I was looking for unusual and simplistic methods of attaching turbochargers to vehicles recently and found a curious set of pictures detailing some very interesting setups for turbocharging an engine, using a carburetor, where it works exactly like a roots supercharger.

This one in particular caught my interest because I already have a huge gaping hole in my hood in the center with a scoop built for the current setup. I have a 4bbl edelbrock intake and matching carb sitting on top of a 2.8 v6. My plan is to eventually replace the 2.8 with an aftermarket 3.4, or pull one from one of the very early Gen4 camaros. After searching for methods of both turbocharging and supercharging, i learned that, While unusual and not particularly the most effective, a drawthrough setup was possible for turbos.

When I found these images and researched it some, I found that this may be one of the most unique designs i have seen, and thus want to apply it to my vehicle. I know it won't be as effective as blowthrough, but I am not concerned with getting the most out of my vehicle. I like the unique nature of the application.

I'd like to know what exactly i've found in these images. The images I have detail a single turbo application. Is there a dual turbo application for draw through? i'm looking for something that is an easier bolt-on application, as these shown bolt directly on to the manifold and the carb bolts directly onto them, its just a matter of fabricating the pipes between the adapter and the turbo.

I prefer this design because it is simple and easy to use. Please let me know if you can help me out with some additional information concerning these!



















This last one I am VERY interested in, as it would allow for a symmetrical design, with a turbo on each side. I like symmetry.

 

theres a sort of reed vale int he bottom of the carb adapter which allows the enigne to suck in fuel directly from the carb instead of sending it threw the turbos , as the turbos spool the plate/valve in the bottom of the carb adapter is closed and this allows all the air and fuel to go threw the turbos

edit the valves on that adapter look like they are controled by vacum against a spring loaded valve

 

I thought at first that would make it leak pressure some, but if it seals properly I think it will work quite well. Is this a custom build adapter or is there a place/company that manufactures these sort of things? I haven't had much luck in that field of search..

 

unfortunatly those types of systems really arent made anymore , try looking for some used martin turbo system stuff , u may be able to find a carb plate u could use


the easiest way to do it would be to mount a carb directly to a single turbos inlet and then plub the turbo directly to the intake manifold

 

These didn't last long because they didn't really work that well.

With the advances in engine control I really can't see why you'd want to go this route.

You also need particularly prepped turbos to deal with the fuel that will be passing through the compressor.

Also forget about any sort of conventional intercooling, draw through set-ups can't use any sort of remote intercooler because the fuel will fall out of suspension and pool in the intercooler and intercooler piping and be a good source of uncontrolled explosion.

 

http://www.beforeblack.net/

 

After some reading and consideration, I think that it would be easier, and cheaper, to build my own adapter. I feel this would be easy, so I am going to run the steps to my idea by your guys and see what you think:

first, I would buy a thin sheet of aluminum, and a 4-5" or larger aluminum carburetor spacer I would weld the sheet inside the spacer at an angle running from the front top to the rear back, making a slope. From there, I would drill a 1" diameter hole inside the center of the plate, and mount a crossmember across the plate. A spring would be mounted on the crossmember, set to pull a rubber plunger from the bottom side against the face of the plate, creating a seal in the presence of positive pressure or no pressure in the lower section, but opening in the presence of negative pressure, such as when the turbos have not wound up yet.

In the back of the spacer, I would drill a large 3" diameter hole and weld a short pipe onto it, which would end in a split curve in both direections. from there plumbing would be ran to the turbo for the draw point. The turbochargers would ideally sit directly on top of the exhaust manifolds on either side of the engine. On the front of the spacer, a similar hole and split would be mounted as well, which would then also be plumbed to the turbochargers for recieving the pressurised mixture. This in essence would create a universal 4bbl mounted draw through twin turbo adapter plate, in its very basic format.

Further modification would be needed for any additional hardware that comes standard with turbochargers of course, but it should give an effective and stylish, symmetrical starting point that takes up very minimal space.

