I am going to be purchasing a 06 G35 Sedan AT. Would installing a plenum spacer give me more HP or would it be a waste of money?

I am looking at installing a K&N Filter and Z-Tube too.

The spacer will work great on the AT. About 10-13 HP.
Tony

I had the MD ½” spacer+ Iso Thermal kit (Aramid gasket and CCV), installed on my 2003 5AT G35C. I disconnected the negative battery cable and pumped the brake pedal to reset the ECU. It’s a 50+ mile drive to the dyno, made sure I showed the ECU I meant business that day.

Found out I could break the tires loose in 1st and 2nd, SLIP light flashing. I was shocked how much faster the G felt throughout the entire RPM range.

I ran the AC, as Hydrazine suggested, for the last 10 minutes of the drive and shop turned it off once it was on the dyno. The dyno shows I gained 15HP and 17 FT-LB. The gain was throughout the entire RPM range. I personally feel this is one of the most powerful mods for a NA motor. Also the biggest bang for the buck

Before
Invidia G200, Z-tube+K&N
234.31 HP 212.49 FT-LB

After
Invidia G200, Z-tube+K&N, MD ½” spacer with Iso Kit
249.00 HP 229.91 FT-LB

I was able to recover the torque I lost, plus add 8 FT-LB. Next plan is to add an X-pipe to my Invidia G200. I’m hoping to add another 4 to 5 FT-LB through out the torque curve.

I could definately feel the difference with the 1/2 iso kit as well! Great Mod!

WHOA... nice gains man!!!

wassup with running the AC for 10 min. before the dyno though? whats the reasoning behind this?

*edit*

nevermind about the AC, i just read your other post, interesting, i'm going to have to try this myself

Is the ECU reset a requirement? If so, can someone describe how this is done?

I've notice on my 03 5AT, resetting the ECU helped my mods.

Pedal Method
https://g35driver.com/forums/engine-drivetrain-forced-induction/6526-easy-ecu-resetting.html

or

Disconnect the negative battery terminal and hit the brake pedal once or twice to discharge the electrical system. Then reconnect the negative battery terminal. You will have to reprogram your presets on your radio.

Has anyone dynoed the spacer vs spacer w/Iso Thermal Kit ?
I know that with the Thermal Kit, the engine will be running cooler, but how much more power does the thermal kit part of it actually add ?
Thanks

i'm not too sure if the ISO kit is supposed to make additional power. From what I gathered, it was to prevent additional power loss due to heat soak.

^^^ Exactly. It will in a sense provide more power on colder days as it prevents warming of the air in the intake. The colder air is denser, hence more air per unit volume is delivered, hence more power.

The only thing holding me back: damn I'm getting tired of taking apart the manifold!

I just installed the Motordyne 5/16 Spacer with the Aramid Spacer this afternoon. I'm waiting for the Copper Throttle Body heater to arrive, and I'll finish up the install.

On my own, it took about 1 1/2 hours, including cleaning all the baked on brownish stuff off all surfaces. (Hint: Use an Intake Cleaner Spray while everything's apart)

The Motordyne is a very complete kit, and quite easy to do. I didn't un-bolt the throttle body from the upper plenum, I just ran a piece of nylon twine from the hood hinge mounts, and through the front hole of the upper plenum to suspend it out of the way.

I did some pre-install 0-60 runs using my G-Timer, and when the ambient temp is similar, I'll try to do some post runs to see if the difference shows there as well. Also measured some pre-install temps at various points on the plenum with an infra-red thermometer, but I suspect that the difference won't be too significant until I install the TB heater.

I didn't have time to do more than a quick drive to the store, but in my brief drive, the spacer seems to be a winner. Drivablility is not negatively affected, and in fact, low rpm response seems to be improved. A couple of WOT runs seems to confirm a stronger pull, so I would say there is a noticeable increase in torque.

Cars usually idle at 800 rpm, but with my 3/8" spacer it now idles at 600 rpm. Anyone else have the same thing happening?

tony... whats the performance difference between the 5/16 and the 1/2 inch spacers? and the only thing about the 1/2 inch is that you remove the engine cover right?

about 1.5 HP. But there is more to it than that.
You will find explicit details of the differences in the next issue of Sport Z Magazine.