vristang.... question about your post on stangnet

[QWKSNKE]

I saw this..

5. Change Injector High/Low Slopes per TwEECer Manual. If using a 190/255lph pump, or using Cobra ecu, then set both same

This is the first time I have seen this statement used. Why do you recommend this?

[vristang]

I saw this..



This is the first time I have seen this statement used. Why do you recommend this?

I think I had read that in the Tweecer manual.
For some reason the Cobra .bins seem to use the same slopes.

I started my X3Z tune this way and it seemed pretty close, but I did need to make some adjustments.
That is about all the detail I can offer on that.

Keep in mind that the initial slope settings are going to be rough anyway. KAMRF based adjustments will probably need to be made regardless.

jason

[QWKSNKE]

yeah I knew that the x3z OEM settings were that way. Just wondered if you had confirmed that all x3z injector slopes should be set that way when modifying

[Italian LX]

Also, I'm curious as to why you would put the fuel pump size stipulation in there.

[93Cobra#2771]

x2

[Cougar5.0]

The pump thing (I've seen that recommended somewhere else on the web - I think that's where he got that from) may be related to how I've had to cut way back on my fuel up top after installing my BAP. OTOH, I am now wondering if they were referencing a returnless system WRT the pump sizing? Anyway, these are the thoughts that popped into my head reading this.

[vristang]

I just pulled up the ZAO .bin for the 95 Cobra R.
Both slopes are set to 24lb.

I just looked at the Tweecer manual, and that said nothing about setting the slopes the same.

Does anyone know what size fuel pumps the 93 Cobra and 95 Cobra R came with?

jason

[QWKSNKE]

Don't know about the 95 r but the 93 came with the same pump as the standard 5.0's (88lph)

[vristang]

Well I guess the pump stipulation didn't come from the Cobras then.

I fear that I won't be able to quote a source, since I didn't start keeping track of most info until a few weeks into my research.

I am glad to hear Cougar5.0 say that he has seen this mentioned before. If I am crazy then atleast I'm not crazy and alone.

I am using the X3Z, 30lb injectors, and have both slopes set to 30.5.
My KAMRFs seem happy with that.

I'll look some more and see what I can find.

Something I had not considered until just now is the way the A9* series uses the Injector Breakpoint. Maybe this has something to do with it?

jason

[vristang]

Also, I have heard mention that when using larger fuel pumps (190 and 255lph) the stock regulator can have trouble maintaining a fuel pressure setting.

The thought is that the pumps are too strong for the regulator to maintain control.

This may explain the fuel pump recommendation.

jason

EDIT; Qwksnke - Are you using a Tweecer with your x3z?

[Cougar5.0]

I don't know where this rumor got started that the low slope is "feathered in" using the breakpoint "flow" info below 2 ms PW (A9L), but I have to wonder when exactly it is cut in. I recently changed mine from 46.8 to 42.6 & back without really noticing much of a difference - just some light popping in the exhaust on decel when it was lowered to 42.6.

:popcorn:

[Italian LX]

EDIT; Qwksnke - Are you using a Tweecer with your x3z?
:yup:

[vristang]

I have not heard the "feathered in" part before.

Here is what I have written on the A9* use of Injector Breakpoint.
This is from stangnet as well. http://forums.stangnet.com/showthread.php?t=640613

4. The A9L strtategy uses the Function - Injector BreakPoint a little differently than other strategies. For most strategies the Inj PB is the point at which the computer switches between the Injector High Slope and Injector Low Slope, which makes sense.
The A9L however is slightly different in that the Injector BP is actually used as an Injector PulseWidth modifier, and the Injector BP is hard wired into the EEC as 2ms. When you make a change to the Function Inj BP you are actually changing how much fuel is cut from the Inj PW below 1,500rpm. The use of a larger number in the Inj PB Function will pull more fuel from the already calculated PulseWidth, until 1,500rpm.

To the best of my knowledge this is correct.
Let me know if clarification is needed.

jason

[Dale McPeters]

'91lx stock fp reg. with 100,000 mi and a 255lp/hr pump = :baby:

[vristang]

'91lx stock fp reg. with 100,000 mi and a 255lp/hr pump = :baby:

I don't get it?

[93Cobra#2771]

IIRC, the slopes were set the same on the Cobras and the breakpoint was indeed used as described.

