ok honda-tech Guru's... here is my question and i want to see if this has been done or not and if not - why not ... what would make this a bad idea.... or what could make this a good idea to try...

so ive been looking at different styles of intake manifolds for N/A motors and over the years ive seen ones that are built just like the usual honda ones -- sk2 style or edlebrock ones or even the stock ones..... but then ive also see ones that are equal-length runners that lead to a small collector that a throttle body is directly bolted to.... now to my understanding that this type of equal length tubular intake runners allow for a high torque rate lets say compared to the usual honda type manifold...

the equal-leghnt tubular runners version i will say for an example of this is the toyota corolla 1zzffe motor intake manifold... if you take a look of how this manifold is designed it almost looks like some of the honda exhaust manifold for n/a or turbo .....

so my question is has any one every tried creating this type of a spaghetti runner equal length type intake manifold.... or if not y not...

i ask this since lets say we look at the b16a motor that everyone says that its missing torque or no low end power, but with my understanding about this type of intake manifold that toyota brought out for that motor --- that toyota went with this since it produced more torque and low end power but allowing for also a higher top end rpm and power band similar to the honda vtec of that time but was used only on thier single cam vvti motor.... ( and for sakes argument yes i know that the honda has a 1.6 vs the corolla 1.8 but this whole thing is more for the performance of the design of manifolds)

SO my thing is why not try this type of manifold if it produces better torque numbers and still allows for a good wide open throttle at 9k.... i know it would not be good for force induction but for a N/A motor would it be a benifit???

these are images of the toyota corolla 1zzfe intake manifold--- my question is could a style like this be used on a b16a maybe with a little longer runners on the manifold....

http://i.ebayimg.com/00/s/NzY4WDEwMj...)CQ~~60_57.JPG
http://i.ebayimg.com/00/s/NzY4WDEwMj...Bzw~~60_57.JPG


i know this is a long post but this has been on my mind for a bit and im thinking of building this manifold if it seems to be a good idea, i even have a jdm b16a block (stock as of now) with a gsr head and ARP head studs that is ready to be rebuilt for testing trials of this type intake manifold... but also im building the motor for a track car that i putting together, so i want the motor to remain N/A and i think maybe this idea could produce something that would help n/a motors produce some better torque numbers..... but hey this is just a theory, i looking for people ideas and thoughts about this..... ive been searching around for a long time on this subject and idea and so far there is no real information about this type intake for a honda, ive seen some info for toyota's/... so ive now come to my last resort of all information --- the guru's of H-T....


thank you

 

well I'm not a guru... but as far as I know, the length determines end power and torque. With a long duct, torque increase and low end power too, with a loss on high end power. But that's not universal! Could be curious to have a try!

 

Ive seen them and always wondered how they did on a power scale but now that ive seen it better it looks like if you bored it open a lot and stuck a big TB on it, it would respond similar to itbs with long runners

 

There is a point where cost becomes an issue, and for the cost you would expend to get this setup going you could likely just DIY some ITB's and solve the problem with a far simpler solution and likely make more power.

 

length adds friction... so while the numbers work..
the longer the runner the more restriction you'd put to it..

so tis a balancing act... between the victorX and the ITR length style...

between that we have the performerX and now the skunk2 ultra street

have to factor in distribution of air on 4 runners
the plenum does this (bigger plenum slows air down)

transfering the sequence from Low pressure (high airspeed) intake pipe to TB
and high pressure (low airspeed) into plenum

so at the end of the day.. adding length for torque supposedly would add more restriction at the top then adding dia. to runner to gain the top end..would prolly just put u in the same window as an ITR manifold.. as far as compromises go

most of the critical work would be on TB placement and plenum sizing..
to contain the size big enough to be an air tank/reserve for each runner when theyre sucking in... ofcourse runners matter but...at wat cost?