What do you all think of this idea?

 

Terrible idea, because this type of system does not work well, and is why NO ONE uses it anymore.

 

Im trying to re-engineer it to work well, which is why i am still going to use it.. i dont want to copy whats already been done, theres nothing unique about "yet another blow through turbo"

 

I think Martins already engineered this idea to work as best as it can. Like I've already said there's a reason why people don't use this anymore (other than maybe on a few nostalgia restored vehicles). They just simply don't offer any real great performance for the system.

There's more cons than pros to it.

"Just another blow through", sure, but it works, without headaches, it's reliable, no special compressor seals are needed, no chance of fuel puddling in the turbo (on shut down) that could cause an intake/turbo explosion (It's happened with this type of system). The fact that there no way to safely intercool it means that you'll be blowing hot air into the intake, upwards of 200* F I've seen on low boost (around 10 PSIG) non intercooled systems, that's asking for pre-ignition right there, add in the poor fuel distribution characteristics and you'll be limited to only a few PSIG of boost safely. Yes, you can add a meth/water kit to the system, but then you need to make sure that's full all the time, and/or have a way to limit boost if it gets empty.

Or you can go with what works and actually ENJOY the results instead of putting band-aids on a poorly devised system.

I get it, I like to be unique too, but some areas are best to not be unique in. Don't get me wrong a friend of mine has one of these systems sitting on his shelf, I think it's cool as **** and would love to put it on something but I realize it would really be mostly for show and not so much go.

The only way I'd use this is for the looks and instead of using a carb or TBI, go MPFI so that the fuel doesn't actually pass through the turbo and always have the throttle body passing air through the compressor. It would be more conventional without any flappers or air diversion and the throttle body would simply be limiting the air going through the system, the advantage of that is no need for a BOV, but at the expense of throttle response, and return to idle can sometimes be laggy, often described as a mushy throttle response. I believe this also requires a special seal in the turbo as well to deal with the vacuum that will be applied to compressor in the low throttle angle situations.

I'm just trying to help you to not waste your time on a system that will give mediocre results at best.

 

Thanks for the honesty, that makes much more sense with plenty of data to back it up. It paints a much clearer picture of what could happen, which at the same time makes me quite sad though, as I thought it would be a beautiful system to see in action.. Would a supercharger work any better in this scenario? Specifically, if I could find a roots style, one that sat in between the manifold and the carb would be best.. I've heard of one called a Fageol supercharger, it looked like it would be effective in what i'm looking for.

In fact I may be barking up the wrong tree entirely, I'm looking to increase my low end torque as much as possible. The vehicle won't have much time in the upper end of its RPMs, spending most of the time on the low end. I'm wanting to build something with much more emphasis on acceleration rather than top speed.. any suggestions? I feel like i'm getting stuck tunnel visioning a single idea and not looking at all possible scenarios..

 

just put a t3 50trim on it , with a holley 390cfm mechanical secondary carb in blow threw config

 

Would the 390 require modification? Im using an edelbrock 1404 right now, and it would need a large amount of modification from what i have read.

This is the main deterrent for me to not want to use a blow threw setup, i dont want to open up my carb and change everything..

 

iirc the carb mods were very simple on a holley, not much info out there for modding the edelbrocks , but i have heard they are pretty simple as well , if u want to do draw threw u need a special turbo , like one of the old rotomaster turbos with a carbon seal , or if u could find a good one one of the old 301 buick turbos

the buick turbo bolts down in place of the carb on the intake , and the carb bolts to the inlet of the turbo

 

i take that back pontiac 301 turbo

heres part of one to give u an idea of how it works

http://www.ebay.com/itm/GM-PONTIAC-3...dVPOD1&vxp=mtr

 

Thats an interesting design, i may look into that more. I will also have to re-read the modifications for an edelbrock turbo setup, i may have made a massive misunderstanding

Thanks for the additional information. I recently got my hands on a book titled "how to select and install turbochargers" from 1970, h p books. It is a goldmine of information!!