12a turbo option.
Thread Starter
pwned
Joined: Sep 2005
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From: Northern Indiana
im hoping under 1500 becuase i have a lot more i need to put into it... im working in a factory so i can go to college and play with my car at the same time... i think its a good trade off 
OK, maybe I can explain this a little better. If you keep the boost psi under the vacuum hg, it will go into the engine and not come back up out of the carb. But here lies the rub. As intake air through the carb increases, velocity increases, vacuum drops and more gas is drawn in to keep the fuel mix where it needs to be.
When you add the pressurized air from the turbo, the volume of air going through the carb decreases, as will the vacuum. Net result is the more boost, the less gas is pulled through the carb, i.e., the fuel mix will become leaner, the higher the boost. It will not work. I think I understand what you are trying to do, but you are not understanding how the adapter between the carb and intake is configured. All air that goes into the engine MUST go through the carb first.
You can safely run a drawthough, or blowthrough system around 6-8 psi of boost with no intercooler, providing you have proper af ratios and timing. At those pressures, there is minimal heating of the air due to compressing it.
When you add the pressurized air from the turbo, the volume of air going through the carb decreases, as will the vacuum. Net result is the more boost, the less gas is pulled through the carb, i.e., the fuel mix will become leaner, the higher the boost. It will not work. I think I understand what you are trying to do, but you are not understanding how the adapter between the carb and intake is configured. All air that goes into the engine MUST go through the carb first.
You can safely run a drawthough, or blowthrough system around 6-8 psi of boost with no intercooler, providing you have proper af ratios and timing. At those pressures, there is minimal heating of the air due to compressing it.
Rotary Freak
Joined: Jun 2003
Posts: 2,604
Likes: 1
From: Land Of Confusion southern MI, USA
Originally Posted by trochoid
OK, maybe I can explain this a little better. If you keep the boost psi under the vacuum hg, it will go into the engine and not come back up out of the carb. But here lies the rub. As intake air through the carb increases, velocity increases, vacuum drops and more gas is drawn in to keep the fuel mix where it needs to be.
When you add the pressurized air from the turbo, the volume of air going through the carb decreases, as will the vacuum. Net result is the more boost, the less gas is pulled through the carb, i.e., the fuel mix will become leaner, the higher the boost. It will not work. I think I understand what you are trying to do, but you are not understanding how the adapter between the carb and intake is configured. All air that goes into the engine MUST go through the carb first.
You can safely run a drawthough, or blowthrough system around 6-8 psi of boost with no intercooler, providing you have proper af ratios and timing. At those pressures, there is minimal heating of the air due to compressing it.
When you add the pressurized air from the turbo, the volume of air going through the carb decreases, as will the vacuum. Net result is the more boost, the less gas is pulled through the carb, i.e., the fuel mix will become leaner, the higher the boost. It will not work. I think I understand what you are trying to do, but you are not understanding how the adapter between the carb and intake is configured. All air that goes into the engine MUST go through the carb first.
You can safely run a drawthough, or blowthrough system around 6-8 psi of boost with no intercooler, providing you have proper af ratios and timing. At those pressures, there is minimal heating of the air due to compressing it.
this is what i was trying to say the whole time....but if you think about, as the pressure increases, it will go out the carb and not into the motor, so it will kill power, and not actually create any boost, because all of the forced air is going to go where it is easier for it to go.
Originally Posted by gmanuser
ohhh ya 1g is a reasonable price for everything you need from turbo time, blow off valve, ect... thats what i figure at least i have been adding up cost the last little bit trying to figure if i want to go turbo setup or w/o one.
Reno Rotary.
Joined: Jan 2004
Posts: 1,037
Likes: 11
From: Reno
I'm sorry man I can't help you on this arguement, I was helping people understand your comment about you don't need an intercooler without the exhuast. I also don't see how your setup can work unless.
You have the carb set up to be way, way too rich, so that once all that extra compressed air hits it you once again have the correct air/fuel ratio. And you would also need some kind of way like a, I don't know, air lock sort of deal to let the carb's mix of a/f mix into the pressurized air without the pressurized air coming out the carb. (Like Perfect Circle is saying.) Or you have the boost go in through seperate ports and meet the a/f in the combustion chamber.
Yeah, I think I am a sceptic on this one until I see a running setup.
You have the carb set up to be way, way too rich, so that once all that extra compressed air hits it you once again have the correct air/fuel ratio. And you would also need some kind of way like a, I don't know, air lock sort of deal to let the carb's mix of a/f mix into the pressurized air without the pressurized air coming out the carb. (Like Perfect Circle is saying.) Or you have the boost go in through seperate ports and meet the a/f in the combustion chamber.
