This thread is being created because I couldn't find any info on this intake that really helped me. More or less the pictures of the intake is what helped. I hope that others that have this intake or experience with it will post their experiences and insights.
There are a few little details that you can only find out by creating an intake of this nature. Some might ask why bother and the answer is because the fiero intake sucks and this one can be created for less than any other mod that is this beneficial.
The jist - Take a stock middle intake and 2 stock top intakes. Weld tubes or bent pieces of sheet metal ("U" shaped) to the tops of the middle intake.You want the 2 logs to be of equal length. Weld the back plates on. Then cut the TB flanges off the 2 top intake pieces. Weld the flanges to the "logs" or "tubes" you created. Now if you attach the TB to the flanges you will need a way to activate both at the same time...I chose to weld a steel rod, but others have chosen varios methods. Gotta get creative. Hook up all the wiring for the sensors on 1 TB. You will need to drill/tap for vaccum ports and connect the 2 "logs" so they have equal vacuum. (Little more detail on top of page 2).
As this thread progresses I and others will remember more and more about this intake and what we would and should have changed. If something is not posted feel free to ask.
If you are unfamiliar with this intake here are some pics Goatnipples2002's (mine)
RacerX11's
Cooter's
Shaun's
TT Slick's
Last 1 is of unknown origin to me.
DISCLAIMER: IF YOU DON'T KNOW **** ABOUT THIS INTAKE THEN SHUT UP AND LET THOSE MORE EXPERIENCED WITH THIS INTAKE ADVISE THOSE OF US WHO AREN'T.
[This message has been edited by goatnipples2002 (edited 11-29-2007).]
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03:36 PM
PFF
System Bot
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
how about some info on flow requirements & recommended throttle sizes? I still beleive using 2 stock throttle bodies gives way to much airflow at 1/2 throttle & confuses the ECM with full airflow at 1/2 throttle on the TPS tho, new chip/tuning will get rid of some of this, but will make the gas pedal an on/off switch. as fun as this is, makes anything but drag racing tough. cant work a throttle like this in a long wide turn.
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04:11 PM
p8ntman442 Member
Posts: 1747 From: portsmouth RI Registered: Sep 2003
how about some info on flow requirements & recommended throttle sizes? I still beleive using 2 stock throttle bodies gives way to much airflow at 1/2 throttle & confuses the ECM with full airflow at 1/2 throttle on the TPS tho, new chip/tuning will get rid of some of this, but will make the gas pedal an on/off switch. as fun as this is, makes anything but drag racing tough. cant work a throttle like this in a long wide turn.
all that can be changed by hooking both tb cables to a cam that is pulled by the gas pedal, if the cam has a 2:1 ratio, you open each tb half as much as a single. Now hook your tps's in parallel so the resistance is cut in half and your computer will read the same as before. IAC's I am not sure, because you are pulsing the coils so if you simply split the wires and fed both, you are dividing the current, and therefore may render both IAC's Inoperable. You could simply use a single IAC and then have a ballance tube between both banks. I would use a heafty sized tube and mount the map on it, in the middle.
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04:29 PM
Blacktree Member
Posts: 20770 From: Central Florida Registered: Dec 2001
yes, the cam is a good way to go. but, you only need 1 TPS & IAC. the IAC path goes down thru the intake manifold, not thru the plenums & the TPS is should be stay matched with the actual throttle/butterfly movement. and, the throttle should be matched to the engines needs. no way will a 2.8/3.1/3.4 ever need 600 CFM - and thats what 2 stock TB delivers when opened up. even with a cammed butterfly pulley. the cam changes the curve - but the beginning & end are still fixed.
IF you have this intake then I could understand some of the acusations, but the pedal does not have an on/off characteristic. At half throttle the acceleration is awesome at full throttle it is even better.
Why pay extra for some specific throttle body when you can run two stock throttle bodies that are a dime a dozen.
Too much air is only a problem when you don't have enough fuel. I run stock injectors for now.
[This message has been edited by goatnipples2002 (edited 10-09-2006).]
