well, that would give you different runner lengths for different cyls. but, I am seeing that what I was thinking of "intake velocity" is not quite what I thought it was.
many of the minor problems I thought the dual TB setup had, are not problems at all. seems the only valid problem is the oversized throttles making for a very sensitive gas pedal, which for drag use is just fine.
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10:54 AM
tjm4fun Member
Posts: 3781 From: Long Island, NY USA Registered: Feb 2006
Compromise and cost are the biggest factors. as was pointed out the first one has differrent runner lengths, which makes for imbalances in the cylinders. the one you posted is depending on the specific runner lengths from a larger volume plenum with the velocity stacks to even out the air flow. there will still be some slight imbalances, but shouldn;t be too bad. one problem comparing things to stock oem designs is they are always looking for cost effectiveness in the quantity they manufacture. custom performance manifolds are not cheap, as there is alot of r/d and low quantity involved in making them. beam me up scotty! I think the enterprise type manifolds perform better on high end due to the shortened effective runner lengths. if you look at the normal plenum, the runners are actually still formed in part in the upper plenum, adding a few inches of length (along with some restrictions). one of the threads shows the bottom cut off one, so there is some additional length in the top part, before it goes thru that nasty approx 135 degree corner into the lower plenum then intake.putting the common plenum right on the flange cuts the angle down quite a bit which will assist the air in getting to the cylinder more easily. ( I am avoiding saying flow or velocity, let's let that go for now) back to tech, the map ports only need to be big enough for the vacuum to be detected, some screw in tubing ports and a T on two vacuum lines to one to the map should be fine. if the cross connection is too large a diameter, it could act as a cross over between the 2 sides and the flow thru that could lead to misleading map readings. I would put that port on the front side, furthest from the tb to minimize airflow past the port.
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11:13 AM
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
Originally posted by Pyrthian: well, that would give you different runner lengths for different cyls.
quote
Originally posted by tjm4fun: as was pointed out the first one has differrent runner lengths, which makes for imbalances in the cylinders.
cripes... do I have to do all the engineering work?
And before you say "it won't fit under the hood"... just picture a 90 degree bend at the head/intake junction.
This could easily be cast from aluminum, so don't say it's not cost effective to build... it doesn't cost any more than any other intake - I mean take a look at them:
They're already half way there.
[This message has been edited by ryan.hess (edited 10-11-2006).]
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11:34 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
cripes... do I have to do all the engineering work?
And before you say "it won't fit under the hood"... just picture a 90 degree bend at the head/intake junction.
This could easily be cast from aluminum, so don't say it's not cost effective to build... it doesn't cost any more than any other intake - I mean take a look at them:
They're already half way there.
kinda funny how these are starting to look like exhaust headers, eh?
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11:49 AM
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
cripes... do I have to do all the engineering work?
Yes you do have to do all the engineering work. after all the yeling is done, you do a good job at it! besides I'm currently busy repairing a couple of problems on an 18 ton crane. wanna swap?
[This message has been edited by tjm4fun (edited 10-11-2006).]
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06:41 PM
Oct 12th, 2006
5.0Vert Member
Posts: 287 From: Hurst, Tx, USA Registered: Mar 2005
5.0Vert POST THAT DAMN PIC OF THE INTAKE..................................please...I must see.
In all actuallity what does it matter...flow vs velocity. The intake is way better than stock. The acceleration is way better than stock. The looks are way better than stock. Making power all the way to 5.5k is awesome.
I understand that I need to run a balance tube so I can run my vacuum port for the map, but how big should the tube be to connect both plenums. Is 1/2 or 3/4 big enough?
I found it on here or RFL or 60V6. It is ryan falconer's design. They have website and you can buy it for $1500.00.
As requested....sorry I took so long, been trying to get my damn car finished and having issues with fabricating/retrofitting. Also, I couldn't find my digi cam, so I tried taking pics with my cell phone, this was the only decent one.