Yeah, I think I am a sceptic on this one until I see a running setup.
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
Likes: 4
From: Brisbane, Queensland, Australia.
Originally Posted by gmanuser
ack 
sorry i ment to draw the turbo timer and blow off valve on that toop pipe and trochoid i realize what is happening here but if you manage it right you can run a setup like this with a intercooler because it wont puddle up in the intercooler only if done corectly and your pipe going into manifold is higher than manifold because of gravity and the laws of physics unless some massive amount of air is waiting to be expelled in the intake (wich is what the blow off valve is for) you wont have gas pile up. and when this setup is achived the carb while suck in air along with gas into engine so you get compressed air + gas (and eventually a spark from spark plug) = going hella fast!!! 
sorry i ment to draw the turbo timer and blow off valve on that toop pipe and trochoid i realize what is happening here but if you manage it right you can run a setup like this with a intercooler because it wont puddle up in the intercooler only if done corectly and your pipe going into manifold is higher than manifold because of gravity and the laws of physics unless some massive amount of air is waiting to be expelled in the intake (wich is what the blow off valve is for) you wont have gas pile up. and when this setup is achived the carb while suck in air along with gas into engine so you get compressed air + gas (and eventually a spark from spark plug) = going hella fast!!! Now stop acting like you know what you're on about and giving newbies who don't know any better bad ideas.
wheres my calculus book?
Joined: Jan 2006
Posts: 276
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From: st. george UT
heheheh for now i will drop this argument but once i got it running on my car i wil post lots and lots of pics and yes of course you have to run rich. the only thing i have not taken into account is the vacume leak thanks revhead i will figure it out and get back to you peoples. and thanks for trying drift fb.
i see what you guys are saying i am just trying to say that the only diffrence between running an intercooler properly and not is colder air w/ some turbo lag. deppending on size.
just because no one else has done it does not mean it cant be done.
and by the way it meets right as entering the comustion chamgerbs almost literally heheheheh
I realize what i am proposing may seem ridiculus, stupid, not possible, ect...
when Copernicus proposed the sun to be the center of the solar system he was ridiculed and told that it was imppossible and that everyone before him thought other wise so he should to.
i feel horrible about arguing with the most reputiable names on these forums and realize that in fact if i am proven wrong that i will never be taken credibly agian.
so all i am left to do is try like hell to make it work!!! wish me luck ehh?
i see what you guys are saying i am just trying to say that the only diffrence between running an intercooler properly and not is colder air w/ some turbo lag. deppending on size.
just because no one else has done it does not mean it cant be done.
and by the way it meets right as entering the comustion chamgerbs almost literally heheheheh
I realize what i am proposing may seem ridiculus, stupid, not possible, ect...
when Copernicus proposed the sun to be the center of the solar system he was ridiculed and told that it was imppossible and that everyone before him thought other wise so he should to.
i feel horrible about arguing with the most reputiable names on these forums and realize that in fact if i am proven wrong that i will never be taken credibly agian.
so all i am left to do is try like hell to make it work!!! wish me luck ehh?
Last edited by gmanuser; Sep 29, 2006 at 09:25 AM.
Rotary Freak
Joined: Jun 2003
Posts: 2,604
Likes: 1
From: Land Of Confusion southern MI, USA
you see though. nobody gave copernicous factual information to prove him wrong like we are to you.
so lets start off with whats wrong, and well see if you can explain. first off, the car wont run with a free amount of air entering the intake tract. becuase fuel only enters when there is a vacuum to pull it out, and when the air is comming from somewhere else, you have no vacuum on the carb to pull fuel through...
now lets address the boost, you will not make any boost with this set up..beyond the fact taht it wouldnt even run. but if you could get it to run it wouldnt boost, because when the turbo starts making pressure, all of the air will go out the top of the carb. and it will stop running because the motor will have no air, or fuel.
and if you planned on tuning it rich, that would be terrible to drive, you would get poor mileage, and it would run really shitty until you got into your hypothetical "boost".
and as far as you having a blow off valve? that wouldnt work either, because a BOV vents when it gets a vacuum signal i.e. when you let off the throttle, closing the plates, and causeing vacuum in the manifold.. but the way you will have yours plumbed, when you let off the throttle, it will be the only time it makes any boost, because it wont be able to escape out the top of the carb. and at this point your motor will be revving up, while you let off the throttle and are going WTF? and it will boost, and run leaner, and revv, and continue the cycle until you blow your motor, or press the gas pedal to releave the pressure...