Roush actually did the tuning/programming for the 93 Cobra. They had a limited amount of time to get the tune right - in fact, they only had one shot at the tune to get the car to pass emissions, or the car would have been delayed.

Don't know if that was the case on the 95 Cobra.

The deal with bigger fuel pumps is a pretty new one - I heard it a couple weeks ago on the corral, I believe. I have a feeling it is a trickle down deal from the late model returnless fuel systems - course that is a guess on my part.

What Dale's saying is his is just fine, with no problem regulating his 255lph pump. :)

[Dale McPeters]

What Dale's saying is his is just fine, with no problem regulating his 255lph pump. :)

That would be correct.....;)

[vristang]

I recently returned to the stock fuel regulator as well. I didn't seem to have any trouble with fuel pressure and the 255lph pump.
I didn't get to test it very long though, as the motor has now died.

I am starting to think that some returnless fuel system info has worked its way into A9* tuning.



Off Topic -
Since there seems to be a few Cobra tuners here...
Has anyone else had issues with Decel Fuel ShutOff. The car was continuing to run lean several seconds after a shift.
I had to fumble my way through this as I couldn't find any info.
Just curious if other X3Z users have had a similar experience?

jason

[93Cobra#2771]

Decel fuel shutoff is actually disabled on A9* family of processors. And I don't think that would be causing your issue. You need to up your fuel tip-in, methinks...

[Cougar5.0]

I have not heard the "feathered in" part before.

Here is what I have written on the A9* use of Injector Breakpoint.
This is from stangnet as well. http://forums.stangnet.com/showthread.php?t=640613

4. The A9L strtategy uses the Function - Injector BreakPoint a little differently than other strategies. For most strategies the Inj PB is the point at which the computer switches between the Injector High Slope and Injector Low Slope, which makes sense.
The A9L however is slightly different in that the Injector BP is actually used as an Injector PulseWidth modifier, and the Injector BP is hard wired into the EEC as 2ms. When you make a change to the Function Inj BP you are actually changing how much fuel is cut from the Inj PW below 1,500rpm. The use of a larger number in the Inj PB Function will pull more fuel from the already calculated PulseWidth, until 1,500rpm.

To the best of my knowledge this is correct.
Let me know if clarification is needed.

jason

Feathered in means that there is a smooth transition between lo & high slopes - which is true.

I can't verify the statement above, but it does not seem to jibe with what I am understanding after reading up. I will post an explanation & hopefully a graph to help explain the breakpoint stuff as soon as I can figure out how to translate it into words.

[vristang]

Decel fuel shutoff is actually disabled on A9* family of processors. And I don't think that would be causing your issue. You need to up your fuel tip-in, methinks...

The A9L does effectively disable the DFSO by extending the time intervals til activation to 31 seconds (I think?). I have not checked on the other A9* series stuff, but would guess it to be more of the same.
The X3Z is actually quite aggressive in cutting fuel on decel, probably for the reasons you stated above - Roush having to pass emissions on the first go.
I had very little luck messing with the tip-in stuff.
The DFSO settings did make a major difference though.

In my mind there is a difference between lean on tip-in, and remaining lean after a short closed throttle decel or a shift.
It seems that it is fairly common to have issues with lean on tip-in, but very few have had to mess with the DFSO settings.
I could be wrong though, I still feel like a noob with CalEdit.

:metal:
jason

[93Cobra#2771]

The A9L does effectively disable the DFSO by extending the time intervals til activation to 31 seconds

Actually, it is quite a bit longer than that. 200+ seconds, IIRC. Effectively eliminating it's usage all together. Ford software engineers couldn't get it to implement well - it caused bucking when activated (imagine that).

[vristang]

I think I know what Scalar you are thinking of.
That same setting is used for the X3Z though, and the X3Z does cut fuel on decel.

Here is a table I put together and posted on another site.
I haven't had much of a response so maybe you guys can offer some input?

I cannot claim to fully understand all of these settings, but I am trying.
The colored cells are the ones I have had the best results with.

jason

http://www.freewebs.com/vristang/Picture2.gif

[QWKSNKE]

interesting. I have not played with any of those items

[93Cobra#2771]

Nor have I...

[gt90stang]

Well, I messed with all of them except the shift ones. Couldn't find a satisfactory compromise so just locked out the function like Ford did.

YMMV, Don