I have a 2010 M8 which I recently turbo'ed with a used Cutler stage II kit. Now that I have an Air/Fuel (AF) gauge I can see there is a huge lean spot on the factory ECU map from about 3000 RPM to 4000 RPM. It doesn't run really well until 5000 RPM and up. The AF gauge goes from 13.5 to 14.2 up to 3000 and then buries itself past 17 during this lean spot. I am using the Attitude controller because it is simple. I also own a near new PCV which I added back when I piped the sled. The sled always had this low end bog and now with the AF gauge I know why. Here's my thought - the PCV plugs in at the ECU and the Attitude at the injector. Why can't I run both and use the PCV to fix the OEM map and the Attitude for the boost functions. I know Dynojet now offers a Bosch 3 bar boost sensor so you can run a wide band O2 sensor and map by AF ratio but there are no maps available yet. Does this make sense? Anyone else find this black hole in the OEM map?? Thanks!!
Piggy Back Controllers?
- Thread starter ratherbehunting
- Start date
tuning a turbo with AFR
To answer your question first is no it will not work. Its been tried messes up signal.
When tuning a 2 stroke especially a turbo with AFR you can not tune the bottom end. The only place that gauge will do you any good is top end.
I find that they will show 16 to 1700 on bottom end very lean but that is the only way they will run.
To answer your question first is no it will not work. Its been tried messes up signal.
When tuning a 2 stroke especially a turbo with AFR you can not tune the bottom end. The only place that gauge will do you any good is top end.
I find that they will show 16 to 1700 on bottom end very lean but that is the only way they will run.
What throttle positions do you get your lean spot at? My sled when at 0% throttle coming down on RPM goes past 17 aswell in the midrange, 2 stokes simply do that when coming down, completely normal. Not sure if thats what you are talking about or not.
Post your box settings, maybe somebody will see something obviously wrong in your map.
Post your box settings, maybe somebody will see something obviously wrong in your map.
im betting your rich, its gurgling, missfiring and causing your gauge to read lean.
that controler and turbo combo has many happy customers. maybe not record setting throttle response, but it can be setup to run pretty damn clean.
that controler and turbo combo has many happy customers. maybe not record setting throttle response, but it can be setup to run pretty damn clean.
My Current Settings
I'm running 42#'s fuel pressure with the stock ECU and the attitude controller between the ECU and the injectors. I can't post any map figures because the attitude box is a "black box" type of controller. It buffers the output of the ECU and is separated into cruise fuel (set at 2), accel fuel (set at 2), WOT fuel (set at 3) Fuel per lb of boost (set at 8) and WOT rpm switch point (set at 5). You can modify these segments from "0" to "8" in half increments. I think the fuel pressure is at its limit because the sled tends to load up during an idle.
I'm running 42#'s fuel pressure with the stock ECU and the attitude controller between the ECU and the injectors. I can't post any map figures because the attitude box is a "black box" type of controller. It buffers the output of the ECU and is separated into cruise fuel (set at 2), accel fuel (set at 2), WOT fuel (set at 3) Fuel per lb of boost (set at 8) and WOT rpm switch point (set at 5). You can modify these segments from "0" to "8" in half increments. I think the fuel pressure is at its limit because the sled tends to load up during an idle.
These sled run hot in the midrange because of the timing being very advanced. The safest bet is just continually pump the throttle when cruising in the midrange. You can also turn up your green and yellow modes when on the trail, but it can make the sled boggy. I would try turning your fuel pressure down a little if the sled is bogging coming off idle. From reading on here most guys run 38-40 lbs. I have can't run over 34 lbs on my M1000 without it being boggy.
Big Air - thanks for your reply. That makes perfect sense. Mid throttle on the trail is scary. I've hit 1300 F on the Koso's just driving a trail before dropping down to an idle because I was freaking out.
