blwfly

iTrader: (4)

i have my timming set motors stock no emmisions etc mech secondays
new coils plugs,spark plugs dizzy cap rotor etcs


what the main fuel robber well im positive its all about my igniton


whats the usall mpg do u get?

kgray

i got 18 last fill up. exhaust and a carb rebuild helped get me form 13 to 18-19. easy way to do it- shift at 2500 and one day a week or so get some carbon out of there

kgray

oh and thats all city!

blwfly

iTrader: (4)

iv rebuilt the carb my exhaust sounds like itl fall off and day now
maybe i drive a little too hard?

clean85owner

I used to get 15-17, but I had a very rich running streetported 13B 4 port.

Kentetsu

Avoid opening the secondaries when at all possible. With the mech mod, you should be able to feel through the gas pedal when you get up against the secondaries (it will be a little stiffer).

Other than that, make sure your tires are inflated and your brakes aren't dragging. Drive only down hill with a tail wind maybe?

blwfly

iTrader: (4)

lol must be my secondays takin all the gas
it sounds like a trumpet everytime they kick in and i know exsactly what your talkin about
ill try a tank with just primeries and see what i can get its sooooooooo hard not to floor it
specialy drivin nxt to some one lol
at lights im 40feet ahead before people evan cross the line

blwfly

iTrader: (4)

was that casual driving?

steve84GS TII

Even with the old MSD direct fire,my N/A setups only got about 10-12 around town and maybe 18-19 on the highway.Ditto on the secondaries,my easy open vacuum secondaries made a big dip in MPG.

The ignition is DEFINATELY an area that could use improvement on the FB.Even if you dont go with a full MSD setup and super-duper coils,a lot can be gleaned by just stealing from the FC's improved design.Add the stock FC leading coil and then direct fire/wasted spark that juice directly to the leading plugs.The FC coil is very hot and known to be reliable up to 400+HP.
With each generaton,Mazda improved upon the rotaries ignition system.... from dual distributors,to dual points,to electronic,to directfire,to crank fired.....it always improved,and rightfully, so because rotaries need all the fire they can get to ignite the abundance of fuel in that long,goofy combustion chamber....which itself hasent changed much since the beginning.

blwfly

iTrader: (4)

have you done the fc setup yourself?
sounds very interesting

BridgePorted12A

iTrader: (6)

Sorry to hijack, but quick question. I am new to the carb scene (just bought an 85 GS). I have secondaries and when they kick in, the car almost bogs and "hic-ups" and then takes off. Almost like turbo lag. Is this normal?? Is it b/c the car is running way to rich? (which it is)

Thanks!

Ryan

blwfly

iTrader: (4)

did you make it mech?
from the thread i read theres usally a lil bog cause the acellerator pump dosnt have a bigger strok that whats needed for mech secondarys search the faq for the info

BridgePorted12A

iTrader: (6)

yes, they are mech. secondaries. Just making sure it's normal. I really don't like it, sometimes it upsets the car, I could see it working against me at the autox

steve84GS TII

Heh,heh.....more than half of my car is FC!
Although I run an FC engine,I did run directfire/wasted spark MSD on my old N/A engines and it made a marked difference in idle,power and economy.It also

The FC coil is just a very powerful twin tower coil.It will fire both leading plugs at the same time,just like the stock FC setup.This not only adds another leading plug firing near the end of the power cycle,but it also allows you to bypass the distributor cap,eliminating the need for the juice to run through the carbon button and then to jump an air gap to get to the wires/sparkplugs.
You can probably run the stock FB ignitor into the FC coil like stock or better yet,figure out which wires are which and use the FC ignitor thats mounted on the FC coil.The FC ignitors arent known for failing like the FB's.

blwfly

iTrader: (4)

i guess ill have to fined me one and play around would you know what one would cost?
is fc 2gen or 3rdgen?
iv tryed two 2gen coils but they were allways broken only one side would spark

steve84GS TII

Any 2nd gen leading coil will work,they are all the same from 86-92.
Be sure you get the leading coil.Its the one thats mounted up front by the battery.The ones in the back,by the brake master cylinder are the trailing.They are two totally seperate coils with seperate ignitors.Should be cheap on Ebay or from a wrecker.Ive never heard of one failing,but of course its possible....

There are also aftermarket dual post coils out there you can use for direct fire.You can even push a pair of individual coils off an MSD box.I used a pair of Blaster 2 coils with my MSD6 before going TII.The FC option is just a cheaper alternative and its a damn powerful unit right from the factory.

Kentetsu

Check the FAQ section for directions on the 2nd gen direct fire. I did this myself and the results are impressive. You won't be able to use the 2nd gen ignitor though, unless you get the transistor unit (which is still in progress). Check out the "transistor trick" thread that is always running on or near the top page.

For now, just go with the standard 2nd gen mod. Metallic rock put together a decent set of instructions for this, which is in the FAQ section. There is also another thread (I believe) in the archives.

Kentetsu

Yeah, this is due to the mech mod. You have three choices:
1. Follow Sterling's instructions on how to improve the accelorator pump for a bigger squirt (check the FAQ section, or www.sterlingmetalworks.com).
2. Wait until you are at higher rpms before you floor it.
3. Open the secondaries a little more slowly at first, but this takes extreme foot control and is pretty tough to do sometimes.

MosesX605

I usually get 17 MPG in the city and anywhere from 26-29 on the highway. That's in US miles per gallon, BTW. I have seen no real difference in MPG vs granny shifting at 2.5k and shifting at a more reasonable 4k. I've even tried cruising at 3k in 3rd vs ~2k in 4th and have seen no real difference. On the highway the key seems to be cruising at 70 MPH or so to get the best overall economy. Higher than that and the MPG goes down.

clean85owner

Yep. Hardly ever passing 3500 rpm... When I actually got on it, I could watch my gas gauge go down considerably.

I have no doubt that if I actually tuned it, though, it could get 20mpg.

fishbulb95

I always got 15-16, fully stock with emissions. 50city/50 highway.

OneRotor

iTrader: (3)

on the highway i get 24-26 cruising between 75 and 80, playing around a little bit. easy city driving I get about 15, and if i'm out and really on it, i've seen as little as 4mpg. mods:

ported 12a (not sure about the port, sounds like a BP, idles 1800-2k)
Holly 465 from RB
RB intake
RB exhaust from header to tip
MSD Blaster 2's
grounding kit
magnacore 10mm race wires
no ps
no ac
no interior
holly blue pump
-6 a/n lines
holly fpr set at 1 needle above 6psi

aussiesmg

iTrader: (1)

I did a 2GCDFIS upgrade and with a basic tune, note carb not touched my economy went from 18 mpg to 25 mpg for the next 10,000 miles, with better response, I'm a definate fan of this cheap improvement.

blwfly

iTrader: (4)

must of been bad luck my 2gen coils were broken
has anyone tryed the trailing 2gen coils through direct fire ?

Kentetsu

Heard it can't be done, but not sure why. I know it can't be used with the transistor trick because the ignitor is different, but for plain old direct fire it seems a coil is a coil is a coil....