Porting intake manifold, larger tb vs. itb's

[cribbj]

As a cheap test it'd be interesting to see the dyno of a 1UZ with the stock lower manifold and 8 bike throttles slapped on it.

Hopefully, not much low end torque would be lost due to keeping the crossover configuration, and the 8 butterflies should open up the top end a bit?

With 8 x 40mm butterflies, there would now be 8 x 1257 = 10053 mm2 throttle area, instead of 1 x 3850 = 3850mm2 area for the single 70mm OEM butterfly and a restrictive MAF.

Interestingly, losing the plenum apparently hurts an ITB setup for the street. I don't claim to be a fluid mechanics expert, but I know that both sides of the engine benefit from pulse tuning, not just the exhaust, and the plenum is nothing more than a tuned chamber designed to do that. That's why BMW actually lost HP with their straight ITB setup until they restored the air chambers/plenums upstream (before) the butterflies. So now, on nearly all production engine setups (Ferrari, BMW, Lambo, etc.) with ITB's, you see a plenum on each bank before them. Sorta takes away from the bling of the ITB's but they work better.

I think it would be interesting to compare dynos of these cheapie ITB's on the 1UZ when they're sitting in a vertical configuration, and then in a horizontal one (similar to the old Kinsler CanAm setups), which would extend the crossover concept even further. Here's a shot of Kinsler's new crossram ITB setup in carbon for the chebbie LS motors:

 

[ed_ma61]

This is a straight six motor with ITB's... Again, no filtration and this is just a random pic I just grabbed..

I am sure this straight six motor is still gutless out of the blocks even with the ITB's......

Question? How does ITB's effect lowend torque on motors in general? I am not exactly sure if you can expect to lose lowend power from better intake flow.. I know what increased exhaust flow does to a motor, but intake, I really never gave it a second thought because most after market intakes such as the BFI intake you just don't see much gains.....

Glad to see your being civil Jake...

jibby, you have the words in your vocabulary, but you have know idea what they mean, why it is so, and you dont seem interested in going and reading actual technical fundamentals - instead you 'randomly grab' stuff off the net, make stupid assumptions, and as jake very correctly stated, help make this forum look stoopid to the intelligent reader.

less typing - more reading? suggest a book rather than the net?

then, perhaps you might 'get' why the BFI should, and does, sweet f*ck all to overall output figures, what you 'need' to know about intake ports an manifold, rather than just regurgitating some shite about long runners and low end torque - a catch phrase of car forums the 'net wide, with morons happily churning such 'info' out without a clue of what theyre saying

no, im not going to spoon feed you cause its a massive topic, but simply wish to redirect your efforts, highlighting the existing floors in your approach.

 

[rms]

There are some dyno figures with ITB's and std lower manifold here
http://www.v8soarer.com/itb2/index.shtml#Issues

The telling difference to me is that max power was around 5600 and falling sharply, where our straight intake runner showed max power at 6500 and dropped 2% at 7000. In car the engine ran strong to 7500, and would run to 8000 although it was dropping power. This was an unopened std engine.

It is also interesting that he found improved low end (2000 rpm) with the ITB's but when fitting 265 deg cams the low end took a dive and the rpm range was still behind what we found with our base engine.

 

[JustenGT8]

As a cheap test it'd be interesting to see the dyno of a 1UZ with the stock lower manifold and 8 bike throttles slapped on it.

Been done John as Erol pointed out...one of the main pieces of the puzzle we are trying to solve

 

[ed_ma61]

PS - jibby, not deliberately trying to be rude

 

[cribbj]

Thx Erol, I'd forgotten you had thrashed a mule pretty thoroughly before your built motor was ready.

So if your mule responded that well just by going to ITB's and a straight in intake, while Peter's setup with ITB's and the stock lower intake continued to show the drop at 5600 like most, that seems a pretty damning case for the lower intake doesn't it....

But with your mule, weren't you also running extractors, bigger injectors, and had a well tuned standalone EMS?

Could Peter's dropoff been due to exhaust restriction, fueling or ignition problems?

Ed, as an engineer you know that our breed are famous for having difficulty dealing with common folk on technical issues. I used to dread trotting out one of my lab rats when it was time for a dog & pony presentation for management, because invariably the lab guy would become frustrated and arrogant with his nontechnical audience, and management would become confused and p*ssed off enough to want to sack the poor guy. These situations do seem to get better with age, though.

 

[JustenGT8]

Not just Pete's though John, another car with tuneable ECU had the sam,e dyno plot....very damning indeed The theory is there in boundary layer effects so pretty sure we are onto something....will just some down to how big a gain we see.

 

[cribbj]

Cheers Justen, I'm obviously late to this party :doh:

I haven't been paying much attention to the NA side of things, but ITB threads are always interesting.

