Advanced Engineering Tech - Dual throttle bodies

Let me hear your thoughts on how you would engineer twin 90mm throttle bodies on an LS3 drive-by-wire engine. There are two options:

1. Mechanical - extract (with great difficulty) the shaft from a LS3 throttle body and replace with a longer shaft that protrudes from the opposite side. This can be ganged up with standard linkages to drive a "slave" throttle. BTW, has anyone pulled a shaft out of an LS3 TB? - it appears to be welded in place...

2. Electronically - more involved to design & build a voltage following electronic module with error checking between the throttle position sensors. This would be an easy installation though for multiple applications. Not impossible, but difficult and there could be legal issues if it failed.

Hopefully I can figure something out soon.. :secret2:

What exactly would the benefits be? Are you trying to make a "180mm" tb or have them back to back?


:confused:

I believe he is trying to build a manifold with 2 TB's similar to the Viper's . I've always thought this would be a great idea . Are you fabbing the intake ? I want to fab an ITB but I can't get the info I need and I don't have an engine to build it from .

A mechanical linkage wouldnt be difficult. Use an external rod pushing a lever instead of remaking a throttle shaft

there was a guy in town with a 426hemi in his magnum and it had twin tb's but it was one in the front and one in the rear, and only opened up in high rpm's it would be interesting to see some research done on this,

possibly ducting run through the firewall to a "cold air" location, i think if the research, and fab work were done well it could turn out some good power increases.

Subscribed. I would like to see some more on this as well.

It would be similar to a Viper manifold with two throttles at the front opening in parallel. I will either remake a longer LS3 shaft or make a fixture that bolts onto the throttle body and holds a shaft that slots into a groove in the stubby end of the existing shaft. An electronic module will possibly be in the future.

Below is where the problem lies. It looks like it is laser welded in place (typical OEM non-servicable part).
http://i219.photobucket.com/albums/cc156/rjkroggy/LS3drive-by-wire-.jpg

how about this.....

^^^^^^^ sure!

Nice... but wheres the drive-by-wire?

http://www.harrop.com.au/root_folder/misc_images/hurricane-1.html

Why not just set up mechanical linkage to run both off the electronic signal of one? It might present some tuning issues but I would think that would be easier to overcome than setting up two electronic signals. It wouldn't be very pretty though. Mechanical would be simpler but it would still present tuning issues.

why not make it simple?

flip the throttle bodies so the linkage sides face eachother. then simply make a thrttle cable that looks like this


.
.
.
.
.
.
_____________
. .
. .
. .
. .

that was a fail.

put the cable on the top (gas pedal side) in the middle of _________________


put the 2nd cable on the bottom on the other side of ______________

Dont plan on running all motor at the LSX shootout with that. You can only run a single throttle body?:confused: The SAM car would have run faster with there dual T/B setup.

Back to advanced engineering (not the LSX shootout, Harrop intake or running mechanical throttle activation)

The LS3 drive-by-wire is what I need to run a second throttle off. Has anyone ever driven more than 1 throttle off the late model (non LS1/LS2) drive-by-wire motors? Or has anyone ever pulled a shaft out of a later than mid-2009 LS3 throttle body?

The LS3 error checking of the TB is very sensitive and throws codes easily (e.g. if you flip the TB upside down, or higher torque on the shaft). Also the current draw by linking 2 TBs directly to the computer will throw codes.

Why not have the Electronic signal splitted to two throttle bodies like two 90mm ls2/3/7 so they get the same signal. Would that work

im with gogto^^^^^^

Unfortunately it wont work. The electronic signal uses feedback from the throttle position sensors to determine where the butterfly is. e.g. a 4V input to one drive-by-wire (DBW) motor may yield 80% open, and on another DBW motor it could be 75%. This is due to manufacturing tolerances.

Also, splitting the signal will result in twice the current draw through the computer and it doesnt like this...

The only way I see that it can be done (electronically) is to make an integrated circuit with programming to develop a signal to a second DBW motor based on inputs from the 1st DBW throttle position sensors. Then have error checking between the two throttle position sensors and set a max deviation (e.g. 5%).

Here are some of john marcella's intakes. I would try to get with him on this issue.

After consulting with designers at a couple of OEMs, it seems like it will be overly difficult to connect them electronically. I will be tapping into the original shaft and connecting through linkages. I will post some pics when done.

Cool, I'm looking forward to some pictures. Best of luck

why not piggy back off the electronic 90mm throttle body, drill and tap the shaft on it. machine a new shaft for a regular non electronic 90mm throttle body that has threads and a stop (or a locknut for final adjustment) on the one end of it so that it threads into the shaft on the electronic tb?

Could you simply use one DBW and one cable style. Make the shaft on the DBW unit attach to the cable unit. That would be much easier than attempting to connect two DBW units. Either way you go about this tuning is going to be addressed right away be someone who knows what they are doing.

Just put a single plane on it and throw an Accufab 4150 4 BBL throttle body on it.

If you do add another TB the tuning for DBW is going to be daunting. "The throttle just opened 10% but we are getting a ton more air------dump fuel!!!"

I think if you can convert it to cable it would be light years better. And if you can convert it to cable, read my first sentence. :)

^ If it is going in a vette good luck fitting a 4150 on top of a single plane. I agree the tuning issues will be very daunting, but there are ways around it. All it will take is some time, enginuity, and lot so patience.

Do you need twin Throttles? How about an oval.
Harrop made this one off for Sams performance on a HTV2300 with electronic throttle.
http://www.youtube.com/watch?v=suAEuPEzjZ8