our engine bay
adding length
= more bends = more restriction

 

okay.. everyone is making a valid point on this issue, but as for comparing this concept to the itr and sk2 manifold i fully understand that concept of the transference of sequence and other aspects of this , but my whole thing with this it instead of having a large plenum like those manifolds,to distribute and slow air speed, why not have a small like plenum w/ runners to increase the low end of these motor and maintain the higher air speeds within the runners , scarifying the top end a bit to create a better curve and response... remember this idea is for more not drag racing setup but more for a time attack or circuit racing where this motor will be in a high rpm for long time periods... at wot......

now as to just going to itb's thats a whole headache in its self getting the throttle bodies to work in tandem with each other. plus the cost of making this type of manifold wouldnt be near as expansive to make compared to making and itb setup and get it working or buying one already made... you have to think its kinda like a exhaust turbo header in structure and all these runners will met to a point at a small plenum or lets say a collector where you would have your vacuum line ports and a throttle bottle bolted right to that... cost and construction wouldnt be that much... now on another note the whole just go to itb and long runners ... the whole concept with this also is still maintaining the throttle body setup and the ability to tune easier since you would be retaining the oem setup of conectors and sensors within the small plenum.. it would be as easy as switch sensors and plugs and bolt up to motor and go just like a sk2 or oem manifold..... then getting the ecu tune with the new setup....

again eveyone has made good points and great remarks but let's keep this going so anyone with thoughts about all this?

 

i understand wat you mean,

as we do road racing quite alot...

about runners and small like plenum,

plenum will have to relate to displacement size..
if going small then the d16z6 IM is the result.. being under 1liter plenum to a 1.6liter motor

the plenum act as a "reserve" tank... while the TB becomes the "vena contracta"
and the intake pipe as a 3inch or 3.5inch.. this makes the TB sorta like a venturi

the intake pipe and TB's job is to fill the plenum...in some cases get it packed real good
for when the runners (on the firing order) sucks in (valve open/induction stroke)
its getting a packed/denser charge into the runners,valve and into the chamber

this is what gets most to 100% VE and sometimes above 100% VE

without it, it becomes like an ITB aproach (even if u had a small plenum)
using the runner's length or taper to generate airspeed to pack the chamber with attempts of getting 100% VE

length and or taper will gain more friction and flow losses, so a compromise has to be met,

it would be interesting how you go around the challenge

thats a fun development right there man!

 

Most testing I have seen show that relatively tight (small radius) bends on the intake runners looses HP (especially in the high rpms), some say even very nice/long bends looses a little hp (most proper racecar-developed engines have straight runners, but I have seen a few with a significant bed, but most of those have been engines running restrictors).

The only one I have seen with serious bends and serious HP that has been tested against other aftermarket manifolds is the Joe McCarthy 9.0 mani, and the bends on that one is not really that tight. Also he uses huge inner diameter runners (61mm I think), which will take away the gains way down low in the rpms (especially combined with big cams).

The reason why Toyota used this design is probably to take advantage of the 2.order harmonic. If you tune the length of the intake for the 2.order of harmonics to take effect at say 1000rpm below the rev limit, you will get a little "boost" in hp/tq at this point, but most of all you will get the also very important 3.order of harmonic "boost" smack in the middle of the rpm range. Then you will get a tiny bit of extra "boost" from the 4th order of harmonics in the low-mid range.

I you tune the length of the intake runners for the normal 3.order of harmonics at 1000rpm below the rev limit, you will get a significant "boost" here, then you will get another smaller "boost" in the high-mid of the rev range from the 4th order of harmonics, but below this there is no gains to get from the 5th or 6th order of harmonics because these are just to weak.

So I think Toyota wanted the length of the 2.order of harmonics (or more specific the 3.order in the mid range and the 4th in the low-mid), but in the space of a normal 3.order at peak manifold. Which is why they went for this design with the bends and the small plenum.

Check out this link: http://www.bgsoflex.com/cgi-bin/intakeln.cgi?length=19