 

[JustenGT8]

One area where n/a and FI both suffer. Understanding why with FI isn't exactly clear cut, but clear enough to send me down this path to test. i can bring you up to speed if you like?

 

[cribbj]

Always ready to read/listen to a well turned technical presentation, but if it's on fluid mechanics, don't waste your time; that stuff was over my head 40 years ago, and is way over my head now that I've killed off a few million more brain cells.

I am curious about these inlet restrictions, in case the Richwood supercharger manifolds might share some of these issues. I did have the sharply machined corners at inlet ports cleaned up on mine, and put smoother radii on them.

 

[ed_ma61]

i think its likely to be a combination of geometry and x-sectional area - resulting in both too high an absolute intake velocity, and increased boundary layer thickness choking said velocity

 

[jibbby]

This post is directed toward ED and Jake only... Everyone else just continue to stay on topic...

Ed, first of all - I don't have an engineering degree, I don't have a masters degree in physic's...I do not claim to be a rocket scientest nor a neuro surgeon... I do not build race cars for a living... I represent your everyday guy on the forums just trying to learn like everyone else about modding street rods and the Xuzfe motors...The only difference is I have over 10 years of experience or more in doing so on these 1uz-fe motors.... I use to mess with american small blocks growing up all the time, built a few engines here and there that's it...I didn't built F1 motors for race applications but rather built your homemade go-carts, mini-bikes, in my backyard growing up,..etc......So I am confortable about talking about the basics like Throttle bodies, and intakes, etc... I express my opinions based on my personal experiences only..If I am wrong about something which I am at times then I would like to be corrected..NO PROBLEM...

I ask that you please excuse me if you think I don't measure up to your vaste auto intellect ED and Jake....

A life lesson if you care to read - I have experienced close calls with death on several occasions, experienced loved ones dying in my immediate family, nearing 40 years of age now and I realise how precious life really is, so I try to enjoy everyday above ground as if it were my last...With that being said I do not take life so seriously as some of you heads on this forum do. I joke and laugh while trying to learn on these threads and posts, and I do read, search and post....If I offend you some how with my opinionated posts at times, random pics, or what ever, well then too bad my friend and you can kiss my arse.....So Ed, try and lighten up once in while and get a sense of humor because it appears to me you do not possess one.. I also say to all you brilliant heads on this forum, you may possess the smarts which is impressive and an achievement by itself but in the end if your not laughing your really not living as far as I am concerned.....Life is too short fellas to be so rigid by nature.....I like to lighten things up a bit "once in a while", even a shake up things here and there...Some appreciate it, some don't...

I am not offended by your comments ED or Jakes, but we must learn to play nicely together fellas, no?...

Lastly Ed, I pull these pic's to illustrate my points of view for your everyday viewers, not like you. I am not trying to impress, look smarter then I actually am, etc.. Remember not everyone on this forum is as brilliant as you ED..:22: . I am contractor by trade, I play with 2x4's and hammer for a living....I build houses as a job and not race cars.. I am a ham and egger by nature with a budwieser in hand that is all.....:usa2:

Seriously, What's wrong with you people, lighten up once in while? I have noticed some of you pro's/heads only have your wits to fall back on so you overly express your intellect on posts to try to be-little others.. You use certain words and a certain terminology that most can't comprehend, and you do that not to teach but to only impress... I find it annoying and not cool... There are a few on this forum that I see doing that from time to time....You know who you are.. Do understand I do have a great deal of respect for intellent people, wise people, etc.. That is why I stuck with this Lexus forum for so long, so don't get me wrong, just the "I am too smart for you crowd, I laugh at you"...


I am done gents, now carry on please and have a nice day:wave:

 

[Ursus]

lol well said jibby -.0 It seems more often than not people take their "tuning philosifies" as if they were their own personal bibles. People have opinions and its not like you're trying to say your way is the only way. On forums people tend to forget other people have different opinions. And take such differences as a strike upon ones honor. I have no degrees as well my lessons were learned through necessity and my life's mistakes even in my own tuning philosofies. Often time in and time again it was a persons opinionated difference which led me to either prove to myself mine was right or 2 teach myself why mine was wrong. Honestly i enjoy those differences and the challenges they pose upon us.

now back on topic...

the dyno of the itb's on the v8soarer board shown before. I really didn't see any unusual drops but it's most likely caused by the round throttle body openings sitting so close to the ports themselves. In a stock application the round throttle body fills the stock plenum which in turns feed the ovaled ports i'd think that would cause less turbulance within the flow itself, where as the round throttle plates feeding the oval ports i could see a where a turbulent spot in the flow would form right where the tb meets the port. maybe rifling the cross flowing tubes might help by creating a vortex effect similar to the vortex v6's by gm.

