I recently installed a JWT pop charger, Z-tube, and 5/16" plenum spacer (resonated test pipes are being put on soon). Now I've read that the pop charger doesn't really do anything (as is the case with most intakes) and it has a problem with heat soak. Could that be the contributor to reduced fuel economy? Temperatures where I live haven't been blistering, in fact it's about to get a lot cooler with fall temperatures. I don't find myself driving any more aggressively than before I put them in. All of my driving habits seem the same.

I used to get 20-21 mpg in mostly city driving and now, a few weeks after I installed the intake I'm on track to get 17 mpg out of my current tank of gas. I haven't reset the ECU or gotten a tune. I probably won't get a tune just yet; if I reset my ECU would it help with fuel economy? Any other ideas that don't involve recommending me removing the JWT? Or if you will tell me to ditch the pop charger, point me in the direction of something better?

 

Heat soak could cause a little reduction of the gas mileage but not that drastically. I also don't put a lot of stock in gas mileage calculations based on one tank. I'd drive off a half tank, calculate your mileage and then repeat the process a couple of more times and take your average mileage over the 4 fill ups to see what you're getting.

I would also reset the ECU for a more accurate idea of what's going on with your car. Wait until you have done all the breather mods you are going to do before you get tuned. I personally hate pop chargers due to me living in the deep south with brutal summers. I'm running the R2C and have been for 3 years and am very happy with it.

 

^ he speaks the truth saved me the trouble.

 

I'm going to fill up tomorrow and I'll calculate my actual mileage after I do. I also have wheel spacers and lowered suspension added recently... I did get an alignment, I figured that neither of these would contribute to reduced mileage but I thought I'd throw it out there just in case it matters.

Is the R2C worth switching to? What about it sets it apart from the rest?

 

Intakes are a very personal choice as they really don't make much power on the DE motor. So a lot of people use what they think sounds the best and looks the best. I tried 4 different set-ups before settling on the R2C including the popular pop charger which I ran around a month before yankng it off and gladly selling it. Down here in the brutal Texas summers the loss of power from heat soak was dramatic. So I narrowed my choices to the Stillen and R2C, but the technology that R2C brings to the table sold me on it. They have some of, if not the best, filters on the market. They flow well, are very efficient at filtering the air, are a washable dry filter, and are huge. To add to that, the box seals against the hood to help prevent heat soak and they sound great.

As I have recommended before, I'd buy just the front half of the intake. The full intake is ridiculously expensive and I'd pair the R2C front with a z tube or something similar for the same results and lower cost than the full R2C. Read up on their technology here, they make a lot of filters for military vehicles that are used overseas in brutal heat and sandy/dusty conditions. http://www.r2cperformance.com/


Edit: Looks like they have dropped prices on their G35 systems so the full system with the plastic tube seems to be a good deal.

 

Thanks for taking the time to explain. Is there much difference between the polished and plastic tubes? Other than aesthetic appeal. I read that the new polished version does help performance wise, but if the difference in cost is not justified by the difference in performance then I'd consider just the front intake as I already have a z tube.

EDIT: I just filled up 15.8 gallons over 303 miles so that's about 19 mpg.

 

Replace your spark plugs and get a tune.

 

I'm sensing a little bias here Seymore

 

Just tossing this out there... but. I have a 100% stock unmolested low mileage 2004 6MT Coupe... My city mileage after several calculations averaged 17-18 MPG.

Sounds like your car isn't too far off the mark.

 

yep

 

Thanks, I know that the G is rated at around 18-19 mpg. But I was just going off the fact that I've been getting up to 21 mpg regularly and comparing that to my mileage now in similar driving conditions. Perhaps I thought it was due to my modifications but maybe I'm just going crazy.

 

Here's a few facts about the mods you've made and gas mileage. Your brain likes the sound which controls your right foot (gas pedal) that would contribute to lower gas mileage! We have a few choices when it comes to intakes, functional (stillens cai) or pretty/cool. (pop chargers) Stillens CAI isn't effected by heat and flows air thru that giant K&N cone filter. That's my back up when I need to drive to warmer climate areas like Vegas. Test pipes you're intending to install will only make your OE exhaust sound terrible/raspy!
Gary