fc3seeker

Going to have:

RB Full Exhaust, FCD, intake
walbro
s5 turbo to run at 8-10psi
S-afc and profec B

I was thinking of getting the 680cc inj out of a gsl-se to run as my secondaries.

1) will 2x550 and 2x680 suffice?

2) Do I need a better FPR ? (stock right now)

any suggestions and/or comments welcome.

Scott 89t2

if you can keep it down to 8 or 10psi you'll be fine.

but unless you port your wastegate you won't be able to.

fc3seeker

yea i plan on porting the WG but, how much can i safely boost, given that all my injectors will be cleaned and balanced and all that good stuff.

boosted1205

iTrader: (9)

If the sig is what you have so far and you're running upwards of 10 psi, you're heading down a dangerous path. I've been there and so have a lot of people.
I'd suggest you keep the boost down until you have the "going to have". And..get rid of that FCD! You should NOT be boosting well above past factory with that thing. Even if you set your boost at 8 psi, the wastegate is so small that it will creep upwards of 15 psi easily.
Unless you're going full turbo upgrade, there's no need to upgrade the fuel system since it's good as it is except the injectors. 720cc in the secondaries should be a minimum but not much larger than that since the SAFC will be hard to adjust the changeover.
Just to give you an example. When I had a compressor upgrade and 720c secondaries, I had to bump up the 5500 and 7200 4% and 5%. 680cc will be too small to be in the safe side. You don't want to run upwards of 90% duty cycle on the injectors.
Be sure to re-wire the fuel pump.
That is so important if anyone hasn't done so.
I was getting 10V on boost at night which was the culprit to the blown motor. I found the low voltage by accident a few years back which I wondered why I was detonating at night and don't remember doing that during the day.
Sorry for the long post. I tend to babble when I get started.

boosted1205

iTrader: (9)

By the way, as for the Walbro pump. If you are running low voltage to it, it pumps at a very low rate. One of the DSM guys had a chart on flow vs voltage for the 255lph pump. It may flow less than factory pump if voltage is low enough. I was surprised to see the results. I know it flowed most at 13V which is self explanatory.
I'll see if I dig it out somewhere. It's been years since I saw it.

poor college student

wait, what's the fcd for? and when do you need it/not need it?

gsracer

Sounds good, at 10 pounds with the walbro you most likely won't even need the 680cc injectors.

SideWindeRx7

550's will do just fine for 10psi. no need to upgrade them right now.

ilike2eatricers

It basically fools the ECU into thinking you are not running over stock boost levels stopping fuel cut. You need it when you run over stock boost levels (upgraded exhaust mods,etc..) The problem is that it causes the stock gauge to be useless/inaccurate and you need an aftermarket boost gauge. Also just because one is not hitting fuel cut does not mean they are getting enough fuel.

Spraintz

iTrader: (1)

anybody have a link or a how-to for this rewire of the fuel pump I always hear about. I understand why it needs to be done and all but have never seen how.

thanks

Sir Rupert Hobo

i'd also like to know how to rewire it...

and i found some search results... i'm checking them right now.

https://www.rx7club.com/search.php?s...der=descending


hmmm, seems a little complicated.... so far.

fc3seeker

https://www.rx7club.com/showthread.p...ht=fuel+rewire

BlackRx7

I highly doubt that a walbro on a car with out the rewire will flow less than the stock, but it also makes me want to do this rather easy mod