Probably not worth it to do either one.

Roy

 

If I upgrade my stock throttle body on my 3.0 to a performance one is it just a plug and play or do I have to have it on a scanner ? Does anyone know if it is worth it to also do a throttle body spacer as well 🤔 ? Are there other items needed to buy besides the part itself for it to run correctly ? I want my 3.0 to fly !!! View attachment 600816

Be sure to justify your intended modifications. Aftermarket options in my opinion, often do a much better job of selling than they do delivering. You want to install a larger throttle body on a motor that has not been proven to have a deficiency of flow in the stock part. The OE equipment is a systematic design and some times one change, or modification, may require another somewhere else to stay within design function. The intake plenum volume is included in throttle blade size determination.

If you install a larger diameter throttle on that motor, with all else the same, depending on how much larger you go, you will end up with a flow to throttle position mismatch that may throw the system into limp mode (torque management calculations detect it). There is a calibration table that specifically addresses throttle body flow that would need to be looked at. That is part of the reason a dirty throttle body can affect engine performance.

 

Be sure to justify your intended modifications.

@Louie928 , The test to see if the current throttle body is adequate is fairly straightforward. There's two ways to test. Old school with vacuum gauge(s) and newfangled electronics, with MAP sensors.

OLD SCHOOL METHOD:
Attach a hose barb/nipple to the top of the air filter box. Attach vacuum hose there and run it to the passenger seat/glove box area and mark it "air box". Attach second vacuum hose to itake manifold. Use a "tee" fitting if necessary. Run that hose to the same place in the passenger seat/glove box area and mark it "manifold." Attach vacuum gauges to both vacuum hoses. Sit in the passenger seat while an assistant/friend drives the car. Make several full throttle runs in 2nd or 3rd gear, all the way to redline (7,000 RPMs). Observe the vacuum gauges. Vacuum should fall to zero at full throttle at low RPMs. As RPMs build and flow increases, vacuum might start to develop even at full throttle. If vacuum exceeds a couple inches Hg, there's a restriction. If both gauges read the same vacuum and it rises at full throttle toward high RPMs, the restriction is in the air box or air filter. If only the intake manifold vacuum builds at full throttle toward high RPMs, and there's no vacuum (or much less vacuum) at the airbox, then the thottle body is a restriction.

NEWFANGLED METHOD:
Purchase an additional MAP sensor. Install that MAP sensor in the top of the air filter box. Run wires to the PCM and install pins in PCM connector for "MAP sensor 2" or it may be marked "Baro sensor" or Barometric pressure sensor in the schematics/wiring diagram. Most GM PCMs are provisioned internally for a second MAP sensor or Barometric Pressure Sensor. However, most GM vehicles do not have this sensor or any wiring for it. Once installed, get out the OBD-II scan tool/scan app and look at the live data stream (engine running), find the voltages for both MAP sensors, or find "Barometric Pressure" and "Manifold absolute pressure." Again, sit in the passenger seat with the scan tool/app. If you use a scan app that can log, you can start it logging and do the driving yourself safely, without trying to operate the scan app. Have a friend make several 2nd gear pulls at full throttle from ~2000 RPMs up to 7000 RPMs. Compare data from the two sensors. Same voltage at MAP sensors, or same MAP and Baro pressures all the way to 7000 RPMs means no obstructions anywhere. If the pressure drops on both sensors, there's a restriction at the air filter or before the air filter. If the pressure drops in the manifold, but not in the airbox, the throttle body is a restriction.

If the throttle body is truly a restriction, a larger throttle body will likely help generate a little more power. If the throttle body isn't actually a restriction, a larger one will not make any more power, and will likely confuse the PCM, throw DTCs and make the thing run worse.

There is a calibration table that specifically addresses throttle body flow that would need to be looked at.

There is a calibration table that specifically addresses throttle body flow that would need to be looked at modified.

Fixt!

@Louie928 , A scan tool won't do this. You'll need a tuning tool with the ability to read, modify and update the maps in the PCM. Be careful, the wrong modifications with a tuner can destroy parts and/or destroy the entire engine.

I want my 3.0 to fly

Hmmmm, tough to do. Maybe drive it off a cliff? (Don't try that, it's a joke).

 

I want my 3.0 to fly !!! View attachment 600816

you’d have better luck this way…

 

Hate to say this, but if you want that car to "fly" you'll need to jack up the rear view mirror and install a CTS-V under it.

 

Daaamn.... so maybe I could just buy a performance throttle body for the 3.6 on my 3.0 ? Or will my Lil 3.0 blow up ?

 

A better plan would be to get the entire 3.6L engine and stick it in your car. That is if you're looking for more power.

What exactly are you trying to do with your car? Why do you feel you need more power?

I'm the guy who shows up at the SCCA Solo (autocross) events with the most "wrong car" and proceeds to shock everyone. That's fun, but there's already a bunch of CTSs that show up at my local region (A few Vs, some 3.6's and one other 3.0), so I'm just one of the crowd with this car. It's more fun to take the S10 pickup to that. And the MB 560SEL was a blast for that until the wife killed it. Plus, this year, my friend with the 1978 280Z with the drive train swap from the 2001 Z28 Camaro (plus mods) is serious about the Solo stuff, and that car is a blast to drive, even though it's not my usual choice for the "You brought the wrong car" award.