MAPdot tuning

[ZX-Tex]

OK I have read through the accel enrichment pages, tried MAPdot and TPSdot, tried several settings in both, and am still having some bucking and stalling problems when the throttle is pressed. Mostly it happens when I give it moderate to heavy throttle inputs. It also seems worse when the RPM is around 4000 at cruise. Moderate to heavy throttle inputs cause a quick stall followed by some bucking.

Light throttle input seems OK. Heavy throttle input causes a brief less than 1 sec stall, then it revs OK. When applying heavy throttle at idle I hear what sounds like some faint knocking from the engine, short duration. I've logged data and looked at it in Megatune, even looked at TPdot and MAPdot in the megatune display and made some adjustments. I'm still not getting it to work properly.

Bucking and stalling is worse when the engine is cool. It still happens when the engine is warmed up though. All of what is described above is with a warm engine.

The car is running great otherwise, WOT, cruise, all OK. Idle is OK, its a little rich but it is reasonably steady even with a/c compressor cycling.

So I am hoping that someone running a similar setup can post their accel enrich settings (accel decel mode and acceleration wizard) so I can try them as a base line. Pretty please with boost on top?

My setup is in my sig. RX7 550cc injectors. Req_fuel right now is set at 5.5. Motor is all stock except for the BEGi-S of course.

[paul]

hmm. i run a 99 motor with a megasquirt and 550s

req_fuel is 5.6 on a displacement of 1839cc

[cjernigan]

This is what i'm using now. I had the threshold set to .576 or something, you can use more like .976 or w/e diyautotune uses though.
FWIW, i used to use 5.6 as my req fuel but switched to 6.0 and now for some reason the car runs better after i retuned the fuel map.

[paul]

whats with that 30.078 v/s threshold?

[cjernigan]

I only set it to 30 vs because that is the max value you can enter in that box, it disable all AE when i'm tuning the VE table.
You're actually supposed to leave AE turned on when tuning with MLV, that way it can adjust some of the fuel table to accomodate the AE. Atleast that's what the MLV developer says. If tuning by hand or by other method leave it turned off.

[ZX-Tex]

OK thanks for the information gents. I will try those settings in the morning for my work commute. Are you using the mspnp97 settings in the accel decel trigger dot window?

[paul]

yup

[ZX-Tex]

Thanks for the quick answer

[cjernigan]

Originally Posted by ZX-Tex

Thanks for the quick answer

Let me know if they work.

[ZX-Tex]

I changed the msq this morning to the settings above and drove to work on it. Seems much better. Thanks.

[cjernigan]

Kind of funny, i was scrolling through the thread and realized both of us posted the same exact AE table. Then i realized that it wasn't mine and I had no idea where that one came from. For some reason I had a screenshot of it though.
This is the one i'm running right now, basically the same thing.

[Joe Perez]

Those values seem nearly identical to DIY's numbers for the '94-'97 PNP, which I believe is based on stock 230cc injectors. Since at this level we're dealing directly is ms rather than %, with the 550s, wouldn't it be necessary to cut those numbers down?

Here's my Accel table below. Since I'm running 440cc injectors, I divided the DIY base values more or less in half. Seems to be working:

[cjernigan]

Apparently I don't know how to post the actual AE table i'm using. Here is the one currently in use.


I have a little different question though. No matter how hard I "stab" the throttle the red bar that goes from 0 to 30 never goes up very far. Atleast it doesn't go up to what I would consider 8 v/s.
How are those values generated? If I sit in the car with the key on and stab the throttle with the engine not running is there some way to calculate what that curve should be?

[ZX-Tex]

You could try logging the throttle movements and use TPSdot in MLV.

[Joe Perez]

Still seems like those numbers are awful big.

[Splitime]

Any final word/thoughts on this?

<-- doing his best to absorb months of MS threads he has neglected over the winter... and build up a new nice starting map for the Miotta.

[cjernigan]

Yeah, tune the (ms) values until it feels right and offers the best throttle response.

[ZX-Tex]

Good catch Joe, completely missed that fact myself. I cut my numbers in half, roughly to the same values as Joe posted above, and it seems to be working fine.

[hustler]

any 100% MAP values for us non-tps guys?