 

[JustenGT8]

Ok a quick potted history and no brain melting fluid mechanics.

Looking at dyno plots of various stock and modded UZ's the common theme was a peak hp rpm around 5500rpm.

My car for example, from 6 to 17psi still makes peak hp at the same rpm.

twin throttles, 8 throttles, even cams and headwork had little effect.

FI in particular was the strangest as you are obviously stuffing alot more air in. Initially we though that more air into the same space means higher intake velocity and we were hitting Mach 1+ and that was the prob. Could not be though as the bottleneck would be reached at different points for different boost.

Of course we were having a 'blonde' moment caused by the fact that most engine sim calcs use CFM as the surrogate measure of mass intake air....fair enough when dealing with a constant atm pressure.

This is all good pre turbo but post turbo this unit is meaningless and we should be considering a measure that better represents mass air flow eg lbs/min as a turbo compressor map does. If you look at the increased intake air now it's just density that has increased not velocity.

Now, the increase in intake density is not a perfect process (limited by compressor efficiency) so in reality there is a small increase in velocity (hence Ed's comment in his post).

At this point i was blaming the small cams, until Erol came along with his ITB setup that removed all the stock intake plumbing. Suddenly, even with stock cams/heads we had a n/a UZ making power out to 7000rpm.

looked very much like the intake was guilty by why? Typical excellent toyota design and wasn't limiting my hp increases? This is where boundary layer effects came to the forefront of the discussion.

Air moving over a surface will stall at the interface simply because of friction. In very simple terms this stalled air kind of creates a new surface which creates another interface so as you move along a surface the boundary layer gradually thickens. How thick it starts and how much it thickens as you move along is governed by the surface roughness, the velocity of the air etc but no need to get into this level of detail.

The important point is as you move along your pipe (the intake runner), the thickening boundary layer effectively reduces the pipe diameter and the x-sectional flow area you have.

For us UZers this results in a chock point around 5500rpm, no m,atter how much air you try and stuff into it Simple really

Won't effect you SC guys as you ditch the stock runner and the Richwood intake looks pretty good.

So there you have it. Hopefully my quick and dirty intake mod will deliver an encouraging result and if so we can look to making a lower intake replacment that could truely become the best bang for buck hp mod a UZ can have

 

[Tacoma_Kyle]

How about people shut the **** up and say what the benefits are. Not cost approximations, draw backs, power gains where how or whatever.

I said it several times and it goes back on the personal ****.

If there are no productive questions or statements regarding the benefits then whys it belong here?

"Its like I'm playin cards with my brothers kids or somethin, you nerve rackin sons of bitches." Or somethin close---Tombstone.

 

[ed_ma61]

wtf? whatever dude.

i now accept that horses dont need to drink, even if theyre thirsty. please go on banging in your nails and ignoring sound advice. im just trying to help - really. this is a complex topic, and trying to lift it from the realms of catch-phrase physics is head bendingly hard. but youve got to try and start, otherwise the exercise is useless. that is, of course, assuming that you really want to try and make a functional difference to your car.

your sarcasm is falling on deaf ears mate

2 things you need to look at in an intake:

1- airflow velocity

2- harmonic tuning

the long intake low rpm banter is based on the simple association of a longer pipe having a lower acoustic harmonic. and is almost completely irrelevant if your rpm vs intake velocity graph is all f*cked up, and is generally way over simplified anyway. i can happily point you towards many engines increasing low end torque with shorter runners

trying to 'get' these concepts will build you a better intake than 90% of folks out there.

like i said before in all my smarts, youll need to read a fair whack to bring it all together. pulling random grabs and images off the net will yield you naught. if youre interested, go for it, happy to point you towards some good reading. if not, accept the criticism what you pull stuff out your butt that is plainly wrong

seriously, i dont need to read another personal history. and no, for god's sake, i dont write a damn thing to look cool... my mum thinks im cool, thats good enough for me. suggest you hop off the soapbox

 

[ed_ma61]

How about people shut the **** up and say what the benefits are. Not cost approximations, draw backs, power gains where how or whatever.

what would you like to know exactly? i dont quite get the question

if you mean why go ITBs - throttle response
if you mean why rebuild the manifold - avoid sonic choke

 

[ed_ma61]

the other thing im just chewing on justen - youll remember i gave up on the idea of increased velocity, in preference to your density alone idea. but perhaps we should split the system in two - runner and valve throat. i cant believe that the pressure differential across an open valve wont see a greater velocity, and if the whole mach .6 is getting munched at that point, perhaps we'ere seeing a secondary limit in the intake tract?

 

[Tacoma_Kyle]

Whats sonic choke?

 

[ed_ma61]

http://en.wikipedia.org/wiki/Choked_flow

kyle - got your pm... all good