Sorry if it's a dumb question, but basically.. I've installed a 5/16 Plenum Spacer, JWT Pop Charger + Z Tube, Damper Brace, and soon a 9-wire grounding kit.

I've noticed a decrease in my gas mileage.. And while I've certainly noticed an increase in performance, I'm wondering if a tune would maximize that. I can't seem to get more than 15-15.5 MPG even when I'm not driving like a G-owner haha. Usually, when I'm trying to maximize fuel, I can about 17 city.

I've also recently put some wider tires on.. Might be due to that? Not sure.

So my question is, if I should get a tune, does anyone know someone around the San Diego area that could help out? Or is there a handheld tuner that actually works that someone with intermediate mech skills could use correctly? I've had my car like a year, but only recently started getting into modding it. So I'm new to all the mechanical talk. I do all the maintence and installs on it, etc.. Not sure how complicated a tune is.

Any help would be greatly appreciated! Thanks in advance.

 

Wider tires will reduce your gas mileage! You could get a tune now but I'd wait until you've finished your mods. You need HFCs or ART pipes and a full exhaust system before you get a tune to make it worth while....Gary

 

Did you reset the ECU (leave the batter unhooked for an hour+) after you installed the spacer? A small decrease in MPG is normal since you're letting more air into the engine. More air = more fuel = more power. Maybe you need a tune-up?

 

Well I had to disconnect my battery for the damper brace install, and that was about an hour and a half, so I guess have. Would a full ECU reset throw a CEL?

Also, I should be getting a tuneup soon (55k) for my 60k mileage. Unless you mean something different. Not sure who does tune-ups around SD.. Cause I know Infiniti will charge and arm and a leg.

I'm definitely looking to get some aftermarket headers and maybe a z mid pipe. Or would a full exhaust swap be better?

Thanks for the replies guys!

 

Strange, my gas milage went up by about 10% after installing the spacer.

 

i would deff wait to get a tune, untill your done moding trust me its worth waiting.

 

Alright, I'm definitely going to wait, just wasn't sure if I was harming my engine at all by not having it tuned to the changes.

So that brings me back to my question.. Where should I go for a tune when it's time? And what about handheld tuners? And what about my 60k service?

Thanks guys, you've been great.

 

go to church automotive, and do the 60k maintence yourself.

 

Wider tires does not drastically change your mpg. You wheel diameter does, you don't need to tune yet because it would be a waste of money. You haven't changed anything to your compression ratio so the ecu should be able to modify itself slightly unless your o2 sensors are bad. Since you said your car is about 55k have you checked on your oil consumption yet? The main reason why Infiniti dumped the vq35de and vq35hr was because of poor piston rings. Your daily mpg is close to correct for city driving. Before my mods I was getting 17-19 city and if it was straight hwy I can do well over 30. But like you admitted before, it's all about your driving style. I agree and say you should go to church. There is also a place called R&D in montebello if you need to redo your valve covers (since all you can replace is the gaskets, R&D can actually modify your valve covers so that you can also replace the o-rings) make sure you have all the torque down specs.

 

you do not need a tune, you also did not need to mention you were 17 years old....I have no idea what that has to do with anything?

btw, my advice - get a UPREV tuner kit, learn to tune your own car, being able to tune comes in handy.

 

Because I'm not exactly familiar with everything around me or thoroughly familiar with all the specs of my car.. Not sure what the upset is, my bad?

Anyway, thanks for the advice Flip. I'm still new to all this stuff, but I'll do some research on the issues you've listed. Thanks. I'll start keeping track of my oil as well.. What would be a greater than normal consumption rate for my oil? Just bought a oil change pack of full synthetic last week, haven't gotten around to it.. I think the last change was done about 4.5k miles ago.. But I think they used synth-blend.

 

And SE, thanks for addressing my question as far as tuners go. I'll look into that. Is it something fairly easy to learn?

 

No, worries. Try to find a full manual for your car. As for tuning I agree with se but I suggest you also get a wide band sensor so that you can actively see your fuel to air ratio. Tuning will take a long time to learn but it's a skill not many people know how to do properly. Just remember when you start to stay closer to the rich side (most ecus have a program set that if anything should go wrong it will dump fuel into all cylinders to save the engine).

 

I forgot to ask, Do you have a dropbox account and what year is your car? I have an 03-06 coupe manual that you can peruse, just keep in mind that there have been a few updates as well as recalls. If you want it PM me. IMO if your losing more than 1qt in less than 1500 miles you have an issue. What are your plans for your car? Are you going to follow the trend and go hellaflush? do you intend to do track days like myself? or do you want a fast daily? You need to ask yourself what you want this car to be before you do any more mods. Have a set goal and once you reach it then you can set a new goal.

 

I mean a bit of research, the cool thing is youre still NA so you cant really hurt much (unless you like cut something completely off your tuning chart lol)

its just like a bunch of table charts if that makes sense and you reduce or add what you want where you want it, go do a pull and see if it worked.


http://my350z.com/forum/tuning/51889...ing-101-a.html