Throttle Body setup for 3900

[SSsuperstar]

I have a 2006 Malibu SS with the 3900 and I wanna upgrade my throttlebody to the one thats on the 5.3 Impala. I can get the throttle body from GM and the adapter from here obviously.. What else am i going to need? do i need to change any sensors? i.e. mass airflow sensor, idle module? that sort of stuff? what has to be done for it to run flawlessly and get some nice performance out of it?

[Joseph Upson]

Have you verified that the electric 5.3L TB is compatible with the 3900 PCM signals? The adaptor is specifically for adapting a mechanical 5.3L or Northstar thottle body to the engine for retro swaps. At least that's my understanding.

[SappySE107]

I don't know if you can go with a larger TB with the adapter. There are going to be tuning issues as well that you must take care of, if this does work out at all. Since the computer controls actual throttle adjustments, it will also be set for less cfm per load or however else it adjusts itself. Isn't it 70mm stock?

[Joseph Upson]

That's right, the PCM is another problem. In a mechanical TB when you open the throttle of a larger TB, the PCM adjusts to the flow, in this case the PCM takes your pedal input, translates it into an output quantity and opens the throttle just enough to get it. In other words a higher flowing TB may never be opened to its greatest flow angle even with the pedal to the floor.

I have my moms Saturn Aura on loan until I get my 3900 swap complete. Her cars has the 3.6 DOHC and from my experience so far GM has a lot more work to do with programming. It's sometimes down right defiant when attempting to accelerate modestly and the engine is lugged a lot, and the tiptronic shifting is to slow to make it worth while. I was nearly run down merging on the interstate hear in Atlanta when I floored it to accelerate into traffic and I apparently was moving to fast for the computer because it paused for quite a bit before kicking down and pulling out. The engine runs beautifully and the car is fast, seemingly to fast for the computer to keep up.

If we don't maintain a means of defeating drive by wire throttle control we are doomed as far as performance is concerned.

[SSsuperstar]

how about making the stock throttlebody bigger? can it be bored out to allow more airflow? And I thought the whole idea of the adapter was to make the Northstar or 5.3 TB compatible with the LZ9 motor. And a buddy owns a performance shop that has a dyno..so tuning shouldn't be a problem.

[IsaacHayes]

The adapter is for those who are swapping a 3900 into an older vehicle and running it with the older computers that don't use electric throttle.

[Blackrider]

It’s a 70MM Throttle body stock, you won’t need to upgrade for some time. It’s not worth the money in my opinion.

[El_Diablo]

agreed, do you have an intake? full exhaust?

what have you dont for performance so far? if you can i would try and fine someone who can tune your car but its pretty slim because i dont think dhp or hpt offer tunes for your application but you could always ask

[SSsuperstar]

agreed, do you have an intake? full exhaust?

what have you dont for performance so far? if you can i would try and fine someone who can tune your car but its pretty slim because i dont think dhp or hpt offer tunes for your application but you could always ask

What can I do for an intake? Is there an aftermarket one out there for this motor? And what about headers and high flow cats? I am doing a Borla cat-back exhaust using 2 1/2 inch stainless steel pipes with Y-pipe and eliminating the resonator and 2 1/2 inch Borla Turbo mufflers and 3 1/2 inch outlet tips. I can get someone to tune it I imagine, but I have to look around. Any other thoughts? Thanx for all the help fellas. I'm not looking to make this thing ya know a 10 or 11 second car. But maybe dropping it into the low to mid 14's would be nice. It runs around 15.8 to 15.9 now...so shaving a second or two would okay with me.

[Blackrider]

What can I do for an intake? Is there an aftermarket one out there for this motor? And what about headers and high flow cats? I am doing a Borla cat-back exhaust using 2 1/2 inch stainless steel pipes with Y-pipe and eliminating the resonator and 2 1/2 inch Borla Turbo mufflers and 3 1/2 inch outlet tips. I can get someone to tune it I imagine, but I have to look around. Any other thoughts? Thanx for all the help fellas. I'm not looking to make this thing ya know a 10 or 11 second car. But maybe dropping it into the low to mid 14's would be nice. It runs around 15.8 to 15.9 now...so shaving a second or two would okay with me.

MP Racing, and Doctor Speed both make intakes for the G6/Malibu. There are currently no headers available for the 3900. The cats bolt right up to both manifolds so cutting out the stockers and replacing them with high flow cats is not as easy as traditional setups. Even if you could the stock cats flow just fine.

[SSsuperstar]

I knew about cold air intakes...are there any intake manifolds out there for this motor? Is there a way to open up the headers? what about stroker kits for it?

[Blackrider]

I knew about cold air intakes...are there any intake manifolds out there for this motor? Is there a way to open up the headers? what about stroker kits for it?

I think your getting a bit ahead of yourself. There are no aftermarket manifolds or stroker kits. The aftermarket for the 3900 is very limited.

[SSsuperstar]

I figured there weren't many...but I figured I would ask. Would the Cold Air Box on DoctorSpeed.com give me everything I need to get the most bang for my buck? If I could also get the Stage 4 upgrade would that help out as well?

[Superdave]

are you a member on www.g6performance.com ?

[Blackrider]

I figured there weren't many...but I figured I would ask. Would the Cold Air Box on DoctorSpeed.com give me everything I need to get the most bang for my buck? If I could also get the Stage 4 upgrade would that help out as well?

The CAB probably has the same gains as the "Stage 3" in fender intake. The benefit of the CAB is its not a PITA to remove the filter for cleaning. Doctor Speed discontinued the "Stage 4" a few months ago due to supply problems. However you can do what I'm in the process of doing, order a 3" rubber elbow, and 3" aluminum 90 degree and 45 degree bends and there you have it, a DIY "Stage 4"