FTR a turbo timer, is a device designed to allow the car to run for a designated time after you leave, so it will cool down the turbo charger. so i doubt you will have one of those. i havent seen one on a 12at yet, as far as i remember.
oh and also, dont think your the first person to use an intercooler. almost all of the blowthrough setups ive seen have them. and it will not work at all on a drawthrough. because the fuel will pool in the intercooler. even if you have it setup to be a gravity feed. it would slow the delivery, thus leaning the motor to detonation, and killing it.
keep in mind, im not trying to harass you, im just setting the record straight. and if you feel you need to build this, this way. by all means, go for it. but youve been warned, it will not work. and if you want to try and explain this, i wil contiue to show you the flaws until it is fixxed, at which point it will be a blowthrough setup. but im having fun. so dont let me discourage you
so lets start off with whats wrong, and well see if you can explain. first off, the car wont run with a free amount of air entering the intake tract. becuase fuel only enters when there is a vacuum to pull it out, and when the air is comming from somewhere else, you have no vacuum on the carb to pull fuel through...
now lets address the boost, you will not make any boost with this set up..beyond the fact taht it wouldnt even run. but if you could get it to run it wouldnt boost, because when the turbo starts making pressure, all of the air will go out the top of the carb. and it will stop running because the motor will have no air, or fuel.
and if you planned on tuning it rich, that would be terrible to drive, you would get poor mileage, and it would run really shitty until you got into your hypothetical "boost".
and as far as you having a blow off valve? that wouldnt work either, because a BOV vents when it gets a vacuum signal i.e. when you let off the throttle, closing the plates, and causeing vacuum in the manifold.. but the way you will have yours plumbed, when you let off the throttle, it will be the only time it makes any boost, because it wont be able to escape out the top of the carb. and at this point your motor will be revving up, while you let off the throttle and are going WTF? and it will boost, and run leaner, and revv, and continue the cycle until you blow your motor, or press the gas pedal to releave the pressure...
FTR a turbo timer, is a device designed to allow the car to run for a designated time after you leave, so it will cool down the turbo charger. so i doubt you will have one of those. i havent seen one on a 12at yet, as far as i remember.
oh and also, dont think your the first person to use an intercooler. almost all of the blowthrough setups ive seen have them. and it will not work at all on a drawthrough. because the fuel will pool in the intercooler. even if you have it setup to be a gravity feed. it would slow the delivery, thus leaning the motor to detonation, and killing it.
keep in mind, im not trying to harass you, im just setting the record straight. and if you feel you need to build this, this way. by all means, go for it. but youve been warned, it will not work. and if you want to try and explain this, i wil contiue to show you the flaws until it is fixxed, at which point it will be a blowthrough setup. but im having fun. so dont let me discourage you
Rotary Freak
Joined: Jun 2003
Posts: 2,604
Likes: 1
From: Land Of Confusion southern MI, USA
cartech used to make a kit other than that, idont know of any, you will probably have to piece together your kit, cause they dont come around that often. the best carb, would argueably be the weber/oer carb. although i know some have had great succes with the nikki. you should get the turbo from your friends car, or any tii for that matter. otherwise, just upgrade your fuel system, alot of people use the intercooler out of like an isuzu npr, or a volvo. an ebay bov, and custom turbo piping. then you need a hat, which you can get from rob at rotary shack, unless you get a better deal on a used one.
Thread Starter
pwned
Joined: Sep 2005
Posts: 1,296
Likes: 0
From: Northern Indiana
that is EXACTLY wat i wanted to hear.. thank you.. im going to wait to worry about my exhaust until i get good at welding. i plan on custom fabing everything to fit. i know i should search, but how much would i estimate the weber carb cost?
Rotary Freak
Joined: Jun 2003
Posts: 2,604
Likes: 1
From: Land Of Confusion southern MI, USA
it will fit on the manifold, the footprint for webers/mikunis/dell's are all the same. and a 48 is slighty large for a 12a, but if tuned right, it will work, and when your under boost it doesnt matter. but yea, either a 45 or a 48
Rotary Freak
Joined: Jun 2003
Posts: 2,604
Likes: 1
From: Land Of Confusion southern MI, USA
yea, you could use that kind of intercooler, you dont even really need one. but a TII intercooler front mounted would be fine. either a walbro 255lph or an aeromotive high flow pump. then a mallory 4309 fpr, and a larger feed and return line.