I posted a thread on dfwstangs with the hypothetical question about the TB/velocity/airflow issue, its turned into quite a discussion
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01:14 AM
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
Originally posted by 5.0Vert: I posted a thread on dfwstangs with the hypothetical question about the TB/velocity/airflow issue, its turned into quite a discussion
arguement?
[This message has been edited by ryan.hess (edited 10-12-2006).]
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01:35 AM
tjm4fun Member
Posts: 3781 From: Long Island, NY USA Registered: Feb 2006
I just hunted that thread down, actually pretty civil, but not quite the same discussion we were having as the issue was just based on his hypothetical question. would be closer if he said you take an intake and put 2 tb;s on it of stock size.
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01:41 AM
5.0Vert Member
Posts: 287 From: Hurst, Tx, USA Registered: Mar 2005
I just hunted that thread down, actually pretty civil, but not quite the same discussion we were having as the issue was just based on his hypothetical question. would be closer if he said you take an intake and put 2 tb;s on it of stock size.
Actually, they even said it was civil themselves. Usually people on there are like a pack of rabid wolfs . This board moves alot slower but its nice to talk to civilized people from time to time . Alright, I'll change the question to a 347 with 11:1 compression with heads capable of 400 cfm, and a dual TB setup(stock size).
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01:56 AM
PFF
System Bot
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
As requested....sorry I took so long, been trying to get my damn car finished and having issues with fabricating/retrofitting. Also, I couldn't find my digi cam, so I tried taking pics with my cell phone, this was the only decent one.
I posted a thread on dfwstangs with the hypothetical question about the TB/velocity/airflow issue, its turned into quite a discussion
wow - mighty impressive the upper main section looks like it was made using exhaust pipes
now - to drag this thread off some more.... would a intake benifit from actually being more like a header - as in NOT having the 90* runner to tube bend? not sure it matters as much, being the intake is pulling the air, and the exhaust is pushing it
the intake runners are more or less just drawing air out of a chamber such as the plenum in pulses. what will affect that is a sharp edge all the way around vs a simple trumpeted air-horn shape as it enters the chamber.
whats wrong with the stock fiero plenum is it actually extends the runners forcing them to make a sharp more than 90* turn before entering the main chamber.
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10:54 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
the exhaust is in pulses also in fact, its the same air & the same pulses just way heated & expanded headers with collectors are better than log style manifolds - seems the same should apply but, I expect much of that is volume. the exhaust & throttle are close to the same size, yet the exhaust carries MUCH more volume, even tho its the same air that went thru the intake, due to the combustion.
the exhaust is in pulses also in fact, its the same air & the same pulses just way heated & expanded headers with collectors are better than log style manifolds - seems the same should apply but, I expect much of that is volume. the exhaust & throttle are close to the same size, yet the exhaust carries MUCH more volume, even tho its the same air that went thru the intake, due to the combustion.
but with the exhaust on an NA setup, you are using the pulses to actually suck exhaust out of the other runners, not doing that on the intake.
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11:47 AM
Reise Member
Posts: 69 From: Berrien Springs, MI, USA Registered: Aug 2006
what happens after we get a clear understanding of the intake? does someone actually start making these better intakes? cause as far as I can tell it's kinda like this https://www.fiero.nl/forum/Archives/Archive-000003/HTML/20060811-6-038175.html I would actually like to see someone start to make an intake to compete with trueleo's intake....might get them to do some r/d on a dyno like they said they probably won't do. just my .02
what happens after we get a clear understanding of the intake? does someone actually start making these better intakes? cause as far as I can tell it's kinda like this https://www.fiero.nl/forum/Archives/Archive-000003/HTML/20060811-6-038175.html I would actually like to see someone start to make an intake to compete with trueleo's intake....might get them to do some r/d on a dyno like they said they probably won't do. just my .02
theres not enough money in fieros for any company to do that kind of R&D - as it is they did more than just about anybody else with before and after dyno runs and then improved them by adding velocity stack horns inside the main body.
want someone to do something better? better do it yourself, otherwise it'll probably never happen
this whole tanget got started by someone claiming that the velocity through the dual TB's being lower than stock was going to hurt power which is completely false and not even part of the debate anymore - -
[This message has been edited by Kohburn (edited 10-12-2006).]
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12:24 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
Originally posted by Kohburn: this whole tanget got started by someone claiming that the velocity through the dual TB's being lower than stock was going to hurt power which is completely false and not even part of the debate anymore - -
yes, I was unclear on intake velocity, and where & when it matters. the header stuff is just mostly ramblings, trying to see if anything in header design might carry over for some new tricks I have basicly no knowledge except what I have picked up here - and Kohburn is a good source when ya poke him the right way by far one of the best creative minds here.
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12:35 PM
tjm4fun Member
Posts: 3781 From: Long Island, NY USA Registered: Feb 2006
I think the oversized tb was more of a possible drivability issue, ie the on/off switch effect, and got sidetracked. Apparently this is not a big issue, from the responses of Goatnipples testing, so now it is more how to fine tune it for the best performance for this config. I don;t think we got to hot n bothered, I would call it more of a spirited discussion in part caused by some different interpretations of terms. what would be good to get is a log of a few winaldl runs with various throttle/gears, ie, normal driving with partial throttle in the proper gear, some lugging points with too high a gear and partial throttle, wot in correct gear, wot in too high a gear. that should give a decent picture of what the ecm is doing tihe the new variations of input data.
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02:17 PM
Raydar Member
Posts: 40912 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Originally posted by Reise:...I would actually like to see someone start to make an intake to compete with trueleo's intake....might get them to do some r/d on a dyno like they said they probably won't do. just my .02
They already dynoed the intake. I believe they said that they didn't have any plans to do back-to-back dyno testing of their headers.
To me, their headers look enough like FOCOA headers that they ought to be comparable.
[This message has been edited by Raydar (edited 10-12-2006).]
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04:29 PM
Oct 13th, 2006
p8ntman442 Member
Posts: 1747 From: portsmouth RI Registered: Sep 2003
the quad 4 uses two style intake manifolds, one with 4 tubes 1/cyl and a log style with four runners. Even though the log looks more restrictive, it makes more power. Log style HO and w41 motors
17lb injectors are what came stock on the 3.4L pushrod engine. Gonna flow more fuel for the same duty cycle/fuel pressure than the stock 3.1L injectors? (don't know their size)
Ok, I moved this question from another thread. If anyone here could get the perfectly sized TB, what would it be? Assume stock 3.4L everything. How do you calculate TB size? Is there a formula like there is for fuel injector sizing? Does it matter if one gets a TB for a V8 and then programs the PCM for optimum performance?
I would like to turbocharge my 3.4L OHV. I really like goatnipples2002 design except I would want the plenums to converge at the front with a single TB so I can hook up the turbo easier. Kinda like the stock 3.4L plenum but bigger.
yes, some 3.1's came with 17# injectors. injector size is based on expected HP output & number of cyls. a search on injector sizes should come up with alot of stuff - but there is a table somewhere of what size to use based on expectd HP's also, there are actual injector calulators online at some sites
2 TB's give better throttle response. Ok. I guess I am thinking more of simplicity with hooking up the turbo.
Are your TB's capable of flowing more air than the lower plenum or heads can flow?
With what I am thinking, certainly a TB made for a V8 would flow more than enough for a boosted 3.4. I need to do my homework and find how TB size affects flow rate.
I appreciate your design though, gets the creative juices flowing!
I can totally understand your simplicity criteria, I look at price as the most important factor then simplicity. You could easily acquire two stock holley TBs. If you run turbo just have a "Y" pipe made to connect the two TBs.
How much money have you invested in the dual TB setup? (If I may ask)
$131.00. Funny huh. I had several intakes laying around and my brother did a 350 swap so he didn't need any stock parts anymore and my buddy is doing a 3800sc swap so he didn't either so I have a few parts from them.
1 on my main things to change was to make the "logs" equal length, mine are not but I got it as good as it wil be for now.
The most important is to talk to darth at sinister performance and get a chip burned. Gotta let the right hand know what the left is doing.
Some things that I am going to do maybe for the next on is that I will have the "logs" shortened so the TB comes right after the runners instead of the overhang being right over my coil OR mount my coil in another spot.
Make sure you have a tube welded or "chopped and pasted" like mine so that it connects the "logs". So when you go they equal out the pressures. That is why I am not seriously concerned about my TBs not being in total alignment, but it is still an improvement that needs to be made.
Can't think of anything else.
[This message has been edited by goatnipples2002 (edited 12-17-2006).]
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01:47 AM
PFF
System Bot
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
I think there's too much concern about balance in this discussion.
Think about what the idle air passage does. It puts each cylinder (excpet #1 and #6) between two others on the opposite bank. If there's any imbalance in air delivery from the throttles (and I don't see why there should be), then it'll get fixed at the idle air passage by allowing each cylinder to draw, to some extent, from both plena. Since only three cylinders pull from each plenum, the plenum only sees intake flow every 240 degrees of engine rotation. So when a cylinder on the opposite bank fires, it pulls from the plenum when none of the plenum's "own" cylinders are pulling from it.
The only reason to run any kind of large-ish tube between the plena is to provide a location for brake booster vacuum to come from both. While I just said that imbalances correct themselves via the idla air passage in the LIM, I was referring to incidental imbalances. It's never good to PLAN imbalances into an engine.
MAP sensor vacuum can come from small tubes and probably ought to be separate from brake booster vacuum so that any actual flow from the brake booster doesn't mess up the MAP reading.
So supply the engine with idle air through one IAC (probably in the forward bank throttle) and the factory idle air passange. Synch the throttles with a linkage and use ONE TPS. Bring off small tubes (1/8"-1/4") from each plenum to feed low demand vacuum accessories (MAP sensor, cruise servo, EGR valve, vapor canister, etc). Bring medium sized tubes (each with at least half the area of the stock brake booster connection) off each plenum to T or Y together to feed the brake booster line.
TUNE!
It's not conceptually difficult and has been done enough that it ought to be cake by now. When are we going to see 160 WHP 2.8's?
BTW, three of the pictures on the first page are of the same manifold. Cooter built it, sold it so Racer X-11 who sold it to Shaun (who has since sold it to Chris Nelson, I think).
[This message has been edited by Will (edited 03-25-2007).]
Originally posted by Will:BTW, three of the pictures on the first page are of the same manifold. Cooter built it, sold it so Racer X-11 who sold it to Shaun (who has since sold it to Chris Nelson, I think).
Not Quite. My intake was designed/built by myself back in 2000, and is not the Cooter/Shaun intake.
My intake is linked by the steel rod and so I had to notch my decklid for the rod the move freely and I left my middle intake runners the stock length.
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04:45 AM
Will Member
Posts: 14249 From: Where you least expect me Registered: Jun 2000
The issue I see is the difference between the low end and high end responses for the dual throttle body.
I know that fatter is better for high rpm, but slim and long is better for low end. With the dual throttlebody, you are going to get more top end for certain, but, I know from experience that when you open up the intake you can lose at the bottom end.
It might be interesting to have a design where the dual throttlebodies were staged for the second one to come on part way up the rpm curve, similar to a primary/secondary carb setup.
Just a thought.
Arn
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09:55 AM
Dec 19th, 2006
NSAN1T Member
Posts: 698 From: Marble Falls, Texas, USA Registered: Mar 2002
I didnt read the all the response so this may have been said. If you want to tune a daul TB setup right, buy a good vacuum gauge (not a boost gauge) or better still, two of them. Also do use a balance tube between the pleniums but don't use a solid welded one. Use one you can take off, like a large dia hose. Connect the vacuum gauge to one plenium and note the reading at idle and then see what the one reads. Adjust you idle stops until they match and reconnect the balance tube.
