Fuel Management Control for S4
 

My newly aquired 10AE has been with a close friend of mine since new. I bought it last week. The car was modified a few months after it original purchase by the good people at HKS in Dec of 1988. It had (if my memory serves me correctly) some HKS kit with a T04B turbo on it, the cats and air pump was removed, as was the stock Intercooler. It was then fitted with a front mounted inter cooler, HKS P-fcon, AIC with 2 additional injectors, HKS EVC. It was safely run on 10-12lbs of boost and made 310 rwhp and was featured in an issue of Turbo magazine in the early '90's(I'm still seaching for that issue).

Then came 1997 here in Kali when all cars had to be dyno'ed and smogged bi-annually. His smog connections dried up, so he removed the Big turbo, installed and HKS Sport turbo kit(don't ask me which size), spellingwhich featured a smaller turbo and allowed the OEM smg equipment to be put back on, however, the front mounted intercooler, AIC,P-Fcon piggy back computer and a "new" HKS EVC remain. The car is now running on 10psi int he low setting and 15lb in the high setting all through legal pre-cat and high flow cat.

My question is, I would like to modernize the car and get rid of the P-fcon and go with the R-tek 1.7 ecu chip with 720 secondary injectors. I don't particularly want the 2.1 setup because I don't want to keep fooling with it. set up with the AIC and Boost controller is enough, however, the car is equipped with and EGT gauge and an AEM widwband AFR meter. This car is a daily driver and will not see the track again. Altough, I am an ex-racer and I do like well performing vehicle...Now the question...am I on the right track?:scratch:

when upgrading any turbo you need an ECU capable of adjusting fuel maps. the stock ECU with 1.7 chip won't cut it.

So then you are saying I should go with the rtek 2.1..?

2.1 or any other aftermaket EMS, the chips are for stock turbos running more boost.

Sounds like it might stay like this for a while untill I find the right setup. I'll find out how much bigger that stock my turbo is, I have and extra one already rebuilt redy to replace this one if/when it goes bad. I also have the old T04B rebuilt and wrapped up. I don't know why I'm keeping it, though.

i think the Fcon+AIC is probably better than the Rtek 1.7, the Rtek is setup for the stock turbo, the Fcon probably has the single turbo chip in it.

you COULD get the Rtek 2.1 to work, but it would require tuning....

IMO the Fcon is primitive, but it DOES work really well, and its simple

I was thinking it was primitive also, but my main reason for wanting the Rtek was the fact that timing in pulled back under boost and I thought that it could handle what the Fcon does better, especially with bringing in the secondaries sooner than 3800 rpm. I'm driving the car everyday and still using the cruise,a/c,etc so keeping the stock ECM is important, plus I have to smog it every other year...and my wife even drives it, we are in our 60's!!! So the car needs to stay nice. I've had race cars before and I believe race cars are race cars and street cars are street cars...this is a street car.

But the car has been modified like this since Dec '88 and was a daily driver until the original owner bought a 2005 GTO. Since then it has sat up a lot. It is on it's 3rd engine in 140,000 miles.

So are you saying you don't plan to put the t04b back on? Will you only be running the stock turbo? If you are running the stock turbo an rtek chip will be fine, the aic will be fine, even the fcon will be fine.

Anything larger than the stock turbo and you should go with the 2.1. Which is easy to set up and doesn't require constant fiddling. You also have the option of trimming fuel for better mpg and adjusting timing to help pass smog if you so choose.

agreed, street cars ARE different than race cars.

the Fcon has different fueling than the stock ecu; HKS still offers a few different chips for it, but the Fcon does not touch timing.

so actually you could use the Rtek 1.7 for timing, and then use either the AIC for fuel, or keep the Fcon.

i'd think it might be a good idea to put a downpipe on it too, too much exhaust backpressure isn't good.

That was my thinking from the start, to use a 1.7 with 720 secondaries and use the AIC if needed, to give me a more modern map of fuel and timing. I just wanted assurance that I was on the right track.

By the way, my turbo is larger than stock, I can't find all of the paperwork and I don't see any numbers on the turbo(it's under a shield), but it was part of the HKS Sport Turbo Kit. It is not the twin scroll stock one but has an internal waste gate like a stock one.

I'm afraid I'm stuck with the the downpipe, this is Kali, but it is a custom piece with high flow 3" precat mounted quite a bit further back than stock and a 3" high flow 3 way main cat. This down pipe also has 2 bungs in it, 1 for my normal O2 sensor(I use the one for an FD RX7) and 1 for my AEM wideband. The rest of the exhaust is the HKS 80mm "Big Exhaust", similar to the Racing Beat exhaust.