skatingsamurai

i own a 88 turbovert and i have this unit. i read on another website that when you step on it the ECU goes into open loop mode, ignoring the O2 sensor and only relying on the MAP sensor for data. So the Gen1 AFC is only usable under WOT. is this true?

what is the maximum power anyone has tuned with this unit exactly? 250..300...350ish? i have a turbonetics hybrid and all the fixins on it now, so im worried that +20% afr isnt going to be enough to handle the WOT of this massive hibrid (massive for me that is)...


and it seems that all the information for this thing has all but disappeared. is it really that old??


thanks in advance.
steve

Evil Aviator

Every stock ECU and standalone EMS does this. Closed loop is only used for cruise, and sometimes idle. Once the engine accelerates or decelerates it goes into open loop mode. In the case of the FC RX-7, open loop fuel delivery is primarily determined by the AFM (air flow meter) and TPS (throttle position sensor).

No

I have seen over 400bhp with an ignition box, but a standalone EMS would be a much better choice for finer engine control, assuming you can find a professional to tune it.

It corrects the airflow rate, not the air-fuel ratio. Also, I could be wrong, but I thought it was +/-50%, not 20%? Anyway, if you are planning on a high-hp application, I would be more worried about running out of fuel than running out of settings. Did you upgrade your fuel injectors and fuel pump?

We have an entire sub-forum dedicated to the S-AFC. Like every other forum, be sure to read the stickies first.
https://www.rx7club.com/super-afc-123/

skatingsamurai

thank you very much.

im currently running new 550/720's, new FPR/FPD, walbro 255, rtek 1.7, safc, 10 mm wires, full exhaust/intake, fresh engine with solid corner seals/ fd springs, RA apex seals/ oem springs, oem side seals/ springs, thermal pellet mod, and that big *** turbonetics hybrid at stock boost.

ps. im getting my innovative lc-1 in a few days!!!! woot....but, your saying that your mostly concerned about the injector sizes and therefore EMS as well?

Evil Aviator

Yes, the fuel system makes a big difference because fuel injectors and fuel pumps can only supply so much fuel, regardless of the setting of the ECU or EMS. Are you aware that the 550/720cc combo is only good for about 285-295bhp at the flywheel? A well-built hybrid with all the fixins is capable of up to 450-475bhp at the flywheel if tuned well. I am hoping that your hybrid turbo isn't as huge as you think, or you are going to need to further upgrade your fuel system.

A standalone EMS allows for much better control over the engine. While band-aids like the S-AFC and Rtek chips are nice for minor upgrades, they still use the old, outdated, 1980's computer chips to run the engine with the moderately-accurate original AFM. The downsides of the standalone EMS are that it requires a professional to tune (and installation isn't all that easy, either), and most of them use a speed-density calculation system that does not compensate for engine wear and upgrades like the stock mass airflow system.

skatingsamurai

hrm, well when i get my wideband, ill try and tune it...luckily it shouldnt go past half bar on stock boost. i do realize the the amounts of air per psi are more on larger turbos. supposedly, this hybrid supports 300 hp at around 9-10 psi, ill double check that though. but ill attempt to tune it. and if i read any signs of lean conditions ill forgo tuning. and post the readings from the log (i will be able to do this with the lc-1 right?)

i thought i saw people that have made 300whp with the 550/720 setup? hrm.

IF it is the case that it is running lean due to injector size, what would be the next best option? do a 720/ 1000 combo with the 2.0? i heard really good things about it, and given that i dont want to ruin or mess with the stock harness, nor do i want to pay a professional to do it, the rtek 2.0 might be the NEXT BEST option? and really, nothing more can be bad as long as i have my wideband to make sure its not leaning out.

i wish i new more about this hybrid turbo of mine. it was a spur of the moment decision to buy the thing. any good resource guides about the turbonetics hybrids?

does the number on the side of the housing mean anything?

Evil Aviator

Yes, the lc-1 can log lambda, but this is not necessarily going to tell you that your fuel injectors are being over-driven.

A non-turbo engine could achieve the .55 BSFC to make that kind of power with those injectors, but it is not likely that an engine with a hybrid turbo run by low-budget electronics and tuned by an amateur is going to to make it. Some of the turbocharged engines on this forum have had a BSFC as high as .80.

For 300bhp at the flywheel 4 x 720 should work, while 550/1000 should be good for about 350bhp at the flywheel. A lot of that depends on the tuning though.

... as long as you don't burn up your fuel injectors in the process.

You could maybe try posting a separate thread in an attempt to identify the turbo. I am not a salesman, so I don't know much about such things.

arghx

iTrader: (3)

rtek 2.0 with at least 720/720

skatingsamurai

bump

can anyone identify the turbo?

and i think i might try my luck for one pull at least. i promise ill be good though! : P
Motors compression is strong thanks to yours truly. I put cerment b coated housings in it during the rebuild. guess i forgot to mention that before.