the motherfuNker upside the head. ----------------------------------------------------------------------- Blown by a T04z - built and mapped by Tweenierob ..... http://www.junsuperlemon.co.uk http://www.neweraimports.com

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22nd August 2006, 07:46 AM	#2 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,357	Yes it would. The runner length is very important for shock wave tuning. I'm not too sure the setup in that pic is very good. Some VTEC engines and motorcycle engines have variable length trumpets/hornh to get the optimum lenght as the engine revs up.

22nd August 2006, 08:48 AM	#4 (permalink)
tarmac terror New Users Join Date: Jul 2003 Location: Hampshire, but Scottish through and through! Posts: 2,638	COSSY, u got a link to an article on that engine?? Sounds MEGA. I assume its a marine engine?? TT

22nd August 2006, 09:02 AM	#6 (permalink)
tarmac terror New Users Join Date: Jul 2003 Location: Hampshire, but Scottish through and through! Posts: 2,638	NO WAY !!!!!. How are you ever going to get that kind of power down on the tarmac. Mr Leno would be as well buying a few hundred new tyres, pouring petrol over them and setting light to them as they're all gonna go that way in the end. Tut-tut........4K HP in a car.......eedjit TT

22nd August 2006, 09:16 AM	#9 (permalink)
ChristianR GTR Register Member Join Date: May 2005 Posts: 1,286	sorry for off topic, but more info on that Camaro please!!

22nd August 2006, 09:33 AM	#11 (permalink)
Asim R32GTR GTR Register Member Join Date: Sep 2003 Location: Norway / Oslo Posts: 945	http://www.popularhotrodding.com/eng...05em_turbo_bb/ i think the engine did about 2200hp, and is a dragcar ?? Asim...

22nd August 2006, 10:25 AM	#13 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,357	As far as I'm aware, the inlet design doesn't change massively for forced induction. You still get shock waves, you just don't get inertial ramming issues with N/A. The problem with the GTR is the physical room around no6, hence no6 suffering from inertial ramming. Fitting a GTS inlet does seem a good way around this but its tuned for a different engine rpm.

22nd August 2006, 11:26 AM	#15 (permalink)
R32 Combat New Users Join Date: Jan 2004 Location: Berkshire Posts: 4,357	I've got a STD GTR inlet with a single throttle at the mo. I've started to make my own plenum, something along the JUN/Veilside design. I ordered a book about inlet designs, but it's gone out of publication so I've ground to a halt. I might just bite the bullet and carry on anyway with my ideas.