D7 tuning issues? Help new to boost and cfi...

[cowboy181d]

Hello all.
I finally got to ride my d7 I picked up. Here's the specs, 07 non intercooled home built kit (setup just the same as a boondocker kit garret 2860 etc) running a Attitude fuel controller. Holley 2:1 pressure regulator .
monitoring everything with a koso x2 setup. My issue is that my afr goes from 12-13 at cruise under maybe a pound of boost. But if I mash on it as soon as it hits about 4.5 pounds of boost my afr shoots up to 17 then drops straight to 11 and acts like it's going into a limp mode.

If I let off to about a third throttle all is well (runs great in this range 13.2 afr @ 2psi). No DET that I've felt and my plugs are a nice golden brown. Super peppy in the trees but I'm very paranoid to harm the motor (took me two years of saving up to put it back together bought it blown up from another member on here)I'm sure it's a tuning issue, as I was playing with the tune thought I had it cured then on the ride out mashed on it built boost to 4.5psi and it just fell on its face. Fuel pressure is 50psi at an idle running 50/50 93 non eth. And av gas. Could someone please school a newbie on acceptable afr ranges.

Thanks
Damen

 

[ez-ryder]

http://www.snowest.com/forum/archive/index.php/t-357837.html

There's one thread about afr readings.

General rules on turbo two-stroke
16 idle
14 cruise
12.5 wide open on boost

Every set up is a little different.
They are just numbers. Compare to egt and plugs. Piston wash i find difficult to see with a light. These anodised piston tops are hard to see the clean spot. But is effective if you can.
Mine will light throttle cruise at 16 with no exhaust temp to speak of.

A 17to 1 reading that flashes to 11, probably means it's overly rich.
An extremely rich condition will read lean in my experience.

With my bd box I start with numbers that i know will be too rich to run. Then lean it out till it sounds right and pulls your arms off.
Then look at the gauges.

 

[cowboy181d]

Hey thanks for the info.
I am feeling that my cruise is ok then im seeing 14.5 to 13.2 no bog to speak of. I was wondering if the 17 reading was really an over rich issue I have seen it on 4 cycles before. any in put helps

Thanks
Damen

 

[ez-ryder]

I'm not sure on the attitude box.
But on my bd it needs a bit of adjustment every 1000 feet of elevation change.

Does your box have another sensor to counteract the stock ecu? Which leans the mixture out as you go up in elevation. But we're turboed and are not seeing same loss in air pressure.

Before boost I have to lean out as I go up.
On boost i have to richen it up.
It's lots of fun!!

 

[RDS88]

What fuel are you running?

 

[cowboy181d]

running a 50/50 mix 93 non eth and avgas.
Yes the attitude box runs its own map sensor to compensate for elevation and boost

 

[ez-ryder]

What elevstion are you riding at?
I'm riding 3000-6000 feet running 8 # straight av gas.

 

[cowboy181d]

4k to 6k.

 

[jared701]

i have a 08 td7 and only running 38psi on fuel presser. Your to rich. Dont try tuning with af gauge going down the trail it needs to have a hard load on it. Put fuel to 38psi and move boost fuel (green/blue) up a .5. I just had this same thnig happen.

 

[RDS88]

Ive been told that AV gas screws the AFR probe up. Better not to use it, and go by EGT's

 

[cowboy181d]

hey guys I talked to Derick over at attitude. seems I had gotten my map way out of spec. i was over fueling clean from the start (my own paranoia from being inexperienced) so i set it to his suggestions and am heading up the mountain on Saturday. So we shall see!

thanks
Damen