Atlanta93LE

iTrader: (5)

So I put the Braineack's theoretical fueling equations into Excel to play around, and if what I see is true...

One could get some 295cc injectors and make them work with an RX-7 AFM on the stock pump, FPR, and ECU for 170hp at 8psi? Doesn't make sense to me, but the equations show that, with 48 rail psi from stock fuel supply equipment, 292cc is what's needed to make 170 hp.

If Braineack can get his 305cc injectors running with stock ECU, I imagine 295cc would work also.

So why wouldn't this work? Thanks

m2cupcar

iTrader: (5)

Ponder this: If AndyFloyd is running 330s on the stock ecu, why wouldn't it work?

Atlanta93LE

iTrader: (5)

But is he using an AFPR/FMU? I bet so...

I notice you have a red 93LE interior in your car. They're pretty nice, aren't they? And in Atlanta, too! Good choice.

Braineack

iTrader: (62)

The 170HP number would be at the crank, so figure maybe 140rwhp. So figure with 295cc injectors you'd be good for about 4psi without an FMU.

What's stopping you from getting one in the first place? the price? I'm selling my Vortech unit with all the discs.

Atlanta93LE

iTrader: (5)

Makes sense now that I think about the HP value being at the crank.

Right now I'm playing/planning to see which direction I should go...I'm looking to find a cheap initial setup that will allow me to slowly upgrade without ditching initial parts.

Braineack

iTrader: (62)

Even with engine management a FMU isn't a bad idea since you can pump up the fuel pressure and extra some extra room to play with on your injectors. Say 240rwhp on 1.8 injectors with EMB. But i'd consider the BEGi unit then, if planning on boosting past 10psi, lots more room for adjustability.

Kelly

iTrader: (6)

I was able to run 3.5 psi with a T3 60 trim with the stock 1.8 injectors and no rrfpr. It had dutycycle headroom as well because I hit a 10:1 mixture a few times under boost while tuning. I was using the Walbro 255 Hp as well though so my fuel pressure was a whopping 4 psi higher.

Braineack

iTrader: (62)

right in line where I figured.

F20turbo

Yes, Im using an FPR but thats doesnt mean that you cant get these to idle and run perfect as long as you keep boost VERY low and dont exceed about 140whp. My FPR does nothing to help it idle, thats all in the AFM spring adjustment...the FPR just gives the extra pressure when I need it. I know for a FACT that 295's will idle just fine...you might have to fiddle with it but it will work.

Atlanta93LE

iTrader: (5)

So this might be a dumb question, but let's say that a turbo had a 7psi wastegate. Upping boost is easy. But what about decreasing max boost? I presume a new wategate would be needed...is this right?

Braineack

iTrader: (62)

You can port the inlet, which will push more boost against it and open it quicker.

OR

You could try an "un" helper spring. Basically a springs thats constantly putting load on the swingarm to pull open. Say attach a bracket to the firewall and connect a spring from that to the swingarm.