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06:44 PM
tjm4fun Member
Posts: 3781 From: Long Island, NY USA Registered: Feb 2006
I think they are looking at it in the theory point. if one tb is rated at 300 cfm for 6 cylinders, then in a split config, you are now supplying 300cfm to 3. Now as I see it,their thinking is: if you are using 1 tps, then at half throttle to the tps you are delivering the equivalent airflow of wide open on a single feed design. There are 2 flaws to that thought. 1. cfm flow is not a linear number, it is more a logarithmic curve plotting cfm vs position of the throttle plate. even a small deviation from the direction of the ariflow will lower the cfm significantly.
2. that the motor is capable of drawing in 300cfm per bank. the motor will draw what it can based on the volumetric efficiency of the intake, heads and exhaust system. the biggest possible issue is bog from reducing velocity by having the throttle wide open before the velocity of air is sufficient to support it. Bogging is the only real issue, same as over sizing a carb on a carbed motor.
I have considered building one of these as a bolt on, along with a few other thoughts on redoing the intake, and have conbsidered all the pluses and minuses of any one design. the tb sync is critical, but not really that hard to do in a dual body manifold. Calibration for optimum performance is another issue, but really no more so with this design than any other new design intake.
Overall, I applaud Goatnipples for spending the time and $$ to build this and try to explain the how to and what he is experiencing. I know anyone can say anything on the internet, so any other people that ride in his car would be a good backup to his observations, tho I see no reason to doubt what he is saying so far.
edit: I think that may have come out too harsh, sorry, not thinking too straight atm. one thing I think that should be addressed is the tps would need recalibrating, either thru the chip or running 2 in parallel. the wiring would be tricky tho, I would think that just using 2 wires to the 2nd to parallel the variable portion would be the correct way to do it, but that would put the idle tps voltage possibly too low. the chip is the right way on a single tps, if it were me.
[This message has been edited by tjm4fun (edited 10-04-2006).]
Thanks tjm4fun, but let me say this I didn't weld my intake, I had it welded by a local shop, but it was my rendition of other member's designs that they used.
I would think that with darthfieros chips being only $40 that the tps, fuel maps or any other sensor or ecm controlled function can be manipulated.
I am a man of theory but I only use theory as a guide not as law because everyone knows theory is good on paper but no always the same in real world experiments.
Originally posted by goatnipples2002: I am a man of theory but I only use theory as a guide not as law because everyone knows theory is good on paper but no always the same in real world experiments.
amen to that.
I was actually thinking of that layout, but with a Y down to one larger tb. or something totally differrent, somehting that would have an equal length to each cylinder from the tb. the geometry of that one is what is rough to figure.
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08:51 PM
TT Slick Member
Posts: 135 From: Columbus, Georgia Registered: Dec 2004
The second to the last picture is the unit that I built for my 85 GT. The picture was taken in north Alabama at Ed Parks' annual swap meet. You will only need one TPS and one IAC. This will keep things simple, and not confuse the computer. Best of luck.
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09:37 PM
PFF
System Bot
I wear pants Member
Posts: 579 From: Columbus, IN Registered: Jun 2005
I am glad that somebody finally made a thread about this. I have been planning to make a dual tb intake since I saw Cooter's, but I haven't had much luck finding info on them.
Mr. TT Slick I have wanted to talk to you for quite sometime...DAMN NICE JOB, I wish my intake looked as nice as yours but then I wouldn't be able to say I have a RATROD!...lol.
What did you do because it looks like no welding was required?
What did you do for the TB linkage?
Did you change fuel delivery anyway?
I forgot who but I read you have a comp cams 260 what else? I have the same cam.
Cooter said something about changing fuel maps so ever since then I have numerous Q's...this is starting to get good.
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10:26 PM
Philphine Member
Posts: 6136 From: louisville,ky. usa Registered: Feb 2000
I remember that but that person didn't go into details about the catera dual TB setup.
