Hi

Ive a AFC Neo with a Rtek 1.5
Running a stock TIIS4 engine,
open exhaust.

For the increased boost Im using the AFC to enrich the mixture.
By checking the exhaust temp Im tuning the thing.

Without AFC I read 1050 °C O_o
so I enriched the map , Im hitting now 970 °C with even more boost.
which is already very helpful

I just want it a little richer in the high rpms
but Im already at +50 there in the AFC

And when Im using the 4 digital display the peak value is not +50 for the correction
but something around +25 to +30

Cant the AFC modifiy the signal anymore ?
Or what can I do to just get a little more fuel,
increase pressure ?
or open the bypass screw at the afm ?

I do believe the stock injection system can liver more fuel.


-Patrick

 

How much boost are you running?

I don't know how accurate you can tune the AFR with EGT. I know you can tune ignition timing with EGT.

Don't know much about the turbo engines.

 

A guy that had bought a Neo,had a Cavalier,and was going to Turbo it,He said that his buddies were saying that the Neo Doesn't Recognize Boost.So, he in Turn ,Sold it,because of that Fact.I honestly Don't know about Fuel systems or Rtek,or Turbo's For that matter,but I thought I would pass that on.Maybe it's true,Maybe not.

 

Maximum boost is about 15 psi ( 1bar )
( only for short time )

I of course connected the AFC to the 7s boost sensor ( S4 TII )
The Rtek 1.5 retracts!? the ignition timing from 0.6bar to 1.0bar

But I was just wondering about the AFC, because when I read the peak values afer a pull:

max rpm: 5100
max thr: 100 % ( = 1.0 bar as I calibrated it )
max correction: +24,7 %

and when I looked in the AFCs map at this point it was set to +30 %

I have to try again what happens at higher rpms, because I set it there to +50%

-Patrick

 

what is you airlow % on the afc?

 

about 70 %

but I have to try again the high rpms when Ive repaired my EGT :/

 

Sooo,

I had 75 % airflow
@ 100 % throttle (boost) and 6700 rpms
max correcting was +35%

settings where set to +50% for high load at 6500 and 7000 rpms

So did I reach the limits of the AFC ?

-Patrick

 

Hello, your problem might be in the throtlle signal that you connected in boost Sensor instead in throttle.

The S-afc works with throttle posicion and has high and low throtle positions. You have LO Throttle and HI Throttle, if you have that confugured 15-50 per example, from 15 to 50 its the Lo throttle config that is working. After 50% of throttle its the HI-THROTTLE map that is working.

Maybe I'm wrong but you maybe tuned only the lo trottle map.
Try connecting the gray whire in SAFC to the throttle signal instead of turbo sensor. I have it on my car and corrects right the value I have tuned.
its meant to work with accelerator not with boost.
Other thing, you tuned to +50% from 6500 to 7000... if you tune before that RPM's in +15% in 6000 rpm per example, SAFC will make a curve from 15 to 50 so you never have 50% in 6700 rpm.

If you tell-me all the correction that you set in each rotation will help.


Hope I've helped you


Let me know some feedback.


Regards,


Nelio

 

If you have it set to Lo 15 and Hi 50, then anything under 15% will be in the LO map and anything above 50 will be in the HI map. In between 15 and 50 the SAFC calcualtes its own map and tries to match the settings from LO to HI for a smooth transition

If he tunes for +50 at 7000 rpm above his set HI throttle point or in his case, load point, then he should hit +50% at 7000 rpm.

I will have to read the thread again but he may have the HI throttle point set to high of a percentage. The boost/pressure sensor may not ever reach the volts the SAFC wants to see for the specific HI load point.

 

I think you reached the limits of your fuel system. I would also use a wideband primarly to tune with not an pyrometer as the egt is slow to react. You should read 100% airflow if you've maxed the signal the afc puts out, but i have an s5 and it might be diff. for an s4.So I would suggest at least an upgraded fuel pump and a set of 720cc injectors, to get all the fuel you will ever need on the stock turbo.

 

Yes you should def use a wideband. Egt gauge will not pick up lean spikes . All it takes is one!