heavydownlowe

Hey everyone, on my 7 I just put on a Bonez down pipe and Bonez mid pipe w/ new O2 Sensor; I didn’t buy a new manifold to down pipe gasket though :-( Well, it was a bitch to get on. Anyways, what is the best way to get better mileage on our 7? i replace my oil and filter evert 2000miles and fuel filter & intake filter every 5000miles.

1993 touring(owner of one year and installed all parts since I got it)
- Greddy Ti exhaust
- Greddy intake
- HKS ignition module
- NGK plugs and wires
- Odyssey battery with Rotary Extreme box
- Bonez down pipe
- Bonez mid pipe

future mods
- Bosch fuel pump is next
- Apexi ECU with commander after that
- C-West N1 body kit after that (the real one)
- Koyo radiator after the C-West kit
- Tien Super Drift coil-overs

impactwrench

They don't get good gas mileage....period.

TRISPEEDFD3S

iTrader: (26)

haha at the entry above. Hey heavy, are you in the navy? I think I've seen your car near the mini nex. PM me if your who I think you are.

heavydownlowe

i know what you mean

this is my only car though. will the down pipe and mid pipe help or was that a stupid move on my part? i am new to the rotary engine thing :-/

Kyro-2

iTrader: (1)

Put an ls1 in it. you will get alot better gas mileage.. ask me how I know

heavydownlowe

yeah, i am in the navy. it pays the bills you know?

anyways, i live in the barracks over at north island

heavydownlowe

i dont have that kind of money :-/

impactwrench

The rotary is not very fuel efficient to start with. It's a kick in the *** to get into boost and go fast. who in their right mind, buys one, with fuel economy in mind. You want fuel economy, pull the motor and transplant a honda hybrid in it

heavydownlowe

let me rephrase, will the downpipe and mid pipe help with fuel efficientcy?

dgeesaman

iTrader: (7)

Changing fuel and air filter at 5k is kinda silly. 10k for an air filter and 15k for a fuel filter is already very conservative.

Unless your O2 sensor is a wideband I have to wonder (b/c I'm not sure) if it has any purpose at all.

The best way to save fuel is to granny drive. Boost = gas.

You can't mod a car for fuel savings save for one thing - a well-tuned aftermarket ECU can get better highway mileage, but in city driving it's easily lost. DP, MP, Intake, exhaust, etc simply provide more air to the engine, and the engine injects more fuel to match. Those don't change the efficiency - only the max output.

Did you port your wastegate yet?

Dave

heavydownlowe

no

dgeesaman

iTrader: (7)

What is your peak boost holding at? Does it creep above 10psi?

Dave

heavydownlowe

no, when i get over 9psi i let off. i am affraid of my car still...

i know, i am lame

impactwrench

As dgeesman said, these mods only allow you a way to higher HP/ more gas consumption. Dont you think that Mazda was trying to get Max fuel mileage out of this when they marketed it. They had to settle for the median between mileage, performance, and still pass emmissions. Lets eliminate the emmissions system, air pump, precat, and cat. What did that do, create less exhaust backpressure so that we can run more air thru the motor. More air needs more gas, right? Seriously, this is a high performance car. Outside of extreme thrills, don't expect infreqeunt trips to the gas station. I don't, and neither does anyone else here.

7racer

you know about potentially blowing your engine with the midpipe correct?

heavydownlowe

what do you suggest?

FDZero

iTrader: (10)

Heh, my FD has slightly better gas mileage than my DD, a Tacoma TRD Xtra cab. I mean literally, I can see my gas meter deplete a lil' bit each day to/from work in the truck (18 miles roundtrip)...but in the FD, I'll see it deplete a lil' bit every couple of days.

But having two cars makes it, of course, more practical to feed gas to the truck more.

Mazda99Nikon

I don't know about the midpipe, but replacing my precat with a downpipe resulted in no change in gas efficiency.

I'm currently getting around 22 mpg combined city/highway miles.

He's my mods: custom forced air intake, downpipe, high performance light weight clutch, boost controller.

Now, here's three tricks I use to maintain good gas mileage.

1. I like to play on the entrance ramps and open it up, but when I'm crusing on the highway from point a to point b I try to watch my engine vacuum. I stay out of boost and try to keep it even, around -10 mm hg. Sometimes this means driving around 70 mph, sometimes 65. Don't look at every Camry in the passing lane as a challenge, and you'll save some money, which I find useful to make my car payments and pay for oil changes. Yes, you may accurately call me grampa.

2. On exit ramps, actually before exit ramps, I coast. What's the point of driving to a stop sign or stop light with your foot on the gas and having to grind down your brakes? These are incredibly light, high performance cars that will coast more than a mile at 70 mph and still get you to a stop sign at the bottom of an exit ramp at 25 mph, needing only a touch on the brake pedal to stop. Saves money again on brake pad replacements.

3. When driving around town- particulary in stop and go rush hour traffic, keep the rpms around 2500. You aren't going to impress anyone driving around bumper to bumper at 4000 rpm in second gear, or first for that matter.

Little stuff like that makes a difference.

TRISPEEDFD3S

iTrader: (26)

take that midpipe off and put your stock cat back on

7racer

either to get the supporting mods for the midpipe, add restrictors, or take it off.

degessaman hinted at what you need. You might want to search the forum for "midpipes"

too many people lose their engine by improperly modding these cars.

heavydownlowe

thank you all, i will get a high flow cat ASAP.

7racer

https://www.rx7club.com/forum/showthread.php?t=531214

rynberg

Why is your next planned mod a very expensive and high end fuel pump? There is ZERO need for this and it will accomplish nothing.

BryanDowns

iTrader: (2)

fwiw, on most engines basic breathing mods will increase mpg. Generally it reduces pumping losses. It is not uncommon at all for cars to pick up 1-2mpg with intakes, exhuast, headers that type of thing. my point? his questioning of if X mods will add mpg isnt so far out there.

However I've no idea if this applies to the rotary of not. I suspect it doesnt.

TRISPEEDFD3S

iTrader: (26)

To add to what tyler said, the supra pump would be just fine. If you're staying with your stock twins.