is it possible to adjust the dashpot values at higher rpm's to help with the "hanging rev" issue?

i seem to remember another way to do this but its right on the tip of my tongue and i cant remember

thanks for the help

is it possible to adjust the dashpot values at higher rpm's to help with the "hanging rev" issue?

i seem to remember another way to do this but its right on the tip of my tongue and i cant remember

thanks for the help

Dashpot is used when the vehicle is moving. If the car is hanging a bit when coming to a stop for instance you can adjust dashpot decay rate. If the car flares on shifts you can look at the dashpot gain.

Or, if idle is a problem there are the ISC tables.

There are a lot of things to consider in this.

what do you mean be flares when shifting? like where the motor gains speed when the clutch is depressed?

What is the "dashpot gain" Blivit? Are you referring to a dashpot function like the preposition or a clip value. Or would it be one of the idle adjustments (ISC drive/neutral idle air)? Or something else?

what do you mean be flares when shifting? like where the motor gains speed when the clutch is depressed?

Basically if you are accelerating, press the clutch in and instead of the rpms dropping or staying where they are they go up; that would be flaring.

What is the "dashpot gain" Blivit? Are you referring to a dashpot function like the preposition or a clip value. Or would it be one of the idle adjustments (ISC drive/neutral idle air)? Or something else?

Dashpot gain would be the ISC dashpot gain which is in the dashpot scalars.

Basically if you are accelerating, press the clutch in and instead of the rpms dropping or staying where they are they go up; that would be flaring.

yeah, thats what my car does. i thought it was me with my foot on the gas still but i made sure i didnt press the gas the next time and the rpms still went up a little.

Dashpot gain would be the ISC dashpot gain which is in the dashpot scalars.

Blivit. There isn't anything labeled as "ISC dashpot gain" as such in the dashpot scalars. I suspect you mean the Dashpot Decel Rate (currently set at 0 (zero). There is no description for these settings. Confirm or clarify please?
Thanks

Blivit. There isn't anything labeled as "ISC dashpot gain" as such in the dashpot scalars. I suspect you mean the Dashpot Decel Rate (currently set at 0 (zero). There is no description for these settings. Confirm or clarify please?
Thanks


No that's not what I mean. There is a parameter specifically labeled isc dashpot gain that may not exist with every vehicle.

If something is already 0 stock then chances are that item is not used in the calibration so changing it will probably not do anything or not do what you expect it to do.

Well, if there is no "isc dashpot gain", then what would you suggest to control flaring?

Well, if there is no "isc dashpot gain", then what would you suggest to control flaring?

I would start by looking at the isc tables under idle and possibly the air flow multipliers also unter idle.

Ahh. I see them Blivit. Ummm. What would you suggest as adjustment steps? like 10% increments? I.E. Is adjusting the ISC valve really 'touchy'? Maybe that is a better question for Tom.
Thanks!

Well, Now I have my doubts after some study. The Air flow multiplier is based on time after startup and goes to 1 after ~ 4 minutes. That leaves ISC Idle air. Is it additive with the Dashpot clip 1? I don't see what would cause the flare based on the data.

Well, if there is no "isc dashpot gain", then what would you suggest to control flaring?

If you are working on a duratec, and that screen shot in your previous post is for your cal, then you'll want to start by reducing the DASHPOT PREPOSITON.

This setting is the starting point where the IAC valve goes to when you are off idle, and it stays there while you are driving etc.

When the throttle closes, and press inthe clutch, this preposition determines where your idle goes. (flares or drops)

It uses the DASHPOT DECAY RATE to control how quickly the ISC will close to meet the target idle RPM.

If you get the preposition right, you should have no flare or abrupt drop in RPM at the point the throttle is first closed, and you step on the clutch.

After you have that correct, then evaluate the decay rate. This will be important for engine braking feel when you take your foot off the throttle & coasting in gear.

A higher decay rate will create more engine braking and it will feel like you threw out an anchor, too slow of a decay rate and you get very little engine braking and it can feel like the revs are hanging when you are trying to coast down in gear.

It's all a balancing act.

I've played with these settings myself using the SCT pro racer SW with good results.

Thanks tb1999. That is exactly what I was hoping as it makes sense to me. I have been farting around with just the decay rates alone without much effect.

S0C0nFused,

I've been away for a while, any updates on your progress?

I never had a chance to look into those details for you.

Still looking for some ideas?

oh man not looking forward to this part of the tune.

ill post my experiences when im done and/or during the process.

S0C0nFused,

I've been away for a while, any updates on your progress?

I never had a chance to look into those details for you.

Still looking for some ideas?

Yes, Think I got it nailed as far as the 'hanging rev' business is concerned. I will prob tweak it a bit more just for fun, but it's great where its at.
As far the the IMRC values, yes I am still waiting for your input. I have looked at them but I don't understand them completely yet. Plus the fact that I am busier than heck lately does not help. I would also like to up the timing 1 degree but again I am unsure where to do that. [cheers]

I would also like to up the timing 1 degree but again I am unsure where to do that. [cheers]


Add spark to your borderline knock table. You then have to make sure that it is not being clipped by the max allowed table or mbt table.