I had a race tonight as I was getting on the interstate to test my intake an integra gets behind me so I floor it...and a sound that I have never heard came from the back. Gotta have one to experience this sound.....kinda sounds like when I hit the juice. Anybody that has a 4 speed (3.65) knows that a top end race is foolish because the stock intake sucks...not this time...where I live all the "yo boys" and "richie riches" drive modded imports. I can kill them at the track but on the street they ownED me. Not any more....I pulled on this cat pretty good and he never passed me. I'm not sure what he was doing or had but his car jumped real hard a couple of times but he only made it to the rear of my door. Well worth the time, money and headaches invested.
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02:49 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
IF you have this intake then I could understand some of the acusations, but the pedal does not have an on/off characteristic. At half throttle the acceleration is awesome at full throttle it is even better.
that is because it is giving 1/2 throttle timing - not WOT timing like it should - and the retarded timing will build heat. there is a reason cars dont come with coffee can size throttles. once you pass the "ideal" size, you now take away driveability. we all know the throttle body & upper plenum are a restriction point of the intake system. and I agree this is absolutely an improvement over the stock or daryl setup. I just think it has much more potential when done with proper sized TB's.
and, of course - I love the look of these setup's - even the hose clamp'd ones.
The valves are open longer and therefore more fuel and air in the cylinder seems like a win win. I just can't wait to run a nitrous nozzle in each TB.
If this intake has TB too big then have you seen the Ryan Falconer intake he design that allowed the 2.8/3.0 race motors to make 100hp/liter. His intake had 6 butterflies the same size as the stock TB. I am at school now but will edit to add picture. His formula was pretty simple...use the GM high compression forged pistons 12.5CR, mechanical cam w/ .540 lift, hi flow intake with individual air delivery per cyclinder, as well as injectors mounted in then top of the intake runners.
I will say this about the pedal it takes a little bit to get used to because it is alot stiffer because you now are pulling on two TB springs, it is about 3 times stiffer.
What do you guys think about the 19lb injectors?
[This message has been edited by goatnipples2002 (edited 10-05-2006).]
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01:03 PM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
Yeah right look at the butterfly hole compared to the injector hole...those injectors are huge too. The intake valve is barely bigger than 1.5" (1.72 to be exact), But if I am wrong the size of two stock TB would still not add up to all 6 of those.
Yeah right look at the butterfly hole compared to the injector hole...those injectors are huge too. The intake valve is barely bigger than 1.5" (1.72 to be exact), But if I am wrong the size of two stock TB would still not add up to all 6 of those.
of course it wont. and, if you add up the area of all the runners, it is much more than the area of the stock throttle body. independant throttle bodies are not flowing at all times. this is also why a single throttle going thru a y-pipe is better: intake velocity so, why do you think they dont put 5" throttles on all cars? but, never mind - you dont seem get it - like a kid with ketchup - if a little is good, alot must be great
and again - I know this is an improvement over the stock setup - I am just trying to show how this could be so much better
I really can't add much to this conversation, other than my own experience and I probably don't know what I am talking about- your results may vary. I ran my 3.4/muncie 4speed with the 4.10 gearset with a G-tech and three different intake manifolds. I set the car weight at 2900 pounds and made the runs. The ported stock intake came up to 140ish horsepower, a modified F-Body intake (that Travis and Myles stole from me...where is my check, assholes?) made 160 and the dual throtte body intake made a little over 200. All this was with the same chip in the ecm without any changes. There was some room to tweak the program for better driveability, but all I was wanting to see was WOT difference, and there was some difference. At full RPM, the factory intake was actually showing to be pulling about 5 inches of vacuum- enough that the ecm was not seeing full load on the map sensor. The F-Body intake and the dual TB intake did not do this- At WOT and full RPM, the manifold pressure was 100kpa so there was not the restriction of the factory intake. As far as the part throttle fueling on the dual TB intake, the only issue I had was acceleration enrichment was a little slim. The fueling and timing are load based (from the MAP sensor) and not from throttle position. So if 1/4 throttle gives the same airflow (manifold pressure) as 1/2 throttle on a stock intake, the ecm will fuel and time the engine for that load, not that throttle position....until you get into power enrichment mode. If you are at half throttle with the dual TB intake, you are flowing about as much air as you would at full throttle on the stocker and you may not be in power enrichment mode. This means that you are fully loading the engine and the ecm may be trying to keep the mix at 14.7 to one instead of the 12ish to 1. I saw EGT's hit 1400 degrees and then drop to 1200 in PE. All in all, if I had to get rid of my POS Caddy V8 and get another v6, I'd make another F-Body intake because it had the best all around performance and response. Your results may vary.
