Design and build throttle body

[Christian Steffen]

Hey guys. I'm progressing on my truck and I'm almost ready to start tuning. Im going to be drivable in a couple weeks, but I'm 100% sure the intake and spidee are going to be a problem.

I've looked around and i cant really find a throttle body replacement that will do what i want, so i think I'm going to design and cut one out on the cnc. (I'm a tooling engineer btw, i design and machine for a living)


I need some help with design intent and refinement from you guys. My current design goals.

1. Fit a standard carb intake
2. Contain provisions for all relevant gm factory sensors and actuators
   • IAT
   • Map
   • MAF
   • IAC
   • TPS
   • Cruise control?
3. Fit old school round airfilter on top of engine
4. Fit under cowl hood
5. Vacuum port provisions

Anything else?


I'll post a rough cad model in the next few days.

I would look at using a single plane manifold that already has injector ports. There isn't a real need to use a dual plane with efi.

Personally, I would not use a round old school airfilter, you'll just be pulling in a lot of hot air. Pulling from the fender would still allow you to run the stock maf/iat, or go SD and use a divorced IAT.

Could just add a hole in the manifold for map.

Are you looking for a project? The easiest route would be to make an adapter to bolt an LS TB to whatever intake style you pick.

 

[Motorsports-X]

I would look at using a single plane manifold that already has injector ports. There isn't a real need to use a dual plane with efi.

Personally, I would not use a round old school airfilter, you'll just be pulling in a lot of hot air. Pulling from the fender would still allow you to run the stock maf/iat, or go SD and use a divorced IAT.

Could just add a hole in the manifold for map.

Are you looking for a project? The easiest route would be to make an adapter to bolt an LS TB to whatever intake style you pick.

I have a cowl hood that im going to be making a plate for to seal off the engine bay. yes its just a project. something to do. but i do have to get the intake changed on my truck so this is the way i prefer to do it.

 

[RichLo]

I've already said my peace about the aftermarket units out there and everyone else has had some good ideas too for easier options which haven't swayed your mind yet.

So that being said, I am really looking forward to seeing this project advance and I hope you include lots of pictures and details about this build because it really is intriguing! If you have a goal set in your mind with the time, equipment and skills to try it, then do it!!

Whats the worst that could happen? You waste a little aluminum and some time and end up going with a bolt-on in the end? Who cares, at least you tried. Whats the best that could happen? You could be competing with those other stand alone EFI units at Summit and JEGS and be making millions in a few years!!

I really do hope you try this and succeed bud!

 

[Biggershaft96]

I have a cowl hood that im going to be making a plate for to seal off the engine bay. yes its just a project. something to do. but i do have to get the intake changed on my truck so this is the way i prefer to do it.

there are better options out there but i think itd be cool to see this. i have one suggestion though... shaker hood. i always thought those were cool as hell.

 

[Christian Steffen]

I have a cowl hood that im going to be making a plate for to seal off the engine bay. yes its just a project. something to do. but i do have to get the intake changed on my truck so this is the way i prefer to do it.

Well as RichLo said, might as well try to do something different! Definitely sounds like fun.

If you're dead set on running a MAF, could you make the TB a bit taller, then make it accept the card style MAF?

 

[Motorsports-X]

could you make the TB a bit taller, then make it accept the card style MAF?

Thats exactly what I am trying to do. I have to figure out first how to convert it over, which i think is fairly simple since they were used with the 411, and then i have to figure out where to put it. Right now Im thinking it will go in one of the runner just above the throttle plate, with just enough sticking out to get air over the sensor.

It may not read as high as it would from the factory in the middle of an air stream, but it still should give me a perfectly good reference point to tune from. I may just have to play with the values in the table a little.


Thats part of why/how im doing this. Ill start with a rough design, get some feedback, make some changes, and eventually I will have design that everyone likes. Then ill start over from scratch and refine that design to make it easily buildable, with proper airflow, fillets, threaded holes, etc.

This is about how far I got today. Didnt have a very long lunch. Ill get more done in the next few days.

You must be registered for see images attach

 

[c1500deathtrap]

MAF's don't like eddy currents and weird flow. It really needs to be stuck in a long straightish tube. Maybe stuff it in a choke collar over the TB? but even then it wouldn't read right. Is this going to be a wet or a dry manifold?

 

[Motorsports-X]

MAF's don't like eddy currents and weird flow. It really needs to be stuck in a long straightish tube. Maybe stuff it in a choke collar over the TB? but even then it wouldn't read right. Is this going to be a wet or a dry manifold?

The TB will be dry. Injectors will be down close to the ports. I'm away the MAF's need to be basically "steady state" and I should be able to place it somewhere in the air stream that effectively give it a nice even air flow.

The way its pictured above, the plates open "inward" if i make them open "outward", then i can put the MAF right there in the side of the runner, and the combination of the throttle plate, and the runner itself will direct air directly over the opening in the sensor. again, I will only have just the sensor opening stick out, and I will most likely replicate it on the other side with aluminum to balance the flow to each half of the engine.

Basically what the MAF boils down to, is that the ECM has 12Khz of resolution. Thats the limit of the ECM. Ideally, you would want to use as much of that resolution as possible for the best accuracy. However, if I am only able to get 6000 out of it, (since I am reading Half of the total flow) thats perfectly fine, as I will still be able to create my tuning points from that. Its just a matter of scaling the table in HP tuners.

 

[c1500deathtrap]

I just don't think that it will give you the resolution you need as you describe it, as you will be directing air over it with the throttle blade.But once you run it and get some data maybe it will be useful? And just a thought, on a dual plane intake with that throttle blade design you would need to make the blades open in sync with one another. Tip in is gonna be a *****.

 

[Motorsports-X]

And just a thought, on a dual plane intake with that throttle blade design you would need to make the blades open in sync with one another. Tip in is gonna be a *****.

The blades will be slightly adjustable, to calibrate them to each other. The will have a vaccum port on each side to set them similar to a motorcycle carb setup. Im not 100% sure this will even be needed, but Im going to provision it just to see if it makes a difference. The blades themselves will be gear driven. Im actually working on that tommorrow so I will post it then. I have a wire edm machine that will cut gears with profiles accurate to .00004 to prevent any backlash or slop between the plates. It should be machined so accurately that there is no need to adjust the plates at all, but Im going to find out for sure on the first one. If i made copies later, I will remove the vacuum ports and adjustment ability if its not needed.