I've just acquired a 2008 G35S Sedan and I've been researching ways to bump up the HP and improve the MPG. Here is what I'm thinking and would like to hear your thoughts..

1 - Installing a intake plenum spacer (either a skunk2, blox racing, or a AAM). Are there any mods needed for this to fit?

2- installing the AAM Test exhaust pipes

3 - installing the stillen stage 3 cold air intake

4- having Z1 do a UPREV reflash/tune?

What should I expect from adding these mods?

 

The plenum spacer is only for the 1st gen Gs so it's no use to you. Test pipes will free up your exhaust so you should see more power, intakes really don't do much for our cars other than making them sound better unless you're tuned, and you typically don't want to tune your car until you've installed all the breather mods you're going to get: test pipes/HFCs, intake, exhaust, etc.

I have a first gen sedan and with an R2C intake, plenum spacer, Art pipes, Motordyne XYZ, MD VQ exhaust and Osiris from UpRev I gained 35 hp/tq over stock

 

Thanks Blue Dream, did you see any improvement in fuel economy?

 

Nah I drive the car harder than ever. One of my maps on Osiris is a fuel saver, when I used it I saw a 2-3 MPG increase but hated the way the car ran.

 

Anyone have 2007-2008 G35S they've modified? Any advise would be appreciated.

 

uhh . . .nope, no one has EVER done that before.

Seriously though, search is your friend; either here or

 

stillen exhaust is a great mod....just so happens mine is for sale

 

I hear one 2nd gen has that spacer

 

ive got the stillen gen 3. only intake worth installing IMO. ive got full boltons (minus headers) with an uprev tune and the car is 100% different than the day i got it. dont expect to gain any MPG though. if anything it will go down bc you will be driving it faster

 

If you are only looking at HP gains there isn't too much unless you want to spend 3-4K on either a turbo or supercharger. The only mod that gives you some noticeable gain would be an Uprev tune, a part from that you gain very minimal power.

 

Yeah, I'm new to the Infiniti and the luxury sport car world. I love this car as it's a blast to drive! Probably what makes me different then most on here is I'm just as interested in bumping up the MPG as I am the HP. So if I'm trying to figure out is what makes the best combo? Heck, the car already has dual intakes but if I need to do the stillen stage 3 CAI to make the tune work the best then I'm game! New intake spacer, whatever! I'm really not wanting the car to be much louder because I drive a lot. I have the discipline to keep my foot out if it and 2-3mpg per year is worth $600-$800 a year in gas. So I'll use it when I need it. What's the best combo to get me there?

 

Uhmm . . . .just a quick mention about that price range; it wouldn't even get you in the door to a working FI setup. Realistically, it would be like 2 or 3 times that much.

People spend well over 2 grand just for the meager gains of IN/EX upgrades & Tune.

 

Currently not interested in installing a turbo. Based on the little research I've done it looks like a stillen CAI and tune might get me another 20-25hp? Also might get a slight bump in MPG if I keep my foot out it... Does that sound about right?

 

i wouldnt hold your breath on 20-25hp for stillen cai and tune. stillen cai might yield some HP in the high end but nothing noticeable. id bet on your MPG going down after that as well

 

Even more than I thought... Thanks for the correction VQsmile.

If you drop some K&N filters in the stock air intakes might help yield a better MPG. Changing the plugs might also help MPG depending how old they are.

Most "Mods" don't improve HP on our G's. It's mostly for looks or sound unless you want to drop serious money as Vqsmile stated.

Expect about 10-15hp gain with both Stillen CAI and Uprev tune from what I've read on the forums.

Anyway, hope this helps.