I played around with the maps for driveability, but the WOT G-tech stuff was done on the same program. They run pig rich at WOT anyway, so the additional airflow probably did not bring it too far to the lean side. Since that time, I've learned a little more about ecm stuff- mostly to leave well enough alone.
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11:29 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
wouldnt you rather see if the mixture was going rich with the 19's rather than "watch the needle drop"? What if your 15's are maxing out and your egt's are hitting 1400 degrees? wbo2 it and find out.
Originally posted by Pyrthian: I still beleive using 2 stock throttle bodies gives way to much airflow at 1/2 throttle & confuses the ECM with full airflow at 1/2 throttle on the TPS
No. The ECM is not confused at all. Fueling is based on engine load, and engine load is based on the vacuum in the plenum (MAP). If your vacuum is at 0, your load is at 100% and your ECM is delivering all the fuel it can to the engine. Specifically, it is in Power Enrichment mode, and that is based on a few different things, but one of them is a minimum MAP enable.
quote
Originally posted by p8ntman442: Now hook your tps's in parallel so the resistance is cut in half and your computer will read the same as before.
Don't do that.
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Originally posted by tjm4fun: 2. that the motor is capable of drawing in 300cfm per bank. the motor will draw what it can based on the volumetric efficiency of the intake, heads and exhaust system. the biggest possible issue is bog from reducing velocity by having the throttle wide open before the velocity of air is sufficient to support it. Bogging is the only real issue, same as over sizing a carb on a carbed motor.
No. It is NOT the same thing as over sizing a carb on a carbed motor. In fact, a car with a larger throttle body will have more acceleration off the line than a car with a smaller throttle body. With a carb, if you lose air velocity, metering and gas vaporization suffer. You get a sh*tty idle, and bogging, like you said. With a throttle body, you don't have to deal with any of that. The fuel injectors take care of idle fuel, and they don't care if you have a 10" throttle body.
However - if you just swap that 10" throttle body on, and do nothing else, you WILL get a hesitation/bog off the line. This is because the second you snap the throttle open, air inside the plenum is *instantly* pressurized to ambient pressure (14.7psia). Whereas before, it took 0.5 seconds to pressurize. This creates a lean spot, which means you need to adjust the chip to provide more Acceleration Enrichment (like a pump shot on a carb). Once that is fixed you will be faster than the car with the smaller TB.
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Originally posted by tjm4fun: one thing I think that should be addressed is the tps would need recalibrating, either thru the chip or running 2 in parallel.
Don't do that.
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Originally posted by Pyrthian: that is because it is giving 1/2 throttle timing - not WOT timing like it should - and the retarded timing will build heat.
Again, there's no such thing as 1/2 throttle timing. Timing is looked up in a table vs engine load (MAP). If the throttle bodies are 1/2 way open, and the engine is taking in all the air it physically can, load will be 100% and it will be in PE, and getting PE timing.
quote
Originally posted by goatnipples2002: Yeah right look at the butterfly hole compared to the injector hole...those injectors are huge too. The intake valve is barely bigger than 1.5" (1.72 to be exact), But if I am wrong the size of two stock TB would still not add up to all 6 of those.
Maybe/maybe not. If you have individual throttle bodies, you can get away with a LOT more throttle body area, with few penalties. It has to do with the progression of area that opens as the throttle shaft turns. Large throttle body = sensitive to tiny movements. Lots of smaller throttle bodies = not so sensitive.
quote
Originally posted by Cooter: As far as the part throttle fueling on the dual TB intake, the only issue I had was acceleration enrichment was a little slim. The fueling and timing are load based (from the MAP sensor) and not from throttle position. So if 1/4 throttle gives the same airflow (manifold pressure) as 1/2 throttle on a stock intake, the ecm will fuel and time the engine for that load, not that throttle position....until you get into power enrichment mode. If you are at half throttle with the dual TB intake, you are flowing about as much air as you would at full throttle on the stocker and you may not be in power enrichment mode. This means that you are fully loading the engine and the ecm may be trying to keep the mix at 14.7 to one instead of the 12ish to 1. I saw EGT's hit 1400 degrees and then drop to 1200 in PE.
He knows. Listen to him.
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Originally posted by p8ntman442: wouldnt you rather see if the mixture was going rich with the 19's rather than "watch the needle drop"? What if your 15's are maxing out and your egt's are hitting 1400 degrees? wbo2 it and find out.
YES!!
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Originally posted by goatnipples2002: I can't afford the wbo2 yet
You can't? What about a new engine? Can you afford one of those? There's WBO2's on ebay for ~$189. When you drastically alter your engine's breathing, you NEED one. I'm not sure if the stock chip is rich enough to keep you safe. Running larger injectors is a bandaid at best.
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10:14 PM
PFF
System Bot
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
Take a 1/4"-1/2" tube off each plenum, and run them to a box. To this box, you'll run the vacuum line for your MAP sensor, and your IAC. This will keep the two halves of the engine getting the same vacuum reading and idle airflow.
I don't remember if the 2.8 throttle bodies have IAC's in them or not, but if they do, you might be able to run them in parallel. GM overbuilds their computers, so it should be able to handle a little extra current.
Otherwise, you need to install an IAC into that box. There's some external IAC's you can pick up at junkyards. I think they're on some V6. I can look that up for you if you want.
I understand the box idea but 1 of the great things about this intake is that you don't have to deal with the upper intake. Why not just run a vacuum line from both plenums for the map?
My idle is great right now...in fact it is better than before, so why do I need to mount my IAC to watch both plenums?
The reason I can't afford an wbo2 is because I blew my budget already... spec stage 3, this intake, poly kit, falken ziex 512s, msd coil, msd window switch, 2 sets of plugs, a/f gauge, coilover sleeves, 4 n2o nozzles/jets, n2o bottle brackets, fuel press. gauge and all the unmentioned what nots to complete the installs (except my clutch...that's next weekend.
I think my injectors are fine, but I was thinking they were 19s because my explorer calls for that size and when I put them in my suv they made the engine bog out and run like **** . So I figured they were low impedance 19s and flowed more because of the 4 holes at the tip. They came out of an 89 taurus. I put them in my fiero and all is well. So they may not be 19s at all. My bad for the confusion I should have triple checked.
[This message has been edited by goatnipples2002 (edited 10-08-2006).]
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01:16 AM
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
Originally posted by goatnipples2002: I understand the box idea but 1 of the great things about this intake is that you don't have to deal with the upper intake. Why not just run a vacuum line from both plenums for the map?
My idle is great right now...in fact it is better than before, so why do I need to mount my IAC to watch both plenums?
The reason I can't afford an wbo2 is because I blew my budget already... spec stage 3, this intake, poly kit, falken ziex 512s, msd coil, msd window switch, 2 sets of plugs, a/f gauge, coilover sleeves, 4 n2o nozzles/jets, n2o bottle brackets, fuel press. gauge and all the unmentioned what nots to complete the installs (except my clutch...that's next weekend.
The "box" can just be a small plastic box you pick up from radioshack. The vacuum needs space to equalize.
You need the idle air bypass to enter both plenums, because otherwise you are running half of your engine rich, and half of your engine lean. At idle it is less dangerous than at WOT, but damage will still occur - it will just take longer to do so.
Why would one side run rich and the other lean since all 6 injectors are being ran by 1 sensor whatever that sensor read all injectors would get. With that being said since both banks have TBs sucking the same amount of air at idle they will also get the same amount of fuel. I don't think what you said is totally accurate. Yes the sensor in a common area to both plenums would/might be more accurate, but I can't see why the sensors controlling fuel running in 1 TB is going to cause damage because the 1 TB is pretty much the same as the other so the a/f ratio would be about the same.
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11:26 AM
Raydar Member
Posts: 40963 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Originally posted by ryan.hess: You need the idle air bypass to enter both plenums, because otherwise you are running half of your engine rich, and half of your engine lean. At idle it is less dangerous than at WOT, but damage will still occur - it will just take longer to do so.
The IAC on a stock V6 is actually piped directly to the lower intake. (That 1/2" pipe that plugs in to the back of the TB.) All the cylinders see the same air. Doesn't really matter where it comes from.
I saw TT Slick's installation at the swap meet. It's amazing. It looks like a factory installation. It actually looks better than a factory installation. It also goes like hell. All weekend at the swap meet, there were cars pulling out with the drivers nailing the gas. It got to be fairly... routine. There were only a few cars that made me turn and say... WTF?! TT Slick's was one of them. When he hammered it, he was gone.
He does not have a balance tube between the logs. When I asked him about it he said that it wasn't necessary. If the TBs are correctly balanced the MAP readings should be the same. Half of the airflow goes through one TB and half through the other. If everything is correct, mechanically, then it should be "a wash".
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12:20 PM
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
Originally posted by Raydar: If the TBs are correctly balanced the MAP readings should be the same. Half of the airflow goes through one TB and half through the other. If everything is correct, mechanically, then it should be "a wash".
and that's the key.
A very small amount of difference at idle is all it takes...
On LT1's, they have the ability to control the fueling for individual cylinders. Imagine an LT1 intake just for a second... All the (short) runners are the same, the cylinders are all the same, etc... IIRC, the IAC and PCV isn't in front of the intake either - there is a distribution system inside the manifold that distributes the IAC air to each cylinder........ BUT, idle fuel between cylinders can be different by 4% or more! This is where theory and real life diverge... they should be the same, but they aren't.
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12:27 PM
ryan.hess Member
Posts: 20784 From: Orlando, FL Registered: Dec 2002
Originally posted by goatnipples2002: Why would one side run rich and the other lean since all 6 injectors are being ran by 1 sensor whatever that sensor read all injectors would get. With that being said since both banks have TBs sucking the same amount of air at idle they will also get the same amount of fuel. I don't think what you said is totally accurate. Yes the sensor in a common area to both plenums would/might be more accurate, but I can't see why the sensors controlling fuel running in 1 TB is going to cause damage because the 1 TB is pretty much the same as the other so the a/f ratio would be about the same.
Okay...
The throttle does what? It stops air from entering the engine.
Now, on your system, you have one throttle body on each bank. If they are slightly off, one half of the engine will be getting more air than the other. Pretend they're off by a LOT. Say when one's closed, the other is all the way open. Half of the engine will be drawing in ALL the air it possibly can, while the other half will be drawing in little air. Lets say you took my advice and built a common plenum box for the MAP sensor. Half the engine is at idle, half the engine is WOT. The difference is 50%, so the map sensor sees a 50% load on the engine, and puts 50% fuel into the engine.
So now the half of the engine at idle is pig rich, and the half of the engine at WOT is burning up because it's running so lean.
If you didn't build a common plenum, and took the map off the idle side of the engine, the ECM would not see any load on the engine and it would give you idle fuel... which means the WOT half of the engine is probably not even firing. If you took the MAP off the WOT side of the engine, the ECM would see full 100% load on the engine and give you lots of fuel. So much you will be rich misfiring, and could possibly hydrolock the engine and bend some rods.
Make sense?
You're not going to see that much of a difference, and if the IAC is going to the manifold then you're probably better than most. But if one throttle is held open just a degree or two more than the other, that bank is going to be running lean.
[This message has been edited by ryan.hess (edited 10-08-2006).]
Okay, I may have missed it through all that reading, but how exactly do you make this intake? I'm talking only about the physical manifold, not the computer adjustments and what not. Is it just replacing the upper intake with the two tubes? Or cutting and modding the middle intake?
I am very much interested in making one of these.
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