Hi everyone,

I'm working on tuning AE on a speed density setup. I have several questions, and have searched and searched, but nobody seems to have answered any of them.

So, lets get started.

I tuned VE and PE. When I turn on AE, and go WOT, the AFR dips to about 9-9.5:1 as read by a wideband. Without the AE, it would be roughly 12.6:1 in the same area, so the AE is "working", but I think it's obviously too rich.

My first question is, what should I see for numbers on a WOT run? Should it dip to 11:1? richer? leaner?

My second question is, depending on what that answer is, how do I go about correcting it? My table looks like this:


Obviously a WOT run is a fast/large Delta TPS. How large? I don't know, according to the datalogs, I go from idle to WOT in 0.25 seconds. How does this translate to a cell on this chart???

Third, and related, I have a lean condition on small, slow changes in throttle. Pulling out of a parking lot for example, it might peak to 16:1 before settling back to 14.7:1. Soooo....... Same question - how do I fix that?


Thanks in advance, and if I missed a thread on this subject, feel free to point me to it.

 

There's a good description of AE in the tuning guide in the stickies.
Link to it here
https://www.thirdgen.org/techbb2/sho...hreadid=195745
Take a look through the 730 section, lots of excellent info.

 

Yep, read that. Basically it sounds like I thought, larger numbers mean more AE fuel. But it doesn't answer my question as to which cells I need to change?

I assume the 50% value, and those directly beneath it are for *really fast* changes in TPS. As in, WOT. Well I tried decreasing the top 3 or 4 values by about 10%, and got no measurable change in the dip!

So then I thought, well either I'm not changing it by enough, or I'm not changing the right cell(s)

BTW, as far as I know, that's the *only* thread on AE in the 730 section.

 

The AE TPS is only half the story. AE MAP is there as well.
Don't concetrate directly on the $8D for all the answers. there is much to be learned on how it works from other masks.
search "enrichment" and pick out some AE related posts.
I've just been doing some refreshing myself

This is the type of info I like to correlate funtionality with.
Its more TBI related but the theories still apply.
https://www.thirdgen.org/techbb2/sho...=AE+Enrichment
Then go bach and rethink my process to attack it with the tools I have.

 

From that thread:
"AE TPS is sampling TPS % change OVER 12.5ms"

I go from idle to WOT in 0.25 seconds. That's 100%/0.25sec, or 5% per 12.5ms sample. So am I changing the wrong cell value? I was changing the 40-50% values, I should be changing the 5% value? And how in the WORLD would you get to 50%? Even with a rocket attached to your foot, I doubt you could hit 20% change per 12.5ms.

 

Also as explained in there (or elswhere) that the throttle opening rate requires different AE depending on the starting position.
The AE requirement is greatest off idle. IIRC Something like 30% physical opening is 60% of the maximum flow rate. As starting from the bottom at idle you'll need a big shot so to speak. Going from 30% to 70% opening requires less.

TPS AE gets you moving, MAP AE keeps you going until PE can get in there.
That's how I'm visualizing it.
if you still get the dip, try MAP instead of TPS. Might indicate something better.

I'll be going through the same learning curve again here shortly when my new setup is running with , bigger cam, bigger TB, bigger injectors, shorter runners and open exhaust. Things will be a bit more difficult than with the restrictive system to get it all nailed down.