mazstro

i have a 1990 with a somewhat greddy kit on it with mitsu turbo,vortech fmu,mbc,rx7 intercooler,msd boost box,flowed and cleaned stock injectors.
i want to run b2600/626 turbo injectors and adjust afm to idle them, so my question is what kind of boost can i run with tuning on my current setup?
i know everyone is going to jump in and say megasquirt but also know before this or any other standalone or piggyback systems people were running more than 5 lbs boost. just wanna find out what boost people have run on fmu and msd boost box alone with injectors and tuning?

rider384

iTrader: (3)

How do you plan to control the injectors?

mazstro

reading the all your answers in one big post i thought it said the factory comp can idle up to a 330 cc injector with afm adjustment? and as far as setting up fmu and getting it to work i was hoping someone will have answers that will help.

rider384

iTrader: (3)

It will work, but not well.

Dude, just get a freakin' MS, you can have one for 240 bucks.

Jeff_Ciesielski

iTrader: (10)

People also used to scramble the prefrontal cortex in mental health patients before the introduction of antipsychotic meds. Sure it seemed to work great at the time. You transformed someone with a hard to control mental disability into a sedate vegetable. However looking back we realize that not only was it a suboptimal solution that only addressed a few immediate problems, but it was also ******* stupid.

mazstro

$240 for megasquirt? will have to buy one i guess, just that i just got my car with this all in it and have not even run it yet.

curly

iTrader: (25)

No, not $240. That's the base kit, but then you'll need larger injectors, sensors, harness, fan control, you'll need to build it, etc, etc. It still ends up being somewhere southish of $400, but not quite $240.

Anyways, you can do the bandaid route fairly easily up to 8ish psi, depending on how good a tune you have. After that, it gets tricky. If the humidity 3000 miles away changes by 1%, your tune is off.

Wildanimal

iTrader: (2)

You also have to look at longevity. A car will run on mickey mouse tuning and we all know that. If you can somehow scrap the cash together for decent fuel management, your motor will thank you with reliability and drivability. You could be surfing the internet on an old 486 computer and it will work but there are much better technologies that make your life much easier.

18psi

iTrader: (76)

agreed with both.
just because it HAS been done doesn't make it any less shitty.
that said if you absolutely MUST run band aids and refuse to embrace technological advancements I think the most you'd get away with would be 8psi

mazstro

k thanks alot for replies i will be buying the ms and injectors and everything else once i run the car at 5-6 psi its at now for a bit. until i get everything ordered and here. still have 8' snowbanks in front of my house so have some time still

samnavy

iTrader: (7)

Your biggest problem is that you're still on the stock fuel pump. On a good day, it'll do 80psi. History shows that's only good for about 7-8psi not to run too lean up top.

Get yourself a Walbro 190lphHP and a used BEGi 2025 FPR that combination should push 130psi of fuel pressure (YOU DEFINITELY WANT A FUEL PRESSURE GAUGE TO HELP TUNE). The Vortech unit doesn't have the fidelity you want to run more boost than you're running now. Once you have those 2 installed along with the 626 injectors, you should be able to run 12-14psi and maintain a respectable fuel curve.

But you'll have a bad lean tip-in problem that can be solved by an O2 Clamp.

Of course you could sell your Vortech, MSD Box, and 626 injectors, and use the money towards a a Megasquirt (have somebody build you a standalone cheaper than the PNP) on the stock injectors and still probably push 5psi, but make more power than you're currently making at the same boost. Save up for some bigger (440's/550's) injectors and a wideband over time and increase boost as your budget allows you parts. It's a way better approach.

mazstro

samnavy that is the exact answer i have been looking for. thanks alot
and i am gonna plan on running 9-10 psi max

Techsalvager

megasquirt, Wouldn't even try running a stock ecu unless you could tune the stock ecu like the honda guys can on their stuff. No way I would do the RRFPR, retard timing route again. put the money towards MS, bigger injectors

fooger03

iTrader: (2)

Most of these guys that are saying "dont use baindaids" are saying it from the experience on having "done it twice". It will cost you more money to buy the band-aids and run a crappy tune than it will to buy the MS and have a good tune.

Consider the upgrade route after about 7psi.
If you're using bandaids, you're going to buy a megasquirt anyways, now you've spent more than DOUBLE the money that you would have, had you bought the MS in the first place.

If you're using a megasquirt, you turn the **** on your MBC.

The end result:
Either do it right the first time, or do it right the second time; you pick.

mazstro

only problem is i didnt build the car i bought it with the turbo in it.
i have never built any of my toys cheap and never will,if i had built this car it would have never gone this route. have not even driven it yet until today for a trip down the road from the shop and back and may just sell it and but another platform to run my own setup in(one with a hardtop already and one i can put all my own system into) or i will turbo the womans bmw first then get into another miata.

mazstro

just curious what lean tip in will cause? hesitation? or just temporary lean/detonation.
i took car for a ride and at 5 psi it is cutting out(almost like its killing fuel or spark) and will not pull through it. it did this once so i took it easy back to shop and was curious if anyone has experienced this?

kotomile

iTrader: (24)

No.

It will cause you to run momentarily lean at a time when you want to be slightly richer than normal (acceleration enrichment), which will in turn cause a hesitation.

mazstro

ok so i went with the 326cc 626 turbo injectors and upped the boost to 7 psi and this car is insane fast and stays in stoich throughout the entire rpm range. i am going to redo all my vacuum lines tomorrow and finish the reroute of the maf and filter. might run 8 psi tops if it stays in tune with the setup it has. it does run rich on startup till it gets warm but is not horrible(will need to let it go into closed loop before taking off) but is perfect other than that and also did not have to tamper with maf spring tension like i figured. might even run more psi just need an o2 clamp. thanks samnavy

18psi

iTrader: (76)

lol @ bold
LOLWAT @ red

Please tell me you're not running 14.7 afr in boost

Techsalvager

lol? ywah wtf lol