New owner g8 questions

[turbo2nr]

So im pretty new to owning the g8, this is my first week of driving it around town. here is a some info on the car:

08 g8 gt
51k miles
mods:
CAI / borla cat back.

i notice on highway speeds around 60-80mpg on partial throttle i hear a loud drone/bassy noise coming from the exhaust.

I figure this is the DOD cutting cylinders. But my question is it suppose to be that noticeable? Im assuming i hear that drone/bass noise because i have a cat back.

Also when i do headers/ x pipe will that sound get better or worse?

another question, how often do you guys change spark plugs, and what plugs do you use? I think im going to do a spark plug change for shit and giggles when i do my oil change.

Also what is the recommended weight of oil to use. the g8 uses 8.8 of oil correct?

I dont see a commander in my car, Any to to tell if it was tuned?

[turbo2nr]

ALSO

what intake do i have?

[tchr49]

Welcome from Michigan.
Yep, the DOD kicking in and out can be annoying, especially with aftermarket exhaust components. You can get it shut off with a tune.
You're not going to lose much in MPG if you do. IMO, more exhaust changes=more sound. The factory exhaust setup does a good job of hiding the activation/ deactivation, but from there things change.
Not a bad idea to change plugs when you do the oil change, although they're probably still good.

Recommended weight is 5w30, and you're correct, the capacity for an 08 is 8.8 quarts. Conventional oil was recommended for the GT, but it sure can't hurt if you go synthetic.
Enjoy your car.

PS the intake is a RotoFab.

[turbo2nr]

Thanks!

that helped alot, what tuner is recommended? I was leaning to Cortex. Im still not sure what else is on the market.

The cortex also tunes the transmission correct? I've read that tuning the trans. makes a big difference in driving feel.

ALso i plan on doing headers (long tubes) and x pipe this year. Which tunner will make max use of my mods?

[BuildItYourSelf]

HP tuners or efi live.
What are you coming from? As far as a last car or a platfore your familiar with. Like Honda, DSM or anything like that. Its easy to compare with what you know sometimes.

[turbo2nr]

I have a 600whp nissan 240sx,
Fully built ka-t
8.8:1 comp forge internals
built head / cams
garret gtx40r
full race manifold
custom v mount intercooler
id2000cc
flex fuel
aem v2 stand alone.
ect ect.

Im not a stranger to modifying. My 240sx is now turning into a track car as its at that point where its annoying to drive on the street with the twin disk clutch and digressive cams.

[TooManyHobbies]

Thanks!

that helped alot, what tuner is recommended? I was leaning to Cortex. Im still not sure what else is on the market.

The cortex also tunes the transmission correct? I've read that tuning the trans. makes a big difference in driving feel.

ALso i plan on doing headers (long tubes) and x pipe this year. Which tunner will make max use of my mods?

If you are staying with CAI and catback, just buy an unlocked used Cortex. If/when you are ready to move to the next stage of mods such as headers or cam then you can sell the Cortex for what you paid for it and then get a custom tune from one of the trusted tuners.

[kevinm0131]

"trusted tuners" =
Rick Crawford
Livernois
Pat G
perhaps Vector Motorsports
just my two cents worth.

If you are staying with CAI and catback, just buy an unlocked used Cortex. If/when you are ready to move to the next stage of mods such as headers or cam then you can sell the Cortex for what you paid for it and then get a custom tune from one of the trusted tuners.

[BuildItYourSelf]

I have a 600whp nissan 240sx,
Fully built ka-t
8.8:1 comp forge internals
built head / cams
garret gtx40r
full race manifold
custom v mount intercooler
id2000cc
flex fuel
aem v2 stand alone.
ect ect.

Im not a stranger to modifying. My 240sx is now turning into a track car as its at that point where its annoying to drive on the street with the twin disk clutch and digressive cams.

I can understand you wanting a streetable car.
I don't know much about nissan so I guess I can't compare. Sounds like you have the bug like all of us.
If you tune your 240 then tune your g8.
Most plug and play "tuners" don't do shit bit make people feel like it runs better after there intake and cat backs but like most (not all) hurt power or change crap around so you think your getting better milage or the feel of power but making your tune worse.
Most people should agree with that but they buy into it and are in denial.
Dyno shops can prove the loss of power. Ex. Camaro ss with a deablo lost 15 hp over stock and the owner was convinced it made it faster. I will say it was almost 2hp over stock for 500rpm around 4k range. And a whole 4 lb-ft. And the "tune" changed corrections so the speedo was off that's where the increased mpg came from. Its a bunch of crap.

I'm sure you can understand you get what you pay for.
Good luck with the g8.

Now let's see the 240!!

[turbo2nr]

Thanks for all the input.

I will look more into tuning, I think for the beginning i will look into a commander that is proven to work. As i get more into the mods i will look into a ecu tune. I totally understand you pay for what you get. I only used the best of the best on my 240sx..

here are some pics:





g8