Actually, it sees alot easier to tune the safc on the stock ecu with a wider range tps. No hesitation, a/f corrections are smoother in transaction, and i am also getting a smoother idle. What is the downfall?

 

What he is saying is that the factory s4 ecu's are programmed from the factory to assume 100% tps is anything over 1/4 throttle. At which point it relies on the vaf and map for its fuel and timing needs. As long as the ecu is seeing the narrow sweep sensor you'll be fine.

 

Yes it sees the narrow sensor. I wired the full range so that i can tune the safc according to true throttle.

 

Will a 6 port turbo conversion run on stock ecu without piggyback? Mine will only run with the safc set for idle. Disconnected, wont run. Someone told me it will run on stock turbo setup, then when i get it running, thats when i hook up the safc for tuning. Thoughts?

 

If it does it probably won't handle much boost, by not much Im saying like 4 psi, you'll want to be conservative running it rich until you have a good baseline tune.

 

I need to know if it will run from somebody who has done it before. TII parts bolted/connected to 6 port n/a STOCK tii parts.

If all is hooked up and connected properly, will it run/idle/rev on its own? Or does it need piggyback/standalone to be tuned to run?

 

Ask Aaron cakes, he has an na turbo, he'd know.

 

You're really starting annoy me. You need to stop making assumptions when you give people "advice" in threads. Please stop making assumptions, speaking from experience or providing information with a citation is best.

It should start and run with the stock ecu, you might run into problems due to the 720 secondaries. I'd put all 550's in and run it like a stock TII. When it works properly then, start modding.
It's like having a base map with a standalone. You need to get it to run before you the it.

 

You said run it like a stock t2 which is assuming youll have similar power, which will take less boost on higher compression rotors, therefore 4 psi would be safe since 5.5 is what is run on a stock s4

Nothing i said was wrong, just because i haven't done something personally doesn't mean Im completely incompetent.

I've personally researched turboing my old na before and owned that car for 6 years.

I apologize for my "annoyance" , Im.just trying to help and i wouldn't offer any advice if i thought i thought wasnt helping resolve a solution to the problem.

 

Fuel cut at 2800+. I need fcd

 

How much boost was it running when it hit fuel cut?

Someone back me up on this, but i.thought fuel cut was only built into the turbo ecu (i remember reading you said you're using the na ecu), and you'd have to be running higher than stock boost.

To me it simply sounds like you're running out of fuel at that rpm.

 

You will need an FCD with the setup, but your problem is somewhere else.

You need to fix the problem before you start doing mods.

You need to get all the electronics working together properly.

Even though it has higher compression rotors, it will run with the stock S4 TII ECU as long as the electronics are right.

Does it need the knock control box, do you have one?

TAKE OFF THE SAFC AND START OVER.

 

Ok i remembered wrong, you are using the t2 ecu.

Hope you get the problem fixed.

What size exhaust are you running?

If its bigger than stock you're probably running higher boost than stock and boost creepin if you haven't ported your wastegate.

Which will easily result in fuel cut.

 

Do i have to advance timing on a 6 port tii conversion or does the ecu do it automatically?

 

By the way.......j.checked the ecu motherboards and go figure, burnt resistors. Got a good one though. Fuel cut at 4lbs now. Running fine. Fcd jndeed.

 

^^^^^

 

Anyone?

 

Whoa...this thread is all over the place, I don't know even where to begin.

Running an S-AFC boost referenced is a valid option and I've even done it in the past several times with great results. In fact I'd dare say that it's BETTER than using the TPS because engine load is a far better tuning method than simple TPS value. And of course, the S4 has only a narrow range TPS.

The key with a setup like this is to use another MAP sensor. I don't recall the part number right now but almost every GM vehicle from the '90s had a 2 bar MAP sensor. Three connections: 5V, signal and ground. 5V is powered via the 5V feed from the stock ECU, ground is self explanatory, and signal is what gets fed into the S-AFC "TPS" connection. Bingo, one boost referenced S-AFC that can adjust fuel based on boost/vacuum. What a concept! Nowhere is the stock boost/pressure sensor used. I have not done this with the newer S-AFC II, but it certainly works on the older unit.

STOP. You need to retard timing under boost, not advance it. The TII ECU will do this automatically.

 

Does it retard timing enough to run a turbo s4 6-port safely? I mean as a permanent solution with the SAFC running boost-referenced fuel adjustment.

Blackrotary23: As stated before, something else is wrong if you're hitting fuel cut at 4 psi. Stock ecu will do it at 8.6 psi.

 

The stock TII ECU doesn't even retard timing enough to make a TII safe when running higher boost than stock. The stock TII ECU timing tables have been posted before and in my opinion, they are disturbingly aggressive when into higher boost. So about as well as in a TII.

The stock ECU is good for a stock or lightly modified vehicle, nothing more. A properly tuned standalone is better than the stock ECU in every way possible.

 

we've seen both the S4 turbo and S4 NA timing maps and the turbo actually runs MORE timing than the NA. the lower compression of the turbo is one difference, the other is that the turbo VE probably drops off at lower RPM, due to the stock exhaust/cats/small turbo.

obviously on a totally stock T2 the timing map is safe, but once you uncork it, and/or raise the compression, you're not stock, and thus the map isn't appropriate anymore.

 

Thanks for the clarification. I was pretty sure that was the case, but your previous statement sounded like you were advocating the use of a TII ecu in this situation.

 

So, since im running a 6 port with stock conversion setup, what could be causing the fuel cut so low then? All my sensors are working correctly, everything is built correctly. If it wasnt, i wouldnt be asking. Im stumped. Maf, pressure sensor, tps, ecu, fuel system.......everything is correct. A/f is good on wideband, good fuel pressure, fuel injectors are working correctly, good spark all the way. I dont know what else to look for.

So if there is something wrong to where it is cutting fuel at 3-4lbs. at 2800-3100 rpms, i dont know what could cause this.

 

It cuts fuel at 8.6 on stock setup. What about 6 port?

 

Anyone know the answer to this^?