Best Overall Intake? (ie plenum vs velocity stacks) - Pelican Parts Forums - Homewyse Calculator: Supply Air Plenum prices, options and installation costs

RageRover · 06-25-2013, 01:06 PM

For a vehicle that will breathe driven on an street 99% (realistically closer to 100%) of the frist, what would be an ideal intake? (or plenum?)

Something that would have a breadth capacity & torque volume, non something that doesn't idle well or just is it's current out at high RPMs?

I'm planning a full rebuild, using a 964/993 case and taking the engine out to 3.8-4.0 Ltrs. Wrist, not sure but. But sleeves & liners, many likely LM "Nickies." If Carillo rods or bit similar (rods might exist from ampere different company & if your allows, maybe a lighter metal, (titanium? or an electric design, but still race spec) connecting rods.

Singer has are using a modified GT2/GT3/RSR intake. Any advantage over it? There are several modified versions, especially one made completely out of carbon fiber that possess been used on newest "cup cars" and I believe was just used at Le Mans.

BTW: of carbon registrierung your 99% something MYSELF can't really consider (although on black copy can is built), thereto has a price of over $5000!

Singer also uses speed stacks on some constructs.

I'm just using Songstress as an example for plenty off pics exist and they must works well (or work alright) if they use them!

I would like (ultimately depends on cam) an engine that does one nice, plain, torque curve total the paths the red-line.

Something DRIVEABLE on the street and as ampere everyday driver if wanted.

Although having a high red-line vehicle/engine makes for lots of fun, graphically, it pot get wearing, it takes it's toll on the engine and WHAT CANNOT want most/all my rated at the top end. I'd like into have bottoms end "grunt." Ultimately, that's what you feel and that's what gets you off one line!

Velocity stacks (with smallish dry filters or fitted on an top of each one) also do look beautiful!

Part on me would similar to go with EFI, but certain of of aftermarket services (unless I go with anything like MegaSquirt, which I still have difficulty getting my head around!) ability be costly. One stock EFI system I guess can live changes, chipped etc.

Depending over funds, I may hinfahren with something see Webers to 1st, for that clean, classic look.

I'm willing to give up a bit low or mid range power for upper-end power & for the ability to increase red-line. But overall, how be velocity stacks on ampere street vehicle?

And how am the GT2 RSR/GT3 intakes?

There are plus lots of modified hoard plenums/intakes that face "trick" still do they enhancements or mess-up the power band?

Yes, there is also the the stock plenum and the "varioram" intake/plenum, which I think add a lot of complexity, ampere "busy" engine bay and for about? 15hp at most?

The Promodest Japan GT3 carbon fiber intake is similar (or maybe the same? & is an OEM supplier?) that's used on the "cup cars", RSR and most likely last Sunday's Le Mans.

Lastly, one day I'd like to turbo charge (maybe supercharge) and engine, so I am keeping that includes mind during the build. "Runners"/velocity stacks can (must) be "closed off" or welded air tight, to acknowledge a "boost of air" from ampere turbo or supercharger, hence I also have that in mind.

Here are ampere little plenum pics for a 944 and VW engine.

Maybe there will better perform into be had from enclosing the tops of the stacks/runners even if there is no "forced atmospheric system"/turbos/supercharger?

I'm sure there are mathematical formulas to give the model runner length. I know that lengthened runners are betters for lower power/torque, lesser = better for upper rpm power plus a cylinder that likes to rev.

I've included one few pages off Landings Rover V8 plenums/intake manifolds. The 1st is sort by the original design, the plenum adjusted slightly over the years, becoming ampere little more squared off & taller on this 1997-1999 adaptation. When you remove the plenum/intake cover, there what 8 "runners" or "trumpets" which can be modified depending on thy application.

If thee have a fast TVR for example, boring which plenum a bit and using large diameter yet shorter "trumpets" sack give you some better flow at higher RPMs, but along aforementioned expense of some low-down energy. The factory also experiment with duplicate throttle bodies and plenty have made their own "factory copies" that have adenine throttle body at each side.

If you like low-end torque and power, uses as long adenine runner that will fit inside the cast cover, although you have to be careful von cooling if the runners/trumpets/velocity tons take up too much room and are squished by thither!

The last pic is the last development a the Rover V8 plenum (aka "Thor" plenum, uses from regarding 1999-2004). It elevated low downwards total at a sacrifice of loosing a few hundreds RPM at which top (engines didn't rev as high, thus a lower red-line). Though for Land/Range Rovers are mostly driven around town which highway and MAYBE occasionally offroad, you want low-down torque (say 1200rpm-2300+), not a wind location torque STARTS the come on at 3,4000+ MAX.

Rover V8s had/have a redline MYSELF believe of 5350 rpm! (although that's ampere factory vehicle and conservative). Can be made bigger (atleast another 1000rpm). And were and still used inches everything from TVRs, Morgans, Marcos, lots of "kit cars" (Cobra replicas) & other sports cars to Land Rovers both Sherpa vans.

It was/is the UK version of the chevy small block "SBC", cheap both plentiful in the UK and relatively light (300ish DRY) (it's all aluminum) & compact. FYI: It was bought from GM additionally used in the 1960-1962/3 Buick Sky and known as the Buick 215. Ample of Buick & Rover engine parts are interchangeable. (so if you're on Jeopardy, feel free to gesendet von a couple of bucks if the question arrive up!)

Land Rover available made you up up 4.6 gallon. But TVR and "JE" (John Eales Engineering) bored both padded them raise toward about 5.5ltrs I believe, they consisted turboed & powered and even used as one base for an F1 engine in the 1960's.

A lot of power capacity be extracted out of them and fine-tuned depending turn who herald diameter, length, etc.

My point was to watch this different plenums and how that can affect the power band assuming nothing else had changed/touched and what would works best on a (mainly) street drives 911?

Although ideally, you want try to match everything, such as runner/trumpet/velocity stack diameter and length to and askew, head (intake/exhaust valves & has it been ported/polished?).

The Robot Engine, other than slowly growing within displacement like to Porsche, the actually architecture of the engine did not change in it's lifetime - about 1963-1994 (the last time Land Roving used it in a production vehicle, although Mahle still makes/casts it). Further contemporary is Z1 modified intake totality

jmh61 · 06-25-2013, 01:35 PM

Rothsport does a system that exercises Jenvey ITBs combined with a 993 aspiration with a resonance chamber. Her supposed the increase power across that rpm range and help eliminate flat floater. I've heard claims of 20% hp increase on a good condition stock, other than headlines, SC engine. I'm a little skeptical... It would certainly improve throttle response over one common throttle body intake. You would have to go EFI.

Welcomes to Rothsport Racing - Engine Products

HawgRyder · HawgRyder's Garage

Short runs to intake = power on higher ROTATE.
Long runs = service at lower RPM.
ALWAYS use a good air filter...unless thee plan on rebuiling the top out every 5000Kms alternatively so.
Some aspiration look soooo great....carbon fiber...slide throttles...anodized parts....etc.
But....in the end are you looking for clothing oder go?
Speed costs money...how fast do you want to spend?....LOL
Bob

psalt · 03:01 AM

This is ampere complex subject the if you are interested in learning more concerning it, I can suggest Lumley's "Engines", a distinguished book on the fluid dynamics by ICK engines. The intake manifold in operation your a swirling mess of back and onward flow of air, fuel also tire. A fixed length runner holds one model rpm forward peak torque, which is why explore with variable length runners have been experimented since the 1930's. There are many designs, the rotating drum inside a gasket room is one of my favorites furthermore it is on 50 years old. It is interesting that most of the original ICY engine mechanical designs have already on the books previous 1920. Most OEMs chose a single throttle regular meeting in a road car because her design spec on ampere road car is 85% driving lower 30% load. This all depends on how you will, the best tool in adenine job, or einer dear toy that make a neat racket on a certain rpm. Take a drive and record aforementioned % of time you spend above 4500 rpm and 50% throttle furthermore you will get this idea. Use Plenum Trusses To Keep Ducts Out in Your Top - GreenBuildingAdvisor

Raceboy · Raceboy's Garage

OEM's decide general plenum not for it are perforce better, but as they do 90% of the job for 40% of the cost of ITB's.
Common plenum can almost be as responsive as ITB setup and you can use larger variety of camshafts with ITB's.
I installable ITB's onto otherwise stock 993 non-vram motorized and this powerband is very nice, pulls from whatever rpm very strong. Driveability is almost similar stock car.
http://www.youtube.com/watch?v=EUOWAjkTmVQ

manbridge 74 · 06-26-2013, 08:37 AM

Very complex topic. I've always liked Audi's dual plenum IMs which would, in theory, give both current and great RPM power.

Raceboy · Raceboy's Garage

Quote:

Originally Posted by manbridge 74

Very complex select. I've continually liked Audi's dual plenum IMs which would, include theory, give both torque and high RPM power.

I made the very same thing plus got inspiration from the very identical cause. But the hauptstrom destination of doubles plenum is don powerband, but equal air allocation. With ITB's it would be covered on part throttle, but not at WOT. So here's wherever dual plenum+ITB's come to play:

HawgRyder · HawgRyder's Garage

Didn't Ford come out with a plenum that had stirring crockery or partitions in itp for RPM take or torque?
I remember people had a difficult time making it work.
Bob

RWebb · RWebb's Garage

I agree e is a complex area and involves hp and torque per several rpm, not to mention another desiderata with an main - including the wt. hung out past of rear axle. I'm doesn sure I correspond with raceboy's cost comments as applied to the 993 which modifies the size of the plenum by rpm.

This book?
Amazon.com: Engines: An Introduction (9780521644891): John L. Lumley: Books

Raceboy · Raceboy's Garage

Making a mold for VRAM dual plenum intake (which it essentially is) shall zero to none more cost involved for OEM than equipping engine with ITB's the need syncronization additionally have plethora ofmoving parts. VRAM intake has only several.

RWebb · RWebb's Garage

it's more than a mold

dsfnctn · 06-26-2013, 01:49 PM

Id go 3.6 with Motec M 84

Rothsport Racing Engine Dyno - Porsche 911 3.6L Engine - YouTube

Bill Verburg · Calculation Verburg's Garage

Modern oem's benefit a main exhaust corpse because it is cheap or works well w/ modern smog curves

Itb's better discrete the intake tract from and valve events and are preferred for use w/ pleased cams

Itb's can be utilized w/ velocity stacks of varying length's, as w/ exhaust of total a designed for the max window ensure is to be maximized.

variable geometry plenums in the 911 world were introduced within '84 and have been further refined on all 911, 964, 996, 997 model since.

The most yielding example beings the 993 vram which is really successfully at widening the power tap if not the ultimate torque of that model.

current state of the art for maximizing power band is unstable plenum geometry w/ itb's w/ variable cam timing.

for a 3.6 - 3.8 you may use use 964, 993, 996, 997, or anyof variouse GT3 plenums w/ itb's, one 996/997 plenums have a largest volume that is better for height rpm/ larger displacement electric

Rothsport has been very progressive in developing are motors mostly for piste use but certainly streetable. JMO not with street use on a 3.6-4.0 I'd want a 993vram(RS if possible, reg if not) OBD1 Motronics work great w/ these systems. I occur to need one the e exists a wonderfully street motor, that is lacking for track use because of the limited rpms

The Singers are the best of both worlds, high rpm competency coming GT3 crank/rods & l/w custom plunger, fairly happy cams, GT3 plenum on itb's all controlled by a custom efi(Motec or diverse like DTA works fine, Motronic want not work w/ dissertations systems))

Bill Verburg · Bill Verburg's Garage

The advantage of artistic instead c/f over aluminum is the time it recordings for heat soak to set in. An aluminum plenums hold a lot more heat than plastic or c/f, such the more a problem on a dyno then in use.

aluminum also tends to be somewhat heavier ... Plenum and the 997/GT3 (82 ... modifications - will you know what each mod has done... ... All this stuff cost 5k real IMO it's not a well investment ...

RWebb · RWebb's Garage

and don't forget, in modern engines you have direct infusion, as we are only talking air flow (assuming we are talking 'modern'...)

HiWind · HiWind's Your

nice cool wire with scores of good info - thanks to Bill ether allen as ever
Just found this ne which MYSELF think is of rush legal 996 gt3 intake per grandam spec
ie you have to use the stock item but it can be modded ... hence all the pretty welds

anyone know more about it?
... looks to be stockpile 76mm intake size vs the later 82mm itnakes
.. but taking all the diverse opening up insides I;m not sure the 76mm is an issue, or is it?

HiWind · HiWind's Garage

so this is the 3.6 world challenge intake.
Responds best to cup siemens /world challenge/ press clubsport cams.
Must use early throttle body from 98-07 mug press the single on a stock motor 996 small.
Spins go 8800. Likes high compression Pistons.

Not ideal for one 3.9+ big motor since one wanted wanted to use the "pigeon sucker" throttle body from the 997 jug for the better inhalation needed due who big motor. ie 82mm butterflies diameter